High prevalence of carbapenemase, AmpC β-lactamase and aminoglycoside resistance genes in extended-spectrum β-lactamase-positive uropathogens from Northern India

Extended-spectrum β - lactamase inhibitory potential of Dichrocephala integrifolia: an in vitro and computational studies

Extended-spectrum β-lactamases (ESBL) producing enterobacteriales are a major global health concern since they often result in the ineffectiveness of empirical antibiotic therapy with β-lactams. This study aims to identify potential medicinal plants that can inhibit β-lactamase and subsequently enhance the activity of the β-lactams against resistant bacterial strains. A synergistic study of Dichrocephala integrifolia extract exhibited good synergistic activity against a CTX-M-producing organism, which was confirmed using an agar-based diffusion bioassay method. Further validation was done by Molecular docking in which, the phytocompound Propanamide, N-[4-(4-chlorophenyl)-2-thiazolyl]-3-(1-pyrrolidinyl)-/NSC339591, obtained from the GC-MS study showed a good binding affinity with favourable hydrogen bond interactions with the active sites of CTX-M-14. This phytocompound was further selected for a Molecular Dynamic Simulation (MD) study with CTX-M-14, where the complex exhibited good stability and maintained a consistent conformation throughout the simulation. NSC339591 cleared the drug-likeness filters.

Dramatic increase in antimicrobial resistance in ESKAPE clinical isolates over the 2010-2020 decade in India

RATIONALE AND OBJECTIVES

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) constitute a threat to humans worldwide. India is now the most populous country. The goal was to investigate the evolution of the rates of antimicrobial resistance in ESKAPE pathogens across India over the 2010-20 decade.

METHODS

The data (89 studies) were retrieved from the Medline PubMed repository using specific keywords.

RESULTS

The study of 20 177 ESKAPE isolates showed that A. baumannii isolates were the most represented (35.9%, n = 7238), followed by P. aeruginosa (25.3%, n = 5113), K. pneumoniae (19.5%, n = 3934), S. aureus (16.3%, n = 3286), E. faecium (2.6%, n = 517) and Enterobacter spp. (0.4%, n = 89). A notable increase in the resistance rates to antimicrobial agents occurred over the 2010-20 decade. The most important levels of resistance were observed in 2016-20 for A. baumannii (90% of resistance to the amoxicillin-clavulanate combination) and K. pneumoniae (81.6% of resistance to gentamycin). The rise in β-lactamase activities was correlated with an increase in the positivity of Gram-negative isolates for β-lactamase genes.

CONCLUSIONS

This review highlighted that, in contrast to developed countries that kept resistance levels under control, a considerable increase in resistance to various classes of antibiotics occurred in ESKAPE pathogens in India over the 2010-2020 decade.

Prevalence and distribution pattern of AmpC β-lactamases in ESBL producing clinical isolates of Klebsiella spp. in parts of Assam, India

The production of extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases is the most common explanation of multidrug resistance in clinical isolates of Klebsiella spp. In the present study, a total of 160 isolates of Klebsiella spp. were procured from the DBT-NER project with ethical clearance no. DU/Dib/ECBHR(Human)/2021-22/02). These were collected from various health settings of Assam and identified as drug-resistant. The isolates were screened for antibiotic susceptibility and phenotypic tests were performed on multidrug resistant isolates to confirm ESBL and AmpC β-lactamases production. The distribution pattern of ESBL and AmpC β-lactamase genotype was investigated by polymerase chain reaction (PCR). The results showed that among 107 multidrug-resistant (MDR) isolates of Klebsiella spp., 67.28% of isolates were ESBL producers and 56.07% were potential AmpC producers. The PCR results revealed that blaCTX-M was the most prevalent ESBL genotype. Among the ESBL producers, 11.11% of isolates showed co-occurrence with plasmid-mediated AmpC β lactamases genotype which indicated the high prevalence of ESBL and AmpC co-producers in K. pneumoniae and K. oxytoca, suggesting the possibility of serious public health concerns. Therefore, it is crucial to regularly monitor the spread of multidrug resistance among clinical isolates.

