Occurrence and Molecular Characteristics of Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Recovered From Chicken, Chicken Meat, and Human Infections in Sao Paulo State, Brazil.

This study aimed to investigate the phylogenetic diversity and epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae from chicken, chicken meat, and human clinical isolates in Sao Paolo, Brazil, and characterize their respective ESBL-encoding plasmids. Three hundred samples from chicken cloaca, chicken meat, and clinical isolates were phenotypically and genotypically assessed for ESBL resistance. Isolates were identified by MALDI TOF-MS and further characterized by MLST analysis and phylogenetic grouping. ESBL genes were characterized and their location was determined by I-Ceu-I-PFGE and Southern blot, conjugation, transformation, and PCR-based replicon typing experiments. Thirty-seven ESBL-producing isolates (28 E. coli and 9 K. pneumoniae) that were positive for the bla CTX-M-1 or bla CTX-M-2 gene groups were obtained. Two isolates were negative in the transformation assay, and the chromosomal location of the genes was deduced by Southern blot. The bla CTX-M genes identified were carried on plasmid replicon-types X1, HI2, N, FII-variants, I1 and R. The E. coli isolates belonged to nine sequence types, while the K. pneumoniae isolates belonged to four sequence types. The E. coli isolates belonged to phylotype classification groups A, B1, D, and F. This study demonstrated that isolates from cloacal swabs, chicken meat, and human feces had genetic diversity, with a high frequency of bla CTX-M-15 among chickens, chicken meat, and human feces. Thus, this reinforces the hypothesis that chickens, as well as their by-products, could be an important source of transmission for ESBL-producing pathogens to humans in South America.

Memory immune responses and protection of chickens against a nephropathogenic infectious bronchitis virus strain by combining live heterologous and inactivated homologous vaccines.

In this study, we evaluated antibody and cell-mediated immune (CMI) responses in the mucosal and systemic compartments and protection against challenge with a nephropathogenic Brazilian (BR-I) strain of infectious bronchitis virus (IBV) in chickens submitted to a vaccination regime comprising a priming dose of heterologous live attenuated Massachusetts vaccine followed by a booster dose of an experimental homologous inactivated vaccine two weeks later. This immunization protocol elicited significant increases in serum and lachrymal levels of anti-IBV IgG antibodies and upregulated the expression of CMI response genes, such as those encoding CD8ß chain and Granzyme homolog A in tracheal and kidney tissues at 3, 7, and 11 days post-infection in the vaccinated chickens. Additionally, vaccinated and challenged chickens showed reduced viral loads and microscopic lesion counts in tracheal and kidney tissues, and their antibody and CMI responses were negatively correlated with viral loads in the trachea and kidney. In conclusion, the combination of live attenuated vaccine containing the Massachusetts strain with a booster dose of an inactivated vaccine, containing a BR-I IBV strain, confers effective protection against infection with nephropathogenic homologous IBV strain because of the induction of consistent memory immune responses mediated by IgG antibodies and TCD8 cells in the mucosal and systemic compartments of chickens submitted to this vaccination regime.

Shigatoxigenic and atypical enteropathogenic Escherichia coli in fish for human consumption.

Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

Characterization of avian pathogenic Escherichia coli isolated from free-range helmeted guineafowl.

Avian pathogenic Escherichia coli (APEC) isolates from apparently healthy free range helmeted guineafowl were characterized. Most of them had a high frequency of virulence associated genes, multi drug resistance and high pathogenicity. We demonstrated that helmeted guineafowl have potential to transmit antibiotic resistant APEC to other species including humans.

