BACKGROUND: Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis (CLA), a chronic and very common disease in sheep and goats, which can lead to severe economic losses in the livestock industry.OBJECTIVES: This study aims to investigate the prevalence of CLA in sheep in Kurdistan province of Iran using phenotypic and molecular methods, and assess the antibiotic resistance of isolated Corynebacterium pseudotuberculosis.METHODS: In this study, from September to March 2022, 270 samples of skin abscesses were collected from sheep in livestock farms of Kurdistan province. Immediately, using the cold chain system, the samples were transferred to the microbiology laboratory of the Faculty of Medicine at Kurdistan University of Medical Sciences. Identification of isolates was done using biochemical tests and polymerase chain reaction (PCR) method. The antibiotic resistance of the isolates was examined using the Kirby-Bauer disk diffusion method.RESULTS: Based on biochemical tests, out of 270 samples, 82 suspected to have Corynebacterium pseudotuberculosis. Out 82 samples, the presence of bacteria was confirmed in 76 samples by the PCR. The antibiotic sensitivity test showed that the isolates had high sensitivity to doxycycline and ceftriaxone and high resistance to streptomycin and kanamycin.CONCLUSIONS: The CLA has a high prevalence in sheep in Kurdistan province. According to high resistance rate of Corynebacterium pseudotuberculosis to streptomycin and kanamycin, it recommended to avoid treatment of CLA cases with these antibiotics.

BACKGROUND: Pigeons can be carriers for some human and animal pathogens, one of the most important of which is Escherichia coli. OBJECTIVES: This bacterium is responsible for outbreaks of many human diseases. Our objective was to determine the prevalence of Escherichia coli in cloacal area of pigeons in Tehran city (Iran), and determine  the prevalence of some virulence genes and also antibiotics resistance pattern of isolates. METHODS: Altogether 117 samples of pigeon feces were collected from cloacal swab. The identification of bacteria was done by culture on differential culture media. Then antibiotic susceptibility test was performed by disk diffusion method. Isolates were tested for the presence of virulence genes stx1, stx2, eae and hlyA using multiplex polymerase chain reaction. RESULTS: Escherichia coli were detected in 82.9% of 277 samples from pigeons. Sulfamethoxazole was the least effective drug (85.6% resistance), followed by tetracycline (83.5%). No resistance was detected to co-amoxiclav. The prevalence of stx1, stx2 and eaeA is 3.09%, 6.18% and 2.06% respectively and hlyA was not found in any of isolates. CONCLUSIONS: The frequency of stx1 and stx2 distribution in animals and birds is not well understood as yet. Due to the close relationship of humans with birds like pigeons and presence of STEC strains in apparently healthy birds, necessitates  considering  precise regulations to restrict and prevent the prevalence of this life- threatening virus in Iran.