Identification of metallo-β-lactamases and AmpC production among Escherichia coli strains isolated from hemodialysis patients with urinary tract infection

Background

This study aimed to identify metallo-β-lactamases (MBLs) and AmpC β-lactamases-producing Escherichia coli isolates obtained from hemodialysis (HD) patients with urinary tract infections (UTI).

Methods and results

A total of 257 HD patients with UTI were included in this study, from which 47 E. coli isolates were collected. Antibiotic susceptibility was tested by disc diffusion method. MBLs and AmpC production were phenotypically detected by imipenem-ethylenediaminetetracetate and cefoxitin/boronic acid assays, respectively. The presence of MBLs and AmpC genes was examined by polymerase chain reaction (PCR). Fosfomycin and ampicillin were the most and the least effective antibiotics against E. coli isolates, respectively. Moreover, 61.7% (29/47) of E. coli isolates were multidrug-resistant with seven different antibiotypes. Antibiotype V (AMP–CIP–IMP–MEM–CPD–CRO–CTX–GEN–LEV–SXT–TOB) was the most prevalent profile. Besides, 24 (51.1%) isolates were simultaneously resistant to imipenem and meropenem. Phenotypic assay showed MBL production in 16 (66.7%) of the 24 carbapenem-resistant E. coli isolates. The distribution of MBL genes in carbapenem-resistant E. coli was as follows: bla_IMP 18 (72%), bla_VIM 7 (28%), and bla_NDM 1 (4%). AmpC was detected in 61.7% (29/47) of the isolates using the phenotypic method. The presence of AmpC genes was confirmed by PCR in only 26 of 29 (86.7%) AmpC producers. The frequencies of bla_DHA-1, bla_ACC, and bla_CMY-2 were 6 (20.7%), 11 (37.9%), and 21 (72.4%), respectively.

Conclusions

The emergence of MBL and AmpC coproducing E. coli isolates calls for an urgent surveillance program for timely diagnosis and screening of these genes in our healthcare systems.

Bacterial Profile, Antibiotic Susceptibility Pattern and Associated Factors Among Patients Attending Adult OPD at Hawassa University Comprehensive Specialized Hospital, Hawassa, Ethiopia

Background

Urinary tract infection (UTI) is a common health problem occurring when infectious agents colonize, invade, and propagate the urinary tract including the urethra, bladder, renal pelvis, or renal parenchyma. The study aimed to determine the prevalence of symptomatic UTI, drug resistance pattern, and its associated factors among patients attending adult outpatient department (OPD) at Hawassa University Comprehensive Specialized Hospital (HUCSH).

Methods

A cross-sectional study was conducted from October 2018 to February 2019 among adults ≥18 years old with symptoms of UTI. Processing of specimens for culture and identification was done. Antimicrobial susceptibility was done for positive urine cultures. Data entry and analysis were performed using SPSS version 23.0 software. Bivariate and multivariate logistic regression analysis test results were used.

Results

The overall prevalence of symptomatic urinary tract infection was 32.8% (95% CI: 28.3–37.6). The predominant isolated bacteria was E. coli 46 (36.2%) followed by S. aureus 21 (16.5%). Gram-negative bacteria were a high level of resistance to ampicillin (71.4%), and tetracycline (68.2%). Gram-positive bacteria were highly resistant to norfloxacin (77.7%). The overall prevalence of multi-drug resistant isolates was 102 (80.3%). Being female, no formal education, and self-medication history had more likely cause UTI.

Conclusion

Urinary tract infection (UTI) among adults was prevalent in the study area. Being female, educational status and self-medication history had a significant association with UTI. Resistance to ampicillin, tetracycline, and norfloxacin was high. Therefore, culture and antibiotic susceptibility testing should be routinely used for the proper management of patients with UTI.

Urinary pathogenic bacterial profile, antibiogram of isolates and associated risk factors among pregnant women in Ambo town, Central Ethiopia: a cross-sectional study

Background

Urinary tract infection (UTI) is a well-known bacterial infection posing serious health problem in pregnant women. A study was conducted in pregnant women with the objectives of estimating prevalence of UTI, determining antibiogram of the bacterial isolates and assessment of the potential risk factors associated with UTI.

Methods

A cross-sectional study design was used to collect 300 mid-stream urine samples from pregnant women from March 2016 to December, 2016. Samples were inoculated into Cysteine Lactose Electrolyte Deficient medium (CLED). Colonies from CLED were subcultured onto MacConkey and Blood agar plates. A standard agar disc diffusion method was used to determine antimicrobial susceptibility. Chi-square (X2) test & logistic regression were used to show associations between UTI and explanatory variables & identify the predictors of UTI, respectively.