Extended-Spectrum β-Lactamases (ESBL): Challenges and Opportunities

The rise of antimicrobial resistance, particularly from extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E), poses a significant global health challenge as it frequently causes the failure of empirical antibiotic therapy, leading to morbidity and mortality. The E. coli- and K. pneumoniae-derived CTX-M genotype is one of the major types of ESBL. Mobile genetic elements (MGEs) are involved in spreading ESBL genes among the bacterial population. Due to the rapidly evolving nature of ESBL-E, there is a lack of specific standard examination methods. Carbapenem has been considered the drug of first choice against ESBL-E. However, carbapenem-sparing strategies and alternative treatment options are needed due to the emergence of carbapenem resistance. In South Asian countries, the irrational use of antibiotics might have played a significant role in aggravating the problem of ESBL-induced AMR. Superbugs showing resistance to last-resort antibiotics carbapenem and colistin have been reported in South Asian regions, indicating a future bleak picture if no urgent action is taken. To counteract the crisis, we need rapid diagnostic tools along with efficient treatment options. Detailed studies on ESBL and the implementation of the One Health approach including systematic surveillance across the public and animal health sectors are strongly recommended. This review provides an overview of the background, associated risk factors, transmission, and therapy of ESBL with a focus on the current situation and future threat in the developing countries of the South Asian region and beyond.

Comparative Investigation into the Roles of Imipenem:Cyclodextrin Complexation and Antibiotic Combination in Combatting Antimicrobial Resistance in Gram-Negative Bacteria

Extensively drug-resistant (XDR), multidrug-resistant (MDR) and pandrug-resistant (PDR) Gram-negative microorganisms (GNBs) are considered a significant global threat. β-lactam and aminoglycoside combinations and imipenem:cyclodextrin inclusion complexes were studied for the treatment of lethal GNBs. This is because of the broad empiric coverage of the two drugs and their possession of different spectra of activity. Two cyclodextrins (β- and hydroxy propyl β-cyclodextrins) were utilized for inclusion complex formation with imipenem using the physical and kneading methods. In silico investigation using the molecular docking and Fourier-infrared spectroscopy (FTIR) were employed to estimate binding constant and confirm complex formation, respectively. The in vitro effects of amikacin and imipenem combination in comparison to the effect of imipenem-β- and hydroxy propyl β-cyclodextrin (CD) complexes against Klebsiella spp. and Acinetobacter baumannii were studied. The isolated microorganisms' antimicrobial responsiveness to various antibiotics (19 antibiotics) was evaluated. It was found that piperacillin/tazobactam and gentamycin (resistance rates were 33.3% and 34%, respectively) were the most effective antimicrobials. The in vitro studies have been performed by the checkerboard technique and time-killing assay. The studied combination of amikacin and imipenem showed a substantial drop in bacterial count (p < 0.05). The in vitro studies demonstrated a synergism for the investigated combination. Conventional PCR was used in molecular studies to identify the resistance genes bla IMP and aac (6')-Ib. The blaIMP and aac (6')-Ib were recorded in 38.2% and 3.6% of the studied isolates, respectively. The in vitro studies showed synergistic effects among the tested antibiotics with FICIs of ≤0.5. Finally, the study compared the reduction in bacterial count between the tested antibiotic combinations and imipenem:CD physical and kneaded mixtures. Imipenem:CD inclusion complexes demonstrated a significant bacterial count reduction over the antibiotic combination. These results highlight the emerging role of CDs as safe biofunctional excipients in the combat against superbug bacterial resistance.

Quinolone resistance and biofilm formation capability of uropathogenic Escherichia coli isolates from an Iranian inpatients' population

BACKGROUND

Uropathogenic Escherichia coli (UPEC) is a major pathogen of the urinary tract infection (UTI), and biofilm formation is crucial as it facilitates the colonization in the urinary tract. We aimed to investigate the antibiotic susceptibility pattern, biofilm formation capability, distribution of quinolone resistance genes, and phylogenetic groups among UPEC isolates from an Iranian inpatients' community.

METHODS AND RESULTS

A collection of 126 UPEC obtained from hospitalized patients with symptomatic UTI at 3 teaching hospitals during 2016 were included. Antibiogram of all isolates against quinolone and fluoroquinolones was performed using the disk diffusion method. Phylogenetic groups and qnr A, B, and S genes were assessed by PCR. Susceptibility pattern showed that more than 50% and 81% of the isolates were resistant to fluoroquinolones and quinolones, correspondingly. The frequency of qnrS and qnrB genes was 22% and 13.5%, correspondingly. Our result indicated no significant association between the presence of fluoroquinolone genes and antibiotic resistance to them. The frequent common phylogroup was B2 (84.1%), followed by D (10.3%), A (3.2%) and B1 (2.4%) groups. Indeed, 80.2% of the isolates were biofilm producers, so that 42.1%, 16.7% and 21.4% of them were classified as weak, moderate and strong producers, respectively.

