Antimicrobial susceptibility pattern and epidemiology of female urinary tract infections in South Korea, 2010-2011

A Five-Year Analysis of Antibiotic Resistance Trends among Bacteria Identified in Positive Urine Samples in a Tertiary Care Hospital from Bucharest, Romania

The rise of multidrug-resistant bacteria (MDR) has resulted in limited treatment options and poorer outcomes for patients. The objective of this study was to analyze the overall antibiotic resistance trends and distribution for pathogens identified in urine samples at the National Institute of Infectious Diseases "Prof. Dr. Matei Balș" from Bucharest, Romania, over a 5-year period. Antibiotic susceptibility testing was performed using automatic systems and the disk diffusion method. ESBL- and carbapenemases-producing strains were identified using immunochromatography tests, and ROSCO Diagnostica kits were used for definitive confirmation. All results were interpreted according to EUCAST clinical breakpoints. Gram-negative rods (GNR) had overall resistance rates higher than 50% for penicillin and 40% for 3rd- and 4th-generation cephalosporins. Escherichia coli resistance to fosfomycin (3%) and nitrofurantoin (2%) remains low, and 33.30% of E. coli, 48% of Klebsiella spp., and 37% of Pseudomonas aeruginosa isolates were multidrug-resistant (MDR). All Acinetobacter baumannii isolates were MDR by the last year of the study. For Gram-positive cocci (GPC), 37% of all Enterococcus faecium strains and 2% of Enterococcus faecalis were vancomycin-resistant (VRE). E. coli's incidence in UTIs' etiology is on a downward trend. The incidence of Klebsiella spp. and GPCs is rising. Antibiotic stewardship strategies should be implemented after carefully considering regional variations in etiology and resistance trends.

Efficacy of fosfomycin compared to second generation cephalosporin flumarin as antimicrobial prophylaxis for transrectal ultrasound-guided prostate biopsy: a single center retrospective study

BACKGROUND

Fluoroquinolone has been the historic choice of antimicrobial prophylaxis for transrectal ultrasound (TRUS) guided prostate biopsy. However, increased fluoroquinolone resistance and recent restrictions of its use for antimicrobial prophylaxis has led to the emergence of alternative agents for antimicrobial prophylaxis for TRUS guided prostate biopsy including fosfomycin and cephalosporins. This study aimed to compare the efficacy of fosfomycin and a second-generation cephalosporin flumarin as alternative antimicrobials for TRUS-guided prostate biopsy in terms of the incidence of infectious complications after TRUS-guided prostate biopsy.

METHODS

A retrospective chart review of all patients who underwent TRUS-guided prostate biopsy between November 2009 to January 2023 was undertaken. Comparison of baseline characteristics and the incidence of infectious complications was done between those who received fosfomycin as antimicrobial prophylaxis for TRUS-guided prostate biopsy and those who received flumarin. Multivariate logistic regression analysis was conducted to identify risk factors for infectious complications after TRUS-guided prostate biopsy.

RESULTS

Of 2,900 patients identified as eligible candidates for analysis, 333 (11.5%) received fosfomycin and 2,567 (88.5%) received flumarin. The overall rate of infectious complications was approximately 3% lower in patients who received fosfomycin, although such difference did not reach statistical significance (5.7% vs. 8.6%, p = 0.074). Multivariate logistic regression analysis showed that history of operation done under general anaesthesia within six months of the biopsy (odds ratio [OR]: 2.216; 95% confidence interval [CI]: 1.042-4.713; p = 0.039) and history of prior antimicrobial use within six months (OR: 1.457; 95% CI: 1.049-2.024; p = 0.025) were significant risk factors for infectious complications after TRUS-guided prostate biopsy.

CONCLUSION

Fosfomycin was comparable to second-generation cephalosporin flumarin in preventing infectious complications after TRUS-guided prostate biopsy. Coupled with its properties such as ease of administration, low adverse effects, low resistance rate, and low collateral damage, fosfomycin might be an attractive alternative antimicrobial prophylaxis for TRUS-guided prostate biopsy.

Antibiotic susceptibility of urine culture specimens in Ontario: a population-based cohort study

BACKGROUND

Surveillance of antimicrobial resistance is essential to mitigate its impact on population health and inform local empiric treatment practices. Our aims were to evaluate urine culture specimen susceptibility from a range of diverse settings and describe antibiotic susceptibility across all organisms and compare susceptibilities to that of Escherichia coli alone.

