Elucidation of antimicrobial susceptibility profiles and genotyping of Salmonella enterica isolates from clinical cases of salmonellosis in New Mexico in 2008

Abstract

In this study, we investigated the antimicrobial susceptibility profiles and the distribution of some well known genetic determinants of virulence in clinical isolates of Salmonella enterica from New Mexico. The minimum inhibitory concentrations (MICs) for various antimicrobials were determined by using the E-test strip method according to CLSI guidelines. Virulence genotyping was performed by polymerase chain reaction (PCR) using primers specific for known virulence genes of Salmonella enterica. Of 15 isolates belonging to 11 different serovars analyzed, one isolate of Salmonella Typhimurium was resistant to multiple drugs namely ampicillin, amoxicillin / clavulanic acid, chloramphenicol and tetracycline, that also harbored class 1 intergron, bla TEM encoding genes for β-lactamase, chloramphenicol acetyl transferase (cat1), plus floR, tet(C) and tet(G). This strain was phage typed as DT104. PCR analysis revealed the presence of invA, hilA, stn, agfA and spvR virulence genes in all the isolates tested. The plasmid-borne pefA gene was absent in 11 isolates, while 5 isolates lacked sopE. One isolate belonging to serogroup E4 (Salmonella Sombre) was devoid of multiple virulence genes pefA, iroB, shdA and sopE. These results demonstrate that clinical Salmonella serotypes from New Mexico used here are predominantly sensitive to multiple antimicrobial agents, but vary in their virulence genotypes. Information on antimicrobial sensitivity and virulence genotypes will help in understanding the evolution and spread of epidemic strains of Salmonella enterica in the region of study.

Antimicrobial and molecular analysis of Salmonella serovar Livingstone strains isolated from humans in Tunisia and Belgium

“…More isolates from different parts of the world and from different origins need to be tested to confirm that the ST543 sequence type was a major worldwide clone based on MLST analysis. Several PCR-based procedures for the detection of known DNA sequences, including virulence genes, have been successfully applied for many Salmonella serovars [15,25,[28][29][45][46]. The main advantages of these approaches were the simplicity, rapidity, and cost effectiveness, which means that many strains could be easily virulotyped [15,32] .…”

“…Virulence genes have been screened using simple [25] or multiplex PCR [26] to determine the distribution of these genes among Salmonella enterica strains [25,27] and to genotype many Salmonella serovars [15,[28][29].…”

Prevalence and Fimbrial Genotype Distribution of Poultry Salmonella Isolates in China (2006 to 2012)

“…The primers used in this study to amplify the fimbrial genes are listed in Table S1 in the supplemental material. PCR amplification of bcfD, csgA, fimA, lpfD, pefA, safC, sefA, stbD, stfH, sthE, stiH, stjA, and tcfA was performed as described previously (10,(15)(16)(17)(18)(19). PCR primers to amplify the pegD, staA, stcA, stdB, steB, stgA, and stkA genes were established and validated in this study, and the gene accession numbers for the fimbrial genes are shown in Table S1 DNA extraction and PCR.…”

Antibiotic resistance and distribution of SodCI, sopE, sefA genes among Salmonella enteric serotype Enteritidis isolates from poultry

“…The correlation between the use of antibiotics and the emergence of resistance has been documented. Moreover, the increasing rate of antibiotic resistance has been reported from 1993 (Threfall et al, 1993) until recently (Smith et al, 2002;Maripandi and Al-Salamah, 2010;Melendez et al, 2010). A variety of antibiotics such as ampicillins, tetracyclines, sulfonamides and streptomycin, have been used for the treatment of salmonellosis leading to the emergence of resistant or multi-resistant strains (Glynn et al, 1998;Metzer et al, 1998;Buyd Περίληψη.…”

“…The presence of sopE gene has been associated with many Salmonella species such as S. typhimurium, S.typhi, S.enteritidis, S.dublin, S.hadar, S. gallinarum and it is associated with epidemic disease in both humans and animals (Hopkins and Threlfall, 2004;Rahman et al, 2004;Smith et al, 2010;Dione et al, 2011). In present study the great majority of the isolates (34/36 or 97.2%) harbored the sopE gene.…”