AUTHOR=Braun Sascha D. , Ahmed Marwa F. E. , El-Adawy Hosny , Hotzel Helmut , Engelmann Ines , Weiß Daniel , Monecke Stefan , Ehricht Ralf 

TITLE=Surveillance of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Dairy Cattle Farms in the Nile Delta, Egypt

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01020

DOI=10.3389/fmicb.2016.01020

ISSN=1664-302X

ABSTRACT=<p><bold>Introduction:</bold> Industrial livestock farming is a possible source of multi-resistant Gram-negative bacteria, including producers of extended spectrum beta-lactamases (ESBLs) conferring resistance to 3rd generation cephalosporins. Limited information is currently available on the situation of ESBL producers in livestock farming outside of Western Europe. A surveillance study was conducted from January to May in 2014 in four dairy cattle farms in different areas of the Nile delta, Egypt.</p><p><bold>Materials and Methods:</bold> In total, 266 samples were collected from 4 dairy farms including rectal swabs from clinically healthy cattle (<italic>n</italic> = 210), and environmental samples from the stalls (<italic>n</italic> = 56). After 24 h pre-enrichment in buffered peptone water, all samples were screened for 3rd generation cephalosporin-resistant <italic>Escherichia coli</italic> using Brilliance™ ESBL agar. Suspected colonies of putatively ESBL-producing <italic>E. coli</italic> were sub-cultured and subsequently genotypically and phenotypically characterized. Susceptibility testing using the VITEK-2 system was performed. All suspect isolates were genotypically analyzed using two DNA-microarray based assays: CarbDetect AS-1 and <italic>E. coli</italic> PanType AS-2 kit (ALERE). These tests allow detection of a multitude of genes and their alleles associated with resistance toward carbapenems, cephalosporins, and other frequently used antibiotics. Serotypes were determined using the <italic>E. coli</italic> SeroGenotyping AS-1 kit (ALERE).</p><p><bold>Results:</bold> Out of 266 samples tested, 114 (42.8%) ESBL-producing <italic>E. coli</italic> were geno- and phenotypically identified. 113 of 114 phenotypically 3rd generation cephalosporin-resistant isolates harbored at least one of the ESBL resistance genes covered by the applied assays [<italic>bla</italic>CTX-M15 (<italic>n</italic> = 105), <italic>bla</italic>CTX-M9 (<italic>n</italic> = 1), <italic>bla</italic>TEM (<italic>n</italic> = 90), <italic>bla</italic>SHV (<italic>n</italic> = 1)]. Alarmingly, the carbapenemase genes <italic>bla</italic>OXA-48 (<italic>n</italic> = 5) and blaOXA-181 (<italic>n</italic> = 1) were found in isolates that also were phenotypically resistant to imipenem and meropenem. Using the array-based serogenotyping method, 66 of the 118 isolates (55%) could be genotypically assigned to O-types.</p><p><bold>Conclusion:</bold> This study is considered to be a first report of the high prevalence of ESBL-producing <italic>E. coli</italic> in dairy farms in Egypt. ESBL-producing <italic>E. coli</italic> isolates with different underlying resistance mechanisms are common in investigated dairy cattle farms in Egypt. The global rise of ESBL- and carbapenemase-producing Gram-negative bacteria is a big concern, and demands intensified surveillance.</p>