The clinical impact of early detection of ESBL-producing Enterobacterales with PCR-based blood culture assays

BACKGROUND

Starting January 4, 2021, our health system core microbiology laboratory changed blood culture identification (BCID) platforms to ePlex BCID from BioFire BCID1 with the additional capability to detect the blaCTX-M-Type gene of ESBL-producing organisms. Clinical outcomes of ESBL bloodstream infections (BSI) after implementing ePlex BCID were unknown.

METHODS

Patients with ESBL BSI were compared pre and postimplementation of ePlex BCID in this 11-hospital retrospective analysis (BioFire BCID1 in 2019 vs ePlex BCID in 2021). The primary outcome was time from the Gram stain result to escalation to a carbapenem. Secondary outcomes included in-hospital mortality, 30-day readmission rate, length of stay (LOS), and the duration of antimicrobial therapy.

RESULTS

A total of 275 patients were analyzed. The median time of Gram stain result to escalation to carbapenem was reduced from 44.5 hours with BioFire BCID1 to 7.9 hours with ePlex BCID (P < .001). There were no significant differences in mortality, 30-day readmission, or LOS. The duration of antimicrobial therapy for ESBL BSI was lower in the ePlex BCID group (from 14.4 days to 12.7 days, P = .014).

CONCLUSIONS

Timely detection of the blaCTX-M-Type gene by BCID provides valuable information for the early initiation of appropriate and effective antimicrobial therapy. Although it was not associated with lower mortality, 30-day readmission, or LOS, it may have benefits such as decreasing antimicrobial exposure to patients.

Epidemiology of multidrug-resistant Klebsiella pneumoniae infection in clinical setting in South-Eastern Asia: a systematic review and meta-analysis

The rising prevalence of multidrug-resistant (MDR) and extended-spectrum beta lactamase-resistant (ESBL) Klebsiella pneumoniae (K. pneumoniae) is an important global public health challenge. This threat is even more pertinent in clinical settings. Morbidity and mortality associated with this condition are alarming particularly in the developing regions of the world. A comprehensive evaluation of the epidemiology of this phenomenon will assist towards the global effort of reducing its burden. So, this systematic review and meta-analysis was conducted to evaluate the epidemiology of MDR K. pneumoniae in South-Eastern Asia (SEA). The study was done under the PRISMA guidelines and was preceded by the development of a priori protocol. The protocol was then registered in PROSPERO-the public registry for systematic reviews. Seven important outcomes which include the assessment of the overall MDR K. pneumoniae prevalence were designed to be evaluated. A literature search was carried out in five selected electronic databases and 4389 were screened. Of these articles, 21 studies that met the eligibility criteria were included in the review. Relevant data were extracted from the included studies. By conducting a quality effect meta-analysis, the pooled prevalence for MDR and ESBL K. pneumoniae in SEA was estimated at 55% (CI 9-96) and 27% (CI 32-100) respectively. The review also identified ESBL genes types of allodemic situations occurring mostly in respiratory tract infections. The high prevalence of MDR and ESBL K. pneumoniae in this subregion is highly significant and of both public health and clinical relevance. Overall, the findings of this review will assist in the effective prevention and control of this threat in SEA.

Characterisation of Bacterial Isolates from Infected Post-Operative Patients in a Malaysian Tertiary Heart Care Centre

Several bacterial species cause post-operative infections, which has been a critical health concern among hospital patients. Our study in this direction is a much-needed exploratory study that was carried out at the National Heart Institute (IJN) of Malaysia to examine the virulence properties of causative bacteria obtained from postoperative patients. The bacterial isolates and data were provided by the IJN. Antibiotic resistance gene patterns, and the ability to form biofilm were investigated for 127 isolates. Klebsiella pneumoniae (36.2%) was the most common isolate collected, which was followed by Pseudomonas aeruginosa (26%), Staphylococcus aureus (23.6%), Streptococcus spp. (8.7%) and Acinetobacter baumannii (5.5%). There were 49 isolates that showed the presence of multidrug resistance genes. The mecA gene was surprisingly found in methicillin-susceptible S. aureus (MSSA), which also carried the ermA gene from those erythromycin-susceptible strains. The phenotypic antibiotic resistance profiles varied greatly between isolates. Findings from the biofilm assay revealed that 44 of the 127 isolates demonstrated the ability to produce biofilms. Our findings provide insights into the possibility of some of these bacteria surviving under antibiotic stress, and some antibiotic resistance genes being silenced.

