ESBL-producing Uropathogens Research Articles

Impact of Antibiotic Prescribing Patterns on Susceptibilities of Uropathogens in Children below 24 Months Old.

Monitoring regional antibiotic resistance patterns of uropathogens are important for deciding suitable empirical antibiotics for urinary tract infections (UTIs) in children. This study aimed to investigate regional differences in antimicrobial susceptibility patterns of E. coli and Klebsiella spp. in children below 24 months old, diagnosed with their first episode of UTI, and to find factors associated with an increased risk for UTI caused by extended-spectrum β-lactamase (ESBL)-producing uropathogens. This was a retrospective cohort study of children diagnosed between 2011 and 2017 in four different hospitals located in four different regions of South Korea; regions A, B, C, and D. The government’s big data repository was used to acquire data on regional antibiotic prescriptions. The pooled antimicrobial susceptibilities of E. coli and Klebsiella spp. (n = 2044) were as follows: ampicillin–sulbactam (61.0%), 3rd generation cephalosporin (3C) (82.8%), and trimethoprim–sulfamethoxazole (72.0%). Multivariate analysis showed that children diagnosed at hospital A (OR, 1.8; 95% confidence interval [CI], 1.2–2.6; P = 0.002) and every year that increased in the study period (OR, 1.1; 95% CI, 1.1–1.2; P < 0.001) were factors associated with an increased risk for UTIs with ESBL-producers. Regions A and B had significantly higher amounts of oral 3Cs prescribed compared to regions C and D (P = 0.009), which correlate with hospitals in the regions that had higher proportions of UTIs with ESBL-producing uropathogens (A and B vs. C and D, P < 0.001). Therefore, children in certain regions are at a higher risk for UTIs caused by ESBL-producers compared to other regions, which correlate with regions that had higher amounts of oral 3Cs prescribed.

English

This present study was designed to determine the occurrence frequency of blaCTX-M and blaTEM genes in extended-spectrum beta-lactamase (ESBL)-producing uropathogenic Escherichia coli, and their antibiotic resistance patterns among hospital attendees in Abakaliki, Nigeria. Out of the 73 uropathogenic E.coli isolates analyzed, 52 were identified to be ESBL producers using double disk synergy technique. The frequency of beta-lactamse (bla) genes (CTX-M and TEM) among E. coli was molecularly determined by polymerase chain reaction (PCR). Out of 52 (71.2%) ESBL-producing uropathogenic E. coli, 17 (32.7%) were positive for blaTEM, 35 (67.3%) were positive for blaCTX-M while 8 (15.3%) harboured both blaTEM and blaCTX-M genes. CTX-M gene was the most prevalent gene. Isolates evaluated in our study were resistant to cefotaxime (83.6%), ceftazidime (79.5%), amoxycillin (72.6%), cefpodoxime (68.5%), aztreonam (61.6%), ceftriaxone (57.5%), and cefepime (37%). This study demonstrated the occurrence frequency of CTX-M and TEM genes in uropathogenic E. coli strains in Abakaliki. Even though molecular techniques are more reliable in the detection of ESBL production, routine clinical screening for ESBL-producing uropathogens using phenotypic method should be introduced and encouraged in clinical settings as they are less expensive. This will go a long way in checkmating drug resistance. &nbsp; Key words: Escherichia coli, uropathogens, extended-spectrum beta-lactamase (ESBL), resistance genes, antibiotics.

Multidrug-resistant and extended-spectrum beta-lactamase-producing uropathogens in children in Bhaktapur, Nepal

