Salmonellosis Outcomes Differ Substantially by Serotype

Introduction: Salmonella is an important infection in Liaoning Province. Serotype and resistance levels are poorly studied. Knowledge of cephalosporin-resistant genes is needed to provide information to support the clinical diagnosis and to guide therapy. Methodology: A total of 172 isolates were collected from January 2009 to March 2014. Resistance to cephalosporin, fluoroquinolones, and other conventional first-line antibiotics was detected using the disk diffusion and agar dilution methods. The relatedness of isolates with the same serotype was analyzed by pulsed-field gel electrophoresis (PFGE). Genes encoding extended-spectrum β-lactamase enzymes (blaCTX-M, blaTEM, blaSHV, and blaOXA) were identified by polymerase chain reaction (PCR) and sequencing in cephalosporin-resistant strains. Results: S. Enteritidis, 1,4,[5],12:i:-, and S .Typhimurium were the most common serotypes. The resistance rate of Salmonella to conventional first-line antibiotics sulfamethoxazole-trimethoprim, tetracycline, chloramphenicol, and ampicillin was 21%,33%,37%, and 55%,respectively. To fluoroquinolones (gatixacin, levofloxacin, and ciprofloxacin), the resistance rates were 7%,18%, and 23%, respectively, whereas for extended-spectrum cephalosporins(ceftazidime, cefepime, and ceftriaxone), there sistance rates were 4%,8%, and 9%. In total, 14blaCTX-M, 14 blaTEM-1, and 1blaOXA-1 were found in 15 Salmonella isolates resistant to cephalosporin. No blaSHVwas detected. The blaCTX-M-55 gene was the most frequently encountered gene. The blaCTX-M-65 gene from S. Enteritidis is described for first time in Salmonella from humans. Results of PFGE indicated strong similarity among Salmonella isolates in Liaoning Province. Conclusions: Extended-spectrum cephalosporins are the first choice for the treatment of infection with Salmonella, but blaCTX-M-encoded resistance, including blaCTX-M-65, is present.

Section: Discussionsupporting

confidence: 93%

Prevalence, resistance, and extended-spectrum beta-lactamases among Salmonella from patients in northeast China

Zhang¹,

Wang²,

Li³

et al. 2017

“…Salmonella enterica is highly diverse, containing over 2,500 different serovars. The representative serovars from this species are the most commonly isolated serovars during outbreaks of foodborne salmonellosis, including S. Enteritidis, S. Typhimurium, S. Virchow, and S. Infantis [24]. S. Enteritidis and S. Typhimurium are the most predominant isolated organisms in most Salmonella cases associated with the consumption of contaminated poultry, pork, and beef products [25].…”

Section: Discussionmentioning

confidence: 99%

Isolation and characterization of Salmonella Enteritidis and Salmonella Typhimurium from chicken meat in Egypt

Tarabees

El-Sayed

Shawish

et al. 2017

Introduction: Salmonella enterica serovars Enteritidis and Typhimurium represent the major serovars associated with human salmonellosis. Contamination of meat products with these serovars is considered the main source of infection. Methodology: In this study, 100 raw chicken meat samples were investigated for the presence of Salmonella spp., which were subsequently identified based on biochemical and serological tests as well as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) profile. Furthermore, the isolated serovars were examined using multiplex polymerase chain reaction (PCR) for the presence of virulence genes suspected to have a role in infection. Results: S. Enteritidis was isolated from two samples (2%), while S. Typhimurium was isolated from three samples (3%) of chicken meat. Of the 17 examined virulence genes using multiplex PCR, the sitC, sopB, sifA, lpfC, spaN, sipB, invA, spiA, and msgA genes were detected in S. Enteritidis. However, the sitC, iroN, sopB, sifA, lpfC, spaN, sipB, invA, and tolC genes were successfully amplified in S. Typhimurium. Conclusions: The detection of S. Enteritidis and S. Typhimurium in meat, even at low incidence, has important implications. In addition, the data presented here is the first attempt to identify a wide range of virulence genes in Egyptian Salmonella isolates recovered from meat products. A strict public health and food safety regime is urgently needed in order to decrease the human health hazard risk associated with salmonellosis.

“…Thus, following the emergence of S. Enteritidis in the country, more invasive infections have been encountered than previously, particularly in patients with underlying diseases. Previously published studies have shown that S. Enteritidis are among a few serotypes that are associated with a higher risk of extra-intestinal infection [16,17]. Immunocompromised patients are also known to be at higher risk for the development of bacteremia with this serotype [17].…”

Section: Discussionmentioning

confidence: 99%

Emergence and clonal dissemination of Salmonella enterica serovar Enteritidis causing salmonellosis in Mauritius

Issack

Hendriksen

Hyytiä-Trees

et al. 2014

Introduction: For decades, Salmonella enterica serovar Enteritidis has been among the most prevalent serovars reported worldwide. However, it was rarely encountered in Mauritius until 2007; since then the number of non-typhoidal Salmonella serogroup O:9 (including serovar Enteritidis) increased. A study was conducted to investigate the genetic relatedness between S. Enteritidis isolates recovered in Mauritius from food and clinical specimens (stool, blood, and exudate). Methodology: Forty-seven isolates of S. Enteritidis obtained in 2009 from human stools, blood cultures and exudates, and from food specimens were characterized by antimicrobial susceptibility testing and Multiple-Locus Variable-number tandem repeat Analysis (MLVA). Results: With the exception of a single isolate which demonstrated intermediate susceptibility to streptomycin, all isolates were pansusceptible to the 14 antimicrobials tested. Thirty seven out of the 47 isolates (78.7%) exhibited an indistinguishable MLVA profile which included isolates from ready-to-eat food products, chicken, and human clinical isolates from stool, blood and exudate. Conclusions: The presence of highly related strains in both humans and raw chicken, and the failure to isolate the serovar from other foods, suggests that poultry is the main reservoir of S. Enteritidis in Mauritius and that the majority of human cases are associated with chicken consumption which originated from one major producer. Stool isolates were indistinguishable or closely related to blood and exudate isolates, indicating that, besides gastroenteritis, the same strain caused invasive infections. Control of S.Enteritidis by poultry breeders would lower the financial burden associated with morbidity in humans caused by this organism in Mauritius.