CONCLUSIONS

Our results showed considerable fluoroquinolone and quinolone resistance among UPEC along with a remarkable rate of biofilm-producing isolates from symptomatic hospitalized patients, making them a serious health concern in the region. This survey highlights the need for awareness on quinolone resistance and careful prescription of them by physicians.

Antimicrobial susceptibility pattern of extended-spectrum beta-lactamase-producing uropathogens in aminu Kano teaching hospital, Northwestern Nigeria

Background

UTI is the most common nosocomial infection among hospitalized patients. Emerging increasing resistance has been observed among uropathogens of the family enterobacterales. Extended spectrum beta lactamase genes encode for multidrug resistance and unrestricted use of antibiotics in hospitals provides an environment for spread of infections with limited treatment options. This necessitates therapies based on culture and antimicrobial sensitivity to improve patients' outcomes We aimed to determine susceptibility pattern of ESBL uropathogens among hospitalized patients in Aminu Kano Teaching Hospital, Kano.

Methodology

Three hundred and eighty-nine urine samples were obtained from in-patients with UTI between April 2020 and April 2021. Five samples were rejected and remaining analyzed. Susceptibility testing was done by modified Kirby Bauer technique. Clinical Laboratory Standards Institute guidelines 2019 (CLSI 2019) and the European Committee on Antimicrobial Susceptibility testing guidelines version 2 (EUCAST version 2) were used for screening and confirmation of ESBL production respectively.

Results

Of the 384-urine processed, 105 (27.3%) were gram negatives and 81 were Enterobacterales, Isolation rates were E. coli-55.6%, K. pneumoniae-29.6%, Citrobacter spp.-12.3%, P. mirabilis-1.2% and Morganella spp.-1.2%. Among Enterobacterales, 32 (39.5%) were ESBL producers. Prevalence of ESBL were 62.5% for Escherichia coli, 28.1% for Klebsiella pneumoniae and 9.4% for Citrobacter species. Susceptibility showed that ESBL-producing Isolates were highly susceptible to amikacin (96.9%). Resistance to other antibiotics varied from 3.1% to 100%.

Conclusion

We recommend strengthening laboratory capacity, antibiotics stewardship and Infection control to prevent spread of resistant pathogens including ESBLs.

Uropathogenic Escherichia coli endeavors: an insight into the characteristic features, resistance mechanism, and treatment choice

Uropathogenic Escherichia coli (UPEC) are the strains diverted from the intestinal status and account mainly for uropathogenicity. This pathotype has gained specifications in structure and virulence to turn into a competent uropathogenic organism. Biofilm formation and antibiotic resistance play an important role in the organism's persistence in the urinary tract. Increased consumption of carbapenem prescribed for multidrug-resistant (MDR) and Extended-spectrum-beta lactamase (ESBL)-producing UPECs, has added to the expansion of resistance. The World Health Organization (WHO) and Centre for Disease Control (CDC) placed the Carbapenem-resistant Enterobacteriaceae (CRE) on their treatment priority lists. Understanding both patterns of pathogenicity, and multiple drug resistance may provide guidance for the rational use of anti-bacterial agents in the clinic. Developing an effective vaccine, adherence-inhibiting compounds, cranberry juice, and probiotics are non-antibiotical approaches proposed for the treatment of drug-resistant UTIs. We aimed to review the distinguishing characteristics, current therapeutic options and promising non-antibiotical approaches against ESBL-producing and CRE UPECs.

Characterization of carbapenem-resistant Escherichia coli and Klebsiella: a role for AmpC-producing isolates

Aim: This study aimed to investigate the role of AmpC enzymes in carbapenem resistance among AmpC/extended-spectrum β-lactamase (ESBL)-producing clinical isolates of Escherichia coli and Klebsiella spp. Methods: Fifty-six bacterial strains that were AmpC producers were examined. The antibiotic susceptibility test was performed by the disk diffusion and E-test. The prevalence of the plasmid carbapenemase was determined using PCR. Results: The resistance to meropenem in the AmpC⁺/ESBL⁺ group was 64%, higher than that reported for the AmpC^-/ESBL⁺ group. Ten isolates of the carbapenem-resistant AmpC producers were negative for carbapenemase-encoding genes. Conclusion: Carbapenem resistance among AmpC-producing isolates with negative results for carbapenemase-encoding genes potentially demonstrates the role of AmpC enzymes among these isolates.

