High rates of multidrug resistance among uropathogenic Escherichia coli in children and analyses of ESBL producers from Nepal

Microbial Infections and Antimicrobial Resistance in Nepal: Current Trends and Recommendations

Antimicrobial resistance is a life threatening challenges to the world. Most of the well-known antibiotics are currently ineffective to several microbial diseases. Ampicillin, metronidazole, amoxicillin, cotrimoxazole, chloramphenicol, ciprofloxacin, nalidixic acid, gentamicin, and ceftazidime are common antibiotics whose resistance pattern has been elevated in recent years. The rise and dissemination of resistant bacteria has contributed in increasing cases of antimicrobial resistance. Multi-drug Resistant (MDR) organism such as Staphylococcus aureus, Pseudomionas aeruginosa, Escherchia coli, and Mycobacterium tuberculosis are principal problems for public health and stakeholders. Globally, issues of antimicrobial resistance are major concern. In the context of Nepal, insufficient surveillance system, lack of appropriate policy, and poor publications regarding the use of antibiotics and its resistance pattern has misled to depict exact scenario of antimicrobial resistance. This mini-review presents current trends of antibiotic use and its resistance pattern in Nepal. In addition, global progression of antibiotic discovery and its resistance has been covered as well. Furthermore, use of antibiotics and possible ways on improvement of effectiveness have been discussed.

Extended-spectrum β-lactamase prevalence and virulence factor characterization of enterotoxigenic Escherichia coli responsible for acute diarrhea in Nepal from 2001 to 2016

Background

Multidrug-resistant (MDR) Gram-negative bacterial species are an increasingly dangerous public health threat, and are now endemic in many areas of South Asia. However, there are a lack of comprehensive data from many countries in this region determining historic and current MDR prevalence. Enterotoxigenic Escherichia coli (ETEC) is a leading cause of both acute infant diarrhea and traveler’s diarrhea in Nepal. The MDR prevalence and associated resistance mechanisms of ETEC isolates responsible for enteric infections in Nepal are largely unknown.

Methods

A total of 265 ETEC isolates were obtained from acute diarrheal samples (263/265) or patient control samples (2/265) at traveler’s clinics or regional hospitals in Nepal from 2001 to 2016. Isolates were screened for antibiotic resistance, to include extended spectrum beta-lactamase (ESBL) production, via the Microscan Automated Microbiology System. ETEC virulence factors, specifically enterotoxins and colonization factors (CFs), were detected using multiplex PCR, and prevalence in the total isolate population was compared to ESBL-positive isolates. ESBL-positive isolates were assessed using multiplex PCR for genetic markers potentially responsible for observed resistance.

Results

A total of 118/265 (44.5%) ETEC isolates demonstrated resistance to ≥2 antibiotics. ESBL-positive phenotypes were detected in 40/265 isolates, with isolates from 2008, 2013, 2014, and 2016 demonstrating ESBL prevalence rates of 1.5, 34.5, 31.2, and 35.0% respectively. No difference was observed in overall enterotoxin characterization between the total ETEC and ESBL-positive populations. The CFs CS2 (13.6%), CS3 (25.3%), CS6 (30.2%), and CS21 (62.6%) were the most prevalent in the total ETEC population. The ESBL-positive ETEC isolates exhibited a higher association trend with the CFs CS2 (37.5%), CS3 (35%), CS6 (42.5%), and CS21 (67.5%). The primary ESBL gene identified was bla_CTX-M-15 (80%), followed by bla_SHV-12 (20%) and bla_CTX-M-14 (2.5%). The beta-lactamase genes bla_TEM-1 (40%) and bla_CMY-2 (2.5%) were also identified. It was determined that 42.5% of the ESBL-positive isolates carried multiple resistance genes.

Conclusion

Over 30% of ETEC isolates collected post-2013 and evaluated in this study demonstrated ESBL resistance. Persistent surveillance and characterization of enteric ETEC isolates are vital for tracking the community presence of MDR bacterial species in order to recommend effective treatment strategies and help mitigate the spread of resistant pathogens.

