Antimicrobial susceptibility of Enterobacteriaceae, including molecular characterization of extended-spectrum beta-lactamase-producing species, in urinary tract isolates from hospitalized patients in North America and Europe: results from the SMART study 2009-2010

Extended-spectrum β-lactamase and carbapenemase producing Enterobacteriaceae among patients suspected with surgical site infection at Hospitals in Southern Ethiopia

Background

Extended-spectrum β-lactamase and carbapenemase-producing Enterobacteriaceae are an increasing problem for patients today. Data on clinical samples for ESBL and carbapenemase-producing Enterobacteriaceae for surgical site infection patients in developing countries are limited, including Ethiopia, mainly due to resource constraints. Hence, this study aimed to determine the prevalence of extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae among patients suspected to have surgical site infection at Hospital in Southern Ethiopia.

Materials and methods

A hospital-based cross-sectional study was conducted on 422 suspected surgical site infections from June 1, 2022 to August 30, 2022 at Hospitals in Southern Ethiopia. Sociodemographic and clinical data were obtained by using a structured questionnaire. Clinical samples (pus, pus aspirates, and wound swabs) were collected aseptically and processed within 30 min by placing the swabs in sterile test tubes containing sterile normal saline (0.5 mL). Samples were cultured on blood and MacConkey agar plates. All positive cultures were characterized by colony morphology, Gram staining, and standard biochemical tests. Antimicrobial sensitivity tests were performed using Kirby Baur disk diffusion on Mueller-Hinton agar. ESBL production was confirmed using a double-disc synergy test (DDST) method. Carbapenemase production was assessed using the modified Hodge test. Logistic regression analysis was used to determine associated factors. A P-value < 0.05 were considered statistically significant.

Result

Bacteria belonging to the order Enterobacterales were cultured in 23.7% out of 422 patients with suspected surgical wound infection. Of all the isolates, Enterobacteriaceae (69 isolates) were the most frequent, with E. coli (29/69) followed by K. pneumoniae (14/69). Of 69 Enterobacteriaceae isolates, 66.6 % (46/69) were positive for ESBL production, and 21.7 (15/69) were positive for carbapenemase-producing Enterobacteriaceae. The majority of Enterobacteriaceae isolates showed sensitivity to meropenem (72.1%); however revealed 63.9% and 70.5% were resistant to gentamicin and ciprofloxacin, respectively. Similarly, a higher resistance rate to cefepime (91.8%), amoxicillin-clavulanic acid (98.4%), ceftriaxone (95.1%), and ceftazidime (91.8%). MDR rate of Enterobacteriaceae isolates was 25/61 (41%) among patients suspected for surgical site infection. The Multivariable analysis revealed that length of hospital stay in hospital [AOR = 3.81 (95% CI 2.08-6.95)] remained statistically significant factor associated with surgical site infection due to ESBL producing Enterobacteriaceae.

Conclusion

Study results showed the severity of ESBL-producing Enterobacteriaceae is critical and CPE is alarming. Meropenem is the most effective antibiotic against the ESBL-producing Enterobacteriaceae. MDR rate of Enterobacteriaceae isolates was 61 (61%) among patients suspected for surgical site infection. Therefore, antibiotic selection should be based on the results of the culture and sensitivity tests.

The role of early use of Carbapenems perioperatively for urolithiasis with ESBL-producing Escherichia coli

BACKGROUND

Urolithiasis combined with ESBL-producing E. coli is often difficult to control and leads to higher postoperative infection-related complications. This study was aim to explore the efficacy and necessity for early use of carbapenem antibiotics perioperatively in urolithiasis patients with urinary tract infections caused by ESBL-producing E. coli.

METHODS

The study included a total of 626 patients who were separated into two groups: Group I (the ESBL-producing E. coli group) and Group II (the non-ESBL-producing E. coli group). Antibiotic susceptibility testing was performed and the two groups induced postoperative infection-related events were recorded. the efficacy of perioperative antibiotics was evaluated.

RESULTS

All strains of E. coli in our research were sensitive to Carbapenems antibiotics. In addition to Carbapenems, the resistance rates of ESBL-producing E. coli to 6 other commonly used antibiotics were higher than those of non-ESBL-producing strains. Based on the preoperative antibiotic susceptibility test for the ESBL-producing E. coli group and the qSOFA score, the Carbapenems were more effective than the β-lactamase inhibitors (p = 0.08), while for the non-ESBL-producing E. coli group, there was no difference in the treatment effects between Carbapenems, β-lactamase inhibitors, Ceftazidime and Quinolones (p = 0.975).

CONCLUSIONS

Carbapenem antibiotics significantly reduced the incidence of postoperative infection-related events compared with other types of antibiotics for ESBL-producing E. coli infections in patient with urolithiasis.

Extended-Spectrum β-Lactamase and Carbapenemase-Producing Gram-Negative Bacteria and Associated Factors Among Patients Suspected of Community and Hospital-Acquired Urinary Tract Infections at Ayder Comprehensive Specialized Hospital, Tigrai, Ethiopia

Background

Little is known about bacteria that produce extended-spectrum beta-lactamases (ESBLs) and carbapenemase in patients with urinary tract infections (UTIs) in Tigrai, Ethiopia. The aim of this study was to describe the magnitude of ESBL- and carbapenemase -producing gram-negative bacteria among patients suspected of community- and hospital-acquired UTIs at a referral hospital in Tigrai, Ethiopia.

Methods

A cross-sectional study was conducted at Ayder Comprehensive Specialized hospital from January 2020 to June 2020. A 10-20 mL sample of morning mid-stream and catheter urine was collected from consenting participants. Urine samples were cultured on cysteine lactose electrolyte deficient medium and MacConkey agar, and bacteria were identified using standard microbiological protocols. The Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility testing. The combination disk and modified Hodge tests were used detect ESBL and carbapenemase production, respectively. The data was entered into EPI 3.1 software and analyzed using SPSS version 21.

Results

Overall, 67 gram-negative bacteria were recovered from 64 participants. Escherichia coli was the predominant isolate (68.6%), followed by Klebsiella pneumoniae (22.4%), while ESBL production was found in both Escherichia coli and Klebsiella pneumoniae (52.2% and 86.7%, respectively). Isolates recovered from patients with hospital-acquired UTIs were more likely to produce ESBLs (AOR= 16.2; 95% CI: 2.95-89.5). Carbapenemase was produced by 4.3% of E. coli and 20% of Klebsiella pneumoniae isolates. High resistance rates were found against tetracycline (84.8%), ampicillin (78.3%), amoxicillin/clavulanic acid (58.7%) for Escherichia coli isolates and against ampicillin (93.3%), sulphamethexazole trimethoprim (93.3%), cefotaxime (86.6%), and ceftazidime (86.6%), and tetracycline (73.3%) for Klebsiella pneumoniae.

Conclusion

Most UTIs were caused by ESBL-producing bacteria, especially those that were related to healthcare. Microbiological-based therapy for patients with UTIs is essential at our study site due to high rates of ESBL and significant carbapenemase production with concomitant high rates of drug resistance to several antibiotics.

Differences in Virulence Factors and Antimicrobial Susceptibility of Uropathogenic Enterococcus spp. Strains in a Rural Area of Uganda and a Spanish Secondary Hospital

Enterococcus faecalis and Enterococcus faecium have become two of the most important agents of nosocomial diseases due to their constantly growing resistance. Enterococcal infections are associated with biofilms, which are intrinsically sensitive to antimicrobials. The main goal of this study was to compare and relate their capacity to form biofilm and their antimicrobial sensitivity, as well as their virulence factors and their implicated genes, of strains isolated from patients with urinary tract infection (UTI) in a rural hospital in Uganda and a secondary hospital in Spain. A prospective study was conducted with 104 strains of E. faecalis and E. faecium isolated from patients with suspected UTI and who presented leukocyturia at the Saint Joseph Kitgum hospital (Uganda) and at the Hospital Universitario Principe de Asturias (Spain). All microorganisms were identified in Spain by MALDI-TOF mass spectrometry. Antimicrobial susceptibility studies were carried out using the Vitek^® 2 system (Biomériux, France). The biofilm formation capacity was studied by photospectrometry. Phenotypic and genotypic virulence factors were studied in all cases by PCR or expression techniques. In Uganda, we found a higher incidence of E. faecium (65.3%, n = 32), contrary to the situation found in Spain where most of the bacteria found belonged to E. faecalis (92.7%, n = 51). All E. faecalis strains were found to have very low levels of resistance to ampicillin, imipenem, and nitrofurantoin. However, E. faecium exhibited more than 25% resistance to these antibiotics. Although the esp gene has been shown in the results obtained to be an important initial agent in biofilm formation, we have also demonstrated in this study the intervention of other genes when esp is not present, such as the ace1 gene. No statistically significant relationships were found between the presence of agg and gelE genes and increased biofilm formation. The significant difference between the incidence of E. faecalis and E. faecium and biofilm formation, between samples from Spain and Uganda, shows us very different profiles between countries.

A review of recent advances in the treatment of adults with complicated urinary tract infection

INTRODUCTION

Complicated urinary tract infections (cUTIs) entail diverse clinical conditions that could be managed differently and not necessarily with premature empiric therapy. Since multidrug-resistant organisms (MDROs) are widely spreading worldwide, the possibility of encountering these resistant bacteria is inevitably part of the daily life of physicians who manage cUTIs.

AREAS COVERED

The advances in the management of cUTIs are explored, illustrating: 1) a proposed therapeutical approach to cUTIs within the antimicrobial stewardship context; 2) evidence regarding novel antibiotics targeting MDROs. Evidence research has been performed through MEDLINE/PubMed using appropriate keywords and terms regarding cUTIs published before June 2022.

