Journal of Global Antimicrobial Resistance

BackgroundTo date, there is a spread of resistance of microorganisms to antibiotics. To solve this problem, the search and development of new drugs with antibacterial activity is necessary. Antimicrobial peptides (AMPs) have pronounced antibacterial activity and may be promising candidates for the role of new drugs. Besides, AMPs can be used to overcome conventional antibiotics resistance due to the possible synergistic effect. In this work, the combined effect of some AMPs (human defensins, HNP-1, hBD-1, hBD-3 and cathelicidin, LL-37) with conventional antibiotics (vancomycin and imipenem) against gram-positive (Enterococcus faecalis; Staphylococcus aureus, methicillin-sensitive, MSSA, and methicillin-resistant, MRSA) and gram-negative (Escherichia coli; Klebsiella pneumoniae; Pseudomonas aeruginosa) bacterial strains was investigated. MethodsBacterial strains were isolated from hospitalized patients of the intensive care unit. Commercially available AMPs (HNP-1, hBD-1, hBD-3, LL-37 by Cloud-Clone Corp., USA) and antibiotics, vancomycin (Sandoz, Slovenia) and imipenem (Merck Sharp and Dohme, USA) were used. Antibiotic resistance phenotypes of isolated bacterial strains were carried out using the disk diffusion method. The standard checkerboard assays were used to study minimum inhibitory concentrations (MIC) of antimicrobials. The combined microbicidal effect of two substances (AMP+conventional antibiotic) was assessed by the fractional inhibitory concentration index (FICI). If FICI [&le;] 0,5, then it was considered that two substances showed synergism of action; if 0.5 < FICI < 4 - no interaction; if FICI > 4 - antagonism. ResultsAll studied AMPs had antibacterial activity against the studied strains. hBD-3 showed the lowest MICs compared to other AMPs. MIC of hBD-3 against S. aureus (MSSA and MRSA), E. coli, K. pneumoniae was the same - 0.5 mg/L, and against P. aeruginosa it was 2 mg/L. The combinations HNP-1+vancomycin (against E. faecalis) and hBD-3+imipenem (against E. coli, K. pneumoniae, P. aeruginosa) according to FICI values have shown the synergistic effect. The results of this study can be used to develop novel antibiotics based on AMPs. Also, in some cases, AMPs can help to overcome resistance to conventional antibiotics.

BackgroundAlthough not fully investigated, studies show that Legionella pneumophila can develop antibiotic resistance. As there is limited data available for Portugal, we determined the antibiotic susceptibility profile of Portuguese L. pneumophila serogroup 1 (LpnSg1) isolates against antibiotics used in the clinical practice in Portugal. MethodsMinimum inhibitory concentrations (MICs) were determined for LpnSg1 clinical (n=100) and related environmental (n=7) isolates, collected between 2006-2022 in the context of the National Legionnaires Disease Surveillance Programme, against azithromycin, clarithromycin, erythromycin, levofloxacin, ciprofloxacin, moxifloxacin, rifampicin, doxycycline, tigecycline, and amoxicillin/clavulanic acid, using 3 different assays. Isolates were also PCR-screened for the presence of the lpeAB gene. ResultsTwelve isolates had azithromycin MICs above the EUCAST tentative highest WT MIC, 9 of which were lpeAB negative; for erythromycin and clarithromycin, all isolates tested within the susceptible range. The number of isolates with MICs above the tentative highest WT MIC for the remaining antibiotics was: ciprofloxacin: 7; levofloxacin: 17; moxifloxacin: 8; rifampicin: 11; doxycycline: 82; tigecycline: 4. EUCAST breakpoints are not available for amoxicillin/clavulanic acid. We estimated the ECOFFs and one isolate had a MIC 8-fold higher than the E-test ECOFF. Additionally, a clinical isolate generated three colonies growing on the E-test inhibition zone that resulted in MICs 4-fold higher than for the parental isolate. ConclusionsWe report, for the first time, elevated MICs against first-line and other antibiotics (including azithromycin, fluoroquinolones and amoxicillin/clavulanic acid commonly used to treat pneumonia patients in Portugal) in Portuguese L. pneumophila strains. Results point towards decreased susceptibility in circulating strains, justifying further investigation.

