[Antimicrobial resistance and molecular subtypes of Salmonella typhi and Salmonella paratyphoid isolates from Jiangsu province, 2012-2015].

Objective: To retrospectively analyze the antimicrobial resistance phenotype and molecular typing characteristics of Salmonella (S.) typhi and S. paratyphi in Jiangsu province from 2012 to 2015. Methods: The samples were collected from typhoid and paratyphoid patients in Jiangsu province. The biochemical identification and serotyping were carried out after isolation and culture. Kirby-Bauer (K-B) testing was used to detect the drug susceptibility of the strains. The molecular typing characteristics of S. typhi and S. paratyphi were analyzed by pulsed field gel electrophoresis (PFGE). Results: The resistant rates of 134 S. typhi and S. paratyphi A strains to nalidixic acid were highest (61.2% and 86.7%), while the resistant rates to remaining antibiotics were less than 15.0%. Most of S. typhi and S. paratyphi A strains were resistant to only one antibiotic. Multidrug-resistant (MDR) strains of S. typhi and S. paratyphi A accounted for 2.6% and 13.3% respectively. The composition of the all-sensitive strains of S. typhi increased by 44.3% in 2015, at the same time, there were also MDR S. paratyphi A strains, which were resistant to 5 and 6 antibiotics. S. paratyphi A could be divided into eight molecular patterns by PFGE, showing that the similarity between the MDR strains and other strains was relatively low. The S. paratyphi A strains with same pattern were resistant to same antibiotics. S. typhi could be divided into 68 molecular patterns by PFGE, with large variability between different patterns. There was no corresponding relationship between the patterns and the drug resistance characteristics. Conclusions: The overall antibiotic resistance of S. typhi and S. paratyphi A strains showed a decreasing trend, but the number of antibiotics to which they were resistant increased. PFGE patterns of S. typhi showed diversity without correspondence to antibiotic characteristics. PFGE patterns of S. paratyphi A were less with correspondence to antibiotic characteristics. We should pay more attention to key patterns in key areas.

Performance of TUBEX® TF in the diagnosis of enteric fever in private tertiary care Hospital Peshawar, Pakistan.

OBJECTIVE: To evaluate the performance of TUBEX® TF in diagnosing enteric fever. METHODS: The retrospective study was performed at the Northwest General Hospital and Research Centre, Peshawar, Pakistan, and comprised data of all patients who had blood cultures and TUBEX®TF performed as part of their evaluation from April 2011 to November 2015. SPSS 16 was used for data analysis. RESULTS: Of the 970 patients, salmonella typhi was isolated in 43(4.43%), paratyphi in 9(0.93%) and other organisms in 162(16.7%). TUBEX® TF was positive in 18(1.86%) cases and negative in 25(2.58%). Of the culture-negative patients, TUBEX® TF was positive in 35(3.6%) and negative in 136(14%). In cases where no organism was cultured, TUBEX® TF was positive in 4(0.4%) and negative in 752(77.5%). The positive predictive value of TUBEX® TF was 31.58% and the negative predictive value was 97.26%. The sensitivity of TUBEX® TF was 41.86% while specificity was 95.97%. CONCLUSIONS: TUBEX® TF with its low sensitivity and positive predictive value was a poor tool for diagnosing enteric fever.

Pattern of antimicrobial drug resistance of Salmonella Typhi and Paratyphi A in a Teaching Hospital in Islamabad.

OBJECTIVE: To see the pattern of antimicrobial drug resistance among Salmonella serovars. METHODS: This longitudinal, observational study was conducted at Khan Research Laboratories Hospital, Islamabad, Pakistan, from May 2012 to December 2014. All patients presenting with typhoid fever with positive blood culture were included. Age, gender, salmonella serovar and sensitivity to 9 antimicrobial drugs were taken into account. The tested antimicrobial drugs were ampicillin, trimethoprim/sulphamethoxazole, chloramphenicol, nalidixic acid, ciprofloxacin, ofloxacin, levofloxacin, ceftriaxone and cefixime. SPSS 22 was used for analysis. RESULTS: Of the 197 patients, 118(59.9%) were males and 79(40.1%) were females. Moreover, there were 78(39.6%) children and 119(60.4%) adults. The overall mean age was 19.58±13.82 years. Patients with positive culture for salmonella typhi were 155(78.7%) while patients with positive cultures for salmonella paratyphi A were 42(21.3%). No other serovar was found in this study. Overall percentage of multidrug resistance for both salmonella typhi and paratyphi was 74(37.5%). CONCLUSIONS: The prevalence of multidrug resistance and quinolone resistance among salmonella serovars was high.