EXPERT OPINION

Novel antimicrobial drugs are available in the clinicians' armamentarium. Selecting the optimal therapy for suitable patients may be challenging given the multifaceted group of cUTIs. Carbapenems use is widely increasing, the role of old β-lactam/β-lactamase inhibitors is constantly revised, and novel drugs lack real-life studies. Understanding the different ranges of the complexity of patients affected by cUTIs may help select the most suitable antibiotic for every single case. More multicentric observational studies targeting cUTIs are needed to elucidate the appropriate drug based on patient characteristics and presentations, providing stronger recommendations for cases encountered in everyday clinical practice.

Antimicrobial resistance and ESBL profile of Uropathogens among pregnant women at Edna Adan Hospital, Hargeisa, Somaliland

BACKGROUND

The emergence and spread of antimicrobial resistance (AMR) among uropathogens is increasing, especially in resource limited settings due to a number of reasons. The production of Extended Spectrum β-Lactamase (ESBL) by some strains of E. coli and methicillin resistant Staphylococcus species, limits the choice of antimicrobials in the treatment of urinary tract infection (UTI) globally. However, little is known about the type of uropathogenes and their current AMR profile among pregnant women in Hargeisa, Somaliland.

METHODS

Clean-catch mid-stream urine samples were collected and processed for bacteriological culture and antimicrobial sensitivity testing (AST). Ceftazidime (30µg) and Cefotaxime (30µg) disks were used for ESBL screening as per CLSI guideline and each ESBL screening positive isolate were phenotypically confirmed by a combination disk test.

RESULTS

Among 376 study participants, 79 (21.0%) had significant bacteriuria (SBU). Majority at 58(73.4%) of the isolates were Gram-negative. The most predominant isolate was E.coli, 36(45.6%) followed by K. pneumonea 16(20.3%) and S. aureus at 9(11.4 %). The proportion of ESBL producing isolates was 25(32.9%). Gram-negatives showed high level resistance to ampicillin, amoxicillin, cefotaxime, and cephalexin at 87%, 85%, 57%, and 52%, respectively. Previous history of UTI, monthly income, educational status and having dysuria were significantly associated with SBU (p<0.05).

CONCLUSION

Relatively high prevalence of uropathogens and an increased level of drug resistance were documented. Therefore, continued surveillance on the type of uropathogens and their AMR pattern is needed to ensure appropriate recommendations for the rational empirical treatment of UTI and for policy input.

Prevalence and molecular characteristics of ESBL and AmpC β -lactamase producing Enterobacteriaceae strains isolated from UTIs in Egypt

BACKGROUND

Infections caused by Enterobacteriaceae are mainly treated with the β-lactam antibiotics, nevertheless, the emergence of species with plasmid-borne β-lactamases has decreased the efficacy of these antibiotics. Therefore, continuing studies on the resistance pattern of different regions is important for assessment of proper antimicrobial therapy protocols. The study aimed to characterize extended-spectrum β-lactamase (ESBL) and AmpC β -lactamase (AmpC) producing Enterobacteriaceae isolated from community-acquired UTIs in Egypt.

METHODS

Out of 705 urine samples, 440 Enterobacteriaceae isolates were investigated to detect ESBL and AmpC β -lactamases producers by phenotypic and molecular methods.

RESULTS

Out of 440 Enterobacteriaceae isolates, 311 were identified as ESBL producers by phenotypic testing. ESBL genes were detected in 308 isolates. BlaCTX-M-type was the most prevalent 254 (81.6%), out of them blaCTXM-15 was the commonest (152, 48.8%) followed by blaCTX-M-1 (140, 45%), blaCTX-M-8 (72, 23.1%) and lastly blaCTX-M-2 (4, 1.3%). blaTEM gene also was detected in a high rate (189, 60.7%). Two hundred and thirty-five (75.5%) of ESBL producers harbored blaCTX-M in combination with blaTEM and/or blaSHV genes. Multiple drug resistance in the ESBL-producers was significantly (P < 0.05) higher than in non-ESBL producers. Imipenem was the most effective drug against ESBL producers. Among 35 cefoxitin resistant isolates, 18 (51.4%) identified as carrying AmpC genes by multiplex PCR. Within AmpC β -lactamase genes, DHA gene was the predominant gene (15, 42.3%). CIT and MOX genes were also present, but in a low rate (5, 14.2% and 4, 11.4%) respectively. Co-existence of multiple AmpC genes was detected exclusively in K. pneumoniae isolates. E. coli isolates harbored DHA gene only. However, FOX gene was not detected in the study isolates. Seventeen of isolates carrying AmpC genes were also positive for ESBL genes.

CONCLUSION

The study shows that the prevalence of ESBL producing Enterobacteriaceae spread in south Egypt is alarming, however AmpC β -lactamase production is not so high.

Occurrence, identification, and antibiogram signatures of selected Enterobacteriaceae from Tsomo and Tyhume rivers in the Eastern Cape Province, Republic of South Africa

The increasing occurrence of multidrug-resistant Enterobacteriaceae in clinical and environmental settings has been seen globally as a complex public health challenge, mostly in the developing nations where they significantly impact freshwater used for a variety of domestic purposes and irrigation. This paper detail the occurrence and antibiogram signatures of the Enterobacteriaceae community in Tsomo and Tyhume rivers within the Eastern Cape Province, the Republic of South Africa, using standard methods. The average distribution of the presumptive Enterobacteriaceae in the rivers ranged from 1 × 102 CFU/100ml to 1.95 × 104 CFU/100ml. We confirmed 56 (70.8%) out of 79 presumptive Enterobacteriaceae isolated being species within the family Enterobacteriaceae through the Matrix-Assisted Laser Desorption Ionization Time of Flight technique. Citrobacter-, Enterobacter-, Klebsiella species, and Escherichia coli were selected (n = 40) due to their pathogenic potentials for antibiogram profiling. The results of the antibiotic susceptibility testing gave a revelation that all the isolates were phenotypically multidrug-resistant. The resistance against ampicillin (95%), tetracycline and doxycycline (88%), and trimethoprim-sulfamethoxazole (85%) antibiotics were most prevalent. The Multiple Antibiotic Resistance indices stretched from 0.22 to 0.94, with the highest index observed in a C. freundii isolate. Molecular characterisation using the PCR technique revealed the dominance of blaTEM (30%; 12/40) among the eight groups of β-lactams resistance determinants assayed. The prevalence of others was blaCTX-M genes including group 1, 2 and 9 (27.5%), blaSHV (20%), blaOXA-1-like (10%), blaPER (2.5%), and blaVEB (0%). The frequencies of the resistance determinants for the carbapenems were blaKPC (17.6%), blaGES (11.8%), blaIMP (11.8%), blaVIM (11.8%), and blaOXA-48-like (5.9%). Out of the six plasmid-mediated AmpC (pAmpC) genes investigated blaACC, blaEBC, blaFOX, blaCIT, blaDHA, and blaMOX, only the first four were detected. In this category, the most dominant was blaEBC, with 18.4% (7/38). The prevalence of the non-β-lactamases include tetA (33.3%), tetB (30.5%), tetC (2.8%), tetD (11.1%), tetK (0%), tetM (13.9%), catI (12%), catII (68%), sulI (14.3%), sulII (22.9%) and aadA (8.3%). Notably, a C. koseri harboured 42.8% (12/28) of the genes assayed for which includes five of the ESBL genes (including the only blaPER detected in this study), two of the pAmpC resistance genes (blaACC and blaCIT), and five of the non-β-lactamase genes. This study gives the first report on C. koseri exhibiting the co-occurrence of ESBL/AmpC β-lactamase genes from the environment to the best of our knowledge. The detection of a blaPER producing Citrobacter spp. in this study is remarkable. These findings provide evidence that freshwater serves as reservoirs of antimicrobial resistance determinants, which can then be easily transferred to human beings via the food chain and water.

Prevalence of multidrug-resistant and extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacilli: A meta-analysis report in Ethiopia

Multidrug-resistant (MDR) extended-spectrum beta-lactamase (ESBL)-producing bacterial isolates have emerged as a global threat to human health. Little is known about the overall prevalence of multidrug resistance profile and ESBL-producing gram-negative bacilli (GNB) in Ethiopia. Therefore, this meta-analysis was performed to produce proportional estimates of multidrug resistance and ESBL-producing GNB in Ethiopia. A web-based search was conducted in PubMed, Google Scholar, Research Gate, Scopus and other databases. Articles published till 2019 on the prevalence and antimicrobial resistance profiles of ESBL-producing GNB in Ethiopia were included in the study. Relevant data were extracted and statistical analysis was performed using comprehensive meta-analysis version 3.3.0 software. Publication bias was analyzed and presented with funnel plots. In this meta-analysis, the overall proportional estimate of ESBL-producing GNB was 48.9% (95% confidence interval [CI]: 0.402, 0.577). The pooled proportional estimates of ESBL-producing Klebsiella pneumoniae, Escherichia coli and other GNB were 61.8%, 41.2% and 42.9%, respectively. Regarding antimicrobial resistance profiles against selected drugs, the pooled proportional estimates of resistance against amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, cefotaxime, ceftazidime, tetracycline, gentamicin and ciprofloxacin was 79.0%, 78.4%, 78.0%, 72.4%, 72.7%, 58.9% and 43.8%, respectively. The pooled proportional estimates of MDR isolates were found to be 82.7% (95% CI: 0.726, 0.896), which are relatively high as compared to other countries. This highlights a need for active surveillance systems which can help understand the actual epidemiology of ESBL, aid in formulating national guidelines for proper screening of ESBL and support developing standardized approaches for managing patients colonized with ESBL.