BackgroundThe emergence of multidrug-resistant (MDR) and extended-spectrum beta-lactamase (ESBL)-producing uropathogens has complicated the treatment of urinary tract infections (UTI). Paediatric UTI is a common illness, which if not treated properly, may lead to acute and long-term complications, such as renal abscess, septicaemia, and renal scarring. This study aimed to determine the prevalence of MDR and ESBL-producing uropathogens among children.MethodsDuring the study period (April 2017–April 2018), midstream urine samples were collected following aseptic procedures from children < 16 years in Siddhi Memorial Hospital. Standard culture and biochemical tests were performed to identify uropathogens and antimicrobial susceptibility test was done by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines. ESBL-producing uropathogens were screened by ceftazidime (30 μg) and cefotaxime (30 μg) discs, and confirmed by the combination disc tests: ceftazidime + clavulanic acid (30/10 μg) or cefotaxime + clavulanic acid (30/10 μg) as recommended by CLSI.ResultsWe processed 5545 non-repeated urine samples from the children with symptoms of UTI. A significant growth of uropathogens was observed in 203 samples (3.7%). The median age of the children was 24 months (interquartile range (IQR), 12–53 months). Escherichia coli (n = 158, 77.8%) and Klebsiella pneumoniae (n = 30, 14.8%) were common among the uropathogens. Among them, 80.3% were resistant to amoxycillin and 51.2% were resistant to cotrimoxazole. Most of them were susceptible to amikacin, nitrofurantoin, and ofloxacin. MDR was detected in 34.5% (n = 70/203) and ESBL producers in 24.6% (n = 50/203) of them. The proportion of MDR isolates was higher in children < 5 years (n = 59/153, 38.6%) than children ≥ 5 years (n = 11/50, 22%) (P = 0.03).ConclusionsNitrofurantoin, ofloxacin, and amikacin can be used for the empirical treatment for UTI in children in Bhaktapur, Nepal. MDR and ESBL-producing uropathogens are prevalent; this warrants a continuous surveillance of antimicrobial resistance.

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

This study investigated the occurrence of extended-spectrum β-lactamase (ESBL) genes coexisting with carbapenemase, AmpC and aminoglycoside resistance gene in uropathogens in India. Antimicrobial susceptibility testing was performed by disk diffusion. Antimicrobial resistance genes were detected by multiplex PCR. Of 1516 consecutive urine samples, 454 (29.9%) showed significant bacteriuria with a single micro-organism, predominantly Escherichia coli (n=343), followed by Klebsiella pneumoniae (n=92), Pseudomonas aeruginosa (n=10) and Proteus mirabilis (n=9). Among the uropathogens, 61 ESBL-producers were identified containing blaCTX-M-15 (n=32), blaCTX-M-15+blaOXA-2 (n=15), blaCTX-M-15+blaOXA-2+blaTEM-1 (n=6), blaOXA-2 (n=5), blaOXA-2+blaSHV-76 (n=1), blaTEM-1+blaSHV-76 (n=1) and blaTEM-1 (n=1). All ESBL genes were located on horizontally transferable plasmids of incompatibility types HI1, I1, FIA+FIB, FIA and Y. Among the 61 ESBL-producers, 59 harboured carbapenemase genes, including blaNDM-5 (n=48), blaNDM-5+blaOXA-48 (n=5), blaNDM-5+blaIMP (n=5) and blaNDM-5+blaIMP+blaVIM (n=1). ESBL-producing uropathogens also harboured 16S rRNA methylase genes, including rmtB (n=9), rmtA (n=4), rmtC (n=1) and armA (n=1). ESBL-positive isolates also contained AmpC genes, including blaCIT (n=8) and blaDHA-1 (n=1). Imipenem and gentamicin had the lowest resistance rates against the uropathogens. This is the first report showing the high prevalence of carbapenemases in ESBL-positive isolates in this area. Regular surveillance for such resistance mechanisms will be useful for health personnel to treat infections by these multidrug-resistant pathogens.

Prevalence and antibiotic resistance pattern of extended spectrum beta lactamase producing Escherichia coli isolated from urinary tract infection

Introduction: Urinary tract infection (UTI) due to extended spectrum beta-lactamase (ESBL)-producing bacteria including Escherichia coli has become widespread. Studies have shown a trend toward higher mortality, longer hospitalization, greater hospital expenses and reduced rates of clinical and microbiologic response in ESBL UTI. Objectives: The aim of this study is to determinate the prevalence and antibiotic resistance pattern of ESBL producing E. coli isolated from UTI. Patients and Methods: This cross-sectional study was conducted on 3126 samples. Urine specimens were cultured on Eosin Methylene Blue (EBM) and blood agar. The disk diffusion standard method (Kirby Bauer) was used to test the susceptibility of the drug on MullerHinton agar plates and results were reviewed based on Clinical and Laboratory Standards Institute (CLSI) criteria. The reviewing of ESBL-producing uropathogens was carried out using Combined Disk Test (CDT) by using cefotaxime (CTX; 30 µg) and cefotaximeclavulanic acid (CTX; 30 µg /CA:10 µg) disks and CLSI protocol. Results: Out of 291 E. coli isolates, 108 (37.11%) are ESBL-producer and 183 (62.89%) are non–ESBL-producer. Among ESBL-producing E. coli, the highest antibiotic resistance was observed with cefotaxime (100%), amoxicillin (97.22%) and piperacillin (96.3%) and the highest antibiotic sensitivity was observed with meropenem (93.5%), nitrofurantoin (81.48%) and gentamicin (55.56%). Conclusion: We recommended that cephalosporins, penicillins and cotrimoxazole are not suggested in the treatment of ESBL-producing E. coli. On the other hand, carbapenems as a first line and aminoglycosides as the next step in the treatment of ESBL-producing E. coli are recommended.