Treatment strategies for OXA-48-like and NDM producing Klebsiella pneumoniae infections

INTRODUCTION

OXA-48 and NDM are amongst the most prevalent carbapenemase types associated with Klebsiella pneumoniae worldwide, with an increase in their prevalence in recent years. Knowledge on the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) comes from KPC-producing CRKP with limited data available for OXA-48-like and NDM producers. Our aim is to review the literature on the treatment of OXA-48-like and NDM-producing CRKP with the goal of providing an update on the available antibiotic treatment strategies, particularly in light of changing carbapenemase epidemiology and increasing antimicrobial resistance.

AREAS COVERED

We reviewed studies looking at the antibiotic treatment and outcome of OXA-48-like and/or NDM-producing CRKP.

EXPERT OPINION

The best available treatment option for OXA-48 producers is ceftazidime-avibactam, where available and when the price permits its use. Colistin remains as the second-line option if in vitro susceptibility is demonstrated with an appropriate method. There is not enough evidence to support the use of meropenem-containing combination therapies for meropenem-resistant OXA-48 producers. Treatment of NDM producers is an unmet need. Ceftazidime-avibactam and aztreonam combination or cefiderocol can be used for NDM producers, where available. Higher cefiderocol MICs against NDM producers is concerning. Aztreonam-avibactam provides hope for the treatment of NDM producers.

Fecal Carriage of Extended-Spectrum β-Lactamases and pAmpC Producing Enterobacterales in an Iranian Community: Prevalence, Risk Factors, Molecular Epidemiology, and Antibiotic Resistance

This study aimed to determine the prevalence and risk factors associated with intestinal carriage of extended-spectrum β-lactamases producing Enterobacterales (ESBL-PE) and plasmid-mediated AmpC β-lactamase producing Enterobacterales (AmpC-PE) in healthy children in Ardabil, Iran. A total of 305 fecal samples were collected. Isolates underwent antimicrobial susceptibility testing, phenotypic and genotypic identification of β-lactamase production, and epidemiologic molecular typing. In total, 21.5%, 1.5%, and 1.2% of volunteers were extended-spectrum β-lactamase (ESBL)-, AmpC-, and simultaneous ESBL/AmpC-PE carriers, respectively. Escherichia coli was the predominant ESBL producing bacterium (70.2%) found in ESBL-PE colonized subjects. Beyond ESBL positive isolates, bla _CTX-M group genes were the most common type (75.6%) and bla _TEM (non-bla _TEM-1 and non- bla _TEM-2) were in the second place (25.6%). Among bla _CTX-M genes, bla _CTX-M-1 (55.3%) and bla _CTX-M-15 (55.3%) were the most predominant types with equal prevalence. Some isolates were multi-enzyme producers. bla _CIT and bla _DHA genes were common AmpC type enzyme encoding genes found in AmpC-PE isolates. Most isolates produced both enzymes at the same time. The number of students in the classes was statistically associated with ESBL-PE intestinal carriage (p < 0.05). Moreover, 46 (65.7%), 3 (60%), 4 (100%), and 98 (39.8%) ESBL-, AmpC-, ESBL/AmpC, and non-ESBL/AmpC-PE isolates were multidrug-resistant, respectively. Overall, regardless of β-lactam antibiotics, 62% and 59.5% of isolates were resistant to co-trimoxazole and tetracycline, respectively. The majority of ESBL producing E. coli isolates (69.2%) belonged to phylogroup A. According to Enterobacterial repetitive intergenic consensus polymerase chain reaction, there was no clonal relatedness between isolates. This study showed a high rate of multi-resistant ESBL-PE intestinal carriage among healthy individuals in Iran.

