Virulence and Antimicrobial Characteristics of Escherichia Coli Isolated from Diseased Chickens in China and Algeria

Abstract

To reveal and compare the prevalence of pathotypes and virulence genes, as well as antimicrobial resistance and genotyping of poultry E. coli isolates from China and Algeria. Pathotype and seven virulence genes were tested by PCR, susceptibility to antimicrobials was evaluated using broth microdilution method, and genotyping was analyzed by PFGE. Six isolates were identified as pathogenic E. coli. Virulence gene testing showed that the frequency of ompT, iss, fimC, iroN, hlyF and iutA was high in the isolates from Shandong, Shanxi, Jiangsu and Xinjiang province, while stx2 was detected in only two isolates from Shandong, and stx2, iss, fimC, hlyF and iutA could not be detected in Tibet isolates. Importantly, nearly all isolates from Algeria carried seven virulence genes. Drug resistance testing of 141 strains showed that 98.2% (109/111) of the isolates from China and all isolates (30/30) from Algeria resist to more than three classes of antimicrobials. The PFGE genotyping of 157 isolates yielded 134 types, demonstrated a high level of genetic diversity among these isolates. Thus, the poultry E. coli from both China and Algeria exhibited either high frequencies of antimicrobial resistance or high rates of virulence genes carrying.

Virulence, Antimicrobial Resistance and Biofilm Production of Escherichia coli Isolates from Healthy Broiler Chickens in Western Algeria

“…Indeed, except for one E. coli strain, which was positive for the stx2 gene detected at one Mostaganem farm, all the isolates were negative for the major genes encoding VFs. This finding is in accordance with previous Algerian studies describing a low prevalence of stx genes in E. coli isolates from poultry origin, i.e., a recent Algerian study showed the presence of stx2 in only one E. coli isolate from broiler chickens, which had just died [35]. Another study conducted in the north of Algeria revealed the total absence of the stx2 gene and the presence of the stx1 gene in only two E. coli strains isolated from diarrheic hens and chickens [36].…”

Antimicrobial resistance of <i>Escherichia coli</i> and <i>Klebsiella</i> spp. conventionally sampled from factory-farmed chickens – clinical submissions

“…Azam et al claimed that the majority of E. coli strains isolated from dead chickens showed resistance to ampicillin (98.6%), tetracycline (97.3%), and ciprofloxacin (72%) [29]. An equally high resistance prevalence was confirmed in various studies conducted on different continents [30] (Tab. 6).…”