RESUMO
BACKGROUND: Poultry and poultry products are among the major sources of Salmonella infections for humans. Increasing occurrence of antimicrobial resistance among Salmonellae has become a serious public health concern
The detection of extended spectrum b-lactamase [ESBL] producers among Salmonella spp. has increased in recent years
OBJECTIVES: The purpose of this study was to investigate the antibiotic resistance pattern of Salmonella, and to understand whether ESBLs were present in Salmonella isolated from poultry farms and slaughterhouses from various parts of Iran
METHODS: A total of 314 isolates of Salmonellaspp., 272 of poultry and 42 from human origin, collected during winter 2005-2011 were characterized for antimicrobial resistance and the presence of ESBLgenes in this study. Phenotypic Disk diffusion method was performed for detection of antimicrobial susceptibility against 16 antimicrobial agents according to the Clinical and Laboratory Standards Institute's recommendations [CLSI, 2005]
To detect the presence of ESBL genes in 30 isolates out of 61 phenotypical resistant isolates, PCR amplification was used by employing specific primers for screening of the CTX-M and CMY groups, respectively
RESULTS: The highest resistance to ceforoxime in poultry and cefixime in human isolates was observed, and multidrug resistance [MDR] was seen with a maximum seven antimicrobial agents
The PCR detection of CTXM and CMY genes in all isolates including five phenotypically ESBLpositive isolates was negative
CONCLUSIONS: This study revealed the incidence of resistance to cephalosporins and the frequency of MDR among Salmonella isolates from poultry farms in Iran. The prevalence of MDR Salmonella isolates from poultry are of particular concern as these strains can transmit to humans through the food chain
RESUMO
Objective: to determine the frequency of potential virulence factors in Escherichia coli isolates from avian colibacillosis
Design: descriptive study
Samples: one hundred E. coli isolates from cases of avian colibacillosis examined in this study were obtained from the bacterial collection of Poultry Diseases Section, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran
Procedure: all isolates were characterized with respect to motility, serum resistance and ability to produce aerobactin, colicin, colicin V and hemolysin
Results: no hemolytic isolate was found. Motility and serum resistance were found in 64 and 94% of isolates, respectively. The percentages of isolates that produced aerobactin, colicin and colicin V were 85, 90 and 22%, respectively
Conclusion: aerobactin production and serum resistance may be important factors associated with virulence of avian E. coli isolates