Prevalence, and virulence determination of Listeria monocytogenes strains isolated from clinical and non-clinical samples by multiplex polymerase chain reaction

Abstract

Introduction: This study aimed to determine the prevalence, and virulence factors of Listeria monocytogenes isolated from various samples by multiplex polymerase chain reaction (MPCR). Methods: A total of 617 isolates were obtained and MPCR was employed for detection of the inlA, inlC, and inlJ genes. Results: L. monocytogenes was detected in 46 (7.45%) of the 617 specimens. inlA, inlC, and inlJ were detected in 100%, 76.26%, and 71% isolates, respectively. Conclusions: This study validated MPCR in the analysis and rapid detection of L. monocytogenes. The role of the genes in pathogenesis of the strains can also be affirmed.

Isolation and characterization of Listeria monocytogenes from environmental and clinical sources by culture and PCR-RFLP methods

“…In this study, 80 samples of feces were collected which 6 (7.5%) samples had a positive culture. This finding was in concordant to the rate of 8.5% reported by Pournajaf et al (22), and 6% in the study of Lyautey et al, which in both studies L. monocytogenes was isolated from fecal samples (24). In disagreement to our study, lower rate of 0.12% L. monocytogenes from fecal samples were reported by Sauders et al in four large metropolitan areas of New York state (25), which the difference in geographical areas may be the reason for this difference.…”

“…Of 80 vaginal samples, 9 (11.3%) were positive for L. monocytogenes . This rate was lower in comparison to the rate of 16.6% in the study of Eslami et al (21), and 14.2% reported by Pournajaf et al, both from Iran (22). In both latter studies, the reason for the difference is the different geographic locations studied.…”

Virulence Profiling of Listeria monocytogenes Isolated from Different Sources

“…Listeria monocytogenes is a gram-positive bacterial pathogen that causes septicaemia, encephalitis, meningitis and gastroenteritis, particularly in children, immunosuppressed individuals and elder's; it also causes miscarriage in pregnant women (Radoshevich and Cossart, 2017) and in animals (Eruteya et al, 2014;Pournajaf et al, 2016). The bacterium is considered as a ubiquitous in nature and can be isolated from the environmental sources, including surface water, soil, sewage, vegetables, milk, milk product and food-processing plants (Pournajaf et al, 2016), even from fish and fishery products (Jallewar et al, 2008).…”

“…Pathogenesis of Listeria monocytogenes is facilitated by the action of a set of virulence genes including hemolysin gene (hlyA), regulatory gene (prfA), Phosphatidylinositol Phospholipase C gene (plcA), Actin gene (actA) and luxS, fla located in a Listeria pathogenicity island-1 (LIPI-1) and other virulence factors located outside LIPI-1 such as internalins, cell-wall-associated proteins internalin A (InlA) and internalin B(InlB), encoded by genes located within the inlAB (internalin) operon (Gregory et al, 1996). Liu et al, (2007) mentioned that internalin A (InlA) and internalin B (InlB) are speciesspecific surface proteins that play essential roles in Listerial entry into host cells, while InlJ (or lmo2821) gene is responsible for passage of L. monocytogenes through the intestinal barrier and can be used for evaluating virulence of L. monocytogenes (Pournajaf et al, 2016).…”

“…Detection of virulent genes by multiplex polymerase chain reaction (mPCR) will be useful to decreases the time and labour required for diagnosis and will be useful in a large-scale investigation for detecting virulent strain of L. monocytogenes species. It has been observed since long time that numerous death and major illness in animals and humans are reported due to naturally virulent strains of L. monocytogenes (Rawool et al, 2016;Pournajaf et al, 2016). Hence, the present study is aimed to standardize multiplex PCR for the simultaneous detection of various virulent genes in the L. monocytogenes isolates form different sources.…”