Programmatic Management of multidrug resistant tuberculosis (MDR TB) services were introduced in the Indian TB control programme in 2007. A pharmacokinetic (PK) study of drugs used to treat MDR TB, namely levofloxacin (LFX), ethionamide (ETH), cycloserine (CS), pyrazinamide (PZA), moxifloxacin (MFX) and isoniazid (INH) was undertaken in adult MDR TB patients treated according to the prevailing guidelines in India. Factors influencing drug PK and end-of-intensive phase (IP) status were also determined. We recruited 350 MDR TB patients receiving anti-TB treatment (ATT) in the Indian Government programme in south India. At steady state, serial blood samples were collected, after supervised drug administration. Status at end of IP was noted from the programme records. Of the 303 patients for whom end-of-IP status was known, 214 were culture negative (responders), while 45 patients were either culture positive or required change of regimen or had died before completion of IP (non-responders). The median Cmax (2.0 vs 2.9g/ml; p = 0.005) and AUC0-12 (12.2 vs 17.0g/ml.h; p = 0.002) of ETH were significantly lower in non-responders than responders at IP. In multivariate logistic regression analysis, after excluding defaulters and adjusting for confounders, AUC0-12 of ETH significantly influenced end-of-IP status (aOR - 1.065; 95% CI: 1.001 - 1.134; p = 0.047). Drug doses used currently in the programme produced optimal drug concentrations in majority of patients. ETH played a major role in the MDR TB combination regimen and was a key determinant of end-of-IP status.

Background: Antimicrobial resistance (AMR) is a growing global health concern driven largely by inappropriate antimicrobial use. Antimicrobial stewardship programs (ASPs), guided by the Centers for Disease Control and Prevention (CDC) core elements, are essential for optimizing antimicrobial use. However, adherence to these practices and the barriers faced by healthcare workers remain inadequately explored, particularly in resource-limited settings. Objective To assess adherence to the CDC antimicrobial stewardship checklist and identify barriers affecting stewardship practices among healthcare workers at a tertiary care hospital in Uttarakhand, India. Methods A quantitative cross sectional descriptive study was conducted among 355 healthcare workers, including nursing officers and physicians. Data were collected using a sociodemographic questionnaire, the CDC antimicrobial stewardship checklist, and a self-structured barrier assessment tool (test retest reliability r = 0.78). Descriptive and inferential statistics were applied using SPSS version 23.0, with a significance level set at p < 0.05. Results The overall adherence to the CDC antimicrobial stewardship checklist was 52.3%, indicating moderate compliance. Higher adherence was observed in action-oriented interventions, while lower adherence was noted in domains such as accountability, pharmacy expertise, reporting, and education. Major barriers identified included lack of antimicrobial supply (89.0%), shortage of key personnel (88.5%), delays in laboratory reports (85.1%), lack of training (83.9%), and inadequate administrative support (79.2%). Significant associations were found between perceived barriers and factors such as working area, designation, qualification, and work experience (p < 0.05), whereas age and gender showed no significant association. Conclusion Adherence to antimicrobial stewardship practices was moderate, with notable gaps in organizational and educational components. Multiple systemic, resource-related, and behavioral barriers hinder effective implementation. Targeted interventions focusing on strengthening infrastructure, workforce capacity, training, and administrative support are essential to improve stewardship practices in tertiary care settings. Keywords: Antimicrobial resistance, Antimicrobial stewardship program, Barriers, CDC Checklist

Antibiotic self-medication is a form of irrational drug use that contributes to antimicrobial resistance, which results in increasing health care costs and morbidity and mortality rates in the population. The misuse of antimicrobial agents is highly linked with the growing problem of antimicrobial resistance within the population globally. Unless addressed, antibiotic self-medication will drive the world back to the pre-antibiotic era, with people dying helplessly due to infectious diseases. This study aimed to investigate the prevalence of antibiotic self-medication and its associated factors in the Otuke District, Northern Uganda. A community-based cross-sectional study was conducted in the Otuke Town Council, Otuke district. The data of adults aged 18 years and above were collected using a semi-structured questionnaire, and the data were coded and entered into SPSS software version 26. The data were descriptively analyzed for frequencies and percentages. Bivariant and multivariant analyses were performed to determine associations between the variables. Out of 385 participants, 68% self-medicated with antibiotics in the past 12 months. Freedom from drug use (AOR: 3.071; 95% CI: 1.203, 7.876) and unregulated use of antibiotics (AOR at 95% CI: 8.288 (2.815, 24.397)) were more likely to lead to ASM (p value <0.001). Other significant factors included knowledge of antibiotics, previous symptom experience, previous successful treatment, long waiting hours and poor staff attitudes (p value <0.05). The most common self-medicated antibiotics were amoxicillin, Ampiclox and metronidazole. Antibiotic self-medication in the Otuke district is very high due to the availability of medicines and lack of functional drug use regulatory frameworks. The district and government of Uganda should design and implement measures to mitigate this widespread antimicrobial misuse to prevent the development of antimicrobial resistance.

