Enteric Fever Caused bySalmonella entericaSerovars with Reduced Susceptibility of Fluoroquinolones at a Community Based Teaching Hospital of Nepal

Abstract

Enteric fever continues to be an important public health problem especially in developing countries of the tropical region including Nepal. In this study, we aimed to investigate the incidence of enteric fever associated with Salmonella enterica and determine its antimicrobial susceptibilities to therapeutic antimicrobials in a community based teaching hospital of Nepal. A total of 2,304 blood samples from suspected enteric fever patients attending Manmohan Memorial Teaching Hospital were processed with standard microbiological methods for the isolation and identification of bacterial pathogens. The Salmonella enterica clinical strains were subjected to antimicrobial susceptibility testing by Kirby–Bauer disk diffusion method, and the results were interpreted according to the criteria suggested by the Clinical and Laboratory Standards Institute (CLSI). A total of 245 (10.6%) cases of enteric fever associated with Salmonella enterica were confirmed by blood culture. Out of them, 162 (66.1%) were caused by Salmonella Typhi and 83 (33.9%) by Salmonella Paratyphi. On Kirby–Bauer disk diffusion antimicrobial susceptibility testing, Salmonella isolates were highly susceptible to cefixime (100%), ceftriaxone (100%), ampicillin (97.9%), cotrimoxazole (94.6%), azithromycin (96.7%), tetracycline (95.5%), and chloramphenicol (97.5%), respectively. Two hundred twenty-six (92.2%) of Salmonella isolates were nalidixic acid resistant with reduced susceptibility to ciprofloxacin (36.7%) and ofloxacin (54.8%), respectively. Although the rate of MDR Salmonella strains was very low (<5%), their reduced susceptibility to fluoroquinolones has restricted their routine empirical use. Third generation cephalosporins are the safest choice for empirical use but ampicillin, cotrimoxazole, azithromycin, and chloramphenicol can be effective alternatives.

<p>Sensitivity Pattern Of <em>Salmonella typhi</em> And Paratyphi A Isolates To Chloramphenicol And Other Anti-Typhoid Drugs: An In Vitro Study</p>

“…It acts as an inhibitor of protein synthesis and results in a clinical cure rate of 90% with fever clearance time of 5–7 days in typhoid fever 54–57. Our results in terms of sensitivity to ceftriaxone, cefixime, and azithromycin were analogous to the previous literature where Salmonella isolates showed 100% sensitivity against ceftriaxone27 and cefixime,58 and 96.3–100% sensitivity to azithromycin 58,59. A battery of studies had also reported azithromycin to be similar or superior to chloramphenicol, fluoroquinolones, extended spectrum cephalosporins in the management of uncomplicated enteric fever with prompt resolution of clinical symptoms and poor relapse rate 60–66.…”

Antimicrobial Resistance in Typhoidal Salmonella: Surveillance for Enteric Fever in Asia Project, 2016–2019

“…Fluoroquinolone non-susceptibility in S . Typhi started rising in 2002 and reached 96.5% globally in 2015 [ 15 , 27 ]. Fluoroquinolones are not only extensively prescribed for humans but are widespread in animal husbandry.…”

Effective therapeutic regimens in two South Asian countries with high resistance to major Helicobacter pylori antibiotics

“…Increased use of quinolones, such as levofloxacin, at an early age is related to poor susceptibility to garenoxacin [50], a quinolone frequently prescribed in children [51], multiple concurrent antibiotic prescriptions, and lack of education regarding usage were reported in Nepal [52]. The high prevalence of Salmonella enterica infection [53] increased the tendency for physicians to prescribe quinolones for gastroenteritis patients, even though it is actually virus related [51], and increased the quinolone resistance rate [54]. Tuberculosis is prevalent in South Asia, and a quinolone regimen, such as gatifloxacin, is also important for short-course treatment of multi-drug–resistant tuberculosis [55].…”