The Continuing Plague of Extended-Spectrum β-Lactamase Producing Enterbacterales Infections: An Update

Antimicrobial resistance is a common iatrogenic complication of modern life and medical care. One of the most demonstrative examples is the exponential increase in the incidence of extended-spectrum β-lactamases (ESBLs) production among Enterobacteriaceae, that is, the most common human pathogens outside of the hospital setting. Infections resulting from ESBL-producing bacteria are associated with devastating outcomes, now affecting even previously healthy individuals. This poses an enormous burden and threat to public health. This article aims to narrate the evolving epidemiology of ESBL infections and highlights current challenges in terms of management and prevention of these common infections.

Molecular epidemiology of antimicrobial resistant microorganisms in the 21th century: a review of the literature

Healthcare-associated infections (HAIs) are the most frequent and severe complication acquired in healthcare settings with high impact in terms of morbidity, mortality and costs. Many bacteria could be implicated in these infections, but, expecially multidrug resistance bacteria could play an important role. Many microbial typing technologies have been developed until to the the bacterial whole-genome sequencing and the choice of a molecular typing method therefore will depend on the skill level and resources of the laboratory and the aim and scale of the investigation. In several studies the molecular investigation of pathogens involved in HAIs was performed with many microorganisms identified as causative agents such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Clostridium difficile, Acinetobacter spp., Enterobacter spp., Enterococcus spp., Staphylococcus aureus and several more minor species. Here, we will describe the most and least frequently reported clonal complex, sequence types and ribotypes with their worldwide geographic distribution for the most important species involved in HAIs.

Risk Factors for Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Carriage in Patients Admitted to Intensive Care Unit in a Tertiary Care Hospital in Thailand

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) are important causes of serious infections in intensive care unit (ICU). This study aimed to investigate the risk factors for intestinal carriage of ESBL-PE among patients admitted to ICU, subsequent ESBL-PE infections, and outcomes of these patients. This study prospectively collected rectal swabs from 215 ICU patients in Northern Thailand and ESBL-PE were isolated. A high prevalence of ESBL-PE carriage (134/215, 62.3%) at ICU admission was observed, with Escherichia coli representing the predominant organism (67.5%) followed by Klebsiella pneumoniae (19.4%). Multivariate logistic regression analysis identified chronic renal disease as the independent risk factor for ESBL-PE carriage (p = 0.009; adjusted odds ratio = 4.369; 95% confidence interval = 1.455-13.119). Among colonized patients, 2.2% (3/134) developed ESBL-PE infections during ICU stay. Phylogenetic analysis of E. coli (n = 108) showed that the predominant group was group A (38.0%), followed by groups B1 (17.6%), D (15.7%), B2 (14.8%), C (7.4%), and F (6.5%). Multilocus sequence typing analysis of the pathogenic groups B2, D, and F revealed 11 different sequence types (STs), with ST131 (n = 13) as the most prevalent, followed by ST648 (n = 5), ST38 (n = 4), ST393 (n = 3), and ST1193 (n = 3). These results are of concern since ESBL-PE may be a prerequisite for endogenous infections and potentially disseminate within the hospital. This is the first study describing ESBL-PE carriage among patients at ICU admission and subsequent ESBL-PE infections in Thailand.

Predominance of CTX-M Type Extended Spectrum β-lactamase (ESBL) Producers Among Clinical Isolates of Enterobacteriaceae in a Tertiary Care Hospital, Kathmandu, Nepal

Background:

ESBL problem is increasing worldwide and only limited studies on genes of ESBL are performed in Nepal.