METHODS

In this descriptive cohort study, we measured the prevalence of organisms in urine culture specimens using linked province-wide administrative databases. Using positive urine cultures collected in Ontario between Jan. 1, 2016, and Dec. 31, 2017, we measured susceptibility to 6 classes of antibiotics using a weighted antibiogram for all organisms compared with E. coli alone.

RESULTS

We included 689 497 cultures derived from 569 399 patients and 879 778 test orders for specimens. For all organisms, the rates of susceptibility in the outpatient, inpatient and long-term care settings were 49.3%, 42.8% and 39.2%, respectively, for ampicillin; 83.1%, 72.7% and 69.7%, respectively, for nitrofurantoin; 80.3%, 64.8% and 73.1%, respectively, for trimethoprim-sulfamethoxazole; 87.2%, 74.1% and 66.2%, respectively, for ciprofloxacin; 90.6%, 73.6% and 85.1%, respectively, for aminoglycosides; and 82.6%, 57.5% and 73.5%, respectively, for cefazolin. We found resistance to 3 or more antibiotic classes in 20.6% of episodes for all organisms compared with 14.0% for E. coli alone. The average absolute difference in antibiotic susceptibility between all organisms and E. coli across all drugs was lowest in the outpatient setting (6.2%) and highest in the inpatient setting (14.6%).

INTERPRETATION

In this study, urinary organism prevalence and antimicrobial susceptibility varied across health care settings and patient populations, with implications for both antimicrobial resistance surveillance and clinical decision-making. Weighted antibiograms may be most useful for guiding empiric treatment of urinary infections in inpatient settings where the diversity of infectious organisms is higher than in the community.

The Path of More Resistance: A Comparison of NHSN and CLSI Criteria in Developing Cumulative Antimicrobial Susceptibility Test Reports and Institutional Antibiograms

Background In the absence of antimicrobial susceptibility data, the institutional antibiogram is a valuable tool to guide clinicians in the empiric treatment of infections. However, there is a misunderstanding on how best to prepare cumulative antimicrobial susceptibility testing reports (CASTRs) to guide empiric therapy (e.g., routine antibiogram) versus monitoring antimicrobial resistance, with the former following guidance from the Clinical Laboratory Standards Institute (CLSI), and the latter from Center for Disease Control and Preventions National Healthcare Safety Network (NHSN). These criteria vary markedly in their exclusion or inclusion of isolates cultured repeatedly from the same patient. Methods We compared rates of non-susceptibility (NS)using annual data from a large teaching healthcare system subset to isolates eligible by either NHSN criteria or CLSI criteria. Results For a panel of the three most prevalent gram-negative pathogens in combination with clinically relevant antimicrobial agents (or priority pathogen-agent combinations, PPACs), we found that the inclusion of duplicate isolates by NHSN criteria yielded higher NS rates than when CLSI criteria (for which duplicate isolates are not included) were applied. Conclusions Patients with duplicate isolates may not be representative of antimicrobial resistance within a population. For this reason, users of CASTR data should carefully consider that the criteria used to generate these reports can impact resulting NS rates, and therefore maintain the distinction between CASTRs created for different purposes.

Febrile urinary tract infection in children: changes in epidemiology, etiology, and antibiotic resistance patterns over a decade

BACKGROUND

Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment.

PURPOSE

This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children.

METHODS

This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated.

RESULTS

A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03).

CONCLUSION

fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

Antimicrobial resistance among uropathogens in the Asia-Pacific region: a systematic review

BACKGROUND

Antimicrobial resistance (AMR) in urinary tract infections (UTI) is a global public health problem. However, estimates of the prevalence of AMR, required for empirical treatment guidelines, are lacking for many regions.

OBJECTIVES

To perform a systematic review and summarize the available information about AMR prevalence among urinary Escherichia coli and Klebsiella pneumoniae, the two priority uropathogens, in the Asia-Pacific region (APAC).