Pseudomonas aeruginosa is an opportunistic pathogen with high clinical relevance in intensive care units (ICU) due to its elevated resistance to various antimicrobials, which lead to high morbidity and mortality in patients in critical situations. In this study, we aimed to detect variants of genes encoding {beta}-lactamases and efflux pumps in P. aeruginosa isolates resistant to {beta}-lactams, fluoroquinolones and aminoglycosides. All genes belonging to the subfamilies were included in this study: blaSHV, blaTEM, blaNDM, blaKPC, blaGES, blaCTX-M. In addition, we investigated the most relevant variants of the blaOXA subfamily and genes belonging to the efflux pumps of the Mex family. We tested 54 isolates of P. aeruginosa with a high prevalence of resistance to the antimicrobials piperacillin/tazobactam, ceftazidime, cefepime, imipenem and meropenem. Resistance genes related to carbapenems and spectrum {beta}-lactamases extended were found, which included blaKPC genes (81.49%), blaCTXM-2 (72.22%) and blaCTXM-1 (66.66%). In relation to the presence of Mex family efflux pumps genes, 100% of positivity were detected. These findings suggest that P. aeruginosa isolates exhibit an arsenal of genes encoding {beta}-lactamases able to induce phenotypic patterns of resistance to several antimicrobials commonly used as first-line treatment. Author SummarySince the introduction of the use of antimicrobials, resistance to antimicrobials has been growing and becoming a global public health problem, as it leads to ineffective treatment and an increased risk of mortality. P. aeruginosa is included in the World Health Organization (WHO) critical list of bacteria that have a higher rate of resistance to antimicrobials, requiring constant epidemiological investigation of the strains, especially in hospital environments, to correctly approach them. In this work, we used a methodology that detects 740 variants of different classes of {beta}-lactamases to evaluate the genotype of the study strains against the phenotype found. We evidenced a high prevalence of strains carrying genes related to carbapenems and extended-spectrum {beta}-lactamases, demonstrating a correlation with the phenotypes. Furthermore, we found a 100% positivity rate among the efflux pumps tested belonging to the MEX family.

Pandrug-resistant (PDR) K. pneumoniae has been reported sporadically in many countries and remains rare in Brazil. The lack of genomic studies limits the comprehension of the determinants mostly involved with the PDR emergence in K. pneumoniae. This study aimed to unravel the main genetic determinants involved with the PDR background of a clinical ST11 K. pneumoniae recovered in the Brazilian Amazon region. The carbapenem-resistant Kp196 was submitted to WGS and its intrinsic and acquired resistome was assessed by CARD and comparison with wild-type genes. Kp196 resistome was composed of acquired resistance determinants and mutations in chromosomal genes. Among the formers, blaCTX-M-15 and blaNDM-1, blaOXA-9, blaOXA-1, aadA1, aacA4, strAB, aph(3)-VI, aac(3)-IId, qnrS1, qnrB1, oqxAB, dfrA14, sul2, catB3 were found in the vicinity of mobile genetic elements, which could contribute to their spread. Kp196 colistin resistance was multifactorial and attributed to modifications in ArnT (M114L/V117I/R372K), PhoQ (D150G), and the mgrB disruption by ISKpn25. Besides the presence of qnr and oqxAB genes, Kp196 also presented altered GyrA (S83I) and ParC (S80I). An in-block deletion in the repressor RamR, contributing to acrAB overexpression, and the presence of an enhanced-function AcrB variant (S966A), probably led to the Kp196 multidrug and tigecycline resistance. Insertions, in-block deletion, and missense mutations were involved with ompK35-36-37 inactivation, also accounting for the Kp196 multidrug resistance, including carbapenems. The Kp196 PDR profile, especially the carbapenem resistance, was due to the accumulation of different mechanisms, in which modifications in housekeeping genes accounted for a more stable resistome.

The study investigated the spectrum of antibiotic resistance and the associated genes for aminoglycoside, macrolide and ESBL class of antibiotics using clinical isolates. A total of 430 preserved bacterial strains (Acinetobacter baumannii, n= 20; Pseudomonas aeruginosa, n= 26; Klebsiella pneumoniae, n= 42; E.coli, n= 85; Staphylococcus aureus, n= 84; Salmonella Typhi, n= 82; Enterococcus spp., n= 27; Streptococcus pneumoniae, n= 36 and CNS, n= 28) were examined. The strains were isolated from patients admitted to various tertiary hospitals of Dhaka city between 2015 and 2019 with either acute respiratory infections, wound infections, typhoid fever or diarrhea. The isolates were reconfirmed by appropriate microbiological and biochemical methods. Antimicrobial susceptibility tests were done using Kirby-Bauer disk diffusion approach. PCR amplification using resistance gene-specific primers for aminoglycoside, macrolide and ESBL class of antibiotics was done and the amplified products were confirmed by Sanger sequencing. Of the total isolates, 53% came out as MDR with 96.6% of E. coli and 90% of Staphylococcus aureus. There was a year-wise gradual increase of MDR isolates from 2015-2018 and by 2019 the increase in MDR isolates became almost 2-fold compared to 2015. Among the five ESBL genes investigated, CTXM-1 came out as the most prevalent (63%) followed by NDM-1 (22%) and E. coli isolates were the predominant reservoir of these genes. ErmB (55%) was the most frequently detected macrolide resistance gene, whereas aac(6)-Ib (35.44%) was the most prevalent aminoglycoside resistance gene and these genes were most prevalent in E. coli and P. aeruginosa isolates, respectively. CTXM-1 and ErmB (16.66%) were the most frequent partners of coexistence followed by CTXM-1 and aac(3)-II.