Objectives:

We aimed to focus on the molecular detection of plasmid-mediatedblaTEM,blaSHVandblaCTX-Mgenes among the ESBL producing Enterobacteriaceae from different clinical samples.

Methods:

A total of 550 clinical samples were processed and organisms of Enterobacteriaceae were identified using standard microbiological process. ESBL producers were screened and confirmed using modified Kirby Bauer disc diffusion method by CLSI guidelines. Plasmids extracted from the confirmed ESBL positives were the template for PCR.blaSHV,blaTEMandblaCTX-Mgenes were amplified using specific primers of respective genes by uniplex PCR. The presence of these genes was confirmed by gel electrophoresis.

Results:

Among 550 different clinical samples 343 (62.36%) were culture positive. Of which, 157 (45.57%) belonged to Enterobacteriaceae.Escherichia coli(45.9%) was predominant. Of these 33.2% (52/157) isolates ESBL positive. ESBL-E. coli(52.8%) were prevalent. All ESBL positive organisms were sensitive to imipenem. Of confirmed ESBL positives, 34.6% harboringblaTEMgene, 30.8% harboringblaSHVgene andblaCTX-Mgenes were present in all ESBL producers. Twenty-eightout of 52 (53.9%) isolates harbored multipleblagenes, the most common combination beingblaCTX-M+blaTEM(21.2%).

Conclusion:

We report 100% plasmid mediated CTX-M genotype among ESBL producers which might indicate rapid dissemination ofblaCTX-Mgenes from the community to the patients. Besides, there is a need for regular monitoring of antibiotic resistance in the country and de-escalate the use of antibiotics so as to preserve the antibiotics for future generation.

The Continuing Plague of Extended-spectrum β-lactamase-producing Enterobacteriaceae Infections

Antimicrobial resistance is a common iatrogenic complication of modern life and medical care. One of the most demonstrative examples is the exponential increase in the incidence of extended-spectrum β-lactamases (ESBLs) production among Enterobacteriaceae, which is the most common human pathogens outside of the hospital settings. Infections resulting from ESBL-producing bacteria are associated with devastating outcomes, now affecting even previously healthy individuals. This development poses an enormous burden and threat to public health. This paper aims to narrate the evolving epidemiology of ESBL infections, and highlight current challenges in terms of management and prevention of these common infections.

Epidemiology and molecular characterization of multidrug-resistant Gram-negative bacteria in Southeast Asia

BACKGROUND

Multidrug-resistant Gram-negative bacteria (MDRGN), including extended-spectrum β-lactamases (ESBLs) and multidrug-resistant glucose-nonfermenting Gram-negative bacilli (nonfermenters), have emerged and spread throughout Southeast Asia.

METHODS

We reviewed and summarized current critical knowledge on the epidemiology and molecular characterization of MDRGN in Southeast Asia by PubMed searches for publications prior to 10 March 2016 with the term related to "MDRGN definition" combined with specific Southeast Asian country names (Thailand, Singapore, Malaysia, Vietnam, Indonesia, Philippines, Laos, Cambodia, Myanmar, Brunei).

RESULTS

There were a total of 175 publications from the following countries: Thailand (77), Singapore (35), Malaysia (32), Vietnam (23), Indonesia (6), Philippines (1), Laos (1), and Brunei (1). We did not find any publications on MDRGN from Myanmar and Cambodia. We did not include publications related to Shigella spp., Salmonella spp., and Vibrio spp. and non-human related studies in our review. English language articles and abstracts were included for analysis. After the abstracts were reviewed, data on MDRGN in Southeast Asia from 54 publications were further reviewed and included in this study.

