Molecular characterization of ciprofloxacin-resistant Salmonella enterica serovar Typhi and Paratyphi A causing enteric fever in India

Background: Enteric fever is a major public health problem in India. The current treatment of choice is the fluoroquinolones. Methods: The minimum inhibitory concentration (MIC) of ciprofloxacin was determined by E-test, HIMEDIA HiComb MIC test and agar dilution. Results: An isolate of Salmonella enterica serovar Typhi (S. Typhi) from a case of enteric fever gave a ciprofloxacin MIC of 64µg/ml. Conclusions: To our knowledge there have been no reports of such high-level resistance to ciprofloxacin in S. Typhi from southern India. HIMEDIA HiComb MIC test method is an alternative to the E-test. Ciprofloxacin resistant typhoid fever responds to treatment with ceftriaxone.

Section: Discussioncontrasting

confidence: 69%

A case report and review of the literature: Ciprofloxacin resistant Salmonella enterica serovar Typhi in India

Harish

Menezes

Sarangapani

et al. 2008

“…A single mutation in quinolone-resistance-determining region of gyr A gene is sufficient to confer resistance to NA and reduced susceptibility to fluoroquinolones. The continued use of ciprofloxacin against NA R strains has led to a steady creep in ciprofloxacin MICs [7,16,19] along with further mutations at the same locus, resulting in recent emergence of fully resistant strains [7,8,[20][21][22]. Saha et al, in 2006, reported a highly ciprofloxacin-resistant S. Typhi strain with the MIC as high as 512 μg/mL from Bangladesh [23].…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial resistance among blood culture isolates of Salmonella enterica in New Delhi

Jain

Chugh

2013

Introduction: Enteric fever is a global public health problem, especially in developing countries. Antimicrobial resistance is a major issue enteric fever management. This study examined current pattern of antimicrobial susceptibility among Salmonella enterica isolates from enteric fever cases at a tertiary care centre in New Delhi, India. Methodology: Blood cultures from patients with enteric fever during January 2010-July 2012 were processed using the BACTEC automated system. Antimicrobial susceptibility was tested using Kirby Bauer's disc diffusion method and/or Phoenix 100 automated system. Results: Of 344 isolates of Salmonella enterica, 266 (77.3%) were S. Typhi, 77 (22.4%) were S. Paratyphi A, and one (0.3%) was S. Paratyphi B. Resistance to nalidixic acid (NA R ) (96.7%) was most common, followed by ciprofloxacin (37.9%), and azithromycin (7.3%). Multi-drug resistance was observed only in S. Typhi (3.4%). Among NA R strains, 61.8% were sensitive, 11.1% were moderately sensitive, and 23.9% were resistant to ciprofloxacin (0.8%, 57.4%, and 37.9% respectively according to revised CLSI breakpoint criteria for ciprofloxacin). Resistance to third-generation cephalosporin was found in seven (2%) strains of S. enterica. Conclusion: Increasing rates of nalidixic acid, fluoroquinolone and azithromycin resistance among S. enterica, particularly in S. Paratyphi A strains, is of concern, as S. Paratyphi A infection is becoming increasingly common and is not prevented by current vaccinations. Our results favour use of cefexime or possibly chloramphenicol as first choice for uncomplicated enteric fever. MICs for third-generation cephalosporins and susceptibility pattern must be closely monitored in view of its emerging resistance among Salmonella enterica.

“…This result may be due to the presence of a tetracycline resistance marker on a large-sized or defective plasmid [30,31]. Moreover, ciprofloxacin and nalidixic acid resistance were not transferred through conjugation and transformation, and this may be due to the chromosomal origin of nalidixic acid and ciprofloxacin resistance [32]. Tetracycline, norfloxacin, amoxycillin/clavulanic acid, trimethoprim/sulfamethoxazole, and ciprofloxacin thus have a greater advantage against resistance, as resistance to these are not transferrable by horizontal gene transfer thereby restricting the spread of drug resistance.…”

Section: Discussionmentioning

confidence: 99%

Antibiogram and characterization of resistance markers among Escherichia coli Isolates from urinary tract infections

Kumar

Sood

Sharma

et al. 2013

Introduction: Urinary tract infection is the most frequently diagnosed kidney and urologic disease, and Escherichia coli is by far its most common etiological agent. Uropathogenic E. coli are responsible for approximately 90% of urinary tract infections seen in individuals with ordinary anatomy therefore, it is essential to review the antibiogram of uropathogenic E. coli periodically to help clinicians decide on the appropriate therapy. Methodology: We evaluated E. coli isolated from urinary tract infections at the National Salmonella and Escherichia Centre for antibiogram, plasmid transferability and stability of resistance markers. Results: In total, 90.9% of the isolates were found to be sensitive to nitrofurantoin while the highest proportion of the isolates was found to be resistant to nalidixic acid. Minimum inhibitory concentrations of all antimicrobials for different isolates were well within the limits specified by the Clinical and Laboratory Standards Institute. Resistance against tetracycline was not transferred either by conjugation and transformation. Streptomycin resistance was found to be lost in the maximum number of tested isolates showing loss at the 10