Increasing ciprofloxacin resistance among prevalent urinary tract bacterial isolates in Bangladesh

Retrospective analysis of the global antibiotic residues that exceed the predicted no effect concentration for antimicrobial resistance in various environmental matrices

BACKGROUND

Antimicrobial resistance (AMR) is a growing public health concern. Recent research has suggested that interactions between pathogens and antibiotic residues in various environmental matrices promote the development and spread of AMR in the environment. The levels of antibiotic residues in the aquatic environment have been analysed globally. Recently, Predicted No Effect Environmental Concentration (PNEC) values for many antibiotics have been suggested, based on their estimated minimal selective concentrations for selected bacterial species. The PNEC values can serve as a guide on the maximum levels of antibiotic residues in an environmental matrix, below which resistance is unlikely to develop.

AIM

We aimed to determine which of the antibiotics, considered as "priority antibiotics" by the World Health Organisation (WHO), most frequently exceeded their PNEC values in the global aquatic environment.

METHODS

We obtained data from the German Environment Agency pharmaceutical database on means, medians or single values of 12 antibiotic types in five different environmental matrices [municipal wastewater treatment plant effluent, industrial wastewater effluent, hospital wastewater effluent, surface water, and drinking water] across 47 countries. We compared the mean levels of the 12 antibiotics in each environmental matrix to their suggested PNEC values to determine which antibiotic types exceeded PNEC and were most likely to select for resistance. We also determined which environmental matrices and countries had the highest burden of antibiotic residues.

RESULTS

Our study revealed that 7.9% of all analyses of antibiotic residues performed in the environmental matrices globally exceeded PNEC. Ciprofloxacin and clarithromycin had the greatest proportion (>30%) of residues exceeding PNEC. Hospital wastewater and industrial wastewater had the highest burden of antibiotic residues exceeding PNEC. No antibiotics exceeded PNEC in drinking water.

CONCLUSION

While most environmental monitoring studies have focused on municipal wastewater treatment plants, the limited number of studies on hospital wastewater and industrial wastewater revealed that a large number of antibiotic residues coming from these sources exceeded their PNEC values. Our study highlights the importance of implementing on-site treatment systems that aim to destroy antibiotics prior to discharging wastewater to surface waters. Attention needs to be focused on the role that environmental matrices, particularly our wastewater sites, play in promoting antibiotic resistance. Novel treatment technologies need to be developed and implemented to increase the removal efficiencies of treatment plants and from antibiotic manufacturing, and decrease the discharge of antibiotic residues into aquatic environments.

Retrospective suspect screening reveals previously ignored antibiotics, antifungal compounds, and metabolites in Bangladesh surface waters

Densely populated countries in Asia, such as Bangladesh, are considered to be major contributors to the increased occurrence of global antimicrobial resistance (AMR). Several factors make low-and middle-income countries vulnerable to increased emergence and spread of AMR in the environment including limited regulations on antimicrobial drug use, high volume of antimicrobials used in human medicine and agricultural production, and poor wastewater management. Previous monitoring campaigns to investigate the presence of antibiotics in the aquatic environment have employed targeted analysis in which selected antibiotics are measured using liquid chromatography with tandem mass spectrometry (LC/MS/MS). However, this approach can miss several important contaminants that can contribute to the selective pressure that promotes maintenance and dissemination of antibiotic resistance genes (ARGs) in the environment. Nontarget analysis by suspect screening and reanalysis of stored digital data of previously ran samples can provide information on analytes that were formerly uncharacterized and may be chemicals of emerging concern (CECs). In this study, surface waters in both urban and rural sites in Bangladesh were collected and analyzed for the presence of antibiotic residues and other pharmaceuticals. Utilizing targeted analysis, the antibiotics with the highest concentrations detected were ciprofloxacin (1407 ng/L) and clarithromycin (909 ng/L). In addition, using high-resolution LC/MS/MS in the first ever application of retrospective analysis in samples from Bangladesh, additional antibiotics clindamycin, lincomycin, linezolid, metronidazole, moxifloxacin, nalidixic acid, and sulfapyridine were detected. Prevalence of amoxicillin transformation products in surface waters was also confirmed. In addition, medicinal and agricultural antifungal compounds were frequently found in Bangladeshi surface waters. This later finding - the near ubiquity of antifungal agents in environmental samples - is of particular concern, as it may be contributing to the alarming rise of multi-drug resistant fungal (e.g. Candida auris) disease recently seen in humans throughout the world.