Bacterial Profile and ESBL Screening of Urinary Tract Infection Among Asymptomatic and Symptomatic Pregnant Women Attending Antenatal Care of Northeastern Ethiopia Region

Background

Urinary tract infection is a common cause of morbidity in pregnant women. Emergence of antimicrobial resistance particularly ESBL production among bacterial uropathogens is increasing and becoming principal cause of treatment failure. The aim of this study was to determine the bacterial profile, their antimicrobial susceptibility patterns, risk factors and identify ESBL-producing bacterial uropathogens.

Patients and Methods

A hospital-based cross-sectional study was conducted in the Northeastern Ethiopia region. A total of 323 pregnant women were included and structured questionnaire was used to collect sociodemographic and risk factor-related data. About 10mL freshly voided midstream urine specimen was collected, transported and processed according to standard operating procedures. The data obtained were entered into SPSS version 22 and descriptive statistics, chi-square, bivariate and multivariate logistic regression analyses were performed. P-value ≤0.05 with corresponding 95% confidence interval were considered for statistical significance.

Results

The overall prevalence of UTI was 15.5% (50/323). The predominant bacterial isolates were Escherichia coli 17 (33.3%) followed by coagulase-negative staphylococci 15 (30.0%) and Staphylococcus aureus 14 (27.5%). Previous history of UTI (AOR=8.824, 95% CI: 3.769,20.654, P<0.001) and history of catheterization (AOR=3.270, 95% CI: 1.316,8.122, P=0.011) were significantly associated with the occurrence of bacterial UTI. Gram-negative isolates showed high level of resistance to ampicillin 12 (60.0%) and relatively low level of resistance to nitrofurantoin 5(25.0%), norfloxacin 5 (25.0%) and ceftazidime 3 (15.0%). Gram-positive uropathogens showed higher resistance for penicillin 29 (93.5%) and trimethoprim-sulfamethoxazole 23 (79.3%) whereas all isolates were sensitive 29 (100.0%) to nitrofurantoin. Moreover, multidrug resistance was observed among 41 (80.4%) of the isolates, and 3 (15.8%) of isolated gram-negative bacteria were ESBL producers.

Conclusion

High prevalence of bacterial UTI and MDR for commonly prescribed drugs were observed with significant number of ESBL producers. Therefore, instant UTI culture assessment of pregnant women, especially those having possible risk factors such as previous histories of UTI and catheterization; moreover, appropriate prescription and use of antibiotics are necessary.

A broad-spectrum beta-lactam-sparing stewardship program in a middle-income country public hospital: antibiotic use and expenditure outcomes and antimicrobial susceptibility profiles

Background

Antimicrobial stewardship programs are an efficient way to reduce inappropriate use of antimicrobials and costs; however, supporting data are scarce in middle-income countries. The aim of this study was to evaluate antibiotic use, bacterial susceptibility profiles, and the economic impact following implementation of a broad-spectrum beta-lactam-sparing antimicrobial stewardship program.

Methods

An interrupted time-series analysis was performed to evaluate antibiotic use and expenditure over a 24-month period (12 months before the antimicrobial stewardship program and in the 12 months after implementation of the antimicrobial stewardship program). Antibiotics were classified into one of two groups: beta-lactam antibiotics and beta-lactam-sparing antibiotics. We also compared the antimicrobial susceptibility profiles of key pathogens in each period.

Results

Beta-lactam antibiotics use decreased by 43.04 days of therapy/1000 patient-days (p = 0.04) immediately following antimicrobial stewardship program implementation, whereas beta-lacta-sparing antibiotics use increased during the intervention period (slope change 6.17 days of therapy/1000 patient-days, p < 0.001). Expenditure decreased by $2089.99 (p < 0.001) immediately after intervention and was maintained at this level over the intervention period ($−38.45; p = 0.24). We also observed that a greater proportion of pathogens were susceptible to cephalosporins and aminoglycosides after the antimicrobial stewardship program.

Conclusions

The antimicrobial stewardship program significantly reduced the use of broad-spectrum beta-lactam-antibiotics associated with a decrease in expenditure and maintenance of the susceptibility profile in Gram-negative bacteria.

Analysis of drug resistance of extended-spectrum beta-lactamases-producing Escherichia coli and Klebsiella pneumoniae in children with urinary tract infection

Objectives:

To investigate the drug resistance of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K.pneumoniae) in children with urinary tract infection (UTI) and to provide the rationale for clinical use of antibiotics.

Methods:

This is a retrospective analysis of drug susceptibility in children with E. coli or K. pneumoniae-positive urine culture between August 2013 and August 2017, Shenzhen Children’s Hospital, Shenzhen, China. Drug resistance was statistically assessed using Fisher exact test and χ² test.

Results:

A total of 698 cases of E. coli, 426 of which were confirmed ESBL-producing strains, and 217 cases of K. pneumoniae, including 111 ESBL-producing strains, were detected, and the difference in proportion of positive ESBL-producing strains (61.03% versus 51.15%) was statistically significant (p=0.010). The average drug resistance rates of E. coli and K. pneumoniae to piperacillin/tazobactam, meropenem, ertapenem, imipenem, and amikacin were <15%. The average resistance rates of ESBL-producing E. coli and K. pneumoniae to cefpodoxime, cefixime, cefazolin, and ceftriaxone was >98%, while average resistance rates for non-ESBL-producing bacteria to the above 4 drugs was <20%.

Conclusion:

In southern China, the proportion of ESBL-producing strains and the drug resistance rates of E. coli and K. pneumoniae in UTI in children was high, but their resistance rates to carbapenems and β-lactamase inhibitor complexes containing tazobactam were low. Carbapenems are the most effective antibacterial drugs for the treatment of ESBL-producing bacteria.

Antimicrobial-resistant pathogens in Canadian ICUs: results of the CANWARD 2007 to 2016 study

OBJECTIVES

To describe the microbiology and antimicrobial resistance patterns of cultured samples acquired from Canadian ICUs.

METHODS

From 2007 to 2016, tertiary care centres from across Canada submitted 42938 bacterial/fungal isolates as part of the CANWARD surveillance study. Of these, 8130 (18.9%) were from patients on ICUs. Susceptibility testing guidelines and MIC interpretive criteria were defined by CLSI.

RESULTS

Of the 8130 pathogens collected in this study, 58.2%, 36.3%, 3.1% and 2.4% were from respiratory, blood, wound and urine specimens, respectively. The top five organisms collected from Canadian ICUs accounted for 55.4% of all isolates and included Staphylococcus aureus (21.5%), Pseudomonas aeruginosa (10.6%), Escherichia coli (10.4%), Streptococcus pneumoniae (6.5%) and Klebsiella pneumoniae (6.4%). MRSA accounted for 20.7% of S. aureus collected, with community-associated (CA) MRSA genotypes increasing in prevalence over time (P < 0.001). The highest susceptibility rates among MRSA were 100% for vancomycin, 100% for ceftobiprole, 100% for linezolid, 99.7% for ceftaroline, 99.7% for daptomycin and 99.7% for tigecycline. The highest susceptibility rates among E. coli were 100% for tigecycline, 99.9% for meropenem, 99.7% for colistin and 94.2% for piperacillin/tazobactam. MDR was identified in 26.3% of E. coli isolates, with 10.1% producing an ESBL. The highest susceptibility rates among P. aeruginosa were 97.5% for ceftolozane/tazobactam, 96.1% for amikacin, 94.7% for colistin and 93.3% for tobramycin.

CONCLUSIONS

The most active agents against Gram-negative bacilli were the carbapenems, tigecycline and piperacillin/tazobactam. Against Gram-positive cocci, the most active agents were vancomycin, daptomycin and linezolid. The prevalence of CA-MRSA genotypes and ESBL-producing E. coli collected from ICUs increased significantly over time.

Pharmacological Interventions for Bacterial Prostatitis

Prostatitis is a common urinary tract condition but bring innumerable trouble to clinicians in treatment, as well as great financial burden to patients and the society. Bacterial prostatitis (acute bacterial prostatitis plus chronic bacterial prostatitis) accounting for approximately 20% among all prostatitis have made the urological clinics complain about the genital and urinary systems all over the world. The international challenges of antibacterial treatment (emergence of multidrug-resistant bacteria, extended-spectrum beta-lactamase-producing bacteria, bacterial biofilms production and the shift in bacterial etiology) and the transformation of therapeutic strategy for classic therapy have attracted worldwide attention. To the best of our knowledge currently, there is not a single comprehensive review, which can completely elaborate these important topics and the corresponding treatment strategy in an effective way. This review summarizes the general treatment choices for bacterial prostatitis also provides the alternative pharmacological therapies for those patients resistant or intolerant to general treatment.

Direct identification and susceptibility testing of Gram-negative bacilli from turbid urine samples using VITEK2

INTRODUCTION:

Urinary tract infections (UTIs) are the most common infectious diseases occurring in either the community or healthcare setting. Turnaround time for urine culture is about 24 h, and antimicrobial susceptibility testing (AST) requires another 24 h. Consequently, initial antibiotic therapy is mostly empirical.

MATERIALS AND METHODS:

This study was conducted at Nizam's Institute of Medical Sciences, Hyderabad. Turbid urine samples which showed pus cells and Gram-negative (GN) bacilli of single morphotype were included. The turbidity of the urine was adjusted to 0.5 McFarland and uploaded directly in the VITEK 2 identification (ID) GN and N-280 panel for AST. The specimen was also inoculated on CHROMagar, and the ID and AST of the isolates from the agar plate were repeated on VITEK 2, and the results were compared.

RESULTS:

Out of 844 turbid urines screened, 62 met the inclusion criteria. Escherichia coli was the most common isolate (71.9%). Complete agreement for ID was 80.7%, misidentified were 12.2%, and unidentified were 7%. Complete agreement with AST was 94.3%, very major errors 0.5%, major errors 2.2%, and minor errors 3%.

