Poultry Science
○ Elsevier BV
Preprints posted in the last 30 days, ranked by how well they match Poultry Science's content profile, based on 10 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Luttenschlager, H.; Wever, N.; Jansseune, S. C. G.; Hendriks, W. H.; Beckers, Y.; Carpentier, J.; Richel, A.; Francis, F.; Caparros Megido, R.
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Insect proteins represent a promising and more sustainable alternative to soybean meal in swine nutrition. However, high dietary inclusion levels often result in reduced animal performance, indicating that factors other than crude protein concentration should be considered. This study evaluated the protein quality and degradability of feed-grade defatted black soldier fly (BSF) meal in comparison with a conventional organic protein core for post-weaning piglets. Protein content, amino acid composition, reactive lysine, Maillard reaction markers, buffering capacity, and protein hydrolysability were determined. Our results showed that defatted BSF meal exhibited a protein content and amino acid profile comparable to those of the protein core but contained substantially higher levels of free amino acids. Accounting for free amino acids reduced the estimated lysine damage from 18.4% to 10.4%, highlighting the importance of considering free amino acids when determining reactive lysine. In addition, BSF meal exhibited a higher buffering capacity and lower protein degradability than the protein core. These findings provide new insights into the nutritional limitations of feed-grade BSF meal and suggest that a more accurate assessment of reactive lysine, together with dietary strategies to reduce buffering capacity, may improve its utilization in post-weaning piglet diets.
Ye, F.; Yu, H.; Hong, Y.; Zhao, H.; Kang, H.; Yu, H.; Li, H.
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Cross-beaks are deemed a threat to poultry health, productivity, and animal welfare. Nevertheless, due to sporadic cases, heterogeneity of gene loci and incomplete dominance, the molecular mechanism of cross-beak formation, especially the degree of cross, is not yet clear. Thus, we screen key genes and reveal the possible phenotypic formation mechanism of cross-beak by comparison with different degrees of deformity in Huiyang Bearded chickens by compare whole-genome resequencing-based variant analysis. Comparative analysis between cross-beak and normal-beaked chickens identified differential variants in several candidate genes, including CDH11, CTNNAL1, NRXN3, NRXN1, CDH5, SDC3, and DHFR. Genes harboring these variants were enriched in pathways related to cell adhesion molecules and metabolic processes, with functional annotations involving cell-cell adhesion and neural crest cell migration. Comparative analysis between chickens with severe and slight cross-beak deformities identified additional candidate genes, including MRPL21, NSUN2, DDX55, GNB3, and NFKB2. These genes were associated with enriched terms and pathways related to focal adhesion, amyotrophic lateral sclerosis, steroid 7 -hydroxylase activity, and skin-barrier establishment. These findings provide a preliminary catalogue of genetic variants and candidate genes for future functional studies of cross-beak development and severity in chickens.
Khatun, R.; Bhuiyan, M. R.; Akter, M. N.; Saha, N.; afroz, S.; Ray, A. P.; Hossain, K. M. M.
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BackgroundEscherichia coli contamination of chicken eggs is an important food-safety concern, while antimicrobial-resistant E. coli may contribute to the dissemination of antimicrobial resistance through the food chain. However, information on egg-associated E. coli and its antimicrobial susceptibility in Natore District, Bangladesh, is limited. ObjectivesThis study aimed to determine the prevalence of E. coli in chicken eggs collected from commercial farms, markets and indigenous/backyard flocks in Natore District, identify the isolates based on cultural, morphological and biochemical characteristics, and assess their antimicrobial susceptibility. Materials and MethodsA total of 84 egg-shell swab samples, comprising 28 samples each from commercial farms, markets and indigenous chicken flocks, were collected from seven upazillas of Natore District between January and June 2023. Samples were cultured on selective and differential media, and presumptive isolates were confirmed by Gram staining, motility and biochemical tests. Antimicrobial susceptibility was determined using the Kirby-Bauer disc-diffusion method against seven antimicrobial agents. ResultsE. coli was detected in 56/84 (66.67%) egg samples. Prevalence was highest in indigenous eggs (22/28, 78.57%), followed by farm eggs (18/28, 64.28%) and market eggs (16/28, 57.14%). Among 22 confirmed isolates tested for antimicrobial susceptibility, resistance was highest to neomycin (90.91%) and erythromycin (86.36%), followed by oxytetracycline (77.27%), amoxicillin (68.18%), ciprofloxacin (63.63%), levofloxacin (59.09%) and doxycycline (36.36%). No isolate was sensitive to neomycin or erythromycin. ConclusionThe high prevalence of E. coli and substantial antimicrobial resistance among egg-associated isolates indicate an important food-safety and public-health concern. Improved hygienic egg handling, prudent antimicrobial use and continued antimicrobial-resistance surveillance are warranted throughout the poultry production and marketing chain.