Occurrence and characterization of genetic determinants of β-lactam-resistance in Escherichia coli clinical isolates

β-lactamase mediated resistance in Escherichia coli is a significant problem that requires immediate attention. Herein, we aim to characterize and understand the dynamics of the genetic determinants of β-lactam resistance (i.e. ESBL, AmpC, and MBL) in E. coli. Out of 203 E. coli isolates, genetic determinants of β-lactam resistance were identified in 50% (n = 101) of isolates. ESBL, AmpC, and MBL resistance determinants were detected in 78%, 40%, and 18% of isolates, respectively with bla_{CTX-M group 4} (48%), bla_CMY (40%), and bla_SIM (33%) as the most prevalent β-lactam resistance genes. Among these isolates, 45% harbored plasmid replicon types, with L/M (40%) and Y (33%) as the most dominant replicon types. Integrons were detected in 40% of such isolates, with Class-1 and Class-3 representing 62% and 55%, respectively. Overall, we observed high rate of genetic determinants of β-lactam-resistance in E. coli isolates recovered from patients in clinical settings. The co-occurrence of antimicrobial resistance genes and mobile genetic elements in a high percentage of isolates is a major concern and relates to complex resistance mechanisms. To combat the serious threat of antimicrobial resistance, it is imperative to develop strategies for robust surveillance and understand the molecular basis of resistance acquisition and transmission.

Co-Occurrence of Rare ArmA-, RmtB-, and KPC-2-Encoding Multidrug-Resistant Plasmids and Hypervirulence iuc Operon in ST11-KL47 Klebsiella pneumoniae

The rapid emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the comparatively limited development of new antibiotics pose a major threat to public health. Aminoglycosides are important options that can lower the mortality rate effectively in combination therapy with β-lactam agents. However, in this study, we observed two multidrug-resistant (MDR) K. pneumoniae named 1632 and 1864 that exhibited high-level resistance to both carbapenems and aminoglycosides. Through whole-genome sequencing (WGS), the unusual co-occurrence of rmtB, armA, and bla_KPC-2 genes, associating with two key resistance plasmids, was observed in two isolates. Notably, we also found that the armA resistance gene and virulence factor iuc operon co-occurred on the same plasmid in K. pneumoniae 1864. Detailed comparative genetic analysis showed that all these plasmids were recognized as mobilizable plasmids, as they all carry the essential oriT site. Results of conjugation assay indicated that armA-positive plasmids in two isolates could self-transfer to Escherichia coli J53 effectively, especially, the p1864-1 plasmid, which could cotransfer hypervirulent and multidrug-resistant phenotypes to other isolates. Moreover, multiple insertion sequences (ISs) and transposons (Tns) were also found surrounding the vital resistant genes, which could even form a large antibiotic resistance island (ARI) and could stimulate mobilization of resistant determinants. Overall, we report the uncommon coexistence of armA plasmid, rmtB-bla_KPC-2 plasmid, and even iuc virulence operon-encoding plasmid in K. pneumoniae isolates, which greatly increased the spread of these high-risk phenotypes and which are of great concern.

IMPORTANCE Carbapenemase-producing Klebsiella pneumoniae have become a great challenge for antimicrobial chemotherapy, while aminoglycosides can lower the mortality rate effectively in combination therapy with them. Unfortunately, we isolated two K. pneumoniae from blood sample of patients that not only exhibited high-level resistance to carbapenems and aminoglycosides but also showed the unusual co-occurrence of the rmtB, armA, and bla_KPC-2 genes. These elements were all located on mobile plasmids and flanked by polymorphic mobile genetic elements (MGEs). What’s worse most, we also identified a conjugative virulent MDR plasmid, coharboring multiple resistant determinants, and iuc operon, which was confirmed could transfer such high-risk phenotype to other isolates. The emergence of such conjugative virulence plasmids may promote the rapid dissemination of virulence-encoding elements among Gram-negative pathogens. This uncommon coexistence of rmtB, armA, bla_KPC-2, and iuc virulence operon-encoding plasmids in K. pneumoniae, presents a huge threat to clinical treatment. Future studies are necessary to evaluate the prevalence of such isolates.