Results

The age of pregnant women enrolled in this study ranges from 16 to 46 years (mean ± standard deviation = 25 ± 4.7 years).The overall prevalence of UTI in pregnant women was 18.7% (95% confidence interval [CI]: 14.4-23.54%).The prevalence of symptomatic and asymptomatic UTI was 20.4% (95% CI: 13.09-29.46%) and 17.8% (95% CI: 12.70-23.83%) respectively. The predominant bacteria identified were E. coli (46.4%), S. aureus (14.3%), coagulase negative Staphylococci [CoNS] (14.3%) and Proteus species (10.6%). Majority of Gram-negative bacteria isolates were resistant to ampicillin (70%), ceftriaxon (66%), gentamicin (68%) and nitrofurantoin (64%) while 75-100% of the Gram positive isolates were resistance to ampicillin. Multiple drug resistance was observed in all of the isolates. Multivariable logistic regression revealed that the odds of acquiring UTI was 4.78 times higher in pregnant women earning monthly income of ≤500 Ethiopian Birr (21.18 USD) as compared to those earning monthly income >2001 Ethiopian Birr [84.79 USD] (P = 0.046). Similarly, the risk of UTI was higher in those who eat raw meat (OR = 2.04, 95% CI: 1.09, 3.83, P = 0.026) and had previous UTI history (OR = 2.29, 95% CI = 1.15-4.56, P = 0.019) as compared to those who eat cooked meat and had no previous history of UTI.

Conclusions

The prevalence & antimicrobial resistance of uropathogens was high. Health education, continuous surveillance of UTI and their antimicrobial resistance pattern are essential to reduce the consequence of symptomatic and asymptomatic bacteriuria and multi-drug resistant bacteria in pregnant women.

New Delhi metallo-β-lactamase and extended spectrum β-lactamases co-producing isolates are high in community-acquired urinary infections in Assam as detected by a novel multiplex polymerase chain reaction assay

BACKGROUND

The ability of microorganisms to evade antibiotic pressure is challenging in healthcare as patients have little or no drug treatment options. Detection of the prevalence of antibacterial resistance pattern helps towards improved antibiotic policy and empirical treatment.

OBJECTIVES

We carried out antibiogram profiling and documented the prevalence and co-prevalence of New Delhi metallo-β-lactamase (NDM) and extended spectrum β-lactamases (ESBL) encoding genes in urinary Escherichia coli and Klebsiella pneumonia isolates.

MATERIALS AND METHODS

Antibiotic susceptibilities were tested for 241 isolates of E. coli and K. pneumoniae from urine samples collected from out- and hospitalised patients. Polymerase chain reaction (PCR) was carried out on isolates tested positive for phenotypic production of metallo-β-lactamase and ESBL. A multiplex PCR assay was designed to detect the genes.

RESULTS

Multiplex PCR assay designed had a limit of detection of 10 3 CFU/mL in vitro. NDM detected was significantly higher among K. pneumoniae compared to E. coli (69.2% vs. 18.2%; P = 0.001). Of 17, 14 NDM positive isolates also harboured ESBL genes. The co-production of CTX-M + TEM + NDM (3/9; 33.3% and 5/8; 62.5%) was most common in K. pneumoniae and E. coli, respectively while CTX-M + TEM + SHV + NDM was found in one isolate. Of the 156 phenotypically ESBL producing isolates, CTX-M, TEM and SHV was detected by PCR in 85, 53 and 24 isolates, respectively.

CONCLUSION

NDM and ESBL co-producing isolates were both community (64.7%) and hospital (35.29%) acquired among E. coli. Antibiotic resistance can be effectively evaluated by a cost and time effective molecular method, such as the multiplex PCR used in this study, which complement culture and sensitivity tests.

Profile of Virulence Factors in the Multi-Drug Resistant Pseudomonas aeruginosa Strains of Human Urinary Tract Infections (UTI)

Background:

Putative virulence factors are responsible for the pathogenicity of UTIs caused by Pseudomonas aeruginosa (P. aeruginosa). Resistance of P. aeruginosa to commonly used antibiotics is caused by the extreme overprescription of those antibiotics.

Objectives:

The goal of the present study was to investigate the prevalence of virulence factors and the antibiotic resistance patterns of P. aeruginosa isolates in UTI cases in Iran.

Patients and Methods:

Two hundred and fifty urine samples were collected from patients who suffered from UTIs. Samples were cultured immediately, and those that were P. aeruginosa-positive were analyzed for the presence of virulence genes using polymerase chain reaction (PCR) testing. Antimicrobial susceptibility testing (AST) was performed using the disk diffusion method.

Results:

Of the 250 urine samples analyzed, 8 samples (3.2%) were positive for P. aeruginosa. The prevalence of P. aeruginosa in male and female patients was 2.7% and 3.5%, respectively, (P = 0.035). In patients less than 10 years old, it was 4.2%, and in patients more than 55 years old, it was 4.2%. These were the most commonly infected groups. The highest levels of resistance were seen against ampicillin (87.5%), norfloxacin (62.5%), gentamycin (62.5%), amikacin (62.5%), and aztreonam (62.5%), while the lowest were seen for meropenem (0%), imipenem (12.5%), and polymyxin B (12.5%). LasB (87.5%), pclH (75%), pilB (75%), and exoS (75%) were the most commonly detected virulence factors in the P. aeruginosa isolates.

Conclusions:

It is logical to first prescribe meropenem, imipenem, and polymyxin B in cases of UTIs caused by P. aeruginosa. Medical practitioners should be aware of the presence of levels of antibiotic resistance in hospitalized UTI patients in Iran.