Enterobacterales Producing ESBLs and AmpC in Fresh Vegetables from Tebessa City, Algeria

Abstract

This study aimed to evaluate the contamination levels of fresh products by ESBLs-producing Enterobacterales (ESBLs-E) or AmpC-producing Enterobacterales and characterize ESBLs genes. A total of 132 samples (67 vegetables and 65 fruits) were collected from markets in Tebessa, eastern Algeria. Among the samples, 16 third-generation cephalosporin-resistant Enterobacterales isolates were identified with a prevalence of 19.40% in vegetable samples, while there was no positive finding in fruit samples. Isolates showed resistance to most β-lactams, and all of them displayed multidrug resistance. Phenotypic tests for ESBLs detection, using double-disk synergy test and double-disk test were positive for 14 strains, including Klebsiella pneumoniae ( n = 5), Klebsiella oxytoca ( n = 4), Klebsiella terrigena ( n = 2), Kluyvera spp. ( n = 2), and Enterobacter cloacae ( n = 1). Two AmpC-producing strains ( Citrobacter freundii and E. cloacae ) were identified through the AmpC disk test. Contamination rates of vegetables by ESBLs-E and AmpC-producing Enterobacterales were 19.40% and 2.98%, respectively. PCR results showed the presence of at least one ESBL gene in seven selected strains, with the dominance of bla CTX-M gene. Notably, K. pneumoniae strains showed the co-occurrence of two or three genes. Sequencing identified uncommon variants of ESBLs genes for the first time in Algeria, including bla CTX-M-79 (2/7), bla CTX-M-107 (2/7), bla CTX-M-117 (2/7), bla TEM-112 (1/7), bla TEM-125 (2/7), bla TEM-194 (1/7), and bla SHV-176 (3/7).