Bragg, M.; Muletz-Wolz, C. R.; Freeman, E. W.; Songsasen, N.
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The maned wolf (Chrysocyon brachyurus) is a near-threatened canid species that suffers from gastrointestinal (GI) disease under human care. While the cause remains poorly understood, recent studies report that altered gut microbiota is linked to GI disease in the domestic dog. The goal of this study was to describe the relationship between gut bacteria and environmental factors, GI health, short chain fatty acid (SCFA) peaks, and genetic relatedness in maned wolves. Fresh fecal samples were collected twice from wolves (first collection n = 29; second collection n = 25) housed in six facilities in the United States. Fecal alpha-1 proteinase inhibitor (FA1PI), a biomarker for GI health in canids, and SCFA peaks were quantified. Information on diet, housing group and history of GI disease or inflammation was provided by the zoological facility for each wolf. We characterized gut microbiota using 16S rRNA gene amplicon sequencing with qPCR abundance corrections. We found that dietary fiber gross energy (GE), protein GE, and number of daily produce items influenced gut microbiota. Additionally, there was a negative relationship between dietary fiber GE and Fusobacterium sp. abundance, corroborating previous findings linking fiber to altered gut microbiome composition in canids. Lastly, fiber GE was negatively correlated with FA1PI, connecting fiber to GI health in the maned wolf. Findings from this study suggest that increasing dietary fiber GE changes the gut microbiome and may improve GI health in the maned wolf, highlighting important management decisions that can be considered to maintain a healthy zoo-managed maned wolf population. IMPORTANCEFindings from this study are important because gastrointestinal disease is a common health concern for maned wolves under human care, and the causes are not well understood. The current study found that diet, especially the amount of fiber gross energy, can affect gut bacteria and may support better gastrointestinal health. Diet alterations could be a practical tool for zoos to support management of gastrointestinal health issues in maned wolves. These findings also show the importance of carefully managing diets for a near-threatened species, since better gastrointestinal health may improve overall health and well-being and support reproduction. More research is needed to determine the best amount and type of fiber, but our results provide foundational information for improving care and supporting healthy zoo-managed maned wolf populations.
Akter, M. N.; Bhuiyan, M. R.; Rana, M. S.; Khatun, R.; Ray, A. P.; Hossain, K. M. M.
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BackgroundLive bird markets (LBMs) may facilitate the persistence and dissemination of Escherichia coli and antimicrobial-resistant bacteria because of intensive bird handling, environmental contamination and inadequate sanitation. However, information on E. coli contamination and antimicrobial susceptibility in LBM environments in Rajshahi District, Bangladesh, remains limited. ObjectiveThis study aimed to determine the prevalence, identify the cultural and biochemical characteristics, and assess the antimicrobial susceptibility pattern of E. coli isolated from water, soil and bird-dropping samples collected from LBMs in Rajshahi District. MethodsA total of 60 environmental samples, comprising 20 water, 20 soil and 20 bird-dropping samples, were collected from LBMs across all ten upazillas of Rajshahi District between January and June 2023. E. coli was isolated and identified using cultural characteristics, Gram staining and biochemical tests. Antimicrobial susceptibility was determined by the Kirby- Bauer disc diffusion method against seven antimicrobial agents using CLSI interpretive criteria. ResultsE. coli was detected in 33 of 60 samples, giving an overall prevalence of 55.00%. Prevalence was highest in bird-dropping samples (75.00%), followed by water (55.00%) and soil (35.00%). Among the 33 isolates, resistance was highest to oxytetracycline (78.79%) and amoxicillin (63.64%), followed by ciprofloxacin (48.48%), doxycycline (33.33%), levofloxacin (9.09%), erythromycin (9.09%) and neomycin (6.06%). Sensitivity was highest to neomycin (60.61%), followed by levofloxacin and erythromycin (51.51% each). ConclusionThe high prevalence of E. coli and substantial resistance to several commonly used antimicrobials indicate considerable microbiological and antimicrobial-resistance concerns in LBM environments. Improved sanitation, biosecurity, hygienic poultry handling and prudent antimicrobial use are warranted to reduce environmental contamination and potential transmission of resistant bacteria.
