Suboptimal clinical response to ciprofloxacin in patients with enteric fever due to <Emphasis Type="Italic">Salmonella</Emphasis> spp. with reduced fluoroquinolone susceptibility: a case series

Background

Salmonella spp. with reduced susceptibility to fluoroquinolones have higher than usual MICs to these agents but are still considered "susceptible" by NCCLS criteria. Delayed treatment response to fluoroquinolones has been noted, especially in cases of enteric fever due to such strains. We reviewed the ciprofloxacin susceptibility and clinical outcome of our recent enteric fever cases.

Methods

Salmonella enterica Serotype Typhi (S. Typhi) and Serotype Paratyphi (S. Paratyphi) blood culture isolates (1998–2002) were tested against nalidixic acid by disk diffusion (DD) and agar dilution (AD) and to ciprofloxacin by AD using NCCLS methods and interpretive criteria. Reduced fluoroquinolone susceptibility was defined as a ciprofloxacin MIC of 0.125–1.0 mg/L. The clinical records of patients treated with ciprofloxacin for isolates with reduced fluoroquinolone susceptibility were reviewed.

Results

Seven of 21 (33%) S. Typhi and S. Paratyphi isolates had reduced susceptibility to fluoroquinolones (MIC range 0.125–0.5 mg/L). All 7 were nalidixic acid resistant by DD (no zone) and by AD (MIC 128- >512 mg/L). The other 14 isolates were nalidixic acid susceptible and fully susceptible to ciprofloxacin (MIC range 0.015–0.03 mg/L).Five of the 7 cases were treated initially with oral ciprofloxacin. One patient remained febrile on IV ciprofloxacin until cefotaxime was added, with fever recurrence when cefotaxime was discontinued. Two continued on oral or IV ciprofloxacin alone but had prolonged fevers of 9–10 days duration, one was switched to IV beta-lactam therapy after remaining febrile for 3 days on oral/IV ciprofloxacin and one was treated successfully with oral ciprofloxacin. Four of the 5 required hospitalization.

Conclusions

Our cases provide further evidence that reduced fluoroquinolone susceptibility of S. Typhi and S. Paratyphi is clinically significant. Laboratories should test extra-intestinal Salmonella spp. for reduced fluoroquinolone susceptibility.

     

Typhoid fever as a cause of opportunistic infection: case report

Background  

Typhoid fever is a systemic infection caused by the bacterium Salmonella enterica subspecies enterica serotype typhi, which is acquired by ingestion of contaminated food and water. Each year the disease affects at least 16 million persons world-wide, most of whom reside in the developing countries of Southeast Asia and Africa. In Italy the disease is uncommon with a greater number of cases in Southern regions than in Northern ones.     

Failure of levofloxacin treatment in community-acquired pneumococcal pneumonia

Background  

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia (CAP). High global incidence of macrolide and penicillin resistance has been reported, whereas fluoroquinolone resistance is uncommon. Current guidelines for suspected CAP in patients with co-morbidity factors and recent antibiotic therapy recommend initial empiric therapy using one fluoroquinolone or one macrolide associated to other drugs (amoxicillin, amoxicillin/clavulanate, broad-spectrum cephalosporins). Resistance to fluoroquinolones is determined by efflux mechanisms and/or mutations in the parC and parE genes coding for topoisomerase IV and/or gyrA and gyrB genes coding for DNA gyrase. No clinical cases due to fluoroquinolone-resistant S. pneumoniae strains have been yet reported from Italy.     

Secular Trend and Risk Factors for Antimicrobial Resistance in Escherichia coli Isolates in Switzerland 1997–2007

Background:   

Antibacterial resistance in Escherichia coli isolates of urinary infections, mainly to fluoroquinolones, is emerging. The aim of our study was to identify the secular trend of resistant E. coli isolates and to characterize the population at risk for colonization or infections with these organisms.     

Detection of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> by Phenotypic and Genotypic Methods

Aims  

This research evaluated the utilization of a urease in-house test, culture and molecular method (ureA PCR) as a diagnostic tool for Helicobacter pylori infection. Furthermore, we assessed the presence of the cagA gene in the specimens and in isolated strains that were positive for ureA by PCR positive.     