Burn patients are at high risk for nosocomial infection. Antibiotics are the key drugs for the treatment of infections. Overuse and inappropriate use of antibiotics increase both bacterial resistance and the cost of treatment. The introduction of correct and rational use of antibiotics appears to be impossible without having the knowledge of the current situation of antibiotic consumption. So, the study was conducted to know the current situation of antibiotic utilization pattern in burn patients. MethodsA Retrospective review of medical records was done to analyze the utilization pattern of antibiotics. The data were collected from Kirtipur hospital from June 2018 to May 2019. All the admitted patients irrespective of age, gender who were prescribed antibiotics and presented within three days of burn were included in the study. Patients admitted for less than 24hrs of a time were excluded from the study. ResultsA total of 249 reviewed case records came under inclusion criteria. Among them 51.8% were female and 48.2% were male. Mostly affected age group was 15-29 years (34.5%). Flame burn (51.8%) was the main cause of the burn. The majority had second-degree burn and 36.90% had 0-10% burn. Third-generation cephalosporin, ceftriaxone had the highest DDD/100BD (19.05). The most frequently used antibiotics were ceftriaxone, cefazolin, and piperacillin+tazobactam. DU90% comprises 12 antibiotics out of 30 antibiotics. The average number of antibiotics prescribed was 2.12 with a range of 1 to 7. ConclusionsThis study revealed the trend of antibiotic utilization pattern in burn patients. Third-generation cephalosporin, ceftriaxone was the most prescribed antibiotic. Regular antibiotic consumption using DDD methodology is needed for regular monitoring of antibiotic consumption so that timely intervention can be made and this study can be used as a baseline study.

Bacterial DNA gyrase and topoisomerase IV are the major targets of quinolone antibiotic, and mutational alterations in quinolone resistance determining regions (QRDR) serve as major mechanism of resistance in most bacterial species, including P. aeruginosa. The present investigation was aimed to study the molecular mechanism of fluoroquinolone resistance among clinical P. aeruginosa isolated from Dhaka, including alterations in target sites of the antimicrobial action. Laboratory collection of 53 P. aeruginosa were subjected to conventional cultural and biochemical characterization, followed by molecular identification using 16S rDNA sequencing. Susceptibility to ciprofloxacin and levofloxacin was tested by disc diffusion method followed by MIC assay. Resistant isolates were analyzed for mutation in their QRDR regions of gyrA and parC, and subjected to PCR detection of plasmid mediated quinolone resistance (PMQR) genes qnrA, qnrS and qnrB. Among the isolates, 28% were found to be resistant to both fluoroquinolones tested. All of the fluoroquinolone resistant isolates carried a single mutation in gyrA (Thr-83-Ile), while 20% carried a single parC mutation (Ser-87-Leu). Higher level of MIC was observed in isolates carrying alterations at both sites. None of the isolates harbored any PMQR genes investigated, suggesting that chromosomal mutations in QRDR regions to be the major contributing factor for quinolone resistance in P. aeruginosa under investigation.