CONCLUSIONS

MDRGNs are a major contributor of antimicrobial-resistant bacteria in Southeast Asia. The high prevalence of ESBLs has been a major problem since 2005 and is possibly related to the development of carbapenem resistant organisms in this region due to the overuse of carbapenem therapy. Carbapenem-resistant Acinetobacter baumannii is the most common pathogen associated with nosocomial infections in this region followed by carbapenem-resistant Pseudomonas aeruginosa. Although Southeast Asia is not an endemic area for carbapenem-resistant Enterobacteriaceae (CRE), recently, the rate of CRE detection has been increasing. Limited infection control measures, lack of antimicrobial control, such as the presence of active antimicrobial stewardship teams in the hospital, and outpatient antibiotic restrictions, and travel throughout this region have likely contributed to the increase in MDRGN prevalence.

Antimicrobial Susceptibility of Klebsiella pneumoniae and Escherichia coli with Extended-Spectrum β-lactamase associated Genes in Hospital Tengku Ampuan Afzan, Kuantan, Pahang

BACKGROUND

To assess antimicrobial susceptibility of extended-spectrum β-lactamase- (ESBL-) producing Klebsiella pneumoniae and Escherichia coli isolates from Hospital Tengku Ampuan Afzan (HTAA), as well as to identify ESBL genes.

METHODS

Non-duplicate K. pneumoniae and E. coli isolates were recovered from various clinical samples. Isolates were screened for antimicrobial resistance by disc diffusion method. Isolates resistant to oxyimino-cephalosporins were subjected to phenotypic ESBL production. Detection of resistance genes was then performed using primers specific for ESBL genes (bla CTX-M, bla SHV and bla TEM).

RESULTS

Piperacillin/tazobactam and carbapenems remained the active β-lactam antibiotic against K. pneumoniae and E. coli. ESBLs were detected among 35.5% (39/110) of K. pneumoniae and 18.8% (28/149) of E. coli isolates. CTX-M β-lactamase was detected in 90% of all ESBL-positive isolates, whereas bla SHV and bla TEM genes were found among 56% and 52% of them, respectively. Twenty-eight percent (28%) of the total ESBL-positive isolates harboured the three ESBL genes, while 50% carried two of the tested ESBL genes.

CONCLUSION

ESBLs encoded by at least one ESBL genes are frequently isolated among K. pneumoniae and E. coli in HTAA. The significant proportion rate of these resistant determinants is alarming, thus monitoring their transmission and dissemination is essential to control it at an early phase.

Clinical and Molecular Epidemiology of Extended-Spectrum Beta-Lactamase-Producing Klebsiella spp.: A Systematic Review and Meta-Analyses

Healthcare-related infections caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella spp. are of major concern. To control transmission, deep understanding of the transmission mechanisms is needed. This systematic review aimed to identify risk factors and sources, clonal relatedness using molecular techniques, and the most effective control strategies for ESBL-producing Klebsiella spp. A systematic search of PubMed, Embase, and Outbreak Database was performed. We identified 2771 articles from November 25th, 1960 until April 7th, 2014 of which 148 were included in the systematic review and 23 in a random-effects meta-analysis study. The random-effects meta-analyses showed that underlying disease or condition (odds ratio [OR] = 6.25; 95% confidence interval [CI] = 2.85 to 13.66) generated the highest pooled estimate. ESBL-producing Klebsiella spp. were spread through person-to-person contact and via sources in the environment; we identified both monoclonal and polyclonal presence. Multi-faceted interventions are needed to prevent transmission of ESBL-producing Klebsiella spp.

A realist analysis of hospital patient safety in Wales: applied learning for alternative contexts from a multisite case study

Background

Hospital patient safety is a major social problem. In the UK, policy responses focus on the introduction of improvement programmes that seek to implement evidence-based clinical practices using the Model for Improvement, Plan-Do-Study-Act cycle. Empirical evidence that the outcomes of such programmes vary across hospitals demonstrates that the context of their implementation matters. However, the relationships between features of context and the implementation of safety programmes are both undertheorised and poorly understood in empirical terms.

Objectives

This study is designed to address gaps in conceptual, methodological and empirical knowledge about the influence of context on the local implementation of patient safety programmes.

