Molecular diversity of the invA gene obtained from human and egg samples

Abstract

Background and Aim: Salmonellosis is one of the most common foodborne bacterial diseases in the world. The great majority of Salmonella infections in humans are foodborne with Salmonella enterica and Salmonella Typhimurium accounting for a major part of the problem. The objective of this study was to investigate the presence of invA gene in strains of Salmonellae isolated from eggs and diarrheal swabs from human cases. In addition, the relationship between invA gene nucleotide sequences from different sources (human stool and egg samples) have been studied through phylogenetic tree. Materials and Methods: One hundred and seventy eggs (eggshell and its contents) and 160 stool swabs samples were collected from four poultry farms and medical hospital in Giza Governorate. Results: The study reported the presence of two Salmonella strains in eggshell surface with an overall isolation rate of 1.2 and 0% of the egg content. Salmonella Enteritidis and Salmonella Typhimurium were isolated from eggshell surface with an incidence of 50% for each strain. Six salmonella strains were isolated from human stool with an incidence of 3.75%; the isolated strains are S. Typhimurium, S. Enteritidis, Salmonella Virchow, Salmonella Haifa, and Salmonella Kentucky with an incidence of 33.3%, 16.6%, 16.6%, 16.6%, and 16.6%, respectively. Among eight Salmonella strains, invA gene was detected with percentage of 50%. The phylogenetic analysis of the sequences invA gene, from two isolates included in this study and five isolates retrieved from GenBank showed that sequence from human, layer hens, egg, and water in the same clusters. Conclusion: Close relation between drinking contaminated water and layer hens and contaminated water is one such source.

Multidrug Antimicrobial Resistance and Molecular Detection of mcr-1 Gene in Salmonella Species Isolated from Chicken

“…The pathogenesis of Salmonella is due to a combination of chromosomal and plasmid-mediated factors. A number of genes such as invA , fimA , stn and spv account for salmonellosis, of which the chromosomally located invasion ( invA) gene codes for a protein in the inner membrane of the bacterium, which is necessary for invasion of the host epithelial cells [ 11 , 12 ]. In the present study, detection of the invA gene in 10 tested Salmonella isolates indicated their pathogenic nature.…”

“…However, the invasion gene invA , commonly involved in bacterial virulence, is also routinely used for the accurate detection of Salmonella spp. in clinical samples [ 11 ]. The nucleotide sequences of the invA gene are distinctive to the genus Salmonella , and the amplification of the invA gene by the polymerase chain reaction (PCR) is a suitable diagnostic method of detection of Salmonella due to its reliability, sensitivity, specificity and detection speed [ 12 ].…”

Molecular Characterization of Bacteria, Detection of Enterotoxin Genes, and Screening of Antibiotic Susceptibility Patterns in Traditionally Processed Meat Products of Sikkim, India

“…The invA gene is primarily targeted for the identification of Salmonella in food of animal origin, since it is present in pathogenic serovars and has been demonstrated to be a rapid and effective method for diagnosis of salmonellosis ( Karmi, 2013 ; Carraturo et al, 2016 ). However, there are few reports on the absence of invA gene in certain Salmonella strains, which indicate that they are not invasive or may have other invasive mechanisms ( Kaushik et al, 2014 ; Sharma and Das, 2016 ; Buehler et al, 2019 ; Kadry et al, 2019 ; Yanestria et al, 2019 ).…”

Antimicrobial Resistance Profile andmcr-1Gene Detection inSalmonellaIsolates from Poultry in Bangladesh: Molecular and Bioinformatics Characterization

“…Molecular methods were optimized for rapid identification of Salmonella isolates and its resistance genes in poultry using specific primers followed by nucleotide sequencing and phylogenetic analysis. The virulence of Salmonella is linked to a combination of various factors, for example, invA virulence gene in the inner membrane of bacteria that are necessary for invasion of epithelial cells (18, 19). In this study, detection of virulence invA gene (10 out of 10 isolates) in the isolated Salmonella indicates the pathogenic nature of these isolates.…”

“…However, the invA encoding invasion gene, commonly involved in bacterial virulence, is accountable and routinely used for the detection of Salmonella spp. (18). Moreover, the invA sequences are distinctive to the genus Salmonella and diagnosed by polymerase chain reaction (PCR) is a preferred diagnostic method due to its reliable sensitivity, specificity and detection speed (19, 20).…”