CONCLUSION:

With a 94.3% agreement for AST and a reduced turnaround time by 24 h, the direct inoculation had a potential clinical benefit for initiating timely and appropriate antibiotic therapy for UTI.

Preventing sepsis development in complicated urinary tract infections

Introduction: Urinary tract infections (UTIs) are the most prevalent infections in the community and the most common reason for antimicrobial prescribing in ambulatory care. A UTI is defined as complicated when urinary tract anatomical abnormalities or urinary devices are present, when it is recurrent and when associated with immunodeficiency. Complicated UTIs (cUTIs) have a higher risk of treatment failure and often require longer antimicrobial treatment courses. cUTIs, especially those which are healthcare-associated, are often due to multidrug resistant organisms (MDROs).Areas covered: This article will review the available evidence in relation to prevention of sepsis in cUTI, evaluating the risk factors associated with sepsis development. Published articles from January 2005 to September 2019 on UTIs and sepsis prevention in complicated UTIs were identified by using MEDLINE (National Library of Medicine Bethesda MD) and by reviewing the references of retrieved articles.Expert opinion: Prevention of sepsis relies on prompt and timely diagnosis of cUTI, early identification of the causative organism, removal of obstructions and source control, proper and adequate empirical/targeted antimicrobial treatment. In particular, source control, i.e. removal of urinary obstructions, infected stents, urinary catheters, nephrostomies, and drainage of hydronephrosis/abscess, is essential for preventing the development and progression of sepsis.

Improved Species-Level Clinical Identification of Enterobacteriaceae through Broad-Range dnaJ PCR and Sequencing

Enterobacteriaceae represent a diverse and medically important family of bacteria that are difficult to identify to the species level using the standard molecular method of 16S rRNA gene sequencing. Prior work has demonstrated the value of dnaJ gene sequence analysis in resolving different members of the family. However, existing protocols are not optimized for clinical use and exhibit several limitations in practice. Here, we describe an improved assay for dnaJ-based identification of Enterobacteriaceae which boasts increased broad-range specificity across genera, shorter amplicon sizes that are suitable for use with formalin-fixed or direct patient specimens, and enhanced amplification efficiency and assay sensitivity through the incorporation of locked nucleic acid chemistries. Sequence analysis of public databases indicates that the partial dnaJ sequence interrogated by this design retains high discriminatory power among Enterobacteriaceae genera and species, with only particular lineages of Shigella sp. and Escherichia coli proving unresolvable. Limits of detection studies using 8 disparate species indicated that amplification was consistently achievable across organisms and allowed robust dideoxynucleotide chain terminator sequencing from as little as 10 genome equivalents of template, depending on the species interrogated. Retrospective application of the dnaJ assay to patient specimens enabled unambiguous classification of Enterobacteriaceae to the species level in 22 of 27 (81.5%) positive specimens examined, with most remaining cases representing unresolvable calls between closely related Escherichia coli and Shigella species. We expect that this assay will facilitate the accurate molecular identification of species from the Enterobacteriaceae family in a variety of clinical specimens and diagnostic contexts.

In vitro studies evaluating the activity of imipenem in combination with relebactam against Pseudomonas aeruginosa

BACKGROUND

The prevalence of antibiotic resistance is increasing, and multidrug-resistant Pseudomonas aeruginosa has been identified as a serious threat to human health. The production of β-lactamase is a key mechanism contributing to imipenem resistance in P. aeruginosa. Relebactam is a novel β-lactamase inhibitor, active against class A and C β-lactamases, that has been shown to restore imipenem susceptibility. In a series of studies, we assessed the interaction of relebactam with key mechanisms involved in carbapenem resistance in P. aeruginosa and to what extent relebactam might overcome imipenem non-susceptibility.

RESULTS

Relebactam demonstrated no intrinsic antibacterial activity against P. aeruginosa, had no inoculum effect, and was not subject to efflux. Enzymology studies showed relebactam is a potent (overall inhibition constant: 27 nM), practically irreversible inhibitor of P. aeruginosa AmpC. Among P. aeruginosa clinical isolates from the SMART global surveillance program (2009, n = 993; 2011, n = 1702; 2015, n = 5953; 2016, n = 6165), imipenem susceptibility rates were 68.4% in 2009, 67.4% in 2011, 70.4% in 2015, and 67.3% in 2016. With the addition of 4 μg/mL relebactam, imipenem susceptibility rates increased to 87.6, 86.0, 91.7, and 89.8%, respectively. When all imipenem-non-susceptible isolates were pooled, the addition of 4 μg/mL relebactam reduced the mode imipenem minimum inhibitory concentration (MIC) 8-fold (from 16 μg/mL to 2 μg/mL) among all imipenem-non-susceptible isolates. Of 3747 imipenem-non-susceptible isolates that underwent molecular profiling, 1200 (32%) remained non-susceptible to the combination imipenem/relebactam (IMI/REL); 42% of these encoded class B metallo-β-lactamases, 11% encoded a class A GES enzyme, and no class D enzymes were detected. No relationship was observed between alleles of the chromosomally-encoded P. aeruginosa AmpC and IMI/REL MIC.

CONCLUSIONS

IMI/REL exhibited potential in the treatment of carbapenem-resistant P. aeruginosa infections, with the exception of isolates encoding class B, some GES alleles, and class D carbapenemases.

Methicillin Resistant Staphylococcus aureus and Extended Spectrum Beta-lactamase Producing Enterobacteriaceae: A Therapeutic Challenge in the 21st Century

Antimicrobial resistance is one of the greatest global threats to human health in recent times and it limits the achievement of several of the Sustainable Development Goals. Methicillin-ResistantStaphylococcus aureus(MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) producingEnterobacteriaceaeare among the most important multidrug resistant bacterial pathogens. MRSA and ESBL-producingEnterobacteriaceaehave evolved significantly over the last few decades with important clinical and epidemiological implications. Given the slow progress of development of new antibiotics in recent times, it is likely that these multidrug resistant pathogens will have a greater impact on public health in the 21stCentury, unless other effective control measures are instituted. Effective infection control strategies coupled with antibiotic stewardship programs are required to limit the spread and burden of MRSA and ESBL-producingEnterobacteriacae.

Resistance Trend, Antibiotic Utilization and Mortality in Patients with E. coli Bacteraemia

BACKGROUND:

Incidence of bacteraemia and driving concerns about antibiotic resistance is increasing globally. Risk factors for developing antimicrobial resistance are antibiotic overuse, incorrect dosing and extended duration of administration.

AIM:

This study was conducted to examine the prescription and susceptibility pattern of antibiotics in bacteraemia patients with ESBL producing and Non-ESBL-producing E. coli and their correlation with mortality.

METHODS:

Data were collected from medical records of the patients aged 18 years and above, diagnosed with E. coli bacteremia from January 2013 through July 2017. Institutional ethics committee approval was obtained before the study (IEC 483/2017). Cumulative sensitivity/resistance pattern of isolated microorganisms and DDD/100 bed days of prescribed antibiotics were obtained.

RESULTS:

182 cases of E. coli bacteraemia were reviewed. 59.9% (n = 109) were male with an age range of 20-90 years. The mortality rate was 24.9% (n = 44). 55.5% (n = 101) of the isolated organisms were ESBL-producing. A high percentage of resistance to cephalosporins and fluoroquinolones were observed among the patients, and most of the identified isolates were sensitive to the aminoglycosides, carbapenems and β-lactam and β-lactamase inhibitor combinations (BLBLIs).

CONCLUSIONS:

Frequent utilisation of the high-end antibiotics and increase in microorganism’s resistance to different antibiotics can lead to a worrisome level. Local antibiotic resistance data and consumption policy are essential to prevent and slow down this process. We observed a descending resistance trend for amoxicillin-clavulanic acid combination in our setting to both the ESBL producing and non-producing.

Current options for the treatment of infections due to extended-spectrum beta-lactamase-producing Enterobacteriaceae in different groups of patients

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are a frequent cause of invasive infections worldwide. Carbapenems are nowadays the most used drugs to treat these infections. However, due to the increasing rates of resistance to these antimicrobials, carbapenem-sparing alternatives are being investigated.

OBJECTIVES AND SOURCES

The aim of this narrative literature review is to summarize the published information on the currently available antibiotics for the treatment of ESBL-E infections, providing specific information on three subgroups of patients: Group 1, patients with severe infections or infections from high-risk sources or in severely immunocompromised patients; Group 2, patients with non-severe infections from intermediate-risk source; and Group 3, patients with non-severe urinary tract infection.

CONTENT AND IMPLICATIONS

For patients in Group 1, the current data would support the use of carbapenems. For milder infections, however, particularly urinary tract infections, other non-carbapenem antibiotics can be considered in selected cases, including beta-lactam/beta-lactam inhibitor combinations, cephamycins, temocillin and aminoglycosides. While specific studies should be performed in these situations, individualized decisions may be taken in order to avoid overuse of carbapenems.