The First Report of Phenotypic and Molecular Characterization of Extended-Spectrum Beta-Lactamase-Producing Uropathogens in Sikkim and Darjeeling Hills of India.

Extended-spectrum β-lactamase (ESBL)-producing bacteria are a global health threat both in hospital and in community settings. The emergence of these organisms poses major difficulty in treating infections. This study was carried out to assess major ESBL-producing uropathogens in female patients of Sikkim and Darjeeling by phenotypic and genotypic methods. Out of 1,516 urine samples, 454 uropathogens were isolated with a prevalence rate of 29.94%. Among them, Escherichia coli (74.3%) was the predominant type followed by Klebsiella pneumoniae (20.1%), Pseudomonas aeruginosa (2.4%), and Proteus mirabilis (1.98%). Four different ESBL genes were detected in 63 isolates, which included CTX-M (n = 32), CTX-M+OXA-2 (n = 15), CTX-M-15+OXA-2+TEM (n = 6), OXA-2 (n = 5), TEM+CTX-M-15 (n = 2), TEM+OXA-2+SHV-76 (n = 2), and TEM (n = 1). All ESBL genes (bla genes) were found on a plasmid, which was mostly of HI1, I1, FIA+FIB, FIA, and Y types and was horizontally transferable. Among all ESBL genes, blaCTX-M-I5 group was the most prevalent. The study of urinary tract infection (UTI) caused by ESBL-producing bacteria needs to be studied in other high-altitude parts of India to understand the actual burden of UTI in the female.

Prevalence and Risk Factors of Extended Spectrum Beta-Lactamase-Producing Uropathogens among UTI Patients in the Governmental Hospitals of North West Bank: A Cross-Sectional Study

Background: Urinary tract infections caused by Extended Spectrum Beta-Lactamase producing organisms (UTI-ESBL) are increasing in incidence and pose a great threat to modern medicine. The objective of this study was to assess the prevalence and risk factors of Extended Spectrum Beta-Lactamase (ESBL)-producing uropathogens among patients with urinary tract infections in the north of West Bank and to determine the antimicrobial susceptibility profile of the isolated bacteria. Methods: A total of 427 patients who were attending the governmental hospitals in the northern cities of the West Bank were included in the study. They were older than 12 years and diagnosed with UTI in the period from June 2017 to September 2017. Isolated bacteria was collected from the microbiology labs of the respective hospitals and tested for the ESBL production and their antibiotic susceptibilities were determined. Information regarding the risk factors was collected from the patient's medical records. Univariate analyses were performed for potential risk factors for the development of UTI-ESBL, and then multivariate analyses were performed for all significant variables. Results: Out of the 427 urine cultures screened for ESBL, 163 (38.4%) were confirmed to be ESBL producers. E. coli was the most frequent uropathogen. K. pneumoniae produced the highest rate of ESBL (54.9%), followed by E. coli (42.5%), and Proteus mirabilis (7.14%). Patients with recurrent UTI had 5 times relative risk of having ESBL producing uropathogens (odd ratio (OR), 4.7) followed by previous antibiotic use (OR, 3.07), hemodialysis (OR, 2.92), chronic kidney disease (OR, 2.69) and finally diabetes mellitus (OR, 1.87). ESBL isolates were susceptible to fosfomycin (100%), nitrofurantoin (93.9%), pipracillin/tazobactam (94.5%), ertapenem (98.2%), meropenem (98.8%), and amikacin (93.9%). Conclusion: The prevalence of ESBL-producing uropathogens was 38.4%. Recurrent UTI appeared to be the strongest risk factor for ESBL-UTI. ESBL–producing uropathogens were highly susceptible to amikacin, nitrofurantoin, and much more to fosfomycin and piperacillin/tazobactam in addition to carbapenems.

Incidence of multidrug resistance and extended-spectrum beta-lactamase expression in community-acquired urinary tract infection among different age groups of patients.