Khaeruddin, ; Hermawansyah, ; Junaedi, ; Syamsuryadi, B.; Kasri,
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This study aims to evaluate the effectiveness of curcumin and penicillin-streptomycin as diluents on changes in the structure and diversity of the chicken semen microbiome during storage. Semen was collected from Kampung chickens (native to Indonesia) and divided into five treatment groups: diluted without antibiotics or curcumin (control), and diluted with additions of 10 micromolar, 20 micromolar, and 30 micromolar curcumin, and penicillin-streptomycin, respectively. The semen was stored at 5 C for 24 hours. The composition and diversity of the semen microbiome were analyzed using 16S full-length amplicon sequencing. Analysis of the top 10 species showed that Uncultured Saccharofermentans sp. and Porphyromonas somerae served as the most dominant and stable core microbiome across all treatments. Alpha diversity analysis showed that the addition of curcumin and penicillin-streptomycin reduced microbial richness (Observed, ChaO1, ACE, and Fisher) in a dose-dependent manner, yet maintained overall diversity (Shannon and Simpson), with the penicillin-streptomycin treatment resulting in the highest species evenness (InvSimpson). Beta diversity analysis revealed extreme separation of taxonomic abundance variance in the penicillin-streptomycin group, whereas the curcumin treatment exhibited a dose-dependent pattern of microbial abundance transition. Venn diagram analysis identified 415 OTUs as the core microbiome and confirmed that curcumin acts through selective filtering that stabilizes the ecosystem without triggering the proliferation of opportunistic taxa. Penicillin-streptomycin acts more rapidly and dominantly in suppressing/killing bacterial populations, however, the addition of curcumin is able to modulate the microbial ecosystem in a more balanced manner by suppressing the growth of harmful bacteria without compromising the integrity of the chicken semen environment.
Kannurpatti Srinivasan, S. K.; Afsharnezhad, S.; Paulson, A. R.; Bourne, D. C.; Sun, Z.; Carver, L. F.; Tirani, J.; Wong, H.; Sjaarda, C. J.; He, S.; Sheth, P. M.; Colautti, R. I.
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Tick-borne pathogen (TBP) surveillance strategies that rely exclusively on targeted methods like PCR (PCR) or immunoblots do not benefit from strain-level sequence variation. Bacterial 16S rRNA metabarcoding offers more agnostic detection but is constrained in I. scapularis by the dominance of a maternally inherited endosymbiont, Rickettsia buchneri. Here we report the design and evaluation of three R. buchneri-specific blocking primers to suppress endosymbiont amplification during full-length 16S rRNA library preparation. Of these, primer 18F-Rb-C3 reduced R. buchneri relative abundance approximately 32-fold. We applied 18F-Rb-C3 with V4-16S metabarcode sequencing on 67 ticks collected from farm animals in Eastern Ontario and compared Borrelia species detection against qPCR. The V4-16S rRNA metabarcoding identified Borrelia species in 21 samples, whereas qPCR detected Borrelia in 24 samples and 11 samples were detected by both methods. Additionally, metabarcoding detected Anaplasma phagocytophilum in 12 samples, including seven samples coinfected with Borrelia, in the same assay. Variation relevant to strain surveillance was also detected by sequencing, though V4-16S was not sufficient to resolve closely related Borrelia genospecies or A. phagocytophilum variants. These findings demonstrate that blocking primer 18F-Rb-C3 enhances sensitivity of amplicon sequencing to the level of qPCR while also detecting other pathogens and sequence variants in a single assay.
Fairweather, A. G.; Andrews, A.; Grier, J.; Brierley, L.; Cattarino, L.; Panovsk-Griffiths, J.
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Avian Influenza viruses (AIVs) infect a broad host range despite having a natural reservoir in wild aquatic birds. Whilst most strains stay within their host species, some break the species barrier through genetic adaptations. We are most concerned about zoonotic cases, where a human becomes infected. Despite these events being rare, they are associated with high mortality and introduce the risk of onward human-to-human transmission of AIV. As a novel pathogen within the human population, this could have pandemic potential. Using genetic composition features for 8 AIV proteins drawn from viral sequence data, we employ machine-learning algorithms to classify AIV cases as zoonotic or not. These genetic features encode host 'signatures' which can indicate zoonosis and include frequency measures such as dipeptide composition and amino acid physiochemical properties. We consistently find XGBoost to outperform all other algorithms. We optimise parameters for ten classification models: one for each of the 8 proteins and two combined models. Following this, we show that a multi-model approach gives the best performing prediction for AIV zoonosis. We have identified all 8 proteins as having a role in predicting zoonotic transmission. Of particular importance is the PB2 and HA proteins, with specific amino acid physiochemical properties such as charge, secondary structure and hydrophobicity amongst the most indicative features in our combined models. Our alignment-free computational study can identify AIV cases still within avian hosts which are genetically closest to zoonotic AIV cases, thereby identifying the cases most likely to cross the species barrier. In a resource limited environment, our model could be used to quickly identify high priority cases for further investigation.