Identification of diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> isolated from infants and children in Dar es Salaam,Tanzania

Background  

Relatively few studies have been done in Tanzania to detect and classify diarrheagenic Escherichia coli (DEC) strains among children with diarrhea. This study aimed at investigating DEC among children in Dar es Salaam aged less than five years hospitalized due to acute/persistent diarrhea.     

Spread of a highly mucoid <Emphasis Type="Italic">Streptococcus pyogenes emm</Emphasis>3/ST15 clone

Background  

Hyaluronic acid capsule plays a key role in Streptococcus pyogenes virulence. Circulation of mucoid or highly encapsulated strains has been related to rheumatic fever epidemics and invasive disease in several countries. In 2009, an outbreak of mucoid S. pyogenes isolates was detected in northern Spain. The aim of the study was to describe clinical and molecular characteristics of mucoid strains causing this outbreak and to compare them with a sample of non-mucoid S. pyogenes isolates obtained during the same period of time.     

Imported Enteric Fever: Case Series from the Hospital for Tropical Diseases,London, United Kingdom

Our current knowledge of the clinical characteristics of enteric fever is drawn mainly from population-based studies in disease-endemic countries, and there are limited data published on cases in returning travelers. We report the clinical characteristics of enteric fever in 92 travelers returning to London, United Kingdom. Salmonella typhi and S. paratyphi resulted in an almost indistinguishable clinical picture. Rose spots and relative bradycardia were found only in a few patients. A total of 91% of the patients had a normal leukocyte count, which was associated with a markedly increased level of alanine aminotransferase in 82%. A total of 57% of the S. typhi isolates had decreased susceptibility to ciprofloxacin and resistance to nalidixic acid; these isolates were from southern Asia. Thirty percent were multidrug resistant; all were from southern Asia and Nigeria. None of the paratyphoid isolates were multidrug resistant but rates of decreased susceptibility to fluoroquinolones were higher than in S. typhi (74%).     

Molecular epidemiology of <Emphasis Type="Italic">Enterococcus faecium</Emphasis> isolates from an Italian hospital

Background  

Outbreaks of vancomycin-resistant Enterococcus faecium (VRE) strains is an emerging problem worldwide. Even if still relatively uncommon in European hospitals, infections caused by VRE have also been increasing recently in this continent.     

IS element IS<Emphasis Type="Italic">16</Emphasis> as a molecular screening tool to identify hospital-associated strains of <Emphasis Type="Italic">Enterococcus faecium</Emphasis>

Background  

Hospital strains of Enterococcus faecium could be characterized and typed by various molecular methods (MLST, AFLP, MLVA) and allocated to a distinct clonal complex known as MLST CC17. However, these techniques are laborious, time-consuming and cost-intensive. Our aim was to identify hospital E. faecium strains and differentiate them from colonizing and animal variants by a simple, inexpensive and reliable PCR-based screening assay. We describe here performance and predictive value of a single PCR detecting the insertion element, IS16, to identify hospital E. faecium isolates within a collection of 260 strains of hospital, animal and human commensal origins.     

Detection of multiple strains of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> using MIRU-VNTR in patients with pulmonary tuberculosis in Kampala,Uganda

Background  

Many studies using DNA fingerprinting to differentiate Mycobacterium tuberculosis (MTB) strains reveal single strains in cultures, suggesting that most disease is caused by infection with a single strain. However, recent studies using molecular epidemiological tools that amplify multiple targets have demonstrated simultaneous infection with multiple strains of MTB. We aimed to determine the prevalence of MTB multiple strain infections in Kampala, and the impact of these infections on clinical presentation of tuberculosis (TB) and response to treatment.     

Analysis of antimicrobial susceptibility and virulence factors in <Emphasis Type="Italic">Helicobacter pylori</Emphasis>clinical isolates

Background  

In this study, we evaluated the prevalence of primary resistance of Brazilian H. pylori isolates to metronidazole, clarithromycin, amoxicillin, tetracycline, and furazolidone. In addition, the vacA, iceA, cagA and cagE genotypes of strains isolated from Brazilian patients were determined and associated with clinical data in an effort to correlate these four virulence markers and antibiotic resistance.     

