Resistant gram-negative infections in the outpatient setting in Latin America

Distribution and Antimicrobial Resistance of Complicated Intraabdominal Infection Pathogens in Two Tertiary Hospitals in Egypt

Background: Management of complicated intraabdominal infections (cIAIs) requires containment of the source and appropriate initial antimicrobial therapy. Identifying the local data is important to guide the empirical selection of antimicrobial therapy. In this study, we aimed to describe the pathogen distribution and antimicrobial resistance of cIAI. Methods: In two major tertiary care hospitals in Egypt, we enrolled patients who met the case definition of cIAI from October 2022 to September 2023. Blood cultures were performed using the BACTAlert system (BioMerieux, Marcy l'Etoile, France). A culture of aspirated fluid, resected material, or debridement of the infection site was performed. Identification of pathogens and antimicrobial susceptibility testing were conducted by the VITEK-2 system (BioMerieux, Marcy l'Etoile, France). Gram-negative resistance genes were identified by PCR and confirmed by whole bacterial genome sequencing using the Nextera XT DNA Library Preparation Kit and sequencing with the MiSeq Reagent Kit 600 v3 (Illumina, USA) on the Illumina MiSeq. Results: We enrolled 423 patients, 275 (65.01%) males. The median age was 61.35 (range 25-72 years). We studied 452 recovered bacterial isolates. Gram-negative bacteria were the vast majority, dominated by E. coli, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Proteus mirabilis (33.6%, 30.5%, 13.7%, 13%, and 5.4%, respectively). High rates of resistance were detected to third- and fourth-generation cephalosporins and fluoroquinolones. No resistance was detected to colistin. Resistance to amikacin and tigecycline was low among all isolates. Resistance to meropenem and ceftazidime/avibactam was moderate. ESBL genes were common in E. coli and K. pneumoniae. CTX-M15 gene was the most frequent. Among Enterobacterales, blaOXA-48 and blaNDM were the most prevalent carbapenemase genes. Pseudomonas aeruginosa isolates harbored a wide variety of carbapenemase genes (OXA, NDM, VIM, SIM, GIM, SPM, IMP, AIM), dominated by metallo-beta-lactamases. In 20.6% of isolates, we identified two or more resistance genes. Conclusion: High resistance rates were detected to third- and fourth-generation cephalosporins and fluoroquinolones. Amikacin and tigecyclines were the most active antimicrobials. Our data call for urgent implementation of antimicrobial stewardship programs and reinforcement of infection control.

Prevalence and antimicrobial resistance profile of pathogens isolated from patients with urine tract infections admitted to a university hospital in a medium-sized Brazilian city

This study aimed to determine the antibiotic profile of microorganisms isolated from urine samples of patients with community urine tract infections (UTI) admitted to the University Hospital of the Federal University of Sao Carlos to support an appropriate local empirical treatment. A retrospective cross-sectional study was conducted from October 2018 to October 2020. Data from 1,528 positive urine cultures for bacterial pathogens and antibiograms were tabulated. Bacterial species prevalence and their resistance profile were analyzed and compared by sex and age. For Gram-negative fermenting bacteria, resistance rates were compared between patients with previous hospitalization and the total of infections caused by this group. For comparisons, the Chi-square test was performed, using Fisher's exact test when necessary (BioEstat program, adopting p ≤ 0.05). A multivariate analysis was applied to assess the effect of the studied variables in predicting multidrug resistance. Infections were more prevalent in women and older adults. Gram-negative bacteria represented 90.44% of total cultures. In both sexes, E. coli prevalence was significantly higher in adults compared with older adults (p < 0.0001). For several antibiotics, resistance rates were higher in the older adults compared with other ages and in patients with Gram-negative fermenting infections and previous hospitalization compared with the total of infections by this group of bacteria. The closer to the hospitalization, the higher the number of antibiotics with superior resistance rates. Resistance rates for aminoglycosides, carbapenems, ceftazidime, nitrofurantoin, piperacillin+tazobactam, and fosfomycin were less than 20%, considered adequate for empirical treatment. Only hospitalization in the previous 90 days was statistically significant in predicting infections by multidrug-resistant bacteria.

Dominance of ST131, B2, blaCTX-M-15, and papA-papC-kpsMII-uitA among ESBL Escherichia coli isolated from bloodstream infections in Quito, Ecuador: a 10-year surveillance study (2009-2019)

AIMS

This study aimed to examine antibiotic resistance and the epidemiology of extended-spectrum β-lactamases (ESBL)-producing Escherichia coli associated with bloodstream infections over a period of 10 years.