Kato, M.; Iwakoshi-Ukena, E.; Furumitsu, M.; Narimatsu, Y.; Yatsuda, C.; Nakamura, Y.; Ukena, K.
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Introduction: Central regulation of energy homeostasis is essential for balancing lipid storage and reproductive investment; however, the hypothalamic factors governing this trade-off remain incompletely defined in birds. Neurosecretory protein GM (NPGM), an 83-amino acid hypothalamic factor, was investigated for its role in energy allocation during sexual maturation in Japanese quail (Coturnix japonica). Methods: Male and female quails at the onset of sexual maturation received chronic intracerebroventricular administration of NPGM for 13 days via osmotic pumps, during which their body mass, food intake, and water intake were monitored daily. At the endpoint, peripheral tissue and muscle masses, serum metabolite levels (glucose, fatty acids, triglycerides, testosterone, and 17{beta}-estradiol), hepatic triglyceride content, and gene expression profiles of hypothalamic feeding/reproductive genes and hepatic/adipose lipid metabolic genes were evaluated. Results: NPGM increased subcutaneous and abdominal fat in both sexes and was associated with suppressed gonadal maturation, as indicated by reduced testicular mass relative to body mass and lower testosterone levels in males, as well as a trend toward reduced ovarian mass and lower 17{beta}-estradiol levels in females. Sex-dependent metabolic phenotypes emerged: males exhibited increased body mass gain, hyperphagia, elevated water intake, enlarged liver, pancreas, and heart, higher serum and hepatic triglyceride levels, increased hepatic SCD1 expression, and reduced hepatic CGI-58, PPAR{gamma}, SLC2A2, and CD36. In contrast, females showed fat accumulation without hyperphagia or hepatic triglyceride elevation, accompanied by reduced hepatic VTG2 and APOV1 and decreased adipose ATGL, LPL, and FATP. Hypothalamic AGRP expression decreased in males, whereas both NPY and AGRP decreased in females. Discussion: These findings demonstrate that central NPGM shifts energy allocation from reproduction toward lipid storage through sex-dependent endocrine and metabolic mechanisms, identifying NPGM as a neuroendocrine regulator of energy allocation during sexual maturation in Japanese quails.
Kayiwa, J. T.; Nassuna, C.; Nabatanzi, L.; Yiga, F.; Harris, E.; Wickenkamp, N.; Williams, K.; Matovu, B.; Mutebi, J. M.; Nalukenge, L.; Nalikka, B.; Siya, A.; Nakayiki, T.; Fagre, A.; Hartwick, A.; Cordova, E.; Azerigyik, F.; Castle, K.; Dewey, T.; Kityo, R.; Lutwama, J.; Kading, R. C.
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Bats harbor a diversity of viruses, some of which have the potential to impact human and livestock health. Caves in Eastern Uganda are commonly inhabited by bats in the genera Rhinolophus, Hipposideros, Myonycteris, and others. Human encroachment into these caves for shelter, hunting, mineral harvesting, and tourism poses a risk of exposure to infectious agents these bats may carry, yet little is known about the viruses present in these bats. From 2021 - 2023, 635 unique bats were captured in caves by mist net, with 69 bats resampled over the study for a total of 706 sampling instances. A total of 1,394 oral and rectal swabs were collected non-destructively and screened using molecular techniques for coronaviruses, paramyxoviruses, rhabdoviruses, flaviviruses, and filoviruses. Of these samples, 399 (56.5%) were collected during the rainy season and 307 (43.5%) during the dry season. Coronavirus RNA was detected in 59/706 (8.36%) of samples from Rhinolophus spp. (n = 35), Hipposideros caffer (n = 12), Myonycteris angolensis (n = 6), and Miniopterus spp. (n = 6). Six bats (0.85%) were positive for paramyxoviruses. Finally, (3 H. caffer, 1 M. angolensis, 1 Rhinolophus spp. and 1 Nycteris thebaica) 3 Rhinolophus bats were positive for rhabdoviruses (0.42%, all Rhinolophus spp.). No samples were positive for filovirus or flavivirus RNA. This project has generated novel data on the association of bat species and different viral strains present in these bats, advancing our knowledge of viral ecology and spillover risk at the human/bat interface.
Barrand, Z. A.; Ridenour, C. L.; Erickson, D. E.; Rivas, A. N.; Schmidt, B. K.; Will, J.; Young, S. J.; Busser, N.; Townsend, J.; Enriquez, D.; Murphy, D.; Wong, S.; Keats, J.; Carvalho, S. T.; Attardo, G. M.; Barker, C. M.; Hepp, C. M.