OBJECTIVES:Urinary tract infection (UTI) is a frequent disorder and depends on age and gender. Ineffective empiric treatment of UTI is common when associated with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae. The aim of the study was to investigate the prevalence of Gram-negative uropathogens of E. coli and K. pneumoniae in different age groups along with the identification of ESBL-producing uropathogens and antimicrobial susceptibility profiles.MATERIALS AND METHODS:A total of 247 uropathogens of E. coli and K. pneumoniae were collected over a period of 1 year (January–December 2015) from various diagnostic centers of Karachi city (Pakistan). Antimicrobial susceptibility analysis was performed by disc diffusion method, and identification of ESBL was performed by double disc synergy test. Categorical data of ESBL and non-ESBL uropathogens were analyzed by Pearson's Chi-square test.RESULTS:The study of 247 patients with community-acquired UTI comprised 72% females and 28% males, illustrating an increased prevalence of UTIs among females. It was also revealed that 90% belonged to the age group of 16–30 years whereas 78% related to the age group of 46–60 years. ESBL was found positive in 33.5% (63/188) of E. coli and 15.25% (9/59) in K. pneumonia, with a significant association i.e., (p =0.007). Amikacin, fosfomycin, imipenem, and tazobactam/piperacillin were found to be the effective treatment options. A significant association was found between ESBL-producing uropathogens against ciprofloxacin, enoxacin, and amoxicillin/clavulanic acid resistance (P < 0.05).CONCLUSIONS:It was concluded that for effective treatment of UTIs, appropriate screening of ESBL and culture sensitivity must be employed instead of empiric treatment.

Changing prevalence and antibiotic drug resistance pattern of pathogens seen in community-acquired pediatric urinary tract infections at a tertiary care hospital of North India.

AIMS AND OBJECTIVES:The aim and objective of this study was to assess the temporal changes in the microbiological profiles and antimicrobial resistance patterns of uropathogens in pediatric community-acquired UTI.MATERIALS AND METHODS:This is a retrospective analysis of data collected over a Scattered period of 5 years. The baseline data collected were from January to December 2009, and the second period considered for comparison was from January to December 2014. Urine specimens from children (<17 years) suspected of UTI were cultured by a semi-quantitative method on cysteine lactose electrolyte-deficient medium. Antibiotic sensitivity was put up by Kirby–Bauer disc diffusion method as per the Clinical and Laboratory Standard Institute guidelines.RESULTS:In the year 2009, 340 of 2104 (16.15%) urine specimens yielded significant colony count, whereas in 2014, it was 407 of 2212 (18.39%) (P = 0.051). Escherichia coli was the predominant pathogen and was significantly more prevalent in girls than in boys (P < 0.0001) during both periods. There was a significant overall increase in resistance to ampicillin (from 40.29% to 58.72%), amoxyclav (from 26.17% to 40.54%), nitrofurantoin (from 28.82% to 39.06%), and norfloxacin (from 30% to 41.42%). However, the maximum increase in the resistance was noted for co-trimoxazole from 35.58% in 2009 to 63.39% in 2014 (P = 0.0000058). The prevalence of extended-spectrum beta-lactamases (ESBLs) has also significantly increased from 21.7% to 33.16% (P = 0.0045).CONCLUSION:Although E. coli remains the prime pathogen in pediatric UTI, the prevalence of resistance has dramatically increased over the 5-year study period. Our study highlights the emergence of community-acquired ESBL-producing uropathogens in children proclaiming treatment challenges.

Detection of CTX-M-15 Among Uropathogenic Escherichia coli Isolated from Five Major Hospitals in Tripoli, Libya.

Multidrug resistance (MDR) and emergence of extended-spectrum β-lactamases (ESBLs) among uropathogenic Escherichia coli have been reported worldwide, but there was no information on the detection of blaCTX-M-15 in major teaching hospitals in Libya. The aim of the study was to investigate the occurrence of CTX-M-15 β-lactamases producers isolated from five teaching hospitals in Tripoli, Libya. A total of 346 urine samples were collected from hospitalized patients in five teaching hospitals with a diagnosis of urinary tract infection (UTI). Phenotypic confirmation of ESBLs was confirmed by E-test strip; all ESBL-producing E. coli isolates were screened for the blaCTX-M-15 gene. The distribution of ESBL-producing E. coli varied among the five hospitals. The highest proportion was identified in Tripoli Medical Centre (67.6%). There were extremely high proportions of isolates resistant to ceftriaxone, cefepime, and ceftazidime (93.0-100.0%) among ESBL producers compared to non-ESBL producers (2.2-4.7%). MDR was detected in 22.2% of isolates. The majority of isolates (85.9%) in which blaCTX-M-15 was identified were ESBL producers. There was a correlation (p < 0.001) between expression of CTX-M-15 and resistance to ceftazidime. The isolation of MDR ESBL-producing uropathogens expressing the CTX-M-15 gene will limit the choices clinicians have to treat their patients with UTIs. Continued surveillance and implementation of efficient infection control measures are required.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

Use of cefuroxime for women with community-onset acute pyelonephritis caused by cefuroxime-susceptible or -resistant Escherichia coli.