Outcomes analysis in patients with extended-spectrum beta-lactamase bacteremia empirically treated with piperacillin/tazobactam versus carbapenems

Infections caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria are associated with worse outcomes and have limited treatment options. Carbapenems remain the drug of choice for these infections due to evidence of a mortality benefit and the mixed clinical efficacy associated with piperacillin/tazobactam (PTZ). Though definitive treatment for ESBL infections is well defined, evidence for appropriate empiric therapy remains inconclusive, and the role of rapid molecular assays that identify ESBL has not been evaluated. This multicenter retrospective study at nine Baylor Scott & White Health sites included patients who had positive blood cultures with ESBL-producing bacteria identified by rapid molecular assay and were empirically prescribed PTZ or carbapenems. A total of 117 patients were included in the study; 66 received empiric PTZ and 51 received carbapenems. Results showed no difference in hospital mortality (3% vs 7.8%, P = 0.4), hospital length of stay (6.1% vs 5.9%, P = 0.88), intensive care unit length of stay (4.7% vs 3.3%, P = 0.39), or recurrent ESBL bacteremia (7.6% vs 7.8%, P = 0.99) between the PTZ and carbapenem empiric treatment groups, respectively. In the era of rapid molecular assays, these results suggest that empiric PTZ use and avoidance of empiric carbapenem therapy in the first 24 hours of infection can be considered until a microbiological diagnosis is confirmed.

The rates of quinolone, trimethoprim/sulfamethoxazole and aminoglycoside resistance among Enterobacteriaceae isolated from urinary tract infections in Azerbaijan, Iran

Aim: Antibiotic susceptibility patterns help to select appropriate empirical treatments of urinary tract infections (UTIs). This study aimed to investigate antibiotic resistance among Enterobacteriaceae isolated from UTIs in Azerbaijan, Iran. Methods: This study was carried out during 2016 in hospitals located in Tabriz, Urmia, and Khoy. Midstream urine specimens were cultured and identified by the standard methods. Susceptibility testing was carried out using the disk diffusion agar method for cefotaxime, ceftazidime, ceftriaxone, cefoxitin, imipenem, meropenem, ertapenem, cefepime, ampicillin, cefazolin, cefuroxime, aztreonam, nitrofurantoin, and fosfomycin and the agar dilution method for MIC determination of aminoglycosides, quinolones, sulfamethoxazole, and trimethoprim. Results: A total of 219 non-duplicated Enterobacteriaceae were isolated from UTIs. According to the agar dilution assay, the following resistance rates were determined: trimethoprim/sulfamethoxazole (co-trimoxazole) 69.8%, nalidixic acid 68.9%, ciprofloxacin 66.2%, levofloxacin 58.5%, tobramycin 47.9%, kanamycin 39.3%, gentamicin 27.8%, and amikacin 5.5%. High levels of resistance were observed to trimethoprim (78.5%), sulfamethoxazole (88.1%), ampicillin (86.3%), and cephazoline (79.4%). Conclusion: The most effective agents against Enterobacteriaceae were fosfomycin, carbapenems, and amikacin. Quinolones, trimethoprim and sulfamethoxazole are not appropriate for empirical therapy due to high levels of resistance. Amikacin is more effective among aminoglycosides and may be more effective, in complicated cases, when used in combination with fosfomycin and carbapenems.

The prevalence of plasmid-mediated quinolone resistance and ESBL-production in Enterobacteriaceae isolated from urinary tract infections

INTRODUCTION

β-lactam and fluoroquinolone antibiotics are usually used for the treatment of urinary tract infections (UTIs). The aim of this study was to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) and extended spectrum β-lactamases (ESBLs) in Enterobacteriaceae isolated from UTIs.

MATERIALS AND METHODS

Two hundred and nineteen samples of Enterobacteriaceae isolated from UTIs were collected in the Northwest of Iran. Antimicrobial susceptibility testing was determined by the disk diffusion method. ESBLs were detected by the double-disk test. ESBL and PMQR-encoding genes were screened using the polymerase chain reaction.

RESULTS

The rate of resistance to moxifloxacin, nalidixic acid, gatifloxacin, ofloxacin, ciprofloxacin, and levofloxacin in ESBL-producing isolates was 89.3%, 88%, 84%, 80%, 78.7%, and 73.3%, respectively. PMQR-producing Enterobacteriaceae isolates were identified in 67 samples (89.1%). The most prevalent PMQR genes were aac (6')-Ib-cr 120 (68.6%) followed by oqxB 72 (41.1%), oqxA 59 (33.7%), qnrB 36 (20.6%), qnrS 33 (18.9%), qnrD 19 (10.9%), qepA 13 (7.4 %), qnrA 10 (5.7%), and qnrC 9 (5.1%). There was a strong association between PMQR genes and blaCTX-M-15 and blaTEM-116 and other ESBL genes.

CONCLUSION

High resistance rates were detected to quinolones among ESBL-producing isolates from UTIs. There is a high prevalence of PMQR genes in Enterobacteriaceae in Azerbaijan and Iran, and the most common PMQR is aac(6')-Ib-cr. There is a significant association between PMQR and ESBL-producing isolates.

Antimicrobial susceptibility of gram-negative bacilli isolated from intra-abdominal and urinary-tract infections in Mexico from 2009 to 2015: Results from the Study for Monitoring Antimicrobial Resistance Trends (SMART)

Antimicrobial resistance is an increasing worldwide concern, which poses unique challenges for the effective prevention and treatment of several infections, especially the ones triggered by organisms producing extended-spectrum β-lactamases (ESBL). Here, we present the surveillance results of the Study for Monitoring Antimicrobial Resistance Trends (SMART) of Gram-negative bacilli isolated from intra-abdominal infections (IAI, n = 1,235) and urinary-tract infections (UTI, n = 2,682), collected in Mexico from 2009 to 2015. Susceptibility and ESBL status were determined according to the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Both E. coli (57%) and K. pneumoniae (12%) were the most frequently reported organisms, as well as the ones with the highest prevalence of ESBL-producing isolates (54% and 39%, respectively). The overall prevalence of ESBL-producing organisms was higher in nosocomial infections than in community-acquired infections (21% vs. 27%). The ESBL rates were 36% for IAI (953/2,682) and 37% for UTI (461/1,235). In addition, ertapenem, imipenem and amikacin were the antibiotics that mostly preserved bacterial susceptibility. Our results show consistency with global trends, although higher than the rates observed in Latin America.

The analysis of microbial spectrum and antibiotic resistance of uropathogens isolated from patients with urinary stones

PURPOSE

The characteristics and resistance patterns of urine bacteriology in patients with urinary tract stones have not been extensively studied. This study aims to investigate the microbial spectrum and antibiotic resistance of uropathogens isolated from urinary tract infections in patients with urinary stones and provide a basis for appropriate antimicrobial treatments.

METHODS

The results of positive bladder midstream urine cultures and their antimicrobial susceptibility were retrospectively analysed from hospitalised patients with diagnosis of urinary calculi and urinary tract infections between January 2010 and December 2015.

RESULTS

A total of 3892 samples were analysed during the study period: 2201 were female patients (56.6%) and 1691 were male patients (43.4%). The 4 most common uropathogens were Escherichia coli (48.7%), Klebsiella pneumoniae (10.4%), Enterococcus faecalis (8.7%) and Proteus mirabilis (5.2%). Both E. coli (60.8%) and Proteus mirabilis (7.5%) were higher in female patients than in male patients (32.8%; 2.3%; P < .05). ESBL-positive E. coli accounted for 59.5% of total number of E. coli, while ESBL-positive K. pneumoniae comprised 42.0% of total K. pneumoniae. The majority of uropathogens in patients with stones had high resistance to fluoroquinolones, ceftriaxone, ceftazidime, cefepime, penicillins, sulfonamides and monobactams (resistance >20%).

CONCLUSIONS

The microbial spectrum in patients with urinary stones had a complex pattern. The uropathogens showed marked multidrug resistance and a large proportion of the uropathogens were able to produce β-lactamase.

A Multicenter, Randomized, Double-Blind, Phase 2 Study of the Efficacy and Safety of Plazomicin Compared with Levofloxacin in the Treatment of Complicated Urinary Tract Infection and Acute Pyelonephritis

Increasing antimicrobial resistance among uropathogens limits treatment options for patients with complicated urinary tract infection (cUTI). Plazomicin, a new aminoglycoside, has in vitro activity against multidrug-resistant Enterobacteriaceae, including isolates resistant to currently available aminoglycosides, as well as extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacteriaceae. We evaluated the efficacy and safety of plazomicin in a double-blind, comparator-controlled, phase 2 study in adults with cUTI or acute pyelonephritis. Patients were randomized 1:1:1 to receive intravenous plazomicin (10 or 15 mg/kg of body weight) or intravenous levofloxacin (750 mg) once daily for 5 days. Coprimary efficacy endpoints were microbiological eradication at the test of cure (TOC; 5 to 12 days after the last dose) in the modified intent-to-treat (MITT) and microbiologically evaluable (ME) populations. Overall, 145 patients were randomized to treatment. In the groups receiving plazomicin at 10 mg/kg, plazomicin at 15 mg/kg, and levofloxacin, microbiological eradication rates were, respectively, 50.0% (6 patients with microbiological eradication at TOC/12 patients treated [95% confidence interval {CI}, 21.1 to 78.9%]), 60.8% (31/51 [95% CI, 46.1 to 74.2%]), and 58.6% (17/29 [95% CI, 38.9 to 76.5%]) in the MITT population and 85.7% (6/7 [95% CI, 42.1 to 99.6%]), 88.6% (31/35 [95% CI, 73.3 to 96.8%]), and 81.0% (17/21 [95% CI, 58.1 to 94.6%]) in the ME population. In the MITT population, 66.7% (95% CI, 34.9 to 90.1%), 70.6% (95% CI, 56.2 to 82.5%), and 65.5% (95% CI, 45.7 to 82.1%) of the patients in the three groups, respectively, were assessed by the investigator to be clinically cured at TOC. Adverse events were reported in 31.8%, 35.1%, and 47.7% of the patients in the three groups, respectively. Serum creatinine values were generally stable over the course of the study. No plazomicin-treated patients with evaluable audiometry data had postbaseline sensorineural, conductive, or mixed hearing loss. In summary, plazomicin demonstrated microbiological and clinical success and an overall safety profile supportive of further clinical development. (This study has been registered at ClinicalTrials.gov under identifier NCT01096849.)