METHODS

PubMed, EBSCO and Web of Science databases were searched for articles (2008-20), following PRISMA guidelines. The prevalence of resistance was calculated and reported as point estimate with 95% CI for antimicrobial drugs recommended in WHO treatment guidelines. Data were stratified by country and surveillance approach (laboratory- or population-based surveillance). The quality of included articles was assessed using a modified Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Out of 2400 identified articles, 24 studies, reporting on 11 (26.8%) of the 41 APAC countries, met the inclusion criteria. Prevalence of resistance against trimethoprim/sulfamethoxazole, ciprofloxacin, and ceftriaxone ranged between 33% and 90%, with highest prevalence reported from Bangladesh, India, Sri Lanka and Indonesia. Resistance against nitrofurantoin ranged between 2.7% and 31.4%. Two studies reported data on fosfomycin resistance (1.8% and 1.7%). Quality of reporting was moderate.

CONCLUSIONS

We show very high prevalence estimates of AMR against antibiotics commonly used for the empirical treatment of UTI, in the limited number of countries in the APAC for which data are available. Novel feasible and affordable approaches that facilitate population-based AMR surveillance are needed to increase knowledge on AMR prevalence across the region.

Pattern of Antibacterial Resistance in Urinary Tract Infections: A Systematic Review and Meta-analysis

Background

Urinary tract infection (UTI) is one of the most common infectious diseases ranking next to upper respiratory tract infections. UTIs are often significantly associated with morbidity and mortality. The inappropriate administration of antibiotics to treat these infections increased infection resistance to antibiotics. The aim of this study is to determine the frequency of antibiotic resistance pattern in UTIs.

Methods

We searched several databases including PubMed, Web of Science, Scopus, Google Scholar, Iran Medex, Magiran, IranDoc, MedLib, and Scientific Information Database to identify the studies addressing antibacterial resistance patterns of the most common uropathogenic bacteria in UTIs in Iran. A total of 90 reports published from different regions of Iran from 1992 to May 2015 were involved in this study.

Results

It is shown that the most common pathogen causing UTIs is Escherichia coli with 62%. The resistance among the isolates of E. coli was as follows: ampicillin (86%), amoxicillin (76%), tetracycline (71%), trimethoprim-sulfamethoxazole (64%), cephalexin (61%), and cefalothin (60%). The highest sensitivity among isolates of E. coli was as follows: imipenem (86%), nitrofurantoin (82%), amikacin (79%), chloramphenicol (72%), and ciprofloxacin (72%).

Conclusions

The results of this study showed that the most common resistance are antibiotics that are commonly used. The most effective antibiotics for E. coli were imipenem, nitrofurantoin, amikacin, chloramphenicol, and ciprofloxacin. Considering this study, it had better, use less gentamicin, second-generation cephalosporins, and nalidixic acid in the initial treatment of infections caused by E. coli, and no use penicillins, tetracyclines, cotrimoxazole, and first-generation cephalosporins.

Antimicrobial resistance and risk factors for mortality of pneumonia caused by Klebsiella pneumoniae among diabetics: a retrospective study conducted in Shanghai, China

Purpose: To investigate antimicrobial resistance and risk factors for mortality of Klebsiella pneumoniae (KP) pneumonia in diabetics and nondiabetics. Patients and methods: A retrospective study was conducted among inpatients of KP pneumonia via electronic medical records in a territory hospital between January 2016 and June 2018. Antimicrobial resistance in KP pneumonia was compared between diabetics and nondiabetics. Independent risk factors for mortality in KP pneumonia were identified by univariate and multivariate logistic regression among diabetics and nondiabetics separately. Results: In this study, 456 patients with KP pneumonia were included. There were 156 cases with diabetes and 300 without diabetes. KP showed a lower antimicrobial resistance to a multitude of antimicrobials in pneumonia among diabetics than nondiabetics, namely aztreonam, cefotetan, sulperazone, meropenem, amikacin, tobramycin, sulfamethoxazole, and fosfomycin. In addition, carbapenem-resistant Klebsiella pneumoniae (CRKP) was more prevalent among nondiabetics than diabetics who were admitted to intensive care unit (ICU) (63.0% vs 45.1%, P = 0.038). Multivariable analysis showed that independent risk factors for in-hospital mortality (IHM) in KP pneumonia among diabetics differed from that among nondiabetics as well. Independent predictors for IHM of KP pneumonia among diabetics were male (OR: 5.89, 95% CI: 1.34-25.93, P = 0.019), albumin (ALB) < 35 g/L (OR: 7.00, 95% CI: 2.02-24.28, P = 0.002), bloodstream infection (BSI) (OR: 21.14, 95% CI: 3.18-140.72, P = 0.002), and invasive ventilation during hospitalization (OR: 8.00, 95% CI: 2.99-21.42, P < 0.001). In nondiabetics, independent predictors were higher CURB-65 score (OR: 1.92, 95% CI: 1.29-2.86, P = 0.001), CRKP (OR: 2.72, 95% CI: 1.07-6.90, P = 0.035), BSI (OR: 4.98, 95% CI: 1.34-18.50, P = 0.017), and ICU admission (OR: 4.06, 95% CI: 1.57-10.47, P = 0.004). Conclusion: In KP pneumonia, diabetics showed lower antimicrobial resistance and different independent risk factors for mortality compared with nondiabetics, in line with previous studies. Importantly, further attention should be paid on rational and effective antibiotic and supportive treatments in order to reduce mortality without aggravating antimicrobial resistance and metabolic damage among diabetics.