The genetic background of antibiotic resistance among clinical uropathogenic Escherichia coli strains

The spreading mechanisms of antibiotic resistance are related to many bacterial and environment factors. The overuse of antibiotics is leading to an unceasing emergence of new multidrug resistant strains. This problem also concerns uropathogenic Escherichia coli strains, which is the most common pathogen causing urinary tract infections. The aim of this study was the genetic analysis of antibiotic resistance in comparison to the phenotypic background of E. coli strains. The characterized collection of E. coli strains isolated 10 years ago from the urine samples of patients with urinary tract infections was used for antimicrobial susceptibility testing (the disc diffusion method) and analysis of antibiotic resistance genes (PCR reaction, sequencing). Additionally, the presence of ESBL strains was analyzed. Fourteen genes were associated with resistance to beta-lactams, aminoglycosides, sulfonamides and quinolones. The genetic analysis revealed that bla_TEM-1 and sul2 were present in almost all of the studied strains. Other drug-resistance genes were very rare or non-existent. Otherwise, the phenotypic resistance to fluoroquinolones was well correlated with the genotypic background of the studied bacteria. The presence of particular genes and specific mutations indicate a high bacterial potential to multidrug resistance. On the other hand, it needs to be emphasized that the standard disk diffusion test for the routine antimicrobial susceptibility analysis is still the best way to estimate the current situation of bacterial drug-resistance.

In-vivo monitoring of infectious diseases in living animals using bioluminescence imaging

Traditional methods of localizing and quantifying the presence of pathogenic microorganisms in living experimental animal models of infections have mostly relied on sacrificing the animals, dissociating the tissue and counting the number of colony forming units. However, the discovery of several varieties of the light producing enzyme, luciferase, and the genetic engineering of bacteria, fungi, parasites and mice to make them emit light, either after administration of the luciferase substrate, or in the case of the bacterial lux operon without any exogenous substrate, has provided a new alternative. Dedicated bioluminescence imaging (BLI) cameras can record the light emitted from living animals in real time allowing non-invasive, longitudinal monitoring of the anatomical location and growth of infectious microorganisms as measured by strength of the BLI signal. BLI technology has been used to follow bacterial infections in traumatic skin wounds and burns, osteomyelitis, infections in intestines, Mycobacterial infections, otitis media, lung infections, biofilm and endodontic infections and meningitis. Fungi that have been engineered to be bioluminescent have been used to study infections caused by yeasts (Candida) and by filamentous fungi. Parasitic infections caused by malaria, Leishmania, trypanosomes and toxoplasma have all been monitored by BLI. Viruses such as vaccinia, herpes simplex, hepatitis B and C and influenza, have been studied using BLI. This rapidly growing technology is expected to continue to provide much useful information, while drastically reducing the numbers of animals needed in experimental studies.

Emerging nanotechnology based strategies for diagnosis and therapeutics of urinary tract infections: A review

At present, various diagnostic and therapeutic approaches are available for urinary tract infections. But, still the quest for development of more rapid, accurate and reliable approach is an unending process. The pathogens, especially uropathogens are adapting to new environments and antibiotics day by day rapidly. Therefore, urinary tract infections are evolving as hectic and difficult to eradicate, increasing the economic burden to the society. The technological advances should be able to compete the adaptability characteristics of microorganisms to combat their growth in new environments and thereby preventing their infections. Nanotechnology is at present an extensively developing area of immense scientific interest since it has diverse potential applications in biomedical field. Nanotechnology may be combined with cellular therapy approaches to overcome the limitations caused by conventional therapeutics. Nanoantibiotics and drug delivery using nanotechnology are currently growing areas of research in biomedical field. Recently, various categories of antibacterial nanoparticles and nanocarriers for drug delivery have shown their potential in the treatment of infectious diseases. Nanoparticles, compared to conventional antibiotics, are more beneficial in terms of decreasing toxicity, prevailing over resistance and lessening costs. Nanoparticles present long term therapeutic effects since they are retained in body for relatively longer periods. This review focuses on recent advances in the field of nanotechnology, principally emphasizing diagnostics and therapeutics of urinary tract infections.