Epidemiology and susceptibility of pathogens from SMART 2011-12 Turkey: evaluation of hospital-acquired versus community-acquired urinary tract infections and ICU- versus non-ICU-associated intra-abdominal infections

Objectives

To describe the epidemiology and susceptibility of pathogens (including ESBL producers) from hospital-acquired (HA) versus community-acquired (CA) urinary tract infections (UTIs) and ICU- versus non-ICU-associated intra-abdominal infections (IAIs) in Turkey as a part of the SMART study.

Methods

: For this report, Gram-negative pathogens (363 from UTIs and 458 from IAIs) were collected in 2011 and 2012 at six hospitals in Turkey. HA versus CA UTIs and ICU- versus non-ICU-associated IAIs were compared for the species isolated, percentage of ESBL-positive isolates by species and susceptibility for overall and individual Gram-negative species.

Results

: Escherichia coli was the most common pathogen identified in HA (40.2%) and CA (73.9%) UTIs and ICU-associated (25.8%) and non-ICU-associated (43.3%) IAIs. The rate of ESBL-positive E. coli was significantly higher in HA than in CA UTIs (50.5% versus 38.2%, P  <   0.001) and in non-ICU-associated than in ICU-associated IAIs (52.5% versus 29.2%, P  = 0.029). Of the drugs studied, only amikacin was active against ≥90% of pathogens in UTIs, while ertapenem, imipenem and amikacin were active against ≥90% of E. coli ; and imipenem, amikacin and cefoxitin were active against ≥90% of Klebsiella pneumoniae in IAIs.

Conclusions

Our findings demonstrated that E. coli continues to be the principal pathogen of UTIs and IAIs in Turkey. Along with a high rate of ESBL-positive isolates, high antimicrobial resistance among Gram-negative bacilli from either UTIs or IAIs was noted particularly in the case of HA UTIs and ICU-associated IAIs, with a higher likelihood of carbapenem- or amikacin-based therapy to provide the broadest activity against bacterial pathogens.

Preliminary insights into the occurrence of similar clones of extended-spectrum beta-lactamase-producing bacteria in humans, animals and the environment in Tanzania: A systematic review and meta-analysis between 2005 and 2016

The emergence and spread of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) are complex and of the public health concern across the globe. This review aimed at assessing the ESBL-PE clones circulating in humans, animals and the environment to provide evidence-based insights for combating ESBL-PE using One Health approach. Systematic search from Medline/PubMed, Google Scholar and African Journals Online was carried out and retrieved nine eligible articles (of 131) based on phenotypic and genotypic detection of ESBL-PE between 2005 and 2016 in Tanzania. Analysis was performed using STATA 11.0 software to delineate the prevalence of ESBL-PE, phenotypic resistance profiles and clones circulating in the three interfaces. The overall prevalence of ESBL-PE in the three interfaces was 22.6% (95% CI: 21.1-24.2) with the predominance of Escherichia coli (E. coli) strains (51.6%). The majority of ESBL-PE were resistant to the commonly used antimicrobials such as trimethoprim-sulfamethoxazole and tetracycline/doxycycline, 38%-55% were resistant to ciprofloxacin and all were sensitive to meropenem/imipenem. ESBL-PE infections were more associated with deaths compared to non-ESBL-PE infections. Strikingly, E. coli ST38, ST131 and ST2852 were found to intersect variably across the three interfaces. The predominant allele, bla_CTX-M-15, was found mostly in the conjugative IncF plasmids connoting transmission potential. The high prevalence of ESBL-PE and shared clones across the three interfaces, including the global E. coli ST131 clone, indicates wide and inter-compartmental spread that calls for One Health genomic-driven studies to track the resistome flow.

An update on the management of urinary tract infections in the era of antimicrobial resistance

Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited therapeutic options. Gram-negative bacteria, specifically Enterobacteriaceae, are common causes of both community-acquired and hospital acquired UTIs. These organisms can acquire genes that encode for multiple antibiotic resistance mechanisms, including extended-spectrum-lactamases (ESBLs), AmpC- β -lactamase, and carbapenemases. The assessment of suspected UTI includes identification of characteristic symptoms or signs, urinalysis, dipstick or microscopic tests, and urine culture if indicated. UTIs are categorized according to location (upper versus lower urinary tract) and severity (uncomplicated versus complicated). Increasing rates of antibiotic resistance necessitate judicious use of antibiotics through the application of antimicrobial stewardship principles. Knowledge of the common causative pathogens of UTIs including local susceptibility patterns are essential in determining appropriate empiric therapy. The recommended first-line empiric therapies for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantion or a 3-g single dose of fosfomycin tromethamine. Second-line options include fluoroquinolones and β-lactams, such as amoxicillin-clavulanate. Current treatment options for UTIs due to AmpC- β -lactamase-producing organisms include fosfomycin, nitrofurantion, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems. In addition, treatment options for UTIs due to ESBLs-producing Enterobacteriaceae include nitrofurantion, fosfomycin, fluoroquinolones, cefoxitin, piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, and aminoglycosides. Based on identification and susceptibility results, alternatives to carbapenems may be used to treat mild-moderate UTIs caused by ESBL-producing Enterobacteriaceae. Ceftazidime-avibactam, colistin, polymixin B, fosfomycin, aztreonam, aminoglycosides, and tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriaceae (CRE). Treatment options for UTIs caused by multidrug resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, aminoglycosides, colistin, ceftazidime-avibactam, and ceftolozane-tazobactam. The use of fluoroquinolones for empiric treatment of UTIs should be restricted due to increased rates of resistance. Aminoglycosides, colistin, and tigecycline are considered alternatives in the setting of MDR Gram-negative infections in patients with limited therapeutic options.

High Gastrointestinal Colonization Rate with Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Hospitalized Patients: Emergence of Carbapenemase-Producing K. pneumoniae in Ethiopia

We investigated the gastrointestinal colonization rate and antibiotic resistance patterns of Extended-Spectrum Beta-Lactamase (ESBL)- producing Escherichia coli and Klebsiella pneumoniae in hospitalized patients admitted at Ethiopia's largest tertiary hospital. Fecal samples/swabs from 267 patients were cultured on chrome agar. ESBL. Bacterial species identification, verification of ESBL production and antibiotic susceptibility testing were done using Vitek 2 system (bioMérieux, France). Phenotype characterization of ESBL-E.coli and ESBL- K.pneumoniae was done using Neo-Sensitabs™. ESBL positivity rate was much higher in K. pneumoniae (76%) than E. coli (45%). The overall gastrointestinal colonization rate of ESBL producing Enterobacteriaceae (ESBL-E) in hospitalized patients was 52% (95%CI; 46%-58%) of which, ESBL-E. coli and K.pneumoniae accounted for 68% and 32% respectively. Fecal ESBL-E carriage rate in neonates, children and adults was 74%, 59% and 46% respectively. Gastrointestinal colonization rate of ESBL-E.coli in neonates, children and adults was 11%, 42% and 42% respectively. Of all E. coli strains isolated from adults, children and neonates, 44%, 49% and 22% were ESBL positive (p = 0.28). The prevalence of ESBL-K.pneumoniae carriage in neonates, children and adults was 68%, 22% and 7% respectively. All K. pneumoniae isolated from neonates (100%) and 88% of K. pneumoniae isolated from children were ESBL positive, but only 50% of K.pneumoniae isolated from adults were ESBL positive (p = 0.001). Thirteen patients (5%) were carriers of both ESBL-E.coli and ESBL-KP. The overall carrier rate of ESBL producing isolates resistant to carbapenem was 2% (5/267), all detected in children; three with E.coli HL cephalosporinase (AmpC), resistant to ertapenem and two with K. pneumoniae Carbapenemase (KPC) resistant to meropenem, ertapenem and impenem. We report a high gastrointestinal colonization rate with ESBL-E and the emergence of carbapenems-resistant K. pneumoniae in Ethiopia. Urgent implementation of infection control measures, and surveillance are urgently needed to limit the spread within healthcare facilities and further to the community.

Role of age and sex in determining antibiotic resistance in febrile urinary tract infections

OBJECTIVES

To identify the age- and sex-specific antimicrobial susceptibility patterns of Gram-negative bacteria (GNB) in outpatient febrile urinary tract infections (UTIs) in Korea.

METHODS

A total 2262 consecutive samples collected from patients aged 1-101 years with febrile UTIs, during the period January 2012 to December 2014, were analyzed in this multicentre, retrospective cohort study.

RESULTS

The sensitivities to cefotaxime and cefoxitin were over 85% for females but under 75% for males. Sex played an important role in the susceptibility of GNB to cefotaxime (p<0.001) and cefoxitin (p<0.001). The sensitivity to ciprofloxacin (age >20 years) was under 75% in both sexes, and was not influenced by sex (p=0.204). Age distributions of the incidences of resistance to cefotaxime, cefoxitin, and ciprofloxacin (age >20 years) were similar to the age distribution of the incidence of GNB, which indicates that the resistance patterns to these drugs were not affected by age (Kolmogorov-Smirnov test, female/male: p=0.927/p=0.509, p=0.193/p=0.911, and p=0.077/p=0.999, respectively).

CONCLUSIONS

Age is not a considerable factor in determining the antibiotic resistance in febrile UTIs. Ciprofloxacin should be withheld from both sexes until culture results indicate its use. Second- or third-generation cephalosporins such as cefoxitin and cefotaxime can be used empirically only in females.

Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from blood cultures in Africa

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been isolated from many regions of the world. Epidemiological studies are being conducted in Europe, North America, and Asia. No study has however been conducted in Africa to determine the prevalence and distribution of ESBLs on the continent. This literature review aimed at describing the prevalence of ESBL-producing Enterobacteriaceae isolated from blood cultures, as well as the ESBL genes involved at the international level. Our focus was mainly on Africa. We conducted a literature review on PubMed. Articles related to our study field and published between 1996 and 2014 were reviewed and entirely read for most of them, while we only focused on the abstracts of some other articles. Relevant articles to our study were then carefully reviewed and included in the review. The prevalence of ESBL-producing Enterobacteriaceae differs from one country to another. The results of our literature review however indicate that class A ESBLs prevail over the other types. We took into consideration articles focusing on various types of samples to assess the prevalence of ESBL-producing Enterobacteriaceae, but information on isolates from blood cultures is limited. The worldwide prevalence of ESBL-producing Enterobacteriaceae has increased over time. Evidence of ESBL-producing Enterobacteriaceae can be found in all regions of the world. Studies conducted in Africa mainly focused on the Northern and Eastern parts of the continent, while only rare studies were carried out in the rest of the continent.

Retrospective observational study to assess the clinical management and outcomes of hospitalised patients with complicated urinary tract infection in countries with high prevalence of multidrug resistant Gram-negative bacteria (RESCUING)

INTRODUCTION

The emergence of multidrug resistant (MDR) Gram-negative bacteria (GNB), including carbapenemase-producing strains, has become a major therapeutic challenge. These MDR isolates are often involved in complicated urinary tract infection (cUTI), and are associated with poor clinical outcomes. The study has been designed to gain insight into the epidemiology, clinical management, outcome and healthcare cost of patients with cUTI, especially in countries with high prevalence of MDR GNB.

METHODS AND ANALYSIS

This multinational and multicentre observational, retrospective study will identify cases from 1 January 2013 to 31 December 2014 in order to collect data on patients with cUTI as a cause of hospital admission, and patients who develop cUTI during their hospital stay. The primary end point will be treatment failure defined as the presence of any of the following criteria: (1) signs or symptoms of cUTI present at diagnosis that have not improved by days 5-7 with appropriate antibiotic therapy, (2) new cUTI-related symptoms that have developed within 30 days of diagnosis, (3) urine culture taken within 30 days of diagnosis, either during or after completion of therapy, that grows ≥10(4) colony-forming unit/mL of the original pathogen and (4) death irrespective of cause within 30 days of the cUTI diagnosis.

SAMPLE SIZE

1000 patients afford a power of 0.83 (α=0.05) to detect an absolute difference of 10% in the treatment failure rate between MDR bacteria and other pathogens. This should allow for the introduction of about 20 independent risk factors (or their interaction) in a logistic regression model looking at risk factors for failure.

ETHICS AND DISSEMINATION

Approval will be sought from all relevant Research Ethics Committees. Publication of this study will be considered as a joint publication by the participating investigator leads, and will follow the recommendations of the International Committee of Medical Journal Editors (ICMJE).

TRIAL REGISTRATION NUMBER

NCT02641015; Pre-results.

Discrepancy between genotypic and phenotypic extended-spectrum β-lactamase rates in Escherichia coli from intra-abdominal infections in the USA

Varying rates of false-positive results of phenotypic extended-spectrum β-lactamase (ESBL) tests have been reported for different methods in different settings, species and geographic locations. This report describes discrepancies in Escherichia coli genotypic and phenotypic ESBL rates observed in a surveillance study of 29 US hospitals that participated in the Study for Monitoring Antimicrobial Resistance Trends (SMART). The ESBL phenotype was determined with the Clinical and Laboratory Standards Institute confirmatory broth microdilution test using cefotaxime and ceftazidime with and without clavulanate. Genes encoding ESBLs, carbapenemases and plasmidic AmpC β-lactamases were detected using a combination of microarray and multiplex PCR assays. Among 168 molecularly characterized phenotypically ESBL-positive E. coli isolates from intra-abdominal infections, 4.8 % were genotypically negative from 2009 to 2012 and 29.5 % in 2013. Because of the high rate of false-positive phenotypic ESBL results in 2013, the 5-year phenotypic ESBL trend was skewed and showed a statistically significant increase (P<0.05) in ESBL-positive E. coli in the USA, which was not seen using the genotypic ESBL rates. The majority of false-positive phenotypic profiles had ceftazidime MICs of 2 µg ml-1 and a ≥3 doubling dilution decrease in MIC for only one of the two antimicrobial agents. False-positive ESBL results can adversely impact epidemiological surveillance and patient care (including inappropriate treatment, unnecessary patient isolation and higher costs). Careful evaluation and comparison of phenotypic and genotypic test results can yield the greatest insight, but the most accurate (and faster) detection of ESBL producers is usually based on molecular data.

Susceptibility patterns and ESBL rates of Escherichia coli from urinary tract infections in Canada and the United States, SMART 2010-2014

Increasing antimicrobial resistance in urinary tract infections (UTI) is a concern. To evaluate resistance trends, 3498 Escherichia coli UTI isolates were collected from 2010 to 2014 in the Study for Monitoring Antimicrobial Resistance Trends (SMART) in Canada and United States (US). ESBL phenotype and susceptibility were determined using CLSI microdilution and breakpoints. US ESBL rates increased in 2010-2014 (7.8-18.3%, P < 0.0001), especially among hospital-associated (HA) infections, males, and older patients (≥65 years). Overall, ESBL rates in Canada showed no significant trend (10.4-13.0%. P = 0.079), and were lower than US rates in recent years, but increased significantly among community-associated (CA) infections, females, and older patients. In the US, but not Canada, susceptibility to cephalosporins and fluoroquinolones among 2013-2014 isolates was significantly lower in isolates from HA than CA UTI, males than females, and ≥65- than <65-year-olds. These observations confirm increasing resistance in E. coli. Subgroup analyses like these may help direct empirical therapy.

Genetic characterization of TEM-type ESBL-associated antibacterial resistance in Enterobacteriaceae in a tertiary hospital in Ghana

BACKGROUND

Antibiotic resistance due to the presence of extended-spectrum beta-lactamases (ESBLs) among Enterobacteriaceae is a worldwide problem. Data from Ghana regarding this resistance mechanism is limited. This study was designed to investigate the presence of TEM-type ESBL genes, their locations and their conjugabilities in clinical isolates of enterobacteria collected from the Korle-Bu Teaching Hospital in Ghana.

METHODS

Study isolates were characterized with respect to ESBL phenotype, TEM-type ESBL gene detection, location of the ESBL gene(s) and conjugability of the ESBL phenotype using nalidixic acid-resistant Escherichia coli K-12 as recipient. Phenotyping was by Kirby Bauer disk diffusion using cefpodoxime, ceftazidime, cefotaxime and their combinations with clavulanate. Gene detections were by PCR using blaTEM primers.

RESULTS

Overall, 37.96 % of 137 clinical isolates showed ESBL phenotype. The ESBLs occurred mostly in Klebsiella spp. (42.3 %) and then Escherichia coli (34.6 %). The TEM gene was detected in 48.1 % of ESBL-positive isolates and was determined to be plasmid-borne in 24 of 25 blaTEM detections. Overall, 62.7 % of TEM-producing isolates transferred the ESBL phenotype by conjugation.

CONCLUSIONS

The results highlight the presence of TEM-type ESBLs in the Korle-Bu Teaching Hospital and show considerable risk of environmental contamination through the urine of infected persons. An inhibition zone chart was generated which indicates the possible presence of complex beta-lactamase types. The data points to the fact that the ESBL-producing bacteria may disseminate this resistance mechanism via conjugation.

Activity of Ceftazidime-Avibactam against Extended-Spectrum- and AmpC β-Lactamase-Producing Enterobacteriaceae Collected in the INFORM Global Surveillance Study from 2012 to 2014

The in vitro activity of ceftazidime-avibactam was evaluated against 34,062 isolates of Enterobacteriaceae from patients with intra-abdominal, urinary tract, skin and soft-tissue, lower respiratory tract, and blood infections collected in the INFORM (International Network For Optimal Resistance Monitoring) global surveillance study (176 medical center laboratories in 39 countries) in 2012 to 2014. Overall, 99.5% of Enterobacteriaceae isolates were susceptible to ceftazidime-avibactam using FDA approved breakpoints (susceptible MIC of ≤8 μg/ml; resistant MIC of ≥16 μg/ml). For individual species of the Enterobacteriaceae, the ceftazidime-avibactam MIC inhibiting ≥90% of isolates (MIC90) ranged from 0.06 μg/ml for Proteus species to 1 μg/ml for Enterobacter spp. and Klebsiella pneumoniae Carbapenem-susceptible isolates of Escherichia coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis with a confirmed extended-spectrum β-lactamase (ESBL) phenotype, or a ceftazidime MIC of ≥16 μg/ml if the ESBL phenotype was not confirmed by clavulanic acid inhibition, were characterized further to identify the presence of specific ESBL- and plasmid-mediated AmpC β-lactamase genes using a microarray-based assay and additional PCR assays. Ceftazidime-avibactam demonstrated potent activity against molecularly confirmed ESBL-producing (n = 5,354; MIC90, 0.5 μg/ml; 99.9% susceptible), plasmid-mediated AmpC-producing (n = 246; MIC90, 0.5 μg/ml; 100% susceptible), and ESBL- and AmpC-producing (n = 152; MIC90, 1 μg/ml; 100% susceptible) isolates of E. coli, K. pneumoniae, K. oxytoca, and P. mirabilis We conclude that ceftazidime-avibactam demonstrates potent in vitro activity against globally collected clinical isolates of Enterobacteriaceae, including isolates producing ESBLs and AmpC β-lactamases.

