Clinical characteristics in adult patients with Salmonella bacteremia and analysis of ciprofloxacin-nonsusceptible isolates.

Abstract

BACKGROUND/PURPOSE:

The purpose of this study is to describe clinical characteristics of Salmonella bacteremia in adult patients and analyze ciprofloxacin-nonsusceptible isolates.

METHODS:

A total of 101 Salmonella blood isolates from adult patients were collected from January 2011 to December 2013 in MacKay Memorial Hospital. Eight ciprofloxacin-nonsusceptible Salmonella blood isolates were screened for carbapenemase and other β lactamase genes. Isolates were examined by PCR for the quinolone resistance-determining region (QRDR) of all subunits for DNA gyrase (gyrA and gyrB) genes and topoisomerase IV (parC and parE) genes.

RESULTS:

There were 22 (21.78%) S. enterica serovar B, 5 (4.95%) S. enterica serovar C1, 7 (6.93%) S. enterica serovar C2, 65 (64.36%) S. enterica serovar D, and 2 (1.98%) S. enterica serovar Typhi (S. typhi) isolates. β-lactamase gene screening and sequencing yielded only one blaCMY-2-positive isolate. In multivariate risk factor analysis, renal insufficiency [odds ratio (OR) 3.774; p = 0.020] and heart disease (OR 2.922; p = 0.027) were more common among elderly patients (≥65 years). Independent risk factors for ciprofloxacin-nonsusceptible strains included S. enterica serovar C2 (OR 28.430; p = 0.032), renal insufficiency (OR 13.927; p = 0.032), and immunosuppression agent usage (OR 60.082; p = 0.006). 87.50% (7/8) of isolates had gyrA mutation, 62.50% (5/8) had parC mutation, and none had gyrB and parE mutations. Isolates with both Ser83Phe/Asp87Asn gyrA and Thr57Ser/Ser80Ile parC mutation genes were highly ciprofloxacin-resistant (minimum inhibitory concentration ≥4 mg/L).

CONCLUSIONS:

Elderly patients with renal insufficiency and heart disease were at risk for Salmonella bacteremia. Those for ciprofloxacin-nonsusceptible strains included S. enterica serovar C2, renal insufficiency, and immunosuppression agent usage. The 8 ciprofloxacin-nonsusceptible isolates carried gyrA and parC mutations, which cause resistance that poses a major concern.

• Authors: Ming-Wei Cheng, Chun-Ming Lee, Nai-Yu Wang, Alice Y Wu, Chih-Chen Lin, Li-Chuan Weng, Chang-Pan Liu, Shou-Chuan Shih
• Journal: Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi (J Microbiol Immunol Infect) Vol. 48 Issue 6 Pg. 692-8 (Dec 2015) ISSN: 1995-9133 [Electronic] England
• PMID: 26542649 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015. Published by Elsevier B.V.

Chemical References

• Anti-Bacterial Agents
• Bacterial Proteins
• DNA, Bacterial
• Ciprofloxacin
• beta-Lactamases
• carbapenemase
• DNA Topoisomerase IV
• DNA Gyrase

Topics

• Adult
• Aged
• Anti-Bacterial Agents (therapeutic use)
• Bacteremia (drug therapy, epidemiology)
• Bacterial Proteins (genetics)
• Base Sequence
• Ciprofloxacin (therapeutic use)
• DNA Gyrase (genetics)
• DNA Topoisomerase IV (genetics)
• DNA, Bacterial (genetics)
• Drug Resistance, Bacterial (genetics)
• Female
• Heart Diseases (complications)
• Humans
• Male
• Microbial Sensitivity Tests
• Middle Aged
• Polymerase Chain Reaction
• Renal Insufficiency (complications)
• Salmonella (drug effects, genetics, isolation & purification)
• Salmonella Infections (drug therapy, epidemiology)
• Sequence Analysis, DNA
• beta-Lactamases (genetics)