Community-Acquired Urinary Tract Infection by Escherichia coli in the Era of Antibiotic Resistance

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are the most common types of infections in women. The antibiotic resistance of E. coli is increasing rapidly, causing physicians to hesitate when selecting oral antibiotics. In this review, our objective is to ensure that clinicians understand the current seriousness of antibiotic-resistant E. coli, the mechanisms by which resistance is selected for, and methods that can be used to prevent antibiotic resistance.

Are third-generation cephalosporins associated with a better prognosis than amoxicillin-clavulanate in patients hospitalized in the medical ward for community-onset pneumonia?

OBJECTIVES

We aimed to assess whether treatment with ceftriaxone/cefotaxime is associated with lower in-hospital mortality than amoxicillin-clavulanate in pati0ents hospitalized in medical wards for community-onset pneumonia.

METHODS

We conducted a retrospective and multicentre study of patients hospitalized in French medical wards for community-onset pneumonia between 2002 and 2015. Treatments with ceftriaxone/cefotaxime or amoxicillin-clavulanate were defined by their start in the emergency department for a duration of 5 days or more with no other β-lactam. A logistic regression analysis was performed on the overall population, and a propensity score analysis was restricted to patients treated with either ceftriaxone/cefotaxime or amoxicillin-clavulanate.

RESULTS

1698 patients (median age, 80 y) were included, of which 716 and 198 were treated with amoxicillin-clavulanate and ceftriaxone/cefotaxime, respectively. In-hospital mortality was 10% (9-12%). In multivariate analysis, factors associated with in-hospital mortality were treatment with ceftriaxone/cefotaxime (aOR 2.9; (1.4-5.7)), pneumonia severity index class 4 or 5 (aOR 7.8 (4.3-15.7)), do-not-resuscitate order (aOR 8.7 (5.2-14.6)) and fluid therapy (aOR 6.3 (2.5-15.1)). The propensity score analysis was performed on 178 patients treated with ceftriaxone/cefotaxime matched with 178 patients treated with amoxicillin-clavulanate; no significant association between treatment with ceftriaxone/cefotaxime and in-hospital mortality was found (OR 1.5 (0.7-3.0)).

CONCLUSION

In the largest study aiming to compare amoxicillin-clavulanate and ceftriaxone/cefotaxime in community-onset pneumonia, ceftriaxone/cefotaxime was not associated with lower in-hospital mortality than amoxicillin-clavulanate. Our results suggest that ceftriaxone/cefotaxime should not be preferred over amoxicillin-clavulanate for patients hospitalized in medical wards with community-onset pneumonia.

Is There an Association Between Use of Amoxicillin-Clavulanate and Resistance to Third-Generation Cephalosporins in Klebsiella pneumoniae and Escherichia coli at the Hospital Level?

AIMS

Amoxicillin-clavulanate is extensively used in European hospitals. Whether the hospital use of amoxicillin-clavulanate is associated with nonsusceptibility to third-generation cephalosporins (3GC) in Klebsiella pneumoniae is unknown. Our aim was to assess the relationship between the hospital use of amoxicillin-clavulanate and 3GC nonsusceptibility in K. pneumoniae and Escherichia coli.

METHODS

Yearly data of antibiotic use and 3GC nonsusceptibility in K. pneumoniae and E. coli were obtained from 33 French hospitals between 2011 and 2016. Decreased susceptibility to 3GC and Extended-Spectrum Beta-Lactamase (ESBL) production were modelled from antibiotic use with linear mixed models on years 2011 to 2015, and validated on year 2016.