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Here we report a newly developed method utilizing long-range PCR and long-read Pacific Biosciences HiFi sequencing that successfully obtained two full-length and annotated mitochondrial genomes from Culex quinquefasciatus Say, 1823 and Culex tarsalis Coquillett, 1896, both from Maricopa County, Arizona, USA. Given the substantial burden of West Nile virus in Maricopa County over the past decade, and that these vectors are primarily responsible for spillover to human populations in the county, it is critical to better understand their distribution over time and space. This study begins to approach this need by contributing a novel approach that has resulted in the first West Nile virus vector mitochondrial genomes from Arizona. Our circular Cx. quinquefasciatus mitogenome is 15,587 bp in length, making it the first USA-based mitogenome sequenced through the AT-rich control region. The Cx. tarsalis mitochondrial genome is 16,416 bp long, longer than recently published California-based CTarK1 and Texas-based PQ585801 mitogenomes. The increased length of the Cx. tarsalis mitogenome is a result of a 905 bp insertion in the AT-rich control region, not present in the species publicly available mitogenomes. A maximum likelihood-based phylogenetic reconstruction supports the species designation of these newly-sequenced mitogenomes. The newly developed methodology offers a unique approach to study medically-important vector species around the globe, providing a solution to study populations through pooled vector pathogen surveillance programs.
Saha, N.; afroz, S.; Das, K.; Bhuiyan, M. R.; Ray, A. P.; Jony, M. A. H.; Khatun, R.; Hossain, K. M. M.
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Background: Retail red meat may act as a source of foodborne pathogens, antimicrobial resistant bacteria, and antibiotic residues, posing a significant public health concern in Bangladesh. Objectives: This study aimed to isolate and identify major bacterial pathogens from retail red meat, determine their antimicrobial susceptibility patterns, assess the prevalence of antibiotic resistant bacteria, and detect antibiotic residues in meat samples. Methods: A cross-sectional study was conducted from January to June 2019 using 60 retail red meat samples (20 cattle, 20 goat, and 20 buffalo) collected from Rajshahi and Naogaon districts. Bacterial isolates were identified using standard cultural, morphological, staining, and biochemical techniques. Antimicrobial susceptibility was evaluated by the Kirby Bauer disc diffusion method according to CLSI guidelines. Antibiotic residues were screened in 15 representative samples using thin layer chromatography (TLC). Results: Overall prevalence of Escherichia coli, Salmonella spp., and Staphylococcus aureus was 10.0%, 13.3%, and 28.3%, respectively. E. coli showed complete resistance to penicillin (100%) and high resistance to amoxicillin (83.3%), while remaining highly susceptible to ciprofloxacin (83.3%) and gentamicin (66.7%). Salmonella spp. exhibited highest resistance to penicillin (87.5%) and tetracycline (75.0%), whereas gentamicin (87.5%) and ciprofloxacin (75.0%) remained the most effective agents. S. aureus demonstrated marked resistance to penicillin (94.1%), ampicillin (58.8%), tetracycline (47.1%), and amoxicillin (47.1%), but high susceptibility to gentamicin (88.2%) and ceftriaxone (70.6%). TLC detected ciprofloxacin and oxytetracycline residues in one cattle meat sample each (6.7%). Conclusions: Retail red meat marketed in the study areas harbored multidrug-resistant bacterial pathogens and detectable antibiotic residues, highlighting potential risks to food safety and public health. Continuous surveillance, prudent antimicrobial use, improved slaughterhouse hygiene, and strict compliance with antibiotic withdrawal periods are essential to minimize antimicrobial resistance and residue contamination.
Werner, A. P.; Sachithanandham, J.; Akin, E.; Talukdar, S.; Pinsley, M.; Pekosz, A.
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H5N1 clade 2.3.4.4b avian influenza A viruses pose a significant threat to wild animal populations, domesticated animals, and potentially, the human population. For H5N1s to infect and transmit among mammalian species, mutations for improved utilization of mammalian receptors and enhanced replication at the lower temperatures of the upper respiratory tract need to be acquired. A human H1N1pdm09-like virus was compared to H5N1 genotypes B3.13 and D1.1 for replication at 33{o}C, 37{o}C, and 39{o}C - temperatures consistent with the upper and lower respiratory tract in humans, and dairy cow udder tissue. All H5N1 viruses had increased plaque sizes on MDCK cells at 37{o}C and 39{o}C compared to H1N1pdm09. In primary, differentiated human nasal and bronchial epithelial cultures, all H5N1 viruses show restricted infectious virus production compared to H1N1 at 33{o}C. While H5N1 D1.1 also showed restricted replication at 37{o}C and 39{o}C, the H5N1 B3.13 replicated to nearly equivalent titers as H1N1pdm09. All H5N1 viruses demonstrated similar cell tropism in cells from the upper and lower respiratory tract, infecting more ciliated than non-ciliated cells relative to H1N1pdm09. H1N1, H5N1 B3.13 D1.1 infection induced similar innate immune factors, with nasal epithelial cells producing higher levels compared to bronchial epithelial cells. These data suggest that genotype B3.13 and D1.1 H5N1 viruses show different temperature dependent replication patterns compared to H1N1pdm09.
