[Molecular detection of extended spectrum beta-lactamase [ESBL] genes blaCTX-M, blaTEM and blaSHV in Escherichia coli isolated from water buffalo [Bubalus bubalis] feces in West Azerbaijan province, Iran]

Beta-lactamase enzymes are considered the most important factor of resistance against beta-lactam antibiotics among gram-negative bacteria. In recent years, the production of extended-spectrum beta-lactamases has been prevailed among bacteria, especially bacteria of animal origin, and this is important in terms of public health. The purpose of this study is to evaluate the presence of extended-spectrum beta- lactamase [ESBL]-genes blaCTX-M, blaTEMand blaSHVin E. coli isolates recovered from fecal samples of apparently healthy water buffaloes [Bubalus bubalis] using polymerase chain reaction. In this study, 105 isolates of E. coli, which were obtained from 135 fecal samples of water buffaloes from different areas of West Azerbaijan province [33 isolates from Urmia, 33 isolates from Khoy, 24 isolates from Piranshahr and 15 isolates from Miandoab], were identified using biochemical characteristics as well as 23S rRNA gene amplification. Then, the presence of CTX-M, TEM, and SHVgroups of ESBLgenes were evaluated among the studied E. coli isolates by the PCR method. In the studied isolates, 47 out of 105 E. coli isolates [44.8%] contained blaCTX-M gene and 37 isolates [35.2%] harbored blaTEM gene. Also, 17 isolates [16.2%] contained both blaCTX-M and blaTEM genes simultaneously. According to the results, blaSHV gene was not detected among the studied isolates. Also, no significant difference was seen in distribution of ESBL genes among the studied regions. The results of this study indicate that water Buffalo gastrointestinal E. coli is reservoir for ESBLs, especially CTX-M and TEM types, and this should be considered in terms of public health and the transfer of resistance genes to pathogenic bacteria

Prevalence, molecular characterization and serology of Shiga toxin-producing Escherichia coli isolated from buffaloes in West Azerbaijan, Iran

This present study is the first to report the presence of Shiga toxin-producing Escherichia coli [STEC] in buffaloes in Iran. A total of 360 fecal samples were collected from buffaloes from different regions in the west Azerbaijan province of Iran and cultured for the isolation of E. coli using routine biochemical tests. From the fecal samples, 340 E. coli were isolated and, of these, 26 STEC isolates were identified. The STEC isolates were further analyzed for the presence of specific virulence genes. Among the STEC isolates, 11 [42.3%] isolates were positive for the stx[1] gene, nine [34.6%] were positive for the stx[2] gene and six [23%] were positive for both of these genes. Six [23%] STEC isolates harbored the hly gene and two [7.6%] isolates were positive for the eae gene. Based on serotyping, only one [3.8%] isolate was of the O157 serotype, while the other 25 [96.1%] belonged to non-0157 serotypes. The results of the present study provide the first evidence that buffaloes could be a reservoir for STEC in Iran, especially those belonging to non-0157 serotypes

Bacteriological study of caseous lymphadenitis in pre-scapular lymph nodes of sheep slaughtered in Urmia, northwestern Iran

To identify the causative agent of caseous lymphadenitis in pre-scapular lymph nodes of sheep, the contents of 98 pre-scapular lymph nodes which showed the gross changes compatible with lymphadenitis were cultured. Bacteria isolated included Corynebacterium pseudotuberculosis [79.3%], Arcanobacterium pyogenes [9.4%], Staphylococcus aureus [7.5%] and Streptococcus alphahemolytica [3.8%]. It was shown that Corynebacterium pseudotubercolosis is the main causative agent for lymphadenitis in northwestern Iran