RESULTS

Nonsusceptibility to 3GC increased in K. pneumoniae and E. coli. In a multivariable model that included year and use of 3GC and fluoroquinolones as explanatory variables, amoxicillin-clavulanate use was protective against 3GC nonsusceptibility in K. pneumoniae (incidence rate ratio [IRR], 0.992 [0.988-0.997]), and with ESBL production in K. pneumoniae (IRR, 0.989 [0.985-0.992]). The correlation coefficient between observed and predicted numbers of 3GC-nonsusceptible K. pneumoniae in 2016 was 0.95 (95% confidence interval, 0.89-0.98). There was no significant association between amoxicillin-clavulanate use and 3GC nonsusceptibility in E. coli.

CONCLUSION

Amoxicillin-clavulanate hospital use was protective against nonsusceptibility to 3GC in K. pneumoniae. Conversely, it was not associated with susceptibility to 3GC in E. coli. To decrease the hospital use of 3GC and fluoroquinolones, and 3GC nonsusceptibility in K. pneumoniae, it may be acceptable to increase the hospital use of amoxicillin-clavulanate. Interventional studies are necessary to confirm this hypothesis.

Co-infection Of Ureaplasma urealyticum And Human Papilloma Virus In Asymptomatic Sexually Active Individuals

This study aimed to determine the role of asymptomatic bacterial sexually transmitted infections (STIs), such as Chlamydia trachomatis (Ct), Mycoplasma genitalium (Mg), Mycoplasma hominis (Mh), and Ureaplasma urealyticum (Uu) in human papillomavirus (HPV) infection. In total, 264 asymptomatic outpatients aged between 21 and 80 years were prospectively enrolled in this study during routine gynecological screening tests. Specimens collected with a Cervex Brush were routinely analyzed with the Hybrid Capture 2 assay for HPV. Simultaneously, a specimen obtained with an endocervical swab was used to detect Ct and Mg with a monoplex real-time polymerase chain reaction (PCR) and to confirm Mh and Uu with a Mycoplasma IST 2 kit. The detection rates (%) of HPV, Ct, Mg, Mh, and Uu were 82/264 (31.1), 6/264 (2.3), 5/264 (1.9), 16/264 (6.1), and 95/264 (36.0), respectively. Of 95 Uu, 32 (33.7%) showed high density colonization (HDC, ≥10⁴ color-changing units/mL). HDC-Uu was significantly associated with HPV infection (p=0.014, chi-square test). Mg infection and Mh infection were not associated with HPV infection (p=0.981 and p=0.931, chi-square test). Age was not associated with HPV infection or bacterial infection. Our data suggested that asymptomatic HDC-Uu was closely associated with HPV infection. Therefore, simultaneous evaluation for Uu and HPV should be performed during gynecological screening, even in asymptomatic individuals.

Multi-drug-resistant Enterococcus faecalis among Egyptian patients with urinary tract infection

The prevalence of Enterococcus faecalis (E. faecalis) infections among Egyptians with urinary tract infection (UTI), their antimicrobial susceptibility and mechanisms of resistance are under investigated. In this study, 300 urine samples were collected from UTI patients to identify E. faecalis. Antimicrobial susceptibility to 18 antimicrobial agents was tested. The presence of aac(6)-Ie-aph(2)Ia, erm(B) and mef(A/E) genes was examined by PCR. Fifty-seven (19%) isolates were identified as E. faecalis. All isolates were sensitive to teicoplanin and were completely resistant to nalidixic acid, cefotaxime and cefadroxil. Multi-drug-resistant (MDR) was found to be 100% with 45 different antibiotypes. The aac(6)Ia-aph(2)Ia gene was found in 100 and 90% of the isolates resistant to gentamicin at concentrations of 120 and 10 μg, respectively. erm(B) and mef(A/E) genes were present in 92.5% (37/40) and 2.5% (1/40) of erythromycin-resistant isolates, respectively. We conclude that there is a high prevalence of E. faecalis in UTI cases with a 100% MDR rate indicating a serious problem in treating infections by this organism in Egypt.