AimRecently, the rise in Staphylococcal infection incidence accompanied by a rise of antibiotic-resistant strains is a major threat to public health. In this study, mechanisms leading to the occurrence of high-level multidrug-resistant (MDR) Staphylococcus aureus (S. aureus) strains after fluoroquinolone (FQ) exposure were investigated. MethodologySerially exposing S. aureus ATCC 29213 to ciprofloxacin (CIP), ofloxacin (OFL), or levofloxacin (LEV) at sub-minimum inhibitory concentrations (sub-MICs) for 12 days was performed to obtain S. aureus -1 strains and culturing for another 10 days without antibiotics to obtain S. aureus-2 strains. The genomic alterations in FQ-exposed strains were reached using whole genome sequencing and target sequencing. The expressions of efflux-related genes, alternative sigma factors, and genes involved in FQ resistance were evaluated using RT-qPCR. ResultsAfter serial FQ exposure, we observed a strong and irreversible increase of MICs to all applied FQs, i.e 32 to 128 times in all S. aureus-1 and remained 16 to 32 times in all S. aureus-2. WGS indicated 10 significant mutations including 2 deletions, 1 insertion, and 7 missense mutations that occur in all S. aureus-1 and -2 but not in initial strain. The FQ target, GrlA, was also mutated (R570H) in all S. aureus-1 and -2 which can partly explain the development of FQ resistance over the FQ exposure. Besides, FQ exposure also resulted in overexpression of genes encoding for (1) efflux pumps and their regulator (norA, norB, norC, and mgrA); (2) alternative sigma factors (sigB and sigS); (3) acetyltransferase (rimI); (4) methicillin resistance (fmtB); and (5) hypothetical protein BJI72_0645. ConclusionThe mutations occurred in the FQ-target sequence were associated with high-level FQ resistance while the activation of efflux pump systems and post-translational proteins played an important role in the emergence of MDR in S. aureus. Author summaryAntimicrobial resistance is a major public health problem worldwide. Multiple studies have been performed to understand how bacteria develops resistance during the antibiotic therapy in vitro and in vivo. Here we revealed how Staphylococcus aureus, a stubborn human pathogen, changed its genome and expression of important genes in responding with sub-MIC exposure to flouroquinolone antibiotics. Mutations were found in the target of flouroquinolones such as GrlA (R570H) and interestingly in some hypothetical regions which may be important for gene expression regulation. We have observed an marked overexpression of genes encoding for (1) efflux pumps and their regulator (norA, norB, norC, and mgrA); (2) alternative sigma factors (sigB and sigS); (3) acetyltransferase (rimI); (4) methicillin resistance (fmtB); and (5) hypothetical protein BJI72_0645 in all exposed strains. Importantly, the expression change still remained when the bacteria were no longer exposed to the antibiotics. This study is important to understand response of S. aureus to flouroquinolone and how it obtains the resistance phenotype under antibiotic exposure.

Klebsiella pneumoniae causes life-threatening nosocomial infections and is featured by a remarkable propensity for multidrug resistance acquisition. Infections caused by multidrug- (MDR) and extensively drug-resistant (XDR) strains lead to a limitation of therapeutic options and an increase in persistent infections, and they are usually represented by high-risk lineages. Based on these features and their relevance to global public health, most of the studies focused on such high-risk clones, and little is known about the epidemiological and evolutionary dynamics of new/geographically restricted lineages. This study aimed to unveil the antimicrobial resistance and virulence genetic repertoire of a clinical XDR K. pneumoniae (Kp199) strain belonging to geographically-restricted ST, not linked to any known clonal complex. Its intrinsic (gyrA, parC, ramR, soxR and soxS mutations) and acquired resistome agreed with the observed XDR phenotype. An extensive arsenal of both antibiotic and heavy metal resistance genes was observed, as well as genes involved with resistance to several antiseptics currently used in clinical settings. The co-occurrence of blaKPC-2 and blaNDM-1 carbapenemase genes in Kp199 was an alarming finding since it could contribute to increased carbapenem resistance. Kp199 virulome was associated with bacterial survival and replication during infections. This study raises concern about a novel, geographically restricted K. pneumoniae lineage harbouring a huge resistome and virulome, which may strongly contribute to its successful establishment as an epidemic lineage. Therefore, our findings underscore the importance of vigilant surveillance and control measures to mitigate the threat posed by the potential emergence of new high-risk pandemic clones.

The emergence of multidrug-resistant (MDR) and extremely drug-resistant (XDR) Klebsiella pneumoniae presents a significant challenge to public health, particularly in hospital settings where it is a leading cause of nosocomial infections. Addressing the urgent need for alternative treatments to combat antibiotic-resistant bacteria, this study describes the isolation, characterization, and genomic analysis of a novel bacteriophage, designated as MFS, targeting MDR/XDR K. pneumoniae strains isolated from hospital sewage in Dhaka, Bangladesh. The phage was isolated utilizing a double-agar overlay and characterized using Oxford Nanopore Technologies sequencing. Phage MFS was identified as a member of the Siphoviridae family, under the unclassified Webervirus subfamily, with potent lytic activity against clinical MDR/XDR K. pneumoniae strains. Genomic analysis revealed a 48,780 bp genome with 94 protein-coding sequences, including essential genes for phage replication, structure, and host lysis, but notably lacking genes associated with antimicrobial resistance, virulence, and lysogeny. The presence of specific genes for endolysin and holin underscores the phages lytic capability. Additionally, the study elucidates the phages structural proteins and mechanisms underlying bacterial cell wall degradation, contributing valuable insights into phage-host interactions and applications of phage therapy. Our findings underscore the therapeutic potential of sewage-derived bacteriophages against MDR/XDR clinical K. pneumoniae and emphasize the need for further exploration of bacterio-phage therapy as a viable alternative to traditional antibiotics in combating antibiotic-resistant bacterial infections.