Comparison of Mismatch Amplification Mutation Assay PCR and PCR-Restriction Fragment Length Polymorphism for Detection of Major Mutations in gyrA and parC of Escherichia coli Associated with Fluoroquinolone Resistance

Fluoroquinolones are the drug of choice for most of the infections caused by Escherichia coli, and their indiscriminate use has resulted in increased selective pressure for antibiotic resistance. At present, sequencing is the only reliable and direct technique to detect mutations in the quinolone resistance determining region (QRDR). In this study, a rapid and reliable mismatch amplification mutation assay (MAMA) PCR to detect mutations in the QRDR was evaluated and compared to PCR-restriction fragment length polymorphism (PCR-RFLP). One hundred one clinical isolates of E. coli were subjected to MAMA-PCR and PCR-RFLP to detect QRDR mutations. Overall, 92 (91.08%) resistant isolates harbored a point mutation of S83L in gyrA. Double mutations in gyrA were also detected in 45 (44.55%) isolates. Similarly, 41 (40.59%) isolates possessed a point mutation at parC 80, and 25 (24.75%) isolates possessed a point mutation at parC 84. Additionally, MAMA-PCR-the first of its kind-was also standardized to detect mutations in regions gyrB 447 and parE 416, although no mutations were detected in these regions. The rapid and sensitive MAMA-PCR method evaluated in this study would be helpful in exploring the underlying mechanism of fluoroquinolone resistance to enhance control strategies.

Susceptibility pattern of uropathogens to ciprofloxacin at the Ghana police hospital

INTRODUCTION

Reports of increasing resistance of uropathogens to antimicrobials is of global concern. Culture and drug susceptibility tests remain a vital guide to effective therapy. The aim of this study was to determine the susceptibility pattern of isolated uropathogens to ciprofloxacin at the Ghana Police Hospital.

METHODS

A total of 705 mid-stream urine samples were collected from patients suspected of having urinary tract infection, and visited the Ghana Police Hospital's laboratory from December 2013 to March 2014. Samples were cultured and isolates identified by standard methods, after which isolates susceptibility to ciprofloxacin was determined.

RESULTS

Prevalence of urinary tract infection among patients' whose samples were analyzed was 15.9%. Predominant uropathogens isolated were E. coli (46.4%), Coliform (41.1%) and Coliform spp. with Candida (6.2%). Other isolates were Pseudomonas spp. (2.7%), Salmonella spp. (1.8%), Candida spp. (0.9%) and Klebsiella spp (0.9%). The overall resistance among the top three isolated uropathogens to ciprofloxacin was 35.9%. Resistance pattern demonstrated by respective isolates to ciprofloxacin were: E. coli (38.5%), Coliform (54.3%), and Coliform spp. with Candida (15%). The other isolates showed 100% sensitivity.

CONCLUSION

This study revealed a relatively high ciprofloxacin resistance among isolated uropathogens, hence, the need for prudent prescribing and use of ciprofloxacin in urinary tract infection management.

Prevalence and risk factors for trimethoprim-sulfamethoxazole-resistant Escherichia coli among women with acute uncomplicated urinary tract infection in a developing country

BACKGROUND

Prospective studies from developing countries that have investigated risk factors for trimethoprim-sulfamethoxazole (TMP-SMX)-resistant Escherichia coli in women with uncomplicated urinary tract infection (UTI) remain scarce.

METHODS

Women with acute uncomplicated UTI were enrolled prospectively. Urine was sent for antimicrobial susceptibility testing. Logistic regression analysis was used to identify risk factors for TMP-SMX resistance.

RESULTS

Of 405 participants, 229 (56.5%) had bacteriuria (mean age 31.9 ± 9.5 years). In the previous 12 months, 77 (33.6%) had experienced at least one UTI episode and 106 (46.3%) reported antimicrobial use. The most common uropathogens were E. coli (75.8%) and Staphylococcus saprophyticus (8.9%). For the 179 E. coli, resistance rates were highest for ampicillin (64.3%) and TMP-SMX (41.3%). Resistance to cephalosporins, nitrofurantoin, and fluoroquinolones was much lower compared with the hospital laboratory-based surveillance data. Risk factors for TMP-SMX resistance were UTI in the last 6 months (odds ratio 2.22; p = 0.04) and the number of UTI episodes in the past year (odds ratio 2.06; p = 0.004). The number of UTI episodes (adjusted odds ratio 2.21; p = 0.02) remained significant on multivariate analysis.

CONCLUSIONS

TMP-SMX resistance was high. Number of previous UTI episodes was associated with increased risk of resistance; prior antimicrobial use was not. Hospital antibiograms should be used with caution when treating uncomplicated UTI.