Detection of AmpC and ESBL-producing Enterobacterales isolated from urinary tract infections in Tunisia

Urinary tract infections (UTIs) are the most frequent human infections in community and hospitals. This study aimed to determine the distribution of bacterial uropathogens among urinary tract infections diagnosed within the regional hospital Houcine Bouzaiene (Gafsa, South West Tunisia) during a survey of 54 days from the 8th of November to the 31st of December 2017. Enterobacterales strains were tested for antimicrobial resistance by disk diffusion method and extended-spectrum β-lactamase (ESBL) production was tested by double-disc synergy test. Strains were further subjected to a molecular assessment of ESBL and AmpC β-lactamase production by PCR. Overall, 173 bacterial isolates were studied, out of which 91.3% were Enterobacterales. Escherichia coli was the dominant pathogen, followed by Klebsiella pneumoniae. High to moderate resistance rates were observed, ranging from 66% to 90.7% for penicillins, from 6.7% to 18.6% for cephalosporins and from 16.2% to 25.4% for fluoroquinolones. Enterobacterales with decreased susceptibility to third-generation cephalosporins (3rd GC) carried several resistance genes: blaCTX-M group 1 and group 9, and ACC and FOX AmpC β-lactamase genes. Overall, ESBLs and AmpC β-lactamases were detected in 57% and 14% of the 3rd GC-resistant isolates, respectively. This study proved the high potential of K. pneumaniae species to develop resistance against commonly used antibiotics. Thus, rigorous monitoring of the antibiotic resistance of clinical pathogens have to be implemented in Tunisia. Our results are very relevant to evaluate efficiency of the Tunisian therapeutic strategies against UTIs and adapt them to the emerging problem of antimicrobial resistance.

Antimicrobial resistance in patients with suspected urinary tract infections in primary care in Assam, India

Objectives

We investigated the prevalence and diversity of antimicrobial resistance in bacteria isolated from urine samples of community-onset urinary tract infection (UTI) patients in southern Assam, India.

Methods

Freshly voided midstream urine samples were collected from patients attending primary healthcare centres, with the patients’ epidemiological data also recorded. Species identification was confirmed using a VITEK 2 compact automated system. Phenotypic confirmation of ESBLs was performed using the combined disc diffusion method (CLSI 2017) and carbapenemase production was phenotypically characterized using a modified Hodge test. Common ESBLs and carbapenem-resistance mechanisms were determined in Escherichia coli isolates using PCR assays. Incompatibility typing of the conjugable plasmids was determined by PCR-based replicon typing; the phylotypes and MLSTs were also analysed.

Results

A total of 301 (59.7%) samples showed significant bacteriuria along with symptoms of UTI and among them 103 isolates were identified as E. coli of multiple STs (ST3268, ST3430, ST4671 and others). Among them, 26.2% (27/103) were phenotypically ESBL producers whereas 12.6% (13/103) were carbapenemase producers. This study describes the occurrence of diverse ESBL genes—bla_CTX-M-15, bla_SHV-148, bla_PER-1 and bla_TEM—and two E. coli isolates carrying the bla_NDM-1 carbapenemase gene. ESBL genes were located within transconjugable plasmids of IncP and IncF type whereas bla_NDM-1 was carried in an IncF_repB type plasmid.

Conclusions

This study illustrates the high rate of MDR in E. coli causing UTI in primary care in rural Assam. UTIs caused by ESBL- or MBL-producing bacteria are very difficult to treat and can often lead to treatment failure. Thus, future research should focus on rapid diagnostics to enable targeted treatment options and reduce the treatment failure likely to occur with commonly prescribed antibiotics, which will help to combat antimicrobial resistance and the burden of UTIs.

Phenotypic and Genotypic Characteristics of Uropathogenic Escherichia coli Isolates from Kenya

Introduction: Uropathogenic Escherichia coli (UPECs) are a significant cause of urinary tract infections (UTIs). In Kenya, UTIs are typically treated with β-lactam antibiotics without antibiotic susceptibility testing, which could accelerate antibiotic resistance among UPEC strains.

Aim: This study determined the occurrence of UPEC producing extended-spectrum β-lactamases (ESBLs), the genes conferring resistance to β-lactams, and the phylogenetic groups associated with ESBLs in Kenyan UPECs.

Methodology: Ninety-five UPEC isolates from six Kenyan hospitals were tested for ESBL and plasmid-mediated AmpC β-lactamase (pAmpC) production by combined disk diffusion and disk approximation tests, respectively. Real-time and conventional polymerase chain reactions (PCRs) were used to detect three ESBL and six pAmpC genes, respectively, and phylogenetic groups were assigned by a quadruplex PCR method.

