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

Abstract

PurposeTo investigate the antimicrobial sensitivity pattern of commonly prescribed antimicrobials (chloramphenicol, cefixime, ofloxacin, azithromycin, and ceftriaxone) against Salmonella enterica isolates.MethodsBlood culture positive isolates of S. typhi and S. paratyphi A (N = 251) received at Metropolis Healthcare Limited (Mumbai, India) from four zones of India (North, South, West, and East) between April and August 2018 were tested for antimicrobial susceptibility by E-test method. Based on the minimum inhibitory concentration (MIC), the organism was categorized as sensitive, intermediate, and resistant against the respective antibiotics as per Clinical and Laboratory Standards Institute criteria 2018.ResultsOut of 251 Salmonella isolates, 192 (76.5%) were S. typhi and 59 (23.5%) were S. paratyphi A. All 251 (100%) Salmonella isolates were sensitive to cefixime, ceftriaxone, and azithromycin; 237/251 (94.4%) isolates to chloramphenicol and only 9/251 (3.6%) isolates were sensitive to ofloxacin. Based on average MIC and MIC breakpoints, Salmonella isolates were found to be sensitive to chloramphenicol (MIC: 3.89±6.94 µg/mL), cefixime (MIC: 0.13±0.11 µg/mL), azithromycin (MIC: 3.32±2.19 µg/mL), and ceftriaxone (MIC: 0.11±0.18 µg/mL) and resistant to ofloxacin (MIC: 2.95±6.06 µg/mL). More than 20% of Salmonella isolates had MICs of chloramphenicol as 1.5 µg/mL (27.85% isolates) and 2 µg/mL (29.53% isolates).ConclusionOur study confirms the re‑emergence of susceptibility of Salmonella isolates to chloramphenicol. Further, the concern about fluoroquinolone-decreased susceptibility as indicated by the intermediate susceptibility or resistance was reiterated in this study. Though cefixime, azithromycin, and ceftriaxone showed susceptibility, the possibility of antibiotic resistance with the irrational use of these antibiotics cannot be deterred. This study thus emphasizes the need for continuous evaluation and judicious use of antimicrobials, considering the ever-changing landscape.

Antimicrobial Activities of Laurus nobilis Leaves Ethanol Extract on Staphylococcus aureus, Salmonellae typhi, and Escherichia coli.

“…17 While study of Patil and Mule they found S. typhi sensitive to Cefixime, Ceftriaxone, and Azithromycin and based on average Minimal Inhibitory Concentration and MIC breakpoints. 30 Through the experiment conducted on Rats by Qnais et al (2012) which found L. nobilis aqueous extract has antidiarrheal agent. 31 Study of Nafi s et al exhibited notable potency regarding antimicrobial activity of (EOs) from L. nobilis leaves had the highest activity against E. coli, with MIC: 22.2 mg/mL and IZ 9.00 mm.…”

Antimicrobial Resistance in Typhoidal Salmonellain a Tertiary Care Teaching Centre in North India

“…Non-susceptibility of Typhoidal Salmonella to first-line antimicrobials (chloramphenicol, co-trimoxazole and ampicillin) has decreased over time as also reported by other studies. 5,6,13,14 Hence routine surveillance of resistance determinants is essential to understand the comeback of first generation of antibiotics for the treatment of typhoid fever.…”

Trends of Antimicrobial Resistance in Typhoidal Strains of Salmonella in a Tertiary Care Hospital in Pakistan

“…A study conducted in India showed that all the typhoidal strains of Salmonella were sensitive to ceftriaxone and azithromycin. Ninety-four strains were also sensitive to chloramphenicol, and only 3.6% were sensitive to ofloxacin [17]. [18].…”