Carbon monoxide releasing molecule-2 (CORM-2) inhibits growth of multidrug-resistant uropathogenic Escherichia coli in biofilm and following host cell colonization

Background

Increased resistance to antimicrobial agents is a characteristic of many bacteria growing in biofilms on for example indwelling urinary catheters or in intracellular bacterial reservoirs. Biofilm-related infections caused by multidrug-resistant bacteria, such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, are a major challenge. The aim of this study was to investigate if a carbon monoxide-releasing molecule (CORM-2) has antibacterial effects against ESBL-producing uropathogenic E. coli (UPEC) in the biofilm mode of growth and following colonization of host bladder epithelial cells.

Results

The effect of CORM-2 was examined on bacteria grown within an established biofilm (biofilm formed for 24 h on plastic surface) by a live/dead viability staining assay. CORM-2 (500 μM) exposure for 24 h killed approximately 60 % of the ESBL-producing UPEC isolate. A non-ESBL-producing UPEC isolate and the E. coli K-12 strain TG1 were also sensitive to CORM-2 exposure when grown in biofilms. The antibacterial effect of CORM-2 on planktonic bacteria was reduced and delayed in the stationary growth phase compared to the exponential growth phase. In human bladder epithelial cell colonization experiments, CORM-2 exposure for 4 h significantly reduced the bacterial counts of an ESBL-producing UPEC isolate.

Conclusion

This study shows that CORM-2 has antibacterial properties against multidrug-resistant UPEC under biofilm-like conditions and following host cell colonization, which motivate further studies of its therapeutic potential.

Efficacy of ceftolozane/tazobactam versus levofloxacin in the treatment of complicated urinary tract infections (cUTIs) caused by levofloxacin-resistant pathogens: results from the ASPECT-cUTI trial

OBJECTIVES

Empirical fluoroquinolone therapy is widely used in treating complicated urinary tract infections (cUTIs), even in areas of high fluoroquinolone resistance. While it is believed that high antibiotic concentrations in urine might be sufficient to overcome and effectively treat infections caused by resistant bacteria, clinical trial data validating this assumption are limited. This post hoc analysis evaluated the efficacy of ceftolozane/tazobactam versus levofloxacin in the subgroup of patients with cUTIs caused by levofloxacin-resistant pathogens in a randomized, controlled trial (NCT01345929/NCT01345955).

METHODS

Hospitalized adults with cUTI/pyelonephritis were randomized to 7 days of 1.5 g of ceftolozane/tazobactam every 8 h or 750 mg of levofloxacin once daily, before availability of culture and susceptibility data. A composite of microbiological eradication and clinical cure 5 to 9 days post-therapy was assessed in the microbiological modified ITT (mMITT; n = 800) and microbiologically evaluable (ME; n = 694) populations.

RESULTS

In the mMITT population, there were 212 patients (26.5%) with at least one baseline uropathogen that was resistant to levofloxacin. The majority of uropathogens in this subgroup were Enterobacteriaceae (n = 186) that were susceptible to ceftolozane/tazobactam [MIC ≤2 mg/L, 88.7% (165/186)]. Among patients with levofloxacin-resistant pathogens, ceftolozane/tazobactam demonstrated significantly higher composite cure rates than levofloxacin in both the mMITT [60.0% (60/100) versus 39.3% (44/112); 95% CI for the treatment difference, 7.2%-33.2%] and ME [64.0% (57/89) versus 43.4% (43/99); 95% CI for the treatment difference, 6.3%-33.7%] populations, respectively.

CONCLUSIONS

High urinary levels of levofloxacin did not reliably cure cUTIs. Seven day treatment with ceftolozane/tazobactam was more effective than high-dose levofloxacin treatment in patients with cUTI caused by levofloxacin-resistant bacteria, and it may be an alternative treatment in settings of increased fluoroquinolone resistance.

Bacteriology and antimicrobial susceptibility of ESBLs producers from pus in patients with abdominal trauma associated intra-abdominal infections

PURPOSE

Intra-abdominal infections (IAIs) caused by ESBLs producing bacteria have become a serious clinical concern worldwide as the prevalence of bacterial resistance to antibiotics continues to increase. The objective of this study was to analyze the bacteriology and antimicrobial susceptibility of ESBLs producers using pus samples from IAIs patients caused by abdominal trauma.

METHODS

A total of 113 pus samples aspirated from IAIs patients were collected. The BACTEC 9120 and Vitek 2 system were used for detecting positive pathogens and confirming ESBLs production. The results of susceptibility were determined following the Clinical Laboratory Standards Institute guidelines.

RESULTS

Among the pathogens causing IAIs, Escherichia coli (E. coli) (29.1 %) was the most commonly isolated, followed by Klebsiella pneumoniae (K. pneumoniae) (22.5 %). The incidence rates of ESBLs production among E. coli, K. pneumoniae, and Klebsiella oxytoca were 69.6, 45.1, and 25.0 %, respectively. All pathogens had high resistance rates against studied antibiotics, with imipenem (88.7 %) and ertapenem (90.7 %) remaining the only practical options. Trend analysis documented an increase in ESBLs producing E. coli and K. pneumoniae, and a decrease in susceptibility for carbapenems among ESBLs producing E. coli and K. pneumoniae.

CONCLUSIONS

Escherichia coli and K. pneumoniae were the major pathogens causing abdominal trauma associated IAIs. The most active agents against ESBLs producing E. coli and K. pneumoniae were ertapenem and imipenem. However, the ESBLs rates were alarmingly high and increasing among IAIs associated gram-negative bacilli infections in China, and most agents exhibited decreased susceptibility against ESBLs producing pathogens.

Urological infections due to multidrug-resistant bacteria: what we need to know?

PURPOSE

Recent epidemiological data have confirmed the increasing problem of antimicrobial resistance not only for hospitalized, healthcare-associated patients, but also for outpatients. In particular, the progressive increase in resistance to broad-spectrum antibiotics, such as third-generation cephalosporins, fluoroquinolones or carbapenems in Enterobacteriaceae, is an alarming situation for all urologists and general practitioners. Here, we aimed to review the epidemiological data of multidrug-resistant bacteria in the urological setting, in order to summarize all diagnostic and therapeutic recommendations to use in everyday clinical practice.

METHODS

We collected all recent publications from Medline and Cochrane Library from January 2000 to December 2013. Moreover, data from the abstracts presented at the EAU and AUA Congresses during the last 5 years have also been analyzed. All papers were evaluated by an expert panel on urological infections on behalf of the Italian Urological Association (SIU).

RESULTS

Fluoroquinolone and other antibiotic-resistant bacteria prevalence is normally very high in the lower urinary tract infection patients. In particular, multidrug-resistant bacteria prevalence in urological practice contributes to infectious morbidity increasing the financial costs to healthcare system. The expert panel on urological infections on behalf of the Italian Urological Association formulated new diagnostic pathway and therapeutic protocol in patients affected by urological tract infections due to multidrug-resistant bacteria.

CONCLUSIONS

The recent emergence of multidrug-resistant pathogens is an alarming public health issue also in urological practice with socioeconomic importance. Our practice should be revised on the basis of these new acquisitions.

Empirical therapies among adults hospitalized for community-acquired upper urinary tract infections: A decision-tree analysis of mortality, costs, and resistance

BACKGROUND

Poor outcomes occur when patients with serious infections receive antibiotics to which the organisms are resistant.

METHODS

Decision trees simulated in-hospital mortality, costs, incremental cost-effectiveness ratio per life year saved, and carbapenem resistance according to 3 empirical antibiotic strategies among adults hospitalized for community-acquired (CA) upper urinary tract infections (UTIs): ceftriaxone (CRO) plus gentamicin (GM) in the intensive care unit (ICU), imipenem (IMP), and individualized choice (IMP or CRO) based on clinical risk factors for CA- extended-spectrum β-lactamase (ESBL).

RESULTS

The estimated prevalence of CA-ESBL on admission was 5% (range, 1.3%-17.6%); 3% and 97% were admitted to the ICU and medical ward (MW), respectively. In the ICU, CRO plus GM was dominated; IMP was cost-effective (incremental cost-effectiveness ratio: €4,400 per life year saved compared with individualized choice). In the MW, IMP had no impact on mortality and was less costly (-€142 per patient vs CRO, -€38 vs individualized choice). The dominance of IMP was consistent in sensitivity analyses. Compared with CRO, colonization by carbapenem-resistant pathogens increased by an odds ratio of 4.5 in the IMP strategy.

CONCLUSION

Among the ICU patients, empirical IMP therapy reduces mortality at an acceptable cost. Among MW patients, individualized choice or CRO is preferred to limit carbapenem resistance at a reasonable cost.

The emerging threat of multidrug-resistant Gram-negative bacteria in urology

Antibiotic resistance in Gram-negative uropathogens is a major global concern. Worldwide, the prevalence of Enterobacteriaceae that produce extended-spectrum β-lactamase or carbapenemase enzymes continues to increase at alarming rates. Likewise, resistance to other antimicrobial agents including aminoglycosides, sulphonamides and fluoroquinolones is also escalating rapidly. Bacterial resistance has major implications for urological practice, particularly in relation to catheter-associated urinary tract infections (UTIs) and infectious complications following transrectal-ultrasonography-guided biopsy of the prostate or urological surgery. Although some new drugs with activity against Gram-negative bacteria with highly resistant phenotypes will become available in the near future, the existence of a single agent with activity against the great diversity of resistance is unlikely. Responding to the challenges of Gram-negative resistance will require a multifaceted approach including considered use of current antimicrobial agents, improved diagnostics (including the rapid detection of resistance) and surveillance, better adherence to basic measures of infection prevention, development of new antibiotics and research into non-antibiotic treatment and preventive strategies.