ABSTRACT
Among the important recent observations involving anaerobic respiration was that an electron acceptor produced as a result of an inflammatory response to Salmonella Typhimurium generates a growth advantage over the competing microbiota in the lumen. In this regard, anaerobically, salmonellae can oxidize thiosulphate (S2O32-) converting it into tetrathionate (S4O62-), the process by which it is encoded by ttr gene cluster (ttrSRttrBCA). Another important pathway under aerobic or anaerobic conditions is the 1,2-propanediol-utilization mediated by the pdu gene cluster that promotes Salmonella expansion during colitis. Therefore, we sought to compare in this study, whether Salmonella Heidelberg strains lacking the ttrA, ttrApduA, and ttrACBSR genes experience a disadvantage during cecal colonization in broiler chicks. In contrast to expectations, we found that the gene loss in S. Heidelberg potentially confers an increase in fitness in the chicken infection model. These data argue that S. Heidelberg may trigger an alternative pathway involving the use of an alternative electron acceptor, conferring a growth advantage for S. Heidelberg in chicks.
Subject(s)
Chickens , Salmonella Infections, Animal , Animals , Chickens/metabolism , Propylene Glycol/metabolism , Salmonella , Salmonella typhimurium , ThiosulfatesABSTRACT
Aim: Genomic analysis of a methicillin-resistant Staphylococcus aureus (MRSA) strain cultured from a non-migratory seabird at Fernando de Noronha Archipelago (Brazilian oceanic islands) was carried out to investigate the potential origin of MRSA genetic determinants in an ecological setting with minimal or absent antimicrobial selective pressure, and minimal interaction with humans and domestic animals. Results: The study determined mecA gene homology and the phylogenetic relatedness with mecA described in Staphylococcus sciuri, which was the major Staphylococcus spp. cultured from the birds. Our findings corroborate in silico assumptions that the mecA gene in MRSA strains clinically relevant for humans and animals originates from S. sciuri ancestors. Conclusion: Coagulase-negative staphylococci seem to be natural reservoirs of methicillin-resistant genes to S. aureus, even in environments with very low antimicrobial selection pressure.
Subject(s)
Bacterial Proteins/genetics , Birds/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Penicillin-Binding Proteins/genetics , Staphylococcus/genetics , Animals , Brazil , Islands , Whole Genome SequencingABSTRACT
Neonatal diarrhea determines significant changes in feed conversion, causing productivity loss in caprine herds. The antimicrobial resistance in bacteria is characterized as an important public healthissue; therefore, Escherichia coli may be characterized as an important pathogen due to expressingvirulence mechanisms responsible for significant clinical conditions in humans and animals. Thepresent study evaluated the presence of E. coli among 117 caprine fecal samples and analyzed theisolates for antimicrobial resistance. Suggestive colonies were submitted to biochemical screeningfollowed by genotypic group determination and phylogenetic analysis; further, the sampleswere submitted to antimicrobials susceptibility test. E. coli, Salmonella spp, Shigella sonnei andEnterobacter aerogenes were identified. E. coli isolates were phylogenetically classified as B2 (9/39),D (19/39), B1 (7/39) e A (4/29) groups. The analysis of the isolates also revealed the presence of K99(04/39) and Stx (02/39) virulence factors. Antimicrobial susceptibility test revealed sensitive isolatesto Chloramphenicol, Streptomycin, Amoxicillin and Ciprofloxacin, being all resistant to Lincomycin,Vancomycin and Penicillin. The results support the need of establishing restricted protocols forantimicrobial use, a fundamental procedure for health improvement in Brazilian caprine herds.
A diarreia neonatal determina alterações significativas na conversão alimentar, resultando na queda daprodutividade de caprinos. A resistência antimicrobiana em bactérias caracteriza-se como importanteproblema de saúde pública, assim, a Escherichia coli pode ser caracterizada como importantepatógeno por expressar mecanismos de virulência responsáveis por significativas afecções clínicasem seres humanos e animais. O presente estudo avaliou a presença de E. coli em 117 amostrasfecais de caprinos e analisou a resistência antimicrobiana dos isolados. Colônias sugestivas foramsubmetidas a testes bioquímicos, seguido de determinação do grupo genotípico e análise filogenética;posteriormente foram submetidas à prova de suscetibilidade a antimicrobianos. Foram identificadosisolados de E. coli, Salmonella spp, Shigella sonnei e Enterobacter aerogenes. Isolados de E. coliforam classificados filogeneticamente em B2 (9/39), D (19/39), B1 (7/39) e A (4/29). Os fatores devirulência identificados foram K99 (04/39) e Stx (02/39). À prova de suscetibilidade antimicrobiana,os isolados foram sensíveis a Cloranfenicol, Estreptomicina, Amoxicilina e Ciprofloxacina, sendotodos resistentes à Lincomicina, Vancomicina e Penicilina. Os resultados reforçam a necessidade deestabelecimento de protocolos criteriosos para o uso de antimicrobianos, medida fundamental para oaprimoramento da sanidade dos rebanhos caprinos brasileiros.