METHODS AND RESULTS

Isolates were collected from January 2009 to December 2019 and those testing for E. coli were included. Antibiotic susceptibility was tested using the VITEK® system. Selected isolates were further characterized by amplification of marker genes (virulence traits, phylogroups, and sequence types). A total of 166 ESBL-producing E. coli were recovered. The blaCTX-M-15 allele was the most abundant. Most of the isolates were resistant to ceftriaxone, cefepime, ceftazidime, ampicillin/sulbactam, piperacillin/tazobactam, and ciprofloxacin. No resistance to carbapenems was registered. More than 80% of bacteria were classified as extraintestinal pathogenic E. coli (ExPEC), and the combination of virulence traits:papA-papC-kpsMII-uitA was the most common. Phylogroup B2 was the most prevalent, and bacteria predominantly belonged to ST131.

CONCLUSIONS

There was an increase in the ExPEC ESBL-E coli in bloodstream infections and the relationship between the isolates found in these infections during these 10 years.

Nitrofuran Derivatives Cross-Resistance Evidence-Uropathogenic Escherichia coli Nitrofurantoin and Furazidin In Vitro Susceptibility Testing

The treatment of urinary tract infections is usually empirical. For example, nitrofuran derivatives, mainly nitrofurantoin (but also furazidin), are used in Eastern Europe. A significant problem is the assessment of the usefulness of furazidin, as there are no standards for susceptibility testing. Additionally, a high percentage of strains resistant to nitrofurantoin should prompt caution when choosing furazidin in therapy. This study aimed to answer the question of whether it is possible to use nitrofurantoin susceptibility for furazidin drug susceptibility analyses and if there is any cross-resistance in the nitrofuran derivatives group. One hundred E. coli clinical isolates, obtained from the Central Teaching Hospital of the Medical University of Lodz, were cultured from positive urine samples. For susceptibility testing, microdilution and disk diffusion methods, following EUCAST guidelines, were used. The results showed that the MICs of furazidin were equal to or lower than those of nitrofurantoin in 89% of the tested strains. The MIC50/90 values for furazidin were two times lower than those for nitrofurantoin. Positive correlations were found between MICs and growth inhibition zones for both antibiotics. Based on the obtained data and previous studies, it was assumed that the transfer of susceptibility testing results from nitrofurantoin to furazidin is acceptable due to cross-resistance in nitrofuran derivatives.

Effectiveness of Five Antibiotic Regimens for the Treatment of Intra-Abdominal Infection in Bogotá

Background: Intra-abdominal infection (IAI) results in prolonged in-hospital length-of-stay, critical care unit requirements, and multiple surgical procedures. Several antimicrobial agents are available for treatment of IAI. In Colombia, there are no data on the comparative effectiveness of the different regimens used. Patients and Methods: A multicenter retrospective cohort study was completed in four third-level hospitals by comparing treatment effectiveness of five different antibiotic protocols (ampicillin-sulbactam, clindamycin-amikacin, piperacillin-tazobactam, amikacin-metronidazole, and cefuroxime-metronidazole) in patients with a diagnosis of IAI. Analysis was based on a composed outcome of therapeutic failure (change of antibiotic because of no clinical improvement, requirement of surgical re-intervention, post-operative infection, change of antibiotic because of antimicrobial resistance, and in-hospital mortality). Association of each antibiotic protocol to therapeutic failure was assessed through logistic regression analysis. Results: Five hundred ninety-three individuals were included. Two hundred twenty-nine were prescribed ampicillin-sulbactam; 170, clindamycin-amikacin; 77, amikacin-metronidazole; 83, piperacillin-tazobactam; and 34, cefuroxime-metronidazole. Therapeutic failure rate was 22%. Multivariable analysis showed none of the evaluated antibiotic protocols had an association with the primary outcome. Variables having an association for higher risk were age >70 years old (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.04-4.18); complicated IAI (OR, 3.36; 95% CI, 1.4-8.07); and World Society of Emergency Surgery (WSES) Sepsis Severity Score (OR, 1.31; 95% CI, 1.18-1.45). Adequate source control (OR, 0.16; 95% CI, 0.05-0.45) and hospitalization at Health Center 2 (OR, 0.30; 95% CI, 0.14-0.63) were identified as protective factors. Conclusions: There are no differences between the rate of therapeutic failure among the different antibiotic protocols evaluated. This outcome depends heavily on risk factors related to disease severity when surgical intervention occurs.

Changes in Antimicrobial Resistance and Etiology of Blood Culture Isolates: Results of a Decade (2010-2019) of Surveillance in a Northern Region of Colombia

Background

Bloodstream infections (BSI) are important causes of morbidity and mortality worldwide. Antimicrobial surveillance is essential for identifying emerging resistance