Design

We used concepts from critical realism and institutional analysis to conduct a qualitative comparative-intensive case study involving 21 hospitals across all seven Welsh health boards. We focused on the local implementation of three focal interventions from the 1000 Lives+patient safety programme: Improving Leadership for Quality Improvement, Reducing Surgical Complications and Reducing Health-care Associated Infection. Our main sources of data were 160 semistructured interviews, observation and 1700 health policy and organisational documents. These data were analysed using the realist approaches of abstraction, abduction and retroduction.

Setting

Welsh Government and NHS Wales.

Participants

Interviews were conducted with 160 participants including government policy leads, health managers and professionals, partner agencies with strategic oversight of patient safety, advocacy groups and academics with expertise in patient safety.

Main outcome measures

Identification of the contextual factors pertinent to the local implementation of the 1000 Lives+patient safety programme in Welsh NHS hospitals.

Results

An innovative conceptual framework harnessing realist social theory and institutional theory was produced to address challenges identified within previous applications of realist inquiry in patient safety research. This involved the development and use of an explanatory intervention–context–mechanism–agency–outcome (I-CMAO) configuration to illustrate the processes behind implementation of a change programme. Our findings, illustrated by multiple nested I-CMAO configurations, show how local implementation of patient safety interventions are impacted and modified by particular aspects of context: specifically, isomorphism, by which an intervention becomes adapted to the environment in which it is implemented; institutional logics, the beliefs and values underpinning the intervention and its source, and their perceived legitimacy among different groups of health-care professionals; and the relational structure and power dynamics of the functional group, that is, those tasked with implementing the initiative. This dynamic interplay shapes and guides actions leading to the normalisation or the rejection of the patient safety programme.

Conclusions

Heightened awareness of the influence of context on the local implementation of patient safety programmes is required to inform the design of such interventions and to ensure their effective implementation and operationalisation in the day-to-day practice of health-care teams. Future work is required to elaborate our conceptual model and findings in similar settings where different interventions are introduced, and in different settings where similar innovations are implemented.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

The complex epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae

ABSTRACT 

Antimicrobial resistance is a growing worldwide iatrogenic complication of modern medical care. Extended-spectrum β-lactamases have emerged as one of the most successful resistance mechanisms, limiting our therapeutic options to treat various human infections. The dissemination of these enzymes to the community probably signifies an irreversible step. This paper will review the evolution of human infections associated with extended-spectrum β-lactamase-producing organisms in the past 20 years, and will present and discuss the current challenges, controversies, debates and knowledge gaps in this research field.

Escherichia coli Isolated from Urinary Tract Infections of Lebanese Patients between 2005 and 2012: Epidemiology and Profiles of Resistance

The early treatment of urinary tract infections (UTIs) is directly related to decrease in morbidity, which makes the empirical treatment of great importance. Recently, beta lactamases of several types have emerged as significant mechanisms of resistance in Gram-negative bacilli, especially Escherichia coli. Our aim was to study the urinary E. coli isolated from Lebanese patients and to characterize their mechanisms of resistance. The study analyzed data between 2005 and 2012 of UTIs caused by E. coli. The mechanisms of resistance were characterized by phenotypic and genotypic methods and the pulsed-field gel electrophoresis (PFGE) was used to determine the different bacterial clusters. As expected, the highest incidence was observed with E. coli (60.53–73.98%) followed by K. pneumoniae (5.32–8.33%). ICU isolates were constantly associated with the lowest rates of susceptibility to extended-spectrum cephalosporins, ciprofloxacin, as well as most of the tested antibiotics. A 100% occurrence of CTX-M in extended-spectrum β-lactamase (ESBL)-producing isolates was recorded, followed by TEM, SHV, and OXA. In addition, 15.9% harbored 4 different ESBL enzymes and only 13 isolates (14.8%) harbored only one enzyme (CTX-M). Over the years, the simultaneous susceptibility of E. coli to ceftazidime and ciprofloxacin decreased from 62.5% in 2006 to 48.7% in 2012. PFGE results demonstrated that 10 clusters were 32 generated, denoting diversity among detected isolates. Understanding the epidemiology of resistance is 33 instrumental for the implementation of recommendations for the management of antimicrobials, infection 34 control measures, as well as active surveillance and antimicrobial stewardship.

