Trends in Serotype Distribution and Antimicrobial Susceptibility in Salmonella enterica Isolates from Humans in Belgium, 2009 to 2013

Abstract

Although 377 different serotypes were identified, the landscape is dominated by S. enterica serovars Typhimurium (55%) and Enteritidis (19%) in a ratio which is inverse to European Union averages. With outbreaks of Salmonella serotypes Ohio, Stanley, and Paratyphi B variant Java as prime examples, 20 serotypes displayed significant fluctuations in this 5-year period. Typhoid strains account for 1.2% of Belgian salmonellosis cases. Large-scale antibiotic susceptibility analyses (n ‫؍‬ 4,561; panel of 12 antibiotics) showed declining resistance levels in S. Enteritis and Typhimurium isolates for 8 and 3 tested agents, respectively. Despite low overall resistance to ciprofloxacin (4.4%) and cefotaxime (1.6%), we identified clonal lineages of Salmonella serotypes Kentucky and Infantis displaying rising resistance against these clinically important drugs. Quinolone resistance is mainly mediated by serotype-specific mutations in GyrA residues Ser83 and Asp87 (92.2% not wild type), while an additional ParC_Ser80Ile mutation leads to ciprofloxacin resistance in 95.5% S. Kentucky isolates, which exceeds European averages. Plasmid-mediated quinolone resistance (PMQR) alleles qnrA1 (n ‫؍‬ 1), qnrS (n ‫؍‬ 9), qnrD1 (n ‫؍‬ 4), and qnrB (n ‫؍‬ 4) were found in only 3.0% of 533 isolates resistant to nalidixic acid. In cefotaxime-resistant isolates, we identified a broad range of Ambler class A and C ␤-lactamase genes (e.g., bla SHV-12 , bla TEM-52 , bla CTX-M-14 , and bla CTX-M-15 ) commonly associated with members of the family Enterobacteriaceae. In conclusion, resistance to fluoroquinolones and cefotaxime remains rare in human S. enterica, but clonal resistant serotypes arise, and continued (inter)national surveillance is mandatory to understand the origin and routes of dissemination thereof.

Prevalence, serotyping and antimicrobials resistance mechanism of Salmonella enterica isolated from clinical and environmental samples in Saudi Arabia

“…enterica serotype Typhimurium, which have a broad vertebrate hosts range and cause various symptoms that usually include diarrhoeal disease 3, 4. Although, typhoidal Salmonella caused severe and life-threatening diseases, the non-typhoidal Salmonella is associated with self-limiting diseases such as gastroenteritis, with more severe cases reported in immunocompromised individuals 5 . Generally, Salmonella infections are transmitted to human via consumption of contaminated water and food particularly the animal products, however typhoidal Salmonella , which is restricted to human, is transmitted by fecal oral route or direct contact with the infected persons 6 …”

Identification and Characterization of Conjugative Plasmids That Encode Ciprofloxacin Resistance in Salmonella

“…PMQR elements used to be rare in Salmonella, but they have been increasingly detected, particularly in recent years (11)(12)(13)(14)(15)(16)(17). To date, many different types of PMQR have been reported in Salmonella, including the qnrA, qnrB, qnrD, and qnrS alleles, as well as a new PMQR gene, oqxAB (11,12,15,(17)(18)(19)(20)(21)(22)(23)(24). oqxAB was found in Escherichia coli on plasmid pOLA52 in 2003 and was then detected in Salmonella isolates recovered from various sources (8,25,26).…”

Bloodstream Infection Due to CTX-M-15 and TEM-1 Extended-Spectrum β-Lactamase-Producing <i>Salmonella enterica</i> serovar Virchow ST16

“…However, the prevalence of ESC-resistant Salmonella species from human specimens appears to be low: 1.6% in Belgium, 0.55% in England and Wales, and 0-7% in Southeast Asia (10,11). With the prevalence of ESBL-producing Salmonella enterica serovar Virchow markedly increasing in Korea since 2011, invasive Salmonella enterica serovar Virchow infections such as this bacteremia case may occur more frequently (3).…”