Subject(s)
Animals , Anti-Bacterial Agents/analysis , Classification , Diarrhea/veterinary , Escherichia coli/pathogenicity , Drug Resistance, Microbial/physiology , Drug Resistance, Multiple , Ruminants/physiology , Amoxicillin , Animals, Newborn/physiology , Ciprofloxacin , Enterobacter aerogenes , Streptomycin , Lincomycin , Vancomycin Resistance , Penicillin Resistance , Salmonella , ShigellaABSTRACT
Neonatal diarrhea determines significant changes in feed conversion, causing productivity loss in caprine herds. The antimicrobial resistance in bacteria is characterized as an important public healthissue; therefore, Escherichia coli may be characterized as an important pathogen due to expressingvirulence mechanisms responsible for significant clinical conditions in humans and animals. Thepresent study evaluated the presence of E. coli among 117 caprine fecal samples and analyzed theisolates for antimicrobial resistance. Suggestive colonies were submitted to biochemical screeningfollowed by genotypic group determination and phylogenetic analysis; further, the sampleswere submitted to antimicrobials susceptibility test. E. coli, Salmonella spp, Shigella sonnei andEnterobacter aerogenes were identified. E. coli isolates were phylogenetically classified as B2 (9/39),D (19/39), B1 (7/39) e A (4/29) groups. The analysis of the isolates also revealed the presence of K99(04/39) and Stx (02/39) virulence factors. Antimicrobial susceptibility test revealed sensitive isolatesto Chloramphenicol, Streptomycin, Amoxicillin and Ciprofloxacin, being all resistant to Lincomycin,Vancomycin and Penicillin. The results support the need of establishing restricted protocols forantimicrobial use, a fundamental procedure for health improvement in Brazilian caprine herds.(AU)
A diarreia neonatal determina alterações significativas na conversão alimentar, resultando na queda daprodutividade de caprinos. A resistência antimicrobiana em bactérias caracteriza-se como importanteproblema de saúde pública, assim, a Escherichia coli pode ser caracterizada como importantepatógeno por expressar mecanismos de virulência responsáveis por significativas afecções clínicasem seres humanos e animais. O presente estudo avaliou a presença de E. coli em 117 amostrasfecais de caprinos e analisou a resistência antimicrobiana dos isolados. Colônias sugestivas foramsubmetidas a testes bioquímicos, seguido de determinação do grupo genotípico e análise filogenética;posteriormente foram submetidas à prova de suscetibilidade a antimicrobianos. Foram identificadosisolados de E. coli, Salmonella spp, Shigella sonnei e Enterobacter aerogenes. Isolados de E. coliforam classificados filogeneticamente em B2 (9/39), D (19/39), B1 (7/39) e A (4/29). Os fatores devirulência identificados foram K99 (04/39) e Stx (02/39). À prova de suscetibilidade antimicrobiana,os isolados foram sensíveis a Cloranfenicol, Estreptomicina, Amoxicilina e Ciprofloxacina, sendotodos resistentes à Lincomicina, Vancomicina e Penicilina. Os resultados reforçam a necessidade deestabelecimento de protocolos criteriosos para o uso de antimicrobianos, medida fundamental para oaprimoramento da sanidade dos rebanhos caprinos brasileiros.(AU)
Subject(s)
Animals , Ruminants/physiology , Classification , Drug Resistance, Microbial/physiology , Drug Resistance, Multiple , Anti-Bacterial Agents/analysis , Escherichia coli/pathogenicity , Diarrhea/veterinary , Animals, Newborn/physiology , Salmonella , Shigella , Enterobacter aerogenes , Streptomycin , Amoxicillin , Ciprofloxacin , Lincomycin , Vancomycin Resistance , Penicillin ResistanceABSTRACT
Abstract Neonatal diarrhea determines significant changes in feed conversion, causing productivity loss in caprine herds. The antimicrobial resistance in bacteria is characterized as an important public health issue; therefore, Escherichia coli may be characterized as an important pathogen due to expressing virulence mechanisms responsible for significant clinical conditions in humans and animals. The present study evaluated the presence of E. coli among 117 caprine fecal samples and analyzed the isolates for antimicrobial resistance. Suggestive colonies were submitted to biochemical screening followed by genotypic group determination and phylogenetic analysis; further, the samples were submitted to antimicrobials susceptibility test. E. coli, Salmonella spp, Shigella sonnei and Enterobacter aerogenes were identified. E. coli isolates were phylogenetically classified as B2 (9/39), D (19/39), B1 (7/39) e A (4/29) groups. The analysis of the isolates also revealed the presence of K99 (04/39) and Stx (02/39) virulence factors. Antimicrobial susceptibility test revealed sensitive isolates to Chloramphenicol, Streptomycin, Amoxicillin and Ciprofloxacin, being all resistant to Lincomycin, Vancomycin and Penicillin. The results support the need of establishing restricted protocols for antimicrobial use, a fundamental procedure for health improvement in Brazilian caprine herds.
Resumo A diarreia neonatal determina alterações significativas na conversão alimentar, resultando na queda da produtividade de caprinos. A resistência antimicrobiana em bactérias caracteriza-se como importante problema de saúde pública, assim, a Escherichia coli pode ser caracterizada como importante patógeno por expressar mecanismos de virulência responsáveis por significativas afecções clínicas em seres humanos e animais. O presente estudo avaliou a presença de E. coli em 117 amostras fecais de caprinos e analisou a resistência antimicrobiana dos isolados. Colônias sugestivas foram submetidas a testes bioquímicos, seguido de determinação do grupo genotípico e análise filogenética; posteriormente foram submetidas à prova de suscetibilidade a antimicrobianos. Foram identificados isolados de E. coli, Salmonella spp, Shigella sonnei e Enterobacter aerogenes. Isolados de E. coli foram classificados filogeneticamente em B2 (9/39), D (19/39), B1 (7/39) e A (4/29). Os fatores de virulência identificados foram K99 (04/39) e Stx (02/39). À prova de suscetibilidade antimicrobiana, os isolados foram sensíveis a Cloranfenicol, Estreptomicina, Amoxicilina e Ciprofloxacina, sendo todos resistentes à Lincomicina, Vancomicina e Penicilina. Os resultados reforçam a necessidade de estabelecimento de protocolos criteriosos para o uso de antimicrobianos, medida fundamental para o aprimoramento da sanidade dos rebanhos caprinos brasileiros.