Antibiotic Resistance of Uropathogens Isolated from Al-Shifa Hospital in Gaza Strip in 2002

A survey on clinical isolates from urine samples was conducted and the data obtained were analyzed to determine the most common bacterial causes of urinary tract infection in the Gaza Strip and to evaluate the sensitivity patterns to selected antimicrobials that are commonly used to treat such pathogens. Urine samples were taken for culture from inpatients and outpatients at Al-shifa hospital in Gaza. Urinary tract pathogens were identified and their susceptibility to antimicrobials was determined. Of the 4778 processed urine samples, only 1637 were recorded as positive (34%) and only 1283 were tested for antimicrobial susceptibility. Escherichia coli was the most frequent uropathogen (42%), followed by Klebsiella spp. (12.2%), Pseudomonas spp. < (10.2%), other Gram-negative bacilli (8%), b hemolytic streptococci (7.6%), Enterococcus spp. (6.9%), other Staphylococcus spp. (including S . saprophyticus) (6.5%), Proteus (4.5%), S. aureus (2.1%). Resistance to antimicrobials was extremely alarming. E. coli resistance to amoxicillin reached 97.9%, to piperacillin 78.3%, to doxycycline 90%, to sulfamethoxazole/trimethoprim 63.9% and to cefaclor 42.2%.

Antimicrobial resistance of Escherichia coli strains causing community-acquired urinary tract infections among insured and uninsured populations in a large urban center

We assessed the susceptibility of Escherichia coli strains causing communityacquired urinary tract infection (UTI) in a large urban center in Brazil, comparing two different populations (patients with health insurance vs. uninsured). 581 nonduplicate strains of E. coli were isolated. The prevalence of antimicrobial resistance was greater than 20% for ampicillin (51%), trimethoprim-sulfamethoxazole (43%), tetracycline (41%) and chloramphenicol (22%). Overall, 12% of the E. coli isolates were resistant to ciprofloxacin. Resistance prevalences to most antimicrobials were similar in the two study populations. Our data provide much needed information on the prevalence of antimicrobial resistance among E. coli causing communityacquired UTI in Brazil. Antimicrobial resistance among strains of E. coli causing community-acquired UTIs was relatively high, particularly resistance to ciprofloxacin.

Increasing ciprofloxacin resistance among prevalent urinary tract bacterial isolates in Gaza Strip, Palestine

This article presents the incidence of ciprofloxacin resistance among 480 clinical isolates obtained from patients with urinary tract infection (UTI) during January to June 2004 in Gaza Strip, Palestine. The resistance rates observed were 15.0% to ciprofloxacin, 82.5% to amoxycillin, 64.4% to cotrimoxazole, 63.1% to doxycycline, 32.5% to cephalexin, 31.9% to nalidixic acid, and 10.0% to amikacin. High resistance to ciprofloxacin was detected among Acinetobacter haemolyticus (28.6%), Staphylococcus saprophyticus (25.0%), Pseudomonas aeruginosa (20.0%), Klebsiella pneumonia (17.6%), and Escherichia coli (12.0%). Minimal inhibitory concentration (MIC) of ciprofloxacin evenly ranged from 4 to 32 μg/mL with a mean of 25.0 μg/mL. This study indicates emerging ciprofloxacin resistance among urinary tract infection isolates. Increasing resistance against ciprofloxacin demands coordinated monitoring of its activity and rational use of the antibiotics.

Conventional and molecular epidemiology of trimethoprim-sulfamethoxazole resistance among urinary Escherichia coli isolates

BACKGROUND

Antibiotic resistance is increasing in Escherichia coli, the most common cause of urinary tract infections, but its epidemiology has not been well described. We evaluated the epidemiology of trimethoprim-sulfamethoxazole-resistant E. coli in a large, public health care system in Denver, Colorado.

METHODS

Outpatients with E. coli urinary tract infections during the first 6 months of 1998 were evaluated retrospectively. A prospective study was then performed to confirm the rate of trimethoprim-sulfamethoxazole resistance. We used several strain-typing methods (pulsed-field gel electrophoresis, ribotyping, serotyping) to evaluate the molecular epidemiology of the resistance.

RESULTS

The rate of trimethoprim-sulfamethoxazole resistance was similar in the retrospective (24% [161/681]) and prospective (23% [30/130]) phases of the study (P = 0.89). Almost all trimethoprim-sulfamethoxazole-resistant strains (98%) were resistant to at least one other antibiotic. Risk factors for infection with a resistant strain included age < or =3 years, Hispanic ethnicity, recent travel outside the United States, and a prior urinary tract infection. However, rates of resistance were >15% among nearly all of the subgroups. Most strains had high-level resistance (>1000 microg/mL) to trimethoprim-sulfamethoxazole. Of the 23 resistant isolates evaluated, 10 (43%) belonged to the clone A group. There was no correlation between conventional epidemiologic characteristics and the molecular mechanism of resistance or strain type.