Carbapenem de-escalation therapy in a resource-limited setting

Pulmonary infection (P=.01) and an infectious diseases consultation (P=.04) were associated with carbapenem de-escalation; pulmonary infection and septic shock were associated with unsuccessful de-escalation. Successful de-escalation was associated with lower mortality (0% vs 23%; P<.001) and shorter duration of carbapenem use (4 vs 10 days; P ≤ .001).

Detecting risk and predicting patient mortality in patients with extended-spectrum β-lactamase-producing Enterobacteriaceae bloodstream infections

Extended-spectrum β-lactamases (ESBLs) have been increasingly described worldwide, especially among Enterobacteriaceae isolates, and recently not only in the nosocomial, but also in the community setting. Bloodstream infections (BSIs) caused by ESBL-producing Enterobacteriaceae have been associated with increased rates of treatment failure, mortality and hospital costs. Any delay in the initiation of adequate antibiotic therapy is potentially lethal for patients with BSIs caused by ESBL-producing Enterobacteriaceae. The awareness of changes in bacterial resistance patterns, the careful knowledge of risk factors for ESBL infection and of factors facilitating adverse outcome, giving attention to local epidemiology, can improve the efficacy of empirical treatment protocols. The aim of this review is to focus on the main characteristics of BSIs caused by ESBL-producing Enterobacteriaceae, with particular emphasis on risk factors for these infections and factors related to mortality.

CTX-M-producing Escherichia coli and Klebsiella pneumoniae isolated from community-acquired urinary tract infections in Valledupar, Colombia

OBJECTIVE

Describe the presence of CTX-M-1 phylogenetic subgroup extended-spectrum β-lactamases (ESBL), associated with TEM and SHV genes, and the gene encoding cephalosporinase, CMY-2 in Escherichia coli and Klebsiella pneumoniae isolates from community-acquired urinary tract infections.

METHODS

102 E. coli and 21K. pneumoniae were collected from patients with culture-proven urinary tract infection (UTI), during February and March, 2011. Antimicrobial susceptibility test was performed by disk diffusion according to the standards of the Clinical Laboratory Standard Institute. Screening for cephalosporins-resistant E. coli and K. pneumoniae was performed by PCR assay for bla(TEM), bla(SHV), bla(CTX-M-1),(-2),(-8),(-9), bla(PER-2) and bla(CMY-2) genes. Statistical analysis was performed by chi-squared test and multivariate logistic regression analysis.

RESULTS

ESBL production was detected in 12 (11.7%) E. coli and four (19%) K. pneumoniae isolates. TEM ESBLs were detected in seven E. coli and three K. pneumoniae isolates. SHV ESBLs were found in four K. pneumoniae isolates. CTX-M-1 phylogenetic subgroup was positive in seven E. coli and three K. pneumoniae isolates. CMY-2 β-lactamase gene was detected in nine E. coli and one K. pneumoniae isolates. A significant association of ESBL expression in E. coli was observed with resistance to tobramycin (p≤0.001), tetracycline (p=0.043), and ciprofloxacin (p≤0.001). In K. pneumoniae isolates, significant association was found with resistance to tobramycin and ciprofloxacin (p=0.006), and trimethoprim-sulfamethoxazole (p=0.043). Multivariate analyses did not show association between ESBL production in E. coli and K. pneumoniae, and resistance to non-β-lactams drugs.

CONCLUSIONS

CTX-M ESBL in uropathogens isolated from the community is cause for concern due to the enormous potential for multidrug resistance from strains that produce these enzymes, which could lead to failure of empirically-administered therapies and development of complicated UTIs.