EDGE, D.; TURTON, J.; Adebo, A.; Tuzaktepe, O.; Fraser, B.; Ross, C. S.; James, J.; TERREY, J.; Nazareth, N.; Reid, S. M.; Banyard, A. C.
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Existing molecular diagnostic approaches for notifiable avian diseases (NADs) involve a suite of PCR assays that enable both generic detection, and where positive, subtyping of both avian influenza virus (AIV) and Newcastle disease virus (NDV). Novel rapid and direct diagnostic assays for the detection of AIV and NDV were developed and evaluated using unprocessed cloacal (C) and oropharyngeal (OP) poultry swab material. Both assays employ a closed tube direct real-time reverse transcription polymerase chain reaction (RRT-PCR) approach in which viral lysis is achieved by heat treatment and a dedicated PCR compatible buffer, followed by detection using a RRT-PCR approach. Primer and probe sets were designed using globally circulating AIV and NDV sequences collected over the preceding five years, rather than region-specific sequence datasets, so that the assays detect all circulating genotypes. Analytical performance assessment demonstrated that both assays were highly sensitive and specific, successfully detecting all unextracted target antigens without cross reactivity to a panel of other common poultry pathogens. For each assay, viral lysis and amplification were achieved directly from samples at single digit genome copy numbers. Furthermore, low levels of viral RNA could be reliably detected in the presence of C and OP matrix material, providing proof-of-concept for direct detection of these economically significant avian pathogens in a field setting. Additional use case scenarios, including pooled sample screening and combined C/OP testing from individual birds, were also explored. These findings establish a foundation for ongoing studies incorporating paired-sample testing against validated laboratory reference assays.
Oladipo, P. M.; Jomaa, A.; Zhang, X.; Withey, J. H.; Ram, J. L.
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Increased temperature is one of the first environmental cues encountered by bacteria upon entering a mammalian host. Here, we investigated the effects of temperature on the transcriptome and proteome of Escherichia marmotae and E. coli. Previous studies demonstrated that temperature affects motility in E. marmotae; therefore, we examined how temperature alters gene expression at 37 {degrees}C versus 28 {degrees}C and whether this response is conserved in E. coli. Strains were grown under static conditions at both temperatures, and gene expression and protein abundance were assessed by RNA transcriptome analysis and global proteomics. Temperature altered the expression of 111 genes (2.7%) in E. marmotae and 99 genes (2.5%) in E. coli (adjusted p < 0.05, [≥]2-fold change), with changes concentrated within specific functional pathways. In E. marmotae, flagellar and chemotaxis genes and operons involved in cellulose-dependent biofilm formation and nitrate respiration were markedly downregulated at 37 {degrees}C. In contrast, genes associated with fimbrial adhesion and immune evasion, including fimA/fimB, ompT, and prophage-associated loci, were upregulated. Proteomic analysis corroborated these trends, showing reduced flagellar and chemotaxis proteins and increased stress-adaptation and host-interaction proteins. E. coli showed a distinct response, with stronger enrichment of metabolic and amino-acid biosynthesis pathways and minimal changes in motility regulation. Together, these findings demonstrate that E. marmotae motility is temperature-dependent and may represent a mechanism for immune evasion within the host.
Chen, J.; Zhuang, J.; Li, X.; Lin, M.; Lu, Q.; Yan, N.; Lai, D.-H.; Huang, S.