CONCLUSION

Resistance to trimethoprim-sulfamethoxazole among E. coli isolates among patients in a Denver public health care system is common, with high rates of resistance even among patients without risk factors.

Molecular epidemiology and mutations at gyrA and parC genes of ciprofloxacin-resistant Escherichia coli isolates from a Taiwan medical center

Sixty-five ciprofloxacin-resistant clinical Escherichia coli isolates were collected from a Taiwan Medical Center from December 1998 to February 1999. All 65 clinical isolates were resistant (MICs > or = 4 microg/mL) to the following fluoroquinolones: ofloxacin, levofloxacin, sparfloxacin, and trovafloxacin. These isolates were cross-resistant to chloramphenicol (65 isolates, 100%), tetracycline (65 isolates, 100%), cefuroxime (64 isolates, 98.5%), ampicillin (57 isolates, 87.7%), gentamicin (53 isolates, 81.5%), and cephalothin (24 isolates, 36.9%). Pulsed-field gel electrophoresis (PFGE) revealed a high diversity among the genomes of these isolates and indicated that clonal spread was not responsible for the prevalence of ciprofloxacin resistance in the hospital. Sequencing of the polymerase chain reaction (PCR) amplified products of the quinolone resistance determining regions (QRDRs) of gyrA and parC showed that all isolates carrying double mutations in gyrA at codon 83 and 87 and at least one parC mutation at codon 80 and/or 84. The mutation at codon 83 of GyrA from serine to leucine (S83L) was present in all the clinical isolates. The most prevalent pattern was the S83L mutation and the mutation at codon 87 from an aspartate to an asparagine (D87N) of GyrA plus a mutation from a serine to an isoleucine (S80I) at codon 80 of ParC (63.2%). This indicated that the presence of high-level resistance to quinolones in clinical E. coli isolates were associated with mutations at hot spots, codon 83 and 87 in GyrA and followed by subsequent mutation in either codon 80 and/or 84 in ParC.

Fluoroquinolones in the treatment of acute uncomplicated urinary tract infections in adult women

Urinary tract infections (UTIs) are among the most commonly encountered bacterial infections. Acute uncomplicated UTIs in adults include episodes of cystitis and pyelonephritis. The main uropathogens causing uncomplicated UTIs have, in the past, been fairly predictable and they have generally been susceptible to several commonly used oral antimicrobials. There has been a trend, however, towards increasing antimicrobial resistance among uropathogens over the past few years, especially to beta-lactams and trimethoprim-sulfamethoxazole (TMP-SMX). The current standard of therapy for the empiric treatment of acute uncomplicated cystitis is TMP-SMX for 3 days. Since the prevalence of resistance to TMP-SMX among uropathogens is increasing, however, fluoroquinolones, with their low side effect profile, convenient pharmacokinetics and effectiveness, are increasingly being used first-line for the management of cystitis. Treatment of acute pyelonephritis is less controversial and fluoroquinolones are recommended as first-line agents in the empiric treatment of community-acquired pyelonephritis. Of concern, the increased use of fluoroquinolones for the treatment of UTIs and other infectious processes has resulted in an increasing prevalence of fluoroquinolone-resistant uropathogens worldwide. In light of these changing resistance patterns, prudent use of fluoroquinolones for the treatment of UTIs is warranted.

Antibiotic Selection for Urinary Tract Infection: New Microbiologic Considerations

Urinary tract infection (UTI) is an extremely common clinical condition, especially among women, half of whom will have at least one episode of acute cystitis at some point during adult life. An estimated one quarter of these women will have frequent, recurrent UTI. The microbiology of uncomplicated UTI is very predictable, with the vast majority of cases attributed to Escherichia coli. Recent reports from the United States and Europe have shown that resistance among uropathogens to agents that have traditionally been recommended as firstline therapy for uncomplicated UTI is on the rise. Although resistance to fluoroquinolone antibiotics among community-acquired uropathogens remains very low in the United States, fluoroquinolone resistance in community-acquired UTI isolates from other parts of the world has been increasingly described. Very low levels of resistance to nitrofurantoin among uropathogens has revived interest in this agent. The effect of in vitro resistance in uropathogens on the clinical response to treatment of acute cystitis is not well studied. The implications of emerging resistance among the causative agents of this extremely common infection for therapy of UTI are discussed.