Multicenter Spanish study of ciprofloxacin susceptibility in gram-negative bacteria. The Spanish Study Group on Quinolone Resistance

Global mapping of antibiotic resistance rates among clinical isolates of Stenotrophomonas maltophilia: a systematic review and meta-analysis

INTRODUCTION

Infections caused by Stenotrophomonas maltophilia are clinically important due to its intrinsic resistance to a broad range of antibiotics. Therefore, selecting the most appropriate antibiotic to treat S. maltophilia infection is a major challenge.

AIM

The current meta-analysis aimed to investigate the global prevalence of antibiotic resistance among S. maltophilia isolates to the develop more effective therapeutic strategies.

METHOD

A systematic literature search was performed using the appropriate search syntax after searching Pubmed, Embase, Web of Science and Scopus databases (May 2023). Statistical analysis was performed using Pooled and the random effects model in R and the metafor package. A total of 11,438 articles were retrieved. After a thorough evaluation, 289 studies were finally eligible for inclusion in this systematic review and meta-analysis.

RESULT

Present analysis indicated that the highest incidences of resistance were associated with doripenem (97%), cefoxitin (96%), imipenem and cefuroxime (95%), ampicillin (94%), ceftriaxone (92%), aztreonam (91%) and meropenem (90%) which resistance to Carbapenems is intrinsic. The lowest resistance rates were documented for minocycline (3%), cefiderocol (4%). The global resistance rate to TMP-SMX remained constant in two periods before and after 2010 (14.4% vs. 14.6%). A significant increase in resistance to tigecycline and ceftolozane/tazobactam was observed before and after 2010.

CONCLUSIONS

Minocycline and cefiderocol can be considered the preferred treatment options due to low resistance rates, although regional differences in resistance rates to other antibiotics should be considered. The low global prevalence of resistance to TMP-SMX as a first-line treatment for S. maltophilia suggests that it remains an effective treatment option.

Global prevalence and antibiotic resistance in clinical isolates of Stenotrophomonas maltophilia: a systematic review and meta-analysis

Introduction

Stenotrophomonas maltophilia is a little-known environmental opportunistic bacterium that can cause broad-spectrum infections. Despite the importance of this bacterium as an emerging drug-resistant opportunistic pathogen, a comprehensive analysis of its prevalence and resistance to antibiotics has not yet been conducted.

Methods

A systematic search was performed using four electronic databases (MEDLINE via PubMed, Embase, Scopus, and Web of Science) up to October 2019. Out of 6,770 records, 179 were documented in the current meta-analysis according to our inclusion and exclusion criteria, and 95 studies were enrolled in the meta-analysis.

Results

Present analysis revealed that the global pooled prevalence of S. maltophilia was 5.3 % [95% CI, 4.1-6.7%], with a higher prevalence in the Western Pacific Region [10.5%; 95% CI, 5.7-18.6%] and a lower prevalence in the American regions [4.3%; 95% CI, 3.2-5.7%]. Based on our meta-analysis, the highest antibiotic resistance rate was against cefuroxime [99.1%; 95% CI, 97.3-99.7%], while the lowest resistance was correlated with minocycline [4·8%; 95% CI, 2.6-8.8%].

Discussion

The results of this study indicated that the prevalence of S. maltophilia infections has been increasing over time. A comparison of the antibiotic resistance of S. maltophilia before and after 2010 suggested there was an increasing trend in the resistance to some antibiotics, such as tigecycline and ticarcillin-clavulanic acid. However, trimethoprim-sulfamethoxazole is still considered an effective antibiotic for treating S. maltophilia infections.

Genotypic analysis of Escherichia coli strains from poultry carcasses and their susceptibilities to antimicrobial agents

Plasmid profiling and amplified fragment length polymorphism (AFLP) analysis were used to genotype 50 Escherichia coli strains from poultry carcasses. Thirty different plasmid profiles were evident, and clustering of the AFLP data showed that they were a distinctly heterogeneous group of strains. Susceptibility testing against five antimicrobial agents used in the South African poultry industry showed all strains to be susceptible to danofloxacin and colistin, while the majority (96%) were resistant to two tetracyclines.

Epidemiology of ciprofloxacin resistance and its relationship to extended-spectrum beta-lactamase production in Klebsiella pneumoniae isolates causing bacteremia

A prospective study of Klebsiella pneumoniae bacteremia was performed in 12 hospitals in 7 countries. Of 452 episodes of bacteremia, 25 (5.5%) were caused by K. pneumoniae that was resistant in vitro to ciprofloxacin. Extended-spectrum beta-lactamase (ESBL) production was detected in 15 (60%) of 25 ciprofloxacin-resistant isolates, compared with 68 (16%) of 427 ciprofloxacin-susceptible strains (P=.0001). Multivariate analysis revealed that risk factors for ciprofloxacin resistance in K. pneumoniae included prior receipt of a quinolone (P=.0065) and an ESBL-producing strain (P=.012). In all, 18% of ESBL-producing isolates were also ciprofloxacin-resistant. Pulsed-field gel electrophoresis showed that 11 of the 15 ciprofloxacin-resistant ESBL-producing strains belonged to just 4 genotypes, suggesting that patient-to-patient transmission of such strains occurred. The close relationship between ESBL production and ciprofloxacin resistance is particularly worrisome because the first reported instance of plasmid-mediated ciprofloxacin resistance has been in an isolate of K. pneumoniae also possessing an ESBL.