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Parasitic infections pose multifaceted threats to farmed fish, extending beyond direct pathogenicity to facilitate infections of bacteria, viruses, and microparasites. This synergistic interaction often leads to co-infections that significantly exacerbate disease outbreaks and mortality, presenting a severe challenge to aquaculture sustainability. Recently, a novel trypanosomiasis caused by the Trypanosoma carassii spectrum has emerged in cage-cultured Larimichthys crocea along the southeast coast of China, resulting in widespread prevalence and high mortality rates. Although this pathogen is hypothesized to originate from freshwater fish, its transmission route in marine environments has remained elusive. In this study, we investigated potential vectors and intermediate hosts of T. carassii spectrum, including leeches and monogenean in natural marine settings, and simulated transmission pathways using an established laboratory model involving T. carassii spectrum, Micropterus salmoides and the leech Poecilobdella manillensis. First, our field surveys in the coast of Ningde, Fujian Province, revealed a nearly 100% co-infection rate of T. carassii spectrum and the monogenean Neobenedenia girellae in diseased juvenile L. crocea. PCR analysis detected T. carassii spectrum traces in some N. girellae specimens, and subsequent experiments confirmed that N. girellae ingests the trypanosome while feeding on host blood. Furthermore, bacterial co-pathogens, such as Vibrio harveyi, were also detected within N. girellae. We also document two fatal leech infestations: Zeylanicobdella arugamensis in hybrid groupers (Epinephelus moara [female] X Epinephelus lanceolatus [male]) in Zhangpu, and Limnotrachelobdella okae in E. lanceolatus and E. fuscoguttatus in Raoping. These leeches tested negative for trypanosomes but carried pathogenic bacteria that co-infected the host fish; nonetheless, they are established vectors for trypanosome transmission. In a laboratory cohabitation model simulating T. carassii spectrum transmission, infected M. salmoides were housed with healthy conspecifics under three conditions: Group A (with the leech P. manillensis), Group B (no leeches), and Group C (no leeches, with physical separation between infected and healthy fish). After 14 days, blood smear microscopy and PCR analysis revealed infection rates in healthy fish of 58.33% in Group A, 40.00% in Group B, and 0% in Group C. Conclusively, T. carassii spectrum can be transmitted via leeches (with higher efficiency) and may also spread through direct contact under high-density aquaculture conditions, whereas N. girellae may act as an incidental vector, further research is warranted to clarify transmission dynamics in natural marine ecosystems. Additionally, our findings highlight the role of ectoparasites, including N. girellae and leeches, as potential reservoirs and vectors for bacterial pathogens of fish. In high-density intensive aquaculture, this vectorial capacity transforms parasites from primary pathogens into key drivers of polymicrobial disease outbreaks.
Olilah, P.; Chevalier, F. D.; Oguso, J.; Oyugi, E.; Opot, B. H.; Morales, M.; Le Clecch, W.; Anderson, T. J.; Ndombi, E. M.
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Mass drug administration (MDA) using Praziquantel is central to efforts to eliminate Schistosomiasis. However, regions which respond poorly to MDA ("persistent hotspots") have been reported in many regions of Africa, including in Western Kenya. One possible explanation for persistent hotspots is that these areas contain PZQ resistant schistosome parasites. Recent studies have shown that Sm.TRPMPZQ gene is the molecular target for PZQ in schistosome parasites and that mutations in this gene can result in PZQ resistance. This study characterized mutations within Sm.TRPMPZQ in 23,420 miracidia collected from both hotspot and non-hotspot villages in Siaya County, western Kenya. We collected triplicate pools of 780.67 (SD {+/-} 183.47) miracidia from 135 people in five hotspot villages, where S. mansoni prevalence remains high despite over 5 annual treatments, and from 62 people from 5 non-hotspots villages where annual treatment resulted in reduction in prevalence. We extracted DNA from each miracidia pool, amplified 15 amplicons covering 1,695bp of the Sm.TRPMPZQtransmembrane domain and sequenced these to high read depth (21,110x) using a Miseq at KEMRI-CGHR. We identified five high confidence (frequency [≥] 0.01) Sm.TRPMPZQ variants. These included four synonymous changes and a non-synonymous variant (p.L1476I). p.L1476I is found at similar frequency in non-hotspot (0.040 {+/-} 0.006) and hotspot villages (0.044 {+/-} 0.0050) (Mann Whitney U=18, p= 0.31) and does not impact PZQ-response in Ca2+ reporter assays. Our studies show that resistance variants in Sm.TRPMPZQ are rare or non-existent in the locations studied and do not explain the existence of hotspots in this region.
Pinaria, Y. W.; Pangkerego, N. P.; Kumolontang, G.
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"Lactic acid bacteria (LAB) are one of the dominant groups of bacteria in the palm sap (Arenga pinnata) microbiome. Previous research in the sago palm sap production centers of Tomohon City (Kayawu, Pinaras, and Lahendong) has successfully identified various LAB species, including Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus buchneri, Leuconostoc mesenteroides, and Leuconostoc sp. This study aims to identify LAB species in sago palm sap from a new location, namely the Wawo Plantation in Tomohon, and to evaluate their potential as natural antibacterial agents. Through 16S rDNA gene sequencing analysis, the isolates obtained were identified as belonging to the newly described genera Lacticaseibacillus and Lactiplantibacillus. Four promising isolates Lactiplantibacillus fabifermentans A1.4, Lacticaseibacillus casei B1.5, Lacticaseibacillus paracasei B1.6, and Lacticaseibacillus paracasei B3.5 were tested for their inhibitory activity against the enteric pathogens Salmonella sp. and Escherichia coli using the well diffusion method. The results showed that all isolates exhibited a strong spectrum of pathogen inhibition. The highest inhibitory activity against Salmonella sp. was demonstrated by the L. paracasei B1.6 isolate, with an inhibition zone of 21.25 mm, while optimal inhibition against E. coli was achieved by L. casei B1.5 at 11.0 mm. These findings confirm that the local BAL strain from Tomohon palm sap has great potential for large-scale development as a biopreservative in the food industry and as a functional probiotic agent"
Pradani, G. A. P.; Alifia, A.; Syahbaniati, A. P.; Larasmanah, A. N.; Busaeri, M.; Djunaedy, H.; Choerunisa, T. F.; Massi, M. N.; Rachman, R. W.; Fibriani, A.; van Crevel, R.; van Ingen, J.; Lestari, B. W.