Multi-drug resistant Escherichia coli is an increasing public health problem. Though, PBP3 insertions with blaNDM, blaCMY and blaOXA-48 like is restricted to South-East Asia with few reports from USA. The study suggests ompC/F variants as a core factor to classify ESBL (E), non-ESBL (NE), and ESBL with PBP3 and carbapenemases (EPBP3) clones. EPBP3 results in treatment complication, as most of the time, E. coli with PBP3 insertions co-carries blaNDM (87.5%), blaCMY (96.3%) and blaOXA-48 like (88.8%) implicating it as a predisposing factor for carbapenemase gene acquirement. Cefiderocol and cefepime/zidebactam are the choice against EPBP3 E. coli. Evolutionary BEAST analysis revealed consecutive events of YRIN and YRIK insertions in PBP3 gene leading to a surge in MDR E. coli clones. Further, emergence of the super clones STs 410, 405, 167 and 617 featuring these phenotypes is a major threat for developing and developed countries, which needs close monitoring. ImportanceThe manuscript describes various E. coli resistant genotypes across the globe and their importance in the choice of antimicrobial for treatment. The study identified six clades based on ompC and ompF mutations with a strong correlation to PBP3 insertions co-carried with beta-lactamases including blaNDM. Though, the ompC and ompF mutations were reported to precede the acquisition of carbapenemases in E. coli, clade segregation based on AMR genes as observed in this study reveals the ompC and ompF genes as a potential biomarker for AMR clade identification in E. coli. Currently, cefiderocol and cefepime/zidebactam seems to be the only choice to cover the AMR mechanism mediated by PBP3 insertions. Further, emergence of the super clones STs 410, 405, 167 and 617 featuring these PBP3 phenotypes is a major threat for developing and developed countries, which needs close monitoring.

PurposeThis study, aimed at determining the epidemiology and antimicrobial susceptibility patterns of infectious diseases caused by ESKAPE and non-ESKAPE microorganisms in patients hospitalized at the Nigde Omer Halisdemir University Training and Research Hospital in Nigde, Turkey, is a crucial step in understanding and combating the global public health problem posed by the ESKAPE pathogens. Materials and methodsA retrospective analysis was conducted at a primary tertiary care teaching reference hospital in Nigde. The study included patients admitted to the hospital between June 2022 and June 2024. The hospital information system offered clinical and demographic data for the patients. Furthermore, the hospitals microbiology lab acquired information on bacterial isolates and antibiotic resistance. ResultsThis study included 13378 bacterial isolates, predominantly gram-negative bacteria, particularly those from the Enterobacterales group. Among these isolates, 9798 (73.2%) were identified as ESKAPE pathogens, and 3580 (26.8%) were identified as non-ESKAPE bacteria. The Intensive Care Unit (ICU) accounted for the highest proportion of infections (34.47%), followed by the pediatric unit (22.6%). The most common infections were caused by Escherichia coli (4747 isolates, 35.5%), K. pneumoniae (1921 isolates, 19.6 %), and Acinetobacter baumannii (1049 isolates, 10.7 %). Furthermore, the analysis revealed that approximately 50.86% of the ESKAPE isolates were classified as multidrug-resistant (MDR) or extensively drug-resistant (XDR). XDR was predominantly detected in Acinetobacter baumannii (72.4%), whereas MDR was predominantly detected in Enterococcus faecium (76.9%). In contrast, Non MDR was predominantly detected across non-ESKAPE pathogens in Staphylococcus hemolyticus (96.1%), Staphylococcus epidermidis (86.5%), and Staphylococcus hominis (84.5%). Demographic data from the study highlighted significant age group disparities in individuals infected by the ESKAPE and the non-ESKAPE bacteria, with a more substantial proportion of older and children individuals represented in the research sample. ConclusionsThis study underscores the significant threat posed by multidrug-resistant ESKAPE pathogens in reference hospital settings, emphasizing the urgent need for effective surveillance and control measures.

Enterococcal high-level resistance to streptomycin (HLR-S) (MIC [&ge;] 2000 {micro}g/ml), conferred by production of a variety of aminoglycoside modifying enzymes (AMES), has been reported worldwide and a nucleotidyltransferase (ANT) enzyme encoded by the ant(6)-Ia gene is frequently associated with this phenotype. However, during a study conducted by our group on whole genome sequencing (WGS) analyses of Enterococcus faecium isolates, we observed that 32 E. faecium strains identified as susceptible to high-levels of streptomycin by the disk diffusion method had the of ant(6)-Ia gene annotated in their genomes. Antimicrobial susceptibility to streptomycin was reassessed by phenotypic testing and the presence of the ant(6)-Ia gene was confirmed by PCR in all the isolates. Alignment of the ant(6)-Ia gene with a reference sequence revealed a deletion of the first 48 nucleotides and four nonsynonymous mutations, leading to the substitution of a Glutamine to Methionine and an Aspartic Acid to Asparagine in the amino acid sequence. The protein structure was modelled by using the Phyre2 platform and the results indicated alterations in the N-terminus region leading to changes in the predicted binding site. Also, by searching the NCBI database we identified the genomes of 71 strains carrying the mutated gene. MLST analysis revealed that most strains carrying the mutated gene, including those described in this study belonged to hospital-adapted lineages, suggesting the occurrence of clonal dissemination of a subset of mutated isolates. HIGHLIGHTSO_LIThe presence of a mutated ant(6)-Ia gene was identified among Enterococcus faecium isolates expressing phenotypic susceptibility to high levels of streptomycin. C_LIO_LINonsynonymous mutations and inactivating changes in the ant(6)-Ia gene led to incongruities between phenotypes and genotypes. C_LIO_LIAlterations in the amino acid sequence had impacts on protein structure, with changes in the N-terminus region and the binding site. C_LI