Emergence of ciprofloxacin resistance in Escherichia coli isolates after widespread use of fluoroquinolones

The evolution (from 1990 to 1996) of fluoroquinolone consumption and resistance and the current patterns of fluoroquinolone usage were examined in a 250-bed community hospital in Spain. Fluoroquinolone consumption increased from 1392 g in 1990 to 3203 g in 1996 (p < 0.05). A significant increase in ciprofloxacin resistance was observed in Escherichia coli isolated from urine samples (from 3 to 20%, p < 0.00001), but not in those E. coli isolated from blood or other sample cultures. In 69 randomly selected clinical charts, fluoroquinolone was used as prophylaxis, empirical therapy, and specific directed therapy in 20%, 65%, and 15%, respectively. Evaluation of quinolone indication was: first choice agents (29%), alternative agents (49%), experimental agents (4.3%) and, agents with no role (1.4%). Our study shows that the increase in the use of fluoroquinolones is associated with the emergence of ciprofloxacin-resistant E. coli from urinary tract sources. Based on their indications, current quinolone usage can be greatly reduced.

Microbiological and clinical aspects of infection associated with Stenotrophomonas maltophilia

The gram-negative bacterium Stenotrophomonas maltophilia is increasingly recognized as an important cause of nosocomial infection. Infection occurs principally, but not exclusively, in debilitated and immunosuppressed individuals. Management of S. maltophilia-associated infection is problematic because many strains of the bacterium manifest resistance to multiple antibiotics. These difficulties are compounded by methodological problems in in vitro susceptibility testing for which there are, as yet, no formal guidelines. Despite its acknowledged importance as a nosocomial pathogen, little is known of the epidemiology of S. maltophilia, and although it is considered an environmental bacterium, its sources and reservoirs are often not readily apparent. Molecular typing systems may contribute to our knowledge of the epidemiology of S. maltophilia infection, thus allowing the development of strategies to interrupt the transmission of the bacterium in the hospital setting. Even less is known of pathogenic mechanisms and putative virulence factors involved in the natural history of S. maltophilia infection and this, coupled with difficulties in distinguishing colonization from true infection, has fostered the view that the bacterium is essentially nonpathogenic. This article aims to review the current taxonomic status of S. maltophilia, and it discusses the laboratory identification of the bacterium. The epidemiology of the organism is considered with particular reference to nosocomial outbreaks, several of which have been investigated by molecular typing techniques. Risk factors for acquisition of the bacterium are also reviewed, and the ever-expanding spectrum of clinical syndromes associated with S. maltophilia is surveyed. Antimicrobial resistance mechanisms, pitfalls in in vitro susceptibility testing, and therapy of S. maltophilia infections are also discussed.

Prevalence of bacterial resistance to quinolones and other antimicrobials among avian Escherichia coli strains isolated from septicemic and healthy chickens in Spain

Antimicrobial therapy is an important tool in reducing the enormous losses in the poultry industry caused by Escherichia coli infections (colibacillosis). However, resistance to existing antimicrobials is widespread and of concern to poultry veterinarians. Antimicrobial resistance testing of 468 avian E. coli strains isolated in Spain showed very high levels of resistance to trimethoprim-sulfamethoxazole (67%) and the new fluoroquinolones (13 to 24%). As these antimicrobial agents may cause cross-resistance with human enteric pathogens, prudent use of them in veterinary medicine is highly recommended.

Chryseobacterium meningosepticum: an emerging pathogen among immunocompromised adults. Report of 6 cases and literature review

Chryseobacterium meningosepticum is a ubiquitous Gram-negative bacillus historically associated with meningitis in premature neonates. We report 15 positive cultures and 6 cases of infection among immunocompromised adults at our institution over a 10-year period and review the English-language literature on C. meningosepticum. Excluding the present series, there are 308 reports of positive cultures in the literature, of which 59% were determined to represent true infections. Sixty-five percent of those infected were younger than 3 months of age. Meningitis was the most common infectious syndrome among neonates, seen in 84% of cases and associated with a 57% mortality rate. Less commonly reported infections among infants included sepsis (13%) and pneumonia (3%). Pneumonia was the most frequent infection among the postneonatal group, accounting for 40% of cases, followed by sepsis (24%), meningitis (18%), endocarditis (3%), cellulitis (3%), abdominal infections (3%), eye infections (3%), and single case reports of sinusitis, bronchitis, and epididymitis. The 6 cases in our series were all adults, with a mean age of 58.7 years. Sites of C. meningosepticum infection were limited to the lungs, bloodstream, and biliary tree. Infection in our series was associated with prolonged hospitalization, prior exposure to multiple antibiotics, and host immunocompromise, particularly neutropenia. C. meningosepticum is resistant to multiple antibiotics, and disk dilution is notoriously unreliable for antibiotic sensitivity testing. Sensitivity testing on the 15 isolates from our institution revealed the most efficacious antibiotics to be minocycline (100% sensitive), rifampin (93%), trimethoprim-sulfamethoxazole (67%), and ciprofloxacin (53%). In contrast to reports in the literature, the isolates in our series displayed widespread resistance to vancomycin (100% resistant or intermediately sensitive), erythromycin (100%), and clindamycin (86%). These findings have important implications for the clinician when choosing empiric antibiotic regimens for patients with risk factors for C. meningosepticum infection.