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As drug-resistant tuberculosis (DR-TB) cases rise, resistance detection in a timely manner is essential to lead effective treatment and limit transmission. Targeted next-generation sequencing (tNGS) offers quick results with multiple important drugs covered, but assessments regarding its performance for DR-TB diagnostic use compared to whole genome sequencing (WGS) as the most comprehensive genomic-based tool are still limited. This cross-sectional study compared resistance profiles generated by Deeplex Myc-TB tNGS assay with WGS for 116 prospectively-collected rifampicin resistant TB samples from West Java, Indonesia. All 116 samples were subject to paired analysis, the clinical samples were split to be directly processed for tNGS and to be cultivated for culture-based WGS. Both WGS and tNGS were carried out using Illumina MiSeq platform. High concordance of tNGS and WGS were observed across thirteen anti-TB drugs evaluated, particularly for drugs included in the BPaLM regimen. Isoniazid had the lowest concordance of 86.73%. Of 116 samples, 31.03% (n = 36) had discrepant resistance calling from the two methods for one or more drugs, which came from 73 discordant variants identification. The most common source of discrepancy was when tNGS detected a resistance-conferring mutation while WGS did not (54.8%). tNGS could detect mixed infection better than WGS, but WGS was superior in identifying detailed major Mycobacterium tuberculosis lineage of the sample. tNGS showed a good level concordance with WGS in detecting resistance-conferring mutations in rifampicin-resistant TB samples, with a more rapid turnaround time. Continuous update to tNGS panel and mutation catalogue is needed to keep the tool clinically relevant. ImportanceDrug-resistant tuberculosis (DR-TB) continues to pose worldwide threat, and newer diagnostic tools to generate quick, comprehensive resistance profile are crucial to provide timely appropriate treatment. Targeted next-generation sequencing (tNGS) is a promising new alternative, but more evidence on its performance is needed to support programmatic adoption. By analysing DR-TB samples with both tNGS and whole genome sequencing (WGS) and evaluating their results agreement, this study shows that tNGS works just as well as WGS in detecting TB drug resistance-conferring mutations, confirming its potential for routine diagnostic use. This study also observed that while WGS is superior in identifying Mycobacterium tuberculosis lineage with high resolution, it did not detect mixed infection better than tNGS. Notably, this study demonstrated that tNGS is clinically relevant for DR-TB detection in a high burden setting, providing evidence for programmatic consideration in Indonesia and other settings with similar demographics and TB situation.
Rodriguez, S.; Forero, D.; Benavides Machado, P.; Giraldo-Jaramillo, M.
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The global expansion of Black Soldier Fly (BSF), Hermetia illucens (L.), production systems for organic waste management has increased the need to better understand its reproductive biology in order to optimize mass-rearing programs. In this study, we macroscopically characterized chronological morphological changes in the internal genitalia of adult H. illucens reared on a sustainable alternative larval diet based on coffee pulp and corn bran. Morphological assessments and dissections were conducted on female and male reproductive tracts at 3, 6, and 9 days after adult emergence. Overall, the general organization of both reproductive systems was consistent with previous descriptions. A notable observation was the presence of a tripartite fertilization chamber in females, composed of three distinct compartments apparently associated with the three spermathecae. The functional significance of this anatomical organization remains to be determined. Females showed progressively advanced ovarian development and reached the clearest morphological indicators of reproductive maturity at 9 days, while males showed the greatest testicular distention and opacity at the same age. Compared with maturation times reported in previous studies using conventional larval diets, these observations suggest a later pattern of reproductive maturation under the coffee pulp-based diet. The observed differences may be associated with the nutritional composition and carbohydrate-to-protein balance of the larval diet. These results provide chronological and iconographic information that may contribute to the optimization of laboratory rearing protocols and the use of coffee by-products in H. illucens bioconversion systems.