BackgroundThe prompt identification of carbapenemases, particularly Klebsiella pneumoniae carbapenemases (KPC) and Metallo-{beta}-lactamase (MBL) produced by Klebsiella pneumoniae and Enterobacteriaceae, is imperative in stemming the spread of pathogens carrying these antibiotic-resistant attributes. This retrospective study seeks to delve into the clinical and microbiological characteristics of patients affected by gram-negative bacteria producing KPC and MBL, shedding light on their profiles and impacts. MethodsWe analyzed 147 clinical isolates from tertiary care hospitals in Dhaka, Bangladesh. Bacterial identification and Minimum inhibitory concentration (MIC) analysis were performed using conventional culture and VITEK(R)2 compact system. Carbapenem non-susceptibility (Cns) was defined as a minimum inhibitory concentration (MIC) of [&ge;]1 {micro}g/ml for Enterobacteriaceae while Pseudomonas aeruginosa and Acinetobacter baumannii bacterial isolates Imipenem non-susceptibility was defined as an MIC of [&ge;]2 {micro}g/ml. Detection of KPC and MBL-producing isolates was performed using the disk potentiation test (DPT) method. ResultsAll 147 clinical bacterial isolates demonstrated resistance to Imipenem (MIC 1 -[&ge;]16 {micro}g/ml), with Klebsiella pneumoniae carbapenemase (KPC) detected in 26.53 % (39 out of 147) isolates and metallo-beta-lactamases (MBL) in 44.89% (66 out of 147) isolates. Carbapenem resistance was notably prevalent among older male patients of the "> 60" age group, with the ICU harboring the highest number of resistant isolates, primarily associated with Acinetobacter baumannii followed by Klebsiella pneumoniae. ConclusionOur findings unveiled a concerning prevalence of carbapenem resistance among clinical bacterial isolates, with notable proportions of KPC and MBL producers. The findings underscore the urgent need for effective surveillance and infection control measures to mitigate the spread of multidrug-resistant pathogens in healthcare settings.

Antimicrobial resistance (AMR) presents a significant health problem globally with the majority of the burden coming from lower-middle-income countries. AMR surveillance under a One Health paradigm is critical for determining the relationships between clinical, animal, and environmental AMR levels. Allowing for a thorough knowledge of the interconnected variables contributing to resistance, which enables the development of effective solutions. This systematic review was conducted to determine the impact of antibiotics on the gene expression of Pseudomonas spp. In the East African Community. A comprehensive literature search was conducted across Web of Science, Scopus, and PubMed databases yielding 284 articles with 11 meeting the inclusion criteria after screening. We included the 11 studies from 5 East African Countries that are part of the East African Community, the results revealed a high prevalence of antimicrobial resistance in Pseudomonas aeruginosa, with resistance rates above 90% for most tested antibiotics, exception of Amikacin, which remained effective due to its limited use. Common resistance genes reported included carbapenem-resistant genes like blaNDM-1 and blaVIM, the most common method used was disc diffusion method at (50%). The review also found high-risk clones, such as ST 244 and ST 357, that were associated with multidrug-resistant strains. Environmental isolates showed lower resistance rates (54%) than clinical pathogens (73%), indicating different selecting pressures. Majority of the studies were conducted in Kenya (30%) and Uganda (30%), indicating differences in research capabilities and healthcare facilities. These findings highlight the critical need for more surveillance, effective antimicrobial stewardship programs, and additional research to prevent antibiotic resistance and guide public health initiatives in the region. KEY FINDINGS OF THE STUDYPseudomonas aeruginosa isolates demonstrated substantial resistance to antibiotics, including cefepime, meropenem, levofloxacin, and ticarcillin-clavulanic acid as reported across various studies conducted in East Africa. Amikacin was reported to be more effective in more than 90% of the studies reported across East Africa as a potential treatment choice for multidrug-resistant Pseudomonas infections in the region. Carbapenem-resistant genes such as blaNDM-1, blaVIM, and blaOXA-48 were found in a large number of clinical and environmental isolates. High-risk clones, such as ST 244 and ST 357 were reported to demonstrate clonal spread of multidrug-resistant Pseudomonas aeruginosa across East African healthcare settings. The disc diffusion method was the most popular antimicrobial susceptibility testing method (50%), owing to its low cost and simplicity. DNA extraction and PCR were used in 30% of the studies whereas more advanced approaches such as whole genome sequencing were less popular due to resource constraints. The majority of studies were undertaken in Kenya (30%) and Uganda (30%), with fewer studies in Tanzania and the Democratic Republic of the Congo (20%), demonstrating regional variations in research capacity and healthcare resources.

