Genetic diversity of Salmonella enterica recovered from chickens farms and its potential transmission to human.

BACKGROUND: Salmonella is a zoonotic bacterium transmitted through the food chain and is an important cause of disease in humans. The current study is aimed to characterize Salmonella isolates from broiler breeder chickens farms using, polymerase chain reaction (PCR) and sequencing analysis of representative isolates. METHODS: S. Kentucky (n=11), S. Enteritidis (n=4), S. Typhimurium (n=3), S. Breanderp (n=1), and Sand S. Newport (n=1), were identified from chicken farms. Antimicrobial sensitivity test among the strains were investigated using 13 antibacterial discs. The amplified fragments of fliC and sefA genes were used to characterize S. Kentucky, S. Enteritidis and S. Typhimurium strains. Sequence analysis of the amplified PCR products for Salmonella Kentucky, Enteritidis and Typhimurium were carried out. RESULTS: Antimicrobial sensitivity testing revealed that 95% of the isolates were resistant to penicillin, 85% to norfloxacin and colistin sulfate (each), 75% to gentamicin, 70% to nalidixic acid and 60% to flumequine. The obtained sequences revealed the close identity of the isolated strains with other Salmonella reference strains in different countries. CONCLUSION: Analysis of the selected salmonellae confirm the report of Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Kentucky circulation among broiler breeder flocks and the need to determine antibacterial susceptibility pattern regularly to detect multidrug-resistant salmonellae. The present study reports the circulation of Salmonella Kentucky, Enteritidis and Typhimurium among broiler breeder farms in Egypt. Emergency control of salmonellae is a global public health concern.

Poultry hatcheries as potential reservoirs for antimicrobial-resistant Escherichia coli: A risk to public health and food safety.

Hatcheries have the power to spread antimicrobial resistant (AMR) pathogens through the poultry value chain because of their central position in the poultry production chain. Currently, no information is available about the presence of AMR Escherichia coli strains and the antibiotic resistance genes (ARGs) they harbor within hatchezries. Therefore, this study aimed to investigate the possible involvement of hatcheries in harboring hemolytic AMR E. coli. Serotyping of the 65 isolated hemolytic E. coli revealed 15 serotypes with the ability to produce moderate biofilms, and shared susceptibility to cephradine and fosfomycin and resistance to spectinomycin. The most common ß-lactam resistance gene was blaTEM, followed by blaOXA-1, blaMOX-like, blaCIT-like, blaSHV and blaFOX. Hierarchical clustering of E. coli isolates based on their phenotypic and genotypic profiles revealed separation of the majority of isolates from hatchlings and the hatchery environments, suggesting that hatchling and environmental isolates may have different origins. The high frequency of ß-lactam resistance genes in AMR E. coli from chick hatchlings indicates that hatcheries may be a reservoir of AMR E. coli and can be a major contributor to the increased environmental burden of ARGs posing an eminent threat to poultry and human health.

Characterization and susceptibility of streptococci and enterococci isolated from Nile tilapia (Oreochromis niloticus) showing septicaemia in aquaculture and wild sites in Egypt.

BACKGROUND: The present investigation was an endeavor into the elucidation of the disease-causing pathogen of streptococcosis in Nile tilapia (Oreochromis niloticus) in Egypt affecting adult fish cultured and wild fish in the Nile river. Fish were obtained from commercial fishermen, collected as part of their routine fishing activities. The researchers observed the routine fishing process and selected fish for use in the study, at the point of purchase from the fisherman. RESULTS: Diseased fish showed exophthalmia with accumulation of purulent and haemorrhagic fluid around eyes, and ventral petechial haemorrhages. The Post mortem examination revealed, abdominal fat haemorrhage, pericarditis and enlargement of the liver, spleen and kidney. Gram-stained smears revealed the presence of Gram-positive cocci, ß-hemolytic, oxidase and catalase negative. Analysis of the 16S rRNA gene confirmed that the 17 tilapia isolates studied were 6/17 Enterococcus faecalis, 2/17 Enterococcus gallinarum, 3/17 Streptococcus pluranimalium, 2/17 Aerococcus viridans, 1/17 isolate of each Streptococcus dysgalactiae, Streptococcus anginosus, Lactococcus garvieae and Granulicetella elegans/Leuconostoc mesenteroides cremoris. It should be noted that there was no mixed infection. Multiple resistance was observed and the most frequent antibiotic combination was penicillin, ampicillin, vancomycin, chloramphenicol, rifampicin, ofloxacin, clindamycin, erythromycin and tetracycline representing eight classes. CONCLUSIONS: Consequently, we concluded that Streptococcus species are an emerging pathogen for Nile tilapia aquaculture in Egypt and to be considered as a new candidate in the warm water fish diseases in Egypt with special reference to L. garvieae, S. dysgalactiae in addition to L. mesenteroides cremoris which was not reported before from tilapia and taking into consideration their zoonotic implications for public health.