Role of piperacillin/tazobactam as a carbapenem-sparing antibiotic for treatment of acute pyelonephritis due to extended-spectrum β-lactamase-producing Escherichia coli

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) is a frequent cause of acute pyelonephritis (APN), requiring carbapenem therapy. However, alternatives to carbapenems are needed due to the emergence of carbapenemase-producing micro-organisms. The purpose of this study was to compare the clinical efficacy of piperacillin/tazobactam (TZP) versus ertapenem in the treatment of adult patients with APN caused by ESBL-Ec. A retrospective observational study of APN caused by ESBL-Ec susceptible to TZP was performed at a university-affiliated hospital in the Republic of Korea between February 2011 and June 2013. All adult patients initially treated with in vitro-active TZP were compared with those treated with ertapenem to evaluate antibiotic clinical efficacy. The primary endpoint was treatment failure, defined as a composite of in-hospital mortality, change of initial antibiotic regimen and microbiological eradication failure. During the study period, 68 patients prescribed TZP and 82 patients prescribed ertapenem were eligible for inclusion in the study. There was no significant difference between the two treatment groups in the occurrence of in-hospital mortality, change of initial antibiotic regimen or microbiological eradication failure. In the multivariate analyses, predictors associated with treatment failure included septic shock [odds ratio (OR) = 4.27, 95% confidence interval (CI) 1.66-10.99] and recent administration of immunosuppressive agents (OR = 2.84, 95% CI 1.02-7.91). However, the type of antibiotic was not associated with treatment failure. TZP could be an effective alternative to ertapenem for the treatment of APN caused by ESBL-Ec, sparing carbapenem consumption in the multidrug-resistant era.

Virulence factors and clinical patterns of hypermucoviscous Klebsiella pneumoniae isolated from urine

BACKGROUND

Klebsiella pneumoniae with hypermucoviscosity (HM) phenotype is generally more virulent than HM-negative strains. The aim of this study was to investigate the prevalence of HM phenotype among urinary isolates and to compare the virulence factors, antimicrobial susceptibility patterns and clinical characteristics of HM-positive and -negative K. pneumoniae isolated from urine of hospitalized patients.

METHODS

From June to October 2013, a total of 81 non-repetitive K. pneumoniae strains were isolated from urine. HM phenotype was determined by a string test. The K1 and K2 genotypes, the allS, kfu, rmpA, rmpA2 and wabG, aerobactin gene were detected by polymerase chain reaction.

RESULTS

Of the 81 K. pneumoniae isolates, 12.3% produced a positive string test. The aerobactin (80.0%[8/10] vs. 15.5%[11/71], p = .0001), allS (40.0%[4/10] vs. 9.9%[7/71], p = .009), rmpA (70.0%[7/10] vs. 14.1%[10/71], p = .0001) and rmpA2 (60.0%[6/10] vs. 16.9%[12/71], p = .002) genes were more prevalent in HM positive than in HM negative strains. The K1 (20.0%[2/10) vs. 8.5%[6/71]] and K2 (30.0%[3/10] vs. 4.2%[3/71]) capsular serotypes were more common in HM strains than in non-HM strains (p = .0001). HM-positive K. pneumoniae isolates were more susceptible to amoxicillin/clavulanic acid (p = .02), cefazolin (p = .03), cefotaxime (p = .02) and ciprofloxacin (p = .03) than HM-negative isolates. Multivariate analysis showed that HM phenotype (OR, 23.87; 95% CI, 3.91-145.4, p < .01) and age >60 years (OR, 8.33; 95% CI, 1.25-55.31, p = .03) were significant risk factors for concurrent bacteraemia.

CONCLUSION

Klebsiella pneumoniae with expression of HM phenotype isolated from urine were more likely to be associated with concurrent bacteraemia than isolates without the HM phenotype, and were more susceptible to antibiotics. Physicians have to be aware of the possibility of bacteraemia in patients with K. pneumoniae bacteriuria, especially if strains are HM positive and the patient is >60 years old.

The Antimicrobial Susceptibility of Klebsiella pneumoniae from Community Settings in Taiwan, a Trend Analysis

Drug-resistant Klebsiella pneumoniae, especially extended-spectrum β-lactamase (ESBL)- and/or AmpC β-lactamase-producing strains, is an emerging problem worldwide. However, few data focusing on drug susceptibility of K. pneumoniae from community is available. In this study, we analyzed 1016 K. pneumoniae isolates from outpatients or those visiting emergency rooms collected during 2002–2012 from Taiwan Surveillance of Antimicrobial Resistance program. Significantly decreased susceptibilities to 3^rd generation cephalosporins and ciprofloxacin were found during the study period. By 2012, susceptibility to cefotaxime and ciprofloxacin was 83.6% and 81.6%, respectively. The prevalence of ESBL-producers increased from 4.8% in 2002 to 11.9% in 2012 (P = 0.012), while that of AmpC β-lactamase-producers increased from 0% to 9.5% in the same period (P < 0.001). Phylogenic analysis of the ESBL and AmpC-β-lactamase-producers by pulsed-field gel electrophoresis and multi-locus sequence typing revealed wide genetic diversity even among the most common sequence type 11 isolates (33.0%). By multivariate analysis, later study year, elderly, and urine isolates were associated with carriage of ESBL genes, while only urine isolates were associated with carriage of AmpC β-lactamase genes. Further studies are needed to determine which antibiotics are reasonable empirical therapy options for patients presenting with severe sepsis that might be caused by K. pneumoniae.