Background/Aims:Efforts to decrease the use of extended-spectrum cephalosporins are required to prevent the selection and transmission of multi-drug resistant pathogens, such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. The objectives of this study were to assess the clinical efficacy of intravenous cefuroxime as an empirical antibiotic for the treatment of hospitalized women with acute pyelonephritis (APN) caused by Escherichia coli.Methods:We analyzed the clinical and microbiologic database of 328 hospitalized women with community-onset APN.Results:Of 328 women with APN, 22 patients had cefuroxime-resistant E. coli APN, and 306 patients had cefuroxime-susceptible E. coli APN. The early clinical success rates were significantly higher (p = 0.001) in the cefuroxime-susceptible group (90.8%, 278/306) than in the cefuroxime-resistant group (68.2%, 15/22) at 72 hours. The clinical cure rates at 4 to 14 days after completing antimicrobial therapy were not significantly different in the cefuroxime-resistant or -susceptible groups, with 88.2% (15/17) and 97.8% (223/228; p = 0.078), respectively. The microbiological cure rates were not significantly different and were 90.9% (10/11) and 93.4% (128/137), respectively (p =0.550). The median duration of hospitalization in the cefuroxime-resistant and -susceptible groups was 10 days (interquartile range [IQR], 8 to 13) and 10 days (IQR, 8 to 14), respectively (p =0.319).Conclusions:Cefuroxime, a second-generation cephalosporin, can be used for the initial empirical therapy of community-onset APN if tailored according to uropathogen identification and susceptibility results, especially in areas where the prevalence rate of ESBL-producing uropathogens is low.

Activity of Fosfomycin against Extended-Spectrum-β-Lactamase-Producing Uropathogens in Patients in the Community and Hospitalized Patients.

Few oral antibiotics exist for the empirical treatment of extended-spectrum β-lactamase (ESBL) urinary tract infections (UTI). In this study, we sought to determine the activity of fosfomycin against ESBL-producing uropathogens from patients at 3 Veterans Affairs (VA) facilities between 2010 and 2013. Among the ESBL uropathogens, 19.9% were fosfomycin resistant. Klebsiella species were more likely than Escherichia coli to be resistant (46% versus 4%; P < 0.001). Fosfomycin remains active against a majority of the ESBL uropathogens, although resistance among Klebsiella spp. was higher than that in previous reports.

Extended Spectrum Beta-Lactamase Production in Uropathogens Isolated from Hospitalized Patients with Chronic Pyelonephritis

Background :Increased multidrug resistance of extended-spectrum beta-lactamases (ESBLs) compromises the efficacy of treatment of urinary tract infections.Objective :The objective of this study is to determine the prevalence of ESBL-producing uropathogens from hospitalized patients with chronic pyelonephritis and to identify the presence of genes involved in the resistance.Methods :A cross-sectional study of 105 patients with chronic pyelonephritis, treated in Kharkiv City Clinical Emergency Hospital, Ukraine was carried. Bacterial isolates were collected, antimicrobial susceptibility of isolates was determined by the Kirby Bauer disk diffusion method and screening for the presence of blaSHV, blaTEM, blaCTX-M ESBL genes was performed by polymerase chain reaction.Results :84 (80%) patients had positive urine cultures.Eschеrichia coliwаs the most common microorganism isolated. Among them, 29 (25.2%) were found to be ESBL producers. Out of 53E. coliisolates, 10 (18.9%), 4 (7.5%) and 6 (11.3%) were identified to carry bla(TEM), bla(SHV) and bla(CTX-M) beta-lactamase genes, respectively. The highest resistance was observed against ampicillin (75.9%), ciprofloxacin (48.3%), levofloxacin (41.4%) and gentamicin (41.4%). Beside this, only meropenem (96.6% susceptibility), nitroxolinum (86.2%) and fosfomycin (72.4%) exhibited a good enough activity against ESBLs-producing urinary strains.Conclusion :Isоlation and detеction of ESBL-prоducing strаins are еssential fоr the sеlection оf the mоst effеctive antibiоtic for the empiric trеatment.