Antimicrobial resistance and molecular subtypes of Salmonella typhi and Salmonella paratyphoid isolates from Jiangsu province, 2012-2015 / 中华流行病学杂志

Objective To retrospectively analyze the antimicrobial resistance phenotype and molecular typing characteristics of Salmonella (S.) typhi and S. paratyphi in Jiangsu province from 2012 to 2015. Methods The samples were collected from typhoid and paratyphoid patients in Jiangsu province. The biochemical identification and serotyping were carried out after isolation and culture. Kirby-Bauer (K-B) testing was used to detect the drug susceptibility of the strains. The molecular typing characteristics of S. typhi and S. paratyphi were analyzed by pulsed field gel electrophoresis (PFGE). Results The resistant rates of 134 S. typhi and S. paratyphi A strains to nalidixic acid were highest (61.2%and 86.7%), while the resistant rates to remaining antibiotics were less than 15.0%. Most of S. typhi and S. paratyphi A strains were resistant to only one antibiotic. Multidrug-resistant (MDR) strains of S. typhi and S. paratyphi A accounted for 2.6% and 13.3%respectively. The composition of the all-sensitive strains of S. typhi increased by 44.3%in 2015, at the same time, there were also MDR S. pa ra typhi A strains, which were resistant to 5 and 6 antibiotics. S. paratyphi A could be divided into eight molecular patterns by PFGE, showing that the similarity between the MDR strains and other strains was relatively low. The S. paratyphi A strains with same pattern were resistant to same antibiotics. S. typhi could be divided into 68 molecular patterns by PFGE, with large variability between different patterns. There was no corresponding relationship between the patterns and the drug resistance characteristics. Conclusions The overall antibiotic resistance of S. typhi and S. paratyphi A strains showed a decreasing trend, but the number ofantibiotics to which they were resistant increased. PFGE patterns of S. typhi showed diversity without correspondence to antibiotic characteristics. PFGE patterns of S. paratyphi A were less with correspondence to antibiotic characteristics. We should pay more attention to key patterns in key areas.

Antimicrobial resistance and molecular subtypes of Salmonella typhi and Salmonella paratyphoid isolates from Jiangsu province, 2012-2015 / 中华流行病学杂志

Objective To retrospectively analyze the antimicrobial resistance phenotype and molecular typing characteristics of Salmonella (S.) typhi and S. paratyphi in Jiangsu province from 2012 to 2015. Methods The samples were collected from typhoid and paratyphoid patients in Jiangsu province. The biochemical identification and serotyping were carried out after isolation and culture. Kirby-Bauer (K-B) testing was used to detect the drug susceptibility of the strains. The molecular typing characteristics of S. typhi and S. paratyphi were analyzed by pulsed field gel electrophoresis (PFGE). Results The resistant rates of 134 S. typhi and S. paratyphi A strains to nalidixic acid were highest (61.2%and 86.7%), while the resistant rates to remaining antibiotics were less than 15.0%. Most of S. typhi and S. paratyphi A strains were resistant to only one antibiotic. Multidrug-resistant (MDR) strains of S. typhi and S. paratyphi A accounted for 2.6% and 13.3%respectively. The composition of the all-sensitive strains of S. typhi increased by 44.3%in 2015, at the same time, there were also MDR S. pa ra typhi A strains, which were resistant to 5 and 6 antibiotics. S. paratyphi A could be divided into eight molecular patterns by PFGE, showing that the similarity between the MDR strains and other strains was relatively low. The S. paratyphi A strains with same pattern were resistant to same antibiotics. S. typhi could be divided into 68 molecular patterns by PFGE, with large variability between different patterns. There was no corresponding relationship between the patterns and the drug resistance characteristics. Conclusions The overall antibiotic resistance of S. typhi and S. paratyphi A strains showed a decreasing trend, but the number ofantibiotics to which they were resistant increased. PFGE patterns of S. typhi showed diversity without correspondence to antibiotic characteristics. PFGE patterns of S. paratyphi A were less with correspondence to antibiotic characteristics. We should pay more attention to key patterns in key areas.

Characteristics of drug resistance and molecular type of Salmonella typhi and Salmonella paratyphi isolated in Henan province, 2009-2011 / 中华流行病学杂志

Objective To investigate the antibiotic resistance and pulsed field gel electrophoresis (PFGE) patterns of clinical isolates of Salmonella (S.) typhi and S.paratyphi in Henan province during 2009-2011.Methods According to molecular typing and Salmonella K-B drug susceptibility test method published by international PulseNet bacterial infectious disease monitoring network and USA Clinical and Laboratory Standards Institute (CLSI),the drug susceptibility and PFGE molecule characteristics of 78 S.typhi and S.paratyphi strains isolated from sentinel hospitals in Henan were analyzed.Results The 78 strains orS.typhi and S.paratyphi were resistant to 13 kinds of antibiotics,in which 62 were multidrug resistant (79.5％),4 were resistant to 2-3 kinds of antibiotics (5.1％),41 were resistant to 5-8 kinds of antibiotics (52.6％),14 were resistant to 9-10 kinds of antibiotics (17.9％),3 were resistant to 11-12 kinds of antibiotics (3.8％).The resistant rate to cephalosporins,quinolones and other 3 kinds of antibiotic showed an increase trends.Seventy two strains ofS.typhi and S.paratyphi could be divided 14 molecular patterns by digestion with Xba Ⅰ and PFGE,each pattem contains 1-47 strains which shared the similarity of 66.03％-100.00％.Conclusions The drug resistance of clinical isolates of S.typhi and S.paratyphi was serious in Henan.The PFGE patterns showed diversity,but the predominant patterns could be still found.The PFGE patterns of some strains were associated with their drug resistance.