Urinary Tract Infection in Children: Management in the Era of Antibiotic Resistance-A Pediatric Urologist's View

CONTEXT

Antibiotic resistance to uropathogens has grown significantly worldwide. Today, pediatric urologist experience a situation that needs appropriate action because urinary tract infections are one of the most common bacterial infections in children.

OBJECTIVE

In this overview we aimed at presenting the clinical aspects of antibiotic usage in pediatric urology. Our intention was to take part of the important debate regarding future management of bacterial resistance against antibiotics.

EVIDENCE ACQUISITION

We searched PubMed for the terms: [UTI in children], [Recurrent UTI in children], and [Antibiotic resistance in UTI]. When using these terms, we found a numerous amount (3875) of published clinical articles related to the topic. By means of an overview, we chose not to focus on a specific condition but to an overall understanding of the problems related to pediatric urology in general.

EVIDENCE SYNTHESIS

We found that usage of antibiotics has had an unquestionable benefit to reduce the morbidity and mortality related to urinary tract infections in childhood. However, recent studies suggest that early exposure to antibiotics in childhood might have negative systemic effects related to neurocognitive function, body metabolism, and fat distribution. In addition to increased resistance to common antimicrobial agents, it has resulted in increased costs and inadequate effect in severe infections. This calls for changes in the clinical management of urinary pathogens in pediatric urology.

CONCLUSIONS

As the prevalence of antibiotic resistance grows, pediatric urologists have a key role in managing its consequences and its prevention.

PATIENT SUMMARY

In this overview we looked at the consequences of antibiotic usage treating urinary tract infections in childhood. We found that the prevalence of antibiotic resistance has grown. We concluded that decision-makers must know about the short- and long-term effects of antibiotic usage in children. When we understand the development of antibiotic resistance better, we can build up prevention strategies.

ESBL Production Among E. coli and Klebsiella spp. Causing Urinary Tract Infection: A Hospital Based Study

Introduction:

Increase in extended-spectrum β-lactamases (ESBL) producing microbes in recent years has led to limitations of treatment options. This study aimed to assess the prevalence of ESBL producing E. coli and Klebsiella spp. at a tertiary hospital in Nepal.

Methods:

A total of 2209 non-repetitive mid-stream urine (MSU) samples were collected during the study period (March to September 2014). Identification of the isolates was done by Gram's staining followed by biochemical tests. Antibiotic susceptibility testing was done by modified Kirby-Bauer disc diffusion method and interpretation was done following Clinical and Laboratory Standard Institute (CLSI) guidelines, 2013. ESBL screening among E. coli and Klebsiella spp. isolates were done using ceftriaxone, cefotaxime, ceftazidime and cefpodoxime. The confirmation was done by phenotypic disc diffusion test (combined disc method) using ceftazidime (30µg) and ceftazidime plus clavulanic acid (30/10µg), and cefotaxime (30µg) and cefotaxime plus clavulanic acid (30/10µg) disc as per CLSI guidelines.

Results:

A total of 451 samples showed significant bacteriuria with 365 (80.9%) E. coli, 17 (3.8%) Klebsiella pneumoniae and 3 (0.7%) Klebsiella oxytoca. Of 451 isolates, 236 (52.3%) were found MDR strains. By combined disk test, 33 (91.7%) E. coli and 3 (8.3%) Klebsiella spp. were found ESBL producers.

Conclusion:

Higher prevalence of ESBL producing E. coli and Klebsiella spp. was observed warranting prompt need of surveillance for effective management of such MDR strains.