Antibiotic resistance and virulence factors among Escherichia coli isolates from avian organic fertilizer / Resistência a antibióticos e fatores de virulência entre isolados de Escherichia coli provenientes de fertilizante orgânico aviário

ABSTRACT: Brazilian poultry industry generates large amounts of organic waste, such as chicken litter, which is often used in agriculture. Among the bacteria present in organic fertilizer are members of the Enterobacteriaceae family, such as Escherichia coli. The aim of this study was to analyze the profile of virulence factors and antimicrobial resistance of E. coli isolates from avian organic fertilizer. A total of 47 E. coli strains were tested through Polymerase chain reaction to detect virulence genes (hlyF, iss, ompT, iutA and iroN). Fourteen antimicrobials were used to test antimicrobial susceptibility in the strains. Genes characteristic of Avian Pathogenic E. coli (APEC) were reported among the strains, with the hlyF, iss and ompT genes being the most prevalent. The isolates showed high resistance (˃50%) to tetracycline, gentamicin, cefotaxime, nitrofurantoin, trimethoprim-sulfamethoxazole and ampicillin. Multidrug resistance was reported in a great number of strains (>70%). The results showed the presence of APEC cells with virulence genes and antimicrobial resistance after 15 days of the windrowing process in poultry houses, it means this process should be improved to eliminate these cells.

RESUMO: A indústria avícola brasileira gera grandes quantidades de resíduos orgânicos, como a cama de frango, utilizada frequentemente na agricultura. Entre as bactérias presentes neste fertilizante orgânico estão os membros da família Enterobacteriaceae, entre eles a Escherichia coli. O objetivo deste estudo foi analisar o perfil de fatores de virulência e resistência antimicrobiana de isolados de E. coli provenientes do fertilizante orgânico aviário. Um total de 47 cepas de E. coli foram testadas por meio da reação em cadeia da polimerase para detectar genes de virulência (hlyF, iss, ompT, iutA e iroN). Quatorze antimicrobianos foram utilizados para testar a susceptibilidade antimicrobiana nos isolados. Genes característicos de E. coli Patogênica Aviária (APEC) foram encontrados entre os isolados, sendo os genes hlyF, iss e ompT os mais prevalentes. Os isolados apresentaram alta resistência (˃50%) à tetraciclina, gentamicina, cefotaxima, nitrofurantoína, trimetoprima-sulfametoxazole e ampicilina. Múltipla resistência a drogas antimicrobianas foi encontrada em grande número de isolados (>70%). Os resultados obtidos mostraram a presença de células APEC portando genes de virulência e resistência a antimicrobianos após 15 dias de processo de empilhamento nas granjas, indicando que o processo necessita de um aperfeiçoamento para eliminar estas células.

Characterization of avian pathogenic Escherichia coli isolated from free-range helmeted guineafowl

Abstract Avian pathogenic Escherichia coli (APEC) isolates from apparently healthy free range helmeted guineafowl were characterized. Most of them had a high frequency of virulence associated genes, multi drug resistance and high pathogenicity. We demonstrated that helmeted guineafowl have potential to transmit antibiotic resistant APEC to other species including humans.

Shigatoxigenic and atypical enteropathogenic Escherichia coli in fish for human consumption

ABSTRACT Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

Characterization of avian pathogenic Escherichia coli isolated from free-range helmeted guineafowl

Abstract Avian pathogenic Escherichia coli (APEC) isolates from apparently healthy free range helmeted guineafowl were characterized. Most of them had a high frequency of virulence associated genes, multi drug resistance and high pathogenicity. We demonstrated that helmeted guineafowl have potential to transmit antibiotic resistant APEC to other species including humans.

A liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay for the detection of antibodies against Newcastle disease virus in serum of free-ranging pigeons.

A competitive liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay (LPB-ConA-ELISA) was developed in the current study. The assay used ConA as a capture reagent, and the sera of specific pathogen-free chickens immunized with nonpurified Newcastle disease virus (NDV) suspension as detector antibodies, to detect and quantify specific antiviral antibodies in serum samples from free-ranging pigeons. The comparison between the LPB-ConA-ELISA and the hemagglutination inhibition (HI) test for the detection of antibodies in serum samples from 107 pigeons showed significant correlation between the assays (r = 0.875), a high sensitivity (100%), specificity (95.8%), accuracy (96.3%) for the ELISA, and good agreement (κ = 0.83) between the 2 assays. The results of this study suggest that the LPB-ConA-ELISA could be a useful alternative to HI test in the serodiagnosis of NDV in pigeons, or other species of birds.