Multidrug resistance and extended-spectrum β-lactamases genes among Escherichia coli from patients with urinary tract infections in Northwestern Libya

IntroductionMultidrug resistance (MDR) and emergence of extended-spectrum β-lactamases (ESBLs) that mediate resistance to β-lactam drugs among Escherichia coli and other uropathogens have been reported worldwide. However, there is little information on the detection of ESBLs genes in E. coli from patients with urinary tract infections (UTIs) in the Arab countries using polymerase chain reaction (PCR), and in Libya such information is lacking.MethodsAll patients attending Zawiya Teaching Hospital in Zawiya city between November 2012 and June 2013 suspected of having UTIs and from whom midstream urine samples were taken as part of the clinical workup were included in this prospective study. Samples were examined for uropathogens by standard bacteriological procedures. VITEK-2 automated microbiology system was used to identify the isolated uropathogens and determine the susceptibility of E. coli and Klebsiella spp. isolates to antimicrobials. In addition, phenotypically ESBLs-positive E. coli isolates were tested for ESBLs genes by PCR.ResultsThe present study enrolled 1,790 patients with UTIs. Uropathogens were found in 371 (20.7%) urine specimens examined. Mixed pathogens were detected in two specimens with 373 total pathogens isolated. E. coli and Klebsiella spp. were the predominant uropathogens at 55.8% (208/373) and 18.5% (69/373), respectively. Other pathogens were detected in 25.7% (96/373) of urine samples. Of the E. coli and Klebsiella spp. tested, 69.2 and 100% were resistant to ampicillin, 6.7 and 33.3% to ceftriaxone, and 23.1 and 17.4% to ciprofloxacin, respectively. MDR (resistance to ≥3 antimicrobial groups) was found in 69 (33.2%) of E. coli and in 29 (42%) of Klebsiella spp. isolates. ESBLs were detected phenotypically in 14 (6.7%) of E. coli and in 15 (21.7%) of Klebsiella spp. isolates. Thirteen out of the 14 phenotypically ESBL-positive E. coli were positive for ESBL genes by PCR. blaTEM gene was detected in seven isolates, blaOXA gene in 10 isolates and blaCTX-M gene in six isolates. blaSHV gene was not detected in the present study.ConclusionThe isolation of MDR ESBL-producing uropathogens undoubtedly will limit the choices clinicians have to treat their patients with UTIs. Therefore, there is an urgent need for surveillance studies on antimicrobial resistance and prevalence of ESBLs among uropathogens to guide the clinical treatment of UTIs in Libya in the future.

Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae: In vitro Susceptibility to Fosfomycin, Nitrofurantoin and Tigecycline

Objective: To assess the susceptibility trends of community-acquired extended-spectrum β-Iactamase (ESBL)-producing urinary isolates with particular reference to fosfomycin, nitrofurantoin and tigecycline. Materials and Methods: Seven hospitals across the United Arab Emirates participated in this study from June 2008 to March 2010. The antibiotic sensitivity of ESBL-producing uropathogens to a panel of antibiotics including tigecycline, fosfomycin and nitrofurantoin was assessed. The Hyplex ESBL identification system (h-ES-ID) was used for genotypic identification. Results: Two hundred and ninety-two ESBL-producing Enterobacteriaceae isolates were identified during the study period. Of these, 182 (62%) were urinary isolates and comprised of Escherichia coli: 149 (81.9%), Klebsiella pneumoniae: 30 (16.5%) and Proteus mirabilis: 3 (1.6%). Of the 182 urinary isolates, 179 (98.3%) were from patients with community onset urinary tract infections. The h-ES-ID system identified 172 (94.5%) of the urinary isolates as CTX-M positive. All isolates were susceptible to imipenem and meropenem. Over half of the isolates showed resistance to gentamicin (98; 53.8%), trimethoprim-sulfamethoxazole (139; 76.4%) and ciprofloxacin (143; 78.6%). Sensitivity to nitrofurantoin and fosfomycin was 90 and 100%, respectively. Two CTX-M-positive K. pneumoniae isolates with tigecycline resistance (MIC >4 µg/ml) were identified. Conclusion: There is dissemination of CTX-M ESBL-producing urinary pathogens into the community. Fosfomycin and nitrofurantoin were active against ESBL-positive uropathogens, and emergence of tigecycline resistance needs close monitoring.