Background and objectivesAntimicrobial resistance is a major healthcare burden, aggravated when it extends to multiple drugs. While cross-resistance is well-studied experimentally, it is not the case in clinical settings, and especially not while considering confounding variables. In addition, bacteria from different sample sources may have undergone different evolutionary trajectories, therefore examining cross-resistance across sources is desirable. MethodologyWe employed additive Bayesian network (ABN) modelling to examine antibiotic cross-resistance in five major bacterial species, obtained from different sources (urine, wound, blood, and sputum) in a clinical setting, collected in a large hospital in Israel over a 4-year period. ABN modelling allowed for examination of the relationship between resistance to different drugs while controlling for major confounding variables. ResultsPatterns of cross-resistance differed across sample sources. All identified links between resistance to different antibiotics were positive, and most were present in several culture sources. However, in 15 of 18 instances, the magnitudes of the links were significantly different between sources compared. For example, E coli exhibited adjusted odds ratios of gentamicin-ofloxacin cross-resistance ranging from 3.0 (95%CI [2.3,4.0]) in urine samples to 11.0 (95%CI [5.2,26.1]) in blood samples. Conclusions and implicationsOur results highlight the importance of considering sample sources when assessing likelihood of antibiotic cross-resistance and determining antibiotic treatment regimens and policies. Abstract ImportanceWe examine the patterns of antibiotic resistance of a given bacterial species, obtained from different clinical infection locations, while accounting for potentially relevant clinical variables. We find that such patterns of cross-resistance between pairs of antibiotics vary between culture sources (e.g., urine vs blood samples), indicating different selective pressures. These findings have implications on prescription policies aiming to minimize collateral resistance.

BackgroundThe rise of antimicrobial resistance (AMR) in the Lake Chad Basin poses a significant threat to global health. While Escherichia coli and Klebsiella pneumoniae are primary concerns for the WHO, Proteus species have emerged as important clinical pathogens and potential reservoirs for genetic resistance. This study aimed to analyze the molecular diversity and horizontal gene transfer (HGT) potential of ESBL-producing Proteus species in the region. MethodsA regional surveillance was conducted with 1,500 clinical samples from Borno, Adamawa, Bauchi, Gombe, Taraba, and Yobe states. Proteus isolates were identified biochemically, and antibiotic susceptibility was assessed using the Kirby-Bauer method. Resistance genes (blaTEM, blaSHV, blaCTX-M) were identified via PCR, and HGT was evaluated through conjugation assays. ResultsA total of 144 Proteus isolates were identified, with a prevalence of 9.6%. P. mirabilis was the dominant species (90.97%). Phenotypic screening indicated that 69.44% produced extended-spectrum beta-lactamases (ESBL), with high resistance rates observed for Cefotaxime (80.56%) and Ampicillin (84.72%). Alarmingly, resistance to Ertapenem reached 54.86%. Molecular analysis showed blaTEM as the predominant gene (81.69%), and the conjugation assay revealed a high HGT rate of 76.92%, confirming blaTEM acquisition by E. coli. ConclusionThese results indicate that Proteus species in North-Eastern Nigeria are significant reservoirs for genetic resistance, facilitating the spread of ESBL markers. The high frequency of HGT raises concerns about the effectiveness of beta-lactam therapies in sub-Saharan Africa, underscoring the need to include Proteus in the GLASS framework and promote regional antimicrobial stewardship efforts. Current UnderstandingAntimicrobial resistance (AMR) in Enterobacteriaceae, particularly with Escherichia coli and Klebsiella pneumoniae, is a significant global issue highlighted by the World Health Organizations Global Antimicrobial Resistance and Use Surveillance System (WHO GLASS). While Proteus species are recognized as opportunistic pathogens, their role as genetic reservoirs in sub-Saharan Africa, especially in the Lake Chad Basin, remains inadequately defined in surveillance data. Study ContributionThis study identifies Proteus species as a critical "Genetic Hub" for the transmission of extended-spectrum beta-lactamases (ESBL) in North-Eastern Nigeria, revealing a high horizontal gene transfer (HGT) rate of 76.92% for the blaTEM genotype to E. coli. It also shows a concerning 54.86% resistance rate to Ertapenem, underscoring the urgent need to include Proteus in regional stewardship and global surveillance efforts.