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.

Microbiological Characteristics of Unresolved Acute Uncomplicated Cystitis

This study sought to compare the antimicrobial susceptibility rates between acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who were considered unresolved cases, and newly presenting acute uncomplicated cystitis patients without recent antimicrobial use within 3 months and to determine whether different treatment strategies should be applied according to recent antimicrobial exposure (RAE). Female acute uncomplicated cystitis patients with Escherichia coli growth, who visited our hospital's urology department from 2010 to 2014, were divided according to RAE. The antimicrobial susceptibility of E. coli was compared between the group with RAE and the group with no antimicrobial exposure (NAE) within 3 months. The total number of acute uncomplicated cystitis patients with E. coli growth was 259: 40 patients comprised the RAE group and 219 patients formed the NAE group. The mean age was significantly older and previous recurrent cystitis history was higher in the RAE group (p < 0.05). Furthermore, the antimicrobial susceptibility of E. coli to amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, and trimethoprim-sulfamethoxazole was significantly lower in the RAE group, with susceptibility results of 64.7%/88.0% (RAE/NAE), 77.5%/89.0%, 79.4%/95.3%, 31.3%/64.2%, and 42.5%/70.6%, respectively. RAE was an independent factor for antimicrobial resistance. This study showed that antimicrobial susceptibilities were significantly lower in acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who are defined as unresolved cases. Our results suggest that first-line antimicrobials might show poor efficacy in cases of unresolved, acute uncomplicated cystitis and alternative or secondary antimicrobials should be considered in these cases.

Virulence factors, antibiotic resistance phenotypes and O-serogroups of Escherichia coli strains isolated from community-acquired urinary tract infection patients in Mexico

BACKGROUND/PURPOSE

Uropathogenic Escherichia coli (UPEC) strains isolated from patients with community-acquired urinary tract infections (UTIs) were assessed to determine the prevalence of virulence genes, antibiotic resistance, and the O-serogroup of the strains.

METHODS

Consenting patients with community-acquired UTI were enrolled at Unidad Médica Familiar Number 64 (Instituto Mexicano del Seguro Social, Estado de Mexico, Mexico) and 321 urine samples were collected. Polymerase chain reaction (PCR) was used to assess 24 virulence genes and 14 O-serogroups. The Kirby-Bauer method was used to evaluate the antibiotic susceptibility of the isolated strains to 12 commonly used antibiotics.

RESULTS

A total of 194 strains were identified as E. coli using standard biochemical tests, followed by PCR amplification of 16S ribosomal RNA gene. Only 58.2% of the strains belonged to the assessed 14 O-serogroups. The serogroups O25, O15, O8, and O75 were present in 20.6%, 17%, 6.1%, and 4.6% of strains, respectively. The most frequently occurring virulence genes among UPEC strains included kpsMT (92.2% strains), usp (87.1%), irp2 (79.3%), iha (64.9%), fim (61.3%), set (36%), astA (33.5%), pap (24.7%), and papGII (21.1%). In addition, 97% of the strains were multi-drug resistant (coresistance to 3-11 antibiotics).

CONCLUSION

The isolated UPEC strains predominantly belonged to three serogroups (O25, O15, and O8), harboured numerous virulence genes, and are multiresistant to antibiotics. The findings of this study could be used to orient UTI treatment strategies and in epidemiological studies in Mexico.

Epidemiology of carbapenem resistant Enterobacteriaceae (CRE) during 2000-2012 in Asia

BACKGROUND

Over the past decade, the worldwide emergence of carbapenem resistance in Enterobacteriaceae has become a severe public health issue. This meta-analysis aims to describe the epidemiology of carbapenem resistant Enterobacteriaceae (CRE) during the years of 2000-2012 in Asian area.