High prevalence of extended-spectrum beta-lactamases and plasmid-mediated AmpC beta-lactamases in Enterobacteriaceae isolated from long-term care facilities in Korea

The aim of this study was to investigate for the first time the prevalence and types of extended-spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (PABL) in Enterobacteriaceae in Korean long-term care facilities (LTCFs). ESBL rates were 45.3% (72/159) in Escherichia coli and 42.7% (50/117) in Klebsiella pneumoniae. In E. coli, CTX-M-28, the most prevalent ESBLs, was identified for the first time in Korea in 44 isolates. In K. pneumoniae, SHV-12 was found in 27 isolates (52.9% of ESBLs), among which 25 isolates also contained SHV-11. Twenty-seven isolates had SHV and CTX-M beta-lactamase simultaneously. PABL genes were detected in 39.3% (46/117) of K. pneumoniae and 3.1% (5/159) E. coli. In E. coli, DHA-1(3), CMY-2(1), and CMY-6(1) were detected, whereas in K. pneumoniae, only DHA-1 was detected. Among the PABL-producing organisms, 80.0% (E. coli) and 52.2% (K. pneumoniae) simultaneously produced ESBLs. In conclusion, LTCF residents in Korea have a very high prevalence of E. coli and K. pneumoniae producing ESBLs, PABLs, or both, and the genotypes of ESBL and PABL were identical with those found in general hospitals.

Genotypic detection and molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a regional hospital in central Taiwan

This study was conducted to detect the genes encoding extended-spectrum beta-lactamases (ESBLs) and determine the epidemiological relatedness of 69 Escherichia coli and 33 Klebsiella pneumoniae isolates collected from a regional hospital in central Taiwan, mostly from inpatients (E. coli 87.0%; K. pneumoniae 88.0%). The phenotypes of these isolates were examined according to the combination disc method recommended by the Clinical and Laboratory Standards Institute. Most of the ESBL-producing E. coli and K. pneumoniae isolates (98.6% and 97%, respectively) could be detected using cefotaxime discs with and without clavulanate. Genotyping was performed by PCR with type-specific primers. CTX-M-14 type (53.6%) was the most prevalent ESBL among E. coli isolates while SHV type (57.6%) was the most dominant among K. pneumoniae isolates. Six E. coli and three K. pneumoniae isolates did not carry genes encoding ESBLs of types TEM, SHV, CTX-M-3, CTX-M-14, CMY-2 and DHA-1. The co-existence of two or more kinds of ESBL in a single isolate was common, occurring in 40.6% and 72.7% of E. coli and K. pneumoniae isolates, respectively. PFGE analysis revealed that ESBL producers isolated in this setting were genetically divergent.

Antimicrobial use: risk driver of multidrug resistant microorganisms in healthcare settings

PURPOSE OF REVIEW

This review explores recent evidence on the association between antibiotics usage and resistance.

RECENT FINDINGS

A meta-analysis showed that the risk of acquiring methicillin-resistant Staphylococcus aureus was increased by 1.8-fold in patients who had taken antibiotics. Such risk was almost three-times greater after using quinolones or glycopeptides. Significant heterogeneity between studies was mainly related to study designs. A Cochrane systematic review suggested that, although the quality of the evidence was poor, interventions to improve hospital antibiotic prescribing were associated with a reduction in the incidence of antimicrobial resistant pathogens. Against this evidence, mupirocin-resistant S. aureus and linezolid-resistant vancomycin-resistant enterococci (VRE) were detected in institutions where these drugs were not widely used. Studies assessing the impact of vancomycin prescribing restriction on VRE rates were heterogeneous and the effectiveness of such interventions remains poorly defined. Important confounders of studies, other than study design, are the lack of analysis of secular trends of infections, colonization pressure in the ward and duration of follow up.

SUMMARY

Available evidence, although not always of high quality, suggests that a link between antibiotics usage at individual and institutional levels and resistant bacteria does exist. Benchmark guidelines for empiric therapy in hospitalized patients, taking into consideration not only patients' needs but also ecological costs of resistance, should be rapidly developed.