Outbreak of Salmonella Typhi enteric fever in sub-urban area of North India: A public health perspective

Outbreaks of enteric fever are a major health concern not only due to significant human morbidity and mortality but also fear of spread of multidrug resistant strains. We report an outbreak of enteric fever caused by Salmonella enterica serotype Typhi in a suburban area, in city Chandigarh of North India. Twenty-seven strains of S. typhi were isolated from blood cultures over a period of two weeks with 18 of these 27 patients residing in the same area. Maximum cases were in the age group 5-14 years (10 patients, 55.5%) while 4 (22.2%) cases were children under 5 years. All the strains showed similar resistogram being resistant to ampicillin and nalidixic acid, intermediate to ciprofloxacin and sensitive to chloramphenicol, ceftriaxone, cefotaxime, cotrimoxazole and azithromycin on disc diffusion testing. Minimum inhibitory concentration of ciprofloxacin was determined by agar dilution method and was found to be raised (? 2 μ g/mL). This nalidixic acid resistant S. typhi outbreak report warrants the necessity of implementing stringent sanitation practices in public health interest.     

Symptoms and sources of <Emphasis Type="Italic">Yersinia enterocolitica</Emphasis>-infection: a case-control study

Background  

Yersinia enterocolitica (YE) is the causative agent of yersiniosis. YE encompass strains of diverse pathogenicity: YE biotypes 1B and 2-5 are considered pathogenic, whereas biotype 1A is in general considered nonvirulent. Also YE-like species, which can sometimes be misidentified as YE, are considered nonvirulent.     

<Emphasis Type="Italic">Serratia marcescens</Emphasis> internalization and replication in human bladder epithelial cells

Background  

Serratia marcescens, a frequent agent of catheterization-associated bacteriuria, strongly adheres to human bladder epithelial cells in culture. The epithelium normally provides a barrier between lumal organisms and the interstitium; the tight adhesion of bacteria to the epithelial cells can lead to internalization and subsequent lysis. However, internalisation was not shown yet for S. marcescens strains.     

Activities of colistin- and minocycline-based combinations against extensive drug resistant <Emphasis Type="Italic">Acinetobacter baumannii</Emphasis> isolates from intensive care unit patients

Background  

Extensive drug resistance of Acinetobacter baumannii is a serious problem in the clinical setting. It is therefore important to find active antibiotic combinations that could be effective in the treatment of infections caused by this problematic 'superbug'. In this study, we analyzed the in vitro activities of three colistin-based combinations and a minocycline-based combination against clinically isolated extensive drug resistant Acinetobacter baumannii (XDR-AB) strains.     

<Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> complex drug resistance pattern and identification of species causing tuberculosis in the West and Centre regions of Cameroon

Background  

Data on the levels of resistance of Mycobacterium tuberculosis complex (MTBC) strains to first line anti-tuberculosis drugs in Cameroon, and on the species of MTBC circulating in the country are obsolete. The picture about 10 years after the last studies, and 6 years after the re-organisation of the National Tuberculosis (TB) Control Programme (NTBCP) is not known.     

Detection of virulence genes in Malaysian <Emphasis Type="Italic">Shigella</Emphasis>species by multiplex PCR assay

Background  

In Malaysia, Shigella spp. was reported to be the third commonest bacterial agent responsible for childhood diarrhoea. Currently, isolation of the bacterium and confirmation of the disease by microbiological and biochemical methods remain as the "gold standard". This study aimed to detect the prevalence of four Shigella virulence genes present concurrently, in randomly selected Malaysian strains via a rapid multiplex PCR (mPCR) assay.     

Acquired homotypic and heterotypic immunity against oculogenital <Emphasis Type="Italic">Chlamydia trachomatis</Emphasis> serovars following female genital tract infection in mice

Background  

Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen causing female genital tract infection throughout the world. Reinfection with the same serovar, as well as multiple infections with different serovars, occurs in humans. Using a murine model of female C. trachomatis genital tract infection, we determined if homotypic and/or heterotypic protection against reinfection was induced following infection with human oculogenital strains of C. trachomatis belonging to two serovars (D and H) that have been shown to vary significantly in the course of infection in the murine model.