Document Type : Original Article


Department of Biology, College of Science, University of Baghdad, Baghdad, Iraq


To isolate Klebsiella pneumoniae, two hundred clinical and food samples were cultivated on differential and selective culture media. 120 bacterial isolates were isolated from the food and clinical samples. On MacConkey agar, 81 isolates of lactose fermenters (67.5%) and 39 isolates of non-lactose fermenters (32.5%) were found. Out of 120 bacterial isolates discovered in clinical and food sources, 32 were K. pneumoniae isolates, including 14 from food sources and 18 from clinical sources. K. pneumoniae was determined to be the species of bacteria isolated based on biochemical testing, morphological characteristics, and cultural identities. This conclusion was confirmed by the Vitek system. The findings of this investigation, which used phenotypic methods, revealed a high frequency of isolates of K. pneumoniae that produce Extended Spectrum B-Lactamase (ESBL) from patients in Iraq and a low frequency of isolates from food sources. After bacterial DNA was isolated, pure DNA samples with concentrations between 76 and 91 ng/ml were produced. Utilizing particular primers for the genes bla TEM and bla CTX-M, this work carried out the molecular detection of two ESBL-coding genes. According to the findings of this study, bla TEM was only found in clinical isolates at a detection rate of 27.77% and bla CTX-M at 38.88%. Isolates from food sources tested negative for bla TEM and bla CTX-M.

Graphical Abstract

Molecular Detection of bla TEM and bla CTX-M Genes in Clinical and Food-Borne Klebsiella pneumoniae Isolates



Due to the misuse of antibiotics, the incidence of multidrug-resistant (MDR) human pathogenic microorganisms and their genetic determinants has grown dramatically in clinical and environmental contexts. As a result, infection treatment choices become restricted, especially when MDR bacteria possess genes encoding extended range antibiotic resistance. One of the most important resistance mechanisms among Enterobacteriaceae is the production of β-lactamases, including extended-spectrum- and AmpC-lactamases [1]. According to an epidemiological research, Enterobacteriaceae that produce extended-spectrum-lactamase (ESBL), particularly Escherichia coli and Klebsiella pneumoniae, are the leading sources of community-acquired illnesses [2]. CTX-M, TEM, and SHV genes are the most common and clinically relevant ESBL genes, with CTX-M enzymes emerging as the most common. CTX-M is classified into five groups based on their amino acid identities: CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9, and CTX-M-25. K. pneumoniae typically generates all three kinds of enzymes, but the advent of carbapenemase-producing K. pneumoniae and colistin-resistant K. pneumoniae has caused the most recent public health worry [3]. Extended-spectrum beta lactamases (ESBLs) have played a major role in the clinical area in recent decades in the wide-ranging and complicated world of B-lactamases. Their significant stems the fact that they greatly broaden the range of the earlier B-lactamases, allowing them to hydrolyze all penicillins, cephalosporins (excluding cephamycins) and aztreonam. Furthermore, most ESBL genes are located on plasmids that confer antibiotic resistance to many types of antibiotics and are easily transferred between and among bacterial pathogens [4]. Extended spectrum lactamase, is a Gram-negative bacterium enzyme imparting resistance to penicillins, cephalosporins, and monobactams, provides a unique therapeutic problem. In Enterobacteriaceae from retail food, extended range TEM-, SHV-, and CTX-M type enzymes have been found [5].

Materials and Methods

Bacterial isolation

The collected clinical

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