Results: Twenty-four percent UPEC isolates were ESBL producers with bla_CTX-M (95.6%), bla_TEM (95.6%), and bla_SHV (21.7%) genes detected. Sixteen isolates had bla_CTX-M/TEM, whereas five had bla_{TEM/CTX-M/SHV}. A total of 5/23 ESBLs were cefoxitin resistant, but no AmpC genes were detected. The UPECs belonged predominantly to phylogenetic groups B2 (31/95; 32.6%) and D (30/95; 31.6%), while groups B2 and A had the most ESBL producers.

Conclusions: β-Lactam antibiotics have reduced utility for treating UTIs as a quarter of UPECs were ESBL producing. Single or multiple ESBL genes were present in UPECs, belonging primarily to phylogenetic groups B2 and A.

Antimicrobial Resistance Among Uropathogens: Surveillance Report From South India

Background Urinary Tract Infection (UTI) is one of the most common infections encountered in clinical practice. Evidence supports that empirical treatment guidelines based on local bacterial spectrum and antimicrobial resistance (AMR) surveillance provide the best clinical results and also prevent the emergence of resistant strains. Antimicrobial resistance has been increasing at an alarming rate throughout the world. This warrants continuous reporting and surveillance of the emergence of AMR among the uropathogens across regions and nations. Materials and methods A retrospective cross-sectional study using antibiograms of adult patients with culture-proven UTI during January 2011 and January 2017 was done. Comparative analysis was performed between the two study periods for the prevalence, changing trends of antimicrobial resistance, and usage of antimicrobials for testing. Results The commonest organism cultured during each study period was Escherichia coli (56.6% and 51.6%). The most frequently tested antibiotics were ampicillin (97%, 88%), amikacin (85%, 85%), nitrofurantoin (95%, 95%), cephalexin (84%, 93%), and norfloxacin (83%, 83%). There was a significant increase in resistance proportion noted for imipenem (by 29.8%), meropenem (by 18.3%), ertapenem (by 24.9%), ciprofloxacin (by 26.5%), nitrofurantoin (by 11.2%), amikacin (by 8.7%), and cefotaxime (by 7.4%) in 2017 as compared to 2011. A significant increase in susceptibility was seen for tobramycin (by 32.5%), cefepime (by 14.4%), and polymyxin (by 12.6%) in 2017 when compared to 2011. Conclusion Our analysis has shown that there is an alarmingly increasing trend for AMR among uropathogens in this region as compared to developed countries. Data on changing trends of antimicrobial testing and reporting might help in strengthening antimicrobial surveillance.

Detection of various beta-Lactamases in Escherichia coli and Klebsiella sp.: A study from Tertiary Care Centre of North India

Objective

The emergence of carbapenem-resistant Escherichia coli and Klebsiella species is a global threat. We aimed to compare two phenotypic methods and evaluate the genotypic method for the detection of beta-lactamases produced by E. coli and Klebsiella spp.

Materials and Methods

One hundred and twenty-six E. coli and Klebsiella isolates were examined for phenotypic production of beta-lactamases by using disc diffusion, combined disc test (CDT) and modified carbapenem inactivation method (mCIM). All strains were also studied for the presence of various genes by polymerase chain reaction.

Results

Out of 126 isolates, 96% of the isolates were extended-spectrum β-lactamase (ESBL) producers based on the presence of various ESBL genes. CDT method showed higher number of total (89%) carbapenemases in comparison to mCIM (81%). Among carbapenemases none of the isolates were Klebsiella pneumoniae carbapenemase producer by CDT, while 69% isolates were metallo-beta-lactamase (MBL) producers. Another method, mCIM/ethylene diamine tetraacetic acid mCIM showed 100% agreement for MBL detection. As regards, AmpC and class D carbapenemases; 0.04% and 16% positivity was detected, respectively, based on CDT method. Molecular analysis revealed 91% of the isolates harbouring carbapenemase genes. blaNDMwas the most common gene detected followed byblaOXA-48. Nine of the blaNDM-positive isolates also possessed blaOXA-48gene.

Conclusion

Our finding shows high percentages of ESBL and carbapenemases in E. coli and Klebsiella spp. Among phenotypic methods, CDT seems to be a better choice as prevalence of carbapenemases shows lots of variation in our country. For Class B enzymes, both CDT and mCIM/eCIM can be used in the routine laboratories.