METHODS

PubMed and Embase databases were searched to identify the qualified papers. Random or fixed-effect model was used to deal with the data.

RESULTS

Over all the 49 Asian countries (or regions), only 37.5% [19] of them contributed epidemiology data of CRE, and the rest ones provided either only case reports or no information at all. In Asia, the prevalence of CRE was still low during the study period with average resistance rates of 0.6% (95% CI, 0.6-0.8%, imipenem) and 0.9% (95% CI, 0.7-1.2%, meropenem). Resistance rates to imipenem and meropenem in Enterobacteriaceae exhibited stably escalating trend. Similar trend can also be observed among each Enterobacteriaceae genus, such as E. coli, Klebsiella spp. and Enterobacer spp. Klebsiella spp. accounted for the largest proportion among the isolates resistant to imipenem, and then followed by E. coli and Serratia. The rank order of resistance rates to imipenem among Enterobacteriaceae genus during the period of 2000-2012 was as follows: Serratia spp. (1.8%) > Proteus spp. (1.6%) > Klebsiella spp. (0.8%) = Citrobacter spp. (0.8%) > Enterobacer spp. (0.7%) > E. coli (0.2%).

CONCLUSIONS

Given the fact that the prevalence of CRE was increasing during the past decade, it is urgent for us to establish regional surveillance worldwide, carry out more effective antibiotic stewardship and infection control measures to prevent further spread of carbapenem resistance in Enterobacteriaceae.

Clinical and bacteriological efficacy of amikacin in the treatment of lower urinary tract infection caused by extended-spectrum beta-lactamase-producing Escherichia coli or Klebsiella pneumoniae

Urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria have become a growing problem limiting therapeutic options. The aim of this study was to investigate the clinical and microbiological efficacy of amikacin treatment in adult patients with lower UTIs due to ESBL-producing Escherichia coli (Ec) or Klebsiella pneumonia (Kp). We conducted a retrospective study of 36 outpatients aged >18 years with dysuria or problems with frequency or urgency in passing urine; pyuria and a positive urine culture (10(5) cfu/ml) for ESBL producing Ec or Kp which is also resistant to nitrofurantoin, fosfomycin, quinolones and trimethoprim/sulfamethoxazole, between January 2013 and February 2014. Patients received intramuscular amikacin 15 mg/kg/day for 10 days. Clinical success was defined as disappearance of symptoms. Bacteriological success was defined as sterile control urine cultures. 58.3% of patients were female. Age range was 18-89 years. All of the patients had at least one complicating factor. 77.8% of the isolates were E. coli. Clinical success rate was 97.2%. Overall bacteriological success rates were 91.7% on the 3 day of treatment, 97.1% at the end of the treatment and 94.1% on the 7-10 days after treatment. After 28-32 days following the treatment, reinfection was found in 12% whereas relapse was not determined. Nephrotoxicity was developed in one patient. The clinicians should keep in mind that amikacin treatment is an efficient and safe alternative treatment option before the carbapenem treatment especially in patients with lower UTIs caused by ESBL-producing Ec or Kp that are resistant to all oral antibiotics.

Uncomplicated Urinary Tract Infections and Antibiotic Resistance-Epidemiological and Mechanistic Aspects

Uncomplicated urinary tract infections are typically monobacterial and are predominantly caused by Escherichia coli. Although several effective treatment options are available, the rates of antibiotic resistance in urinary isolates of E. coli have increased during the last decade. Knowledge of the actual local rates of antibiotic resistant pathogens as well as the underlying mechanisms are important factors in addition to the geographical location and the health state of the patient for choosing the most effective antibiotic treatment. Recommended treatment options include trimethoprim alone or in combination with sulfamethoxazol, fluoroquinolones, β-lactams, fosfomycin-trometamol, and nitrofurantoin. Three basic mechanisms of resistance to all antibiotics are known, i.e., target alteration, reduced drug concentration and inactivation of the drug. These mechanisms—alone or in combination—contribute to resistance against the different antibiotic classes. With increasing prevalence, combinations of resistance mechanisms leading to multiple drug resistant (mdr) pathogens are being detected and have been associated with reduced fitness under in vitro situations. However, mdr clones among clinical isolates such as E. coli sequence type 131 (ST131) have successfully adapted in fitness and growth rate and are rapidly spreading as a worldwide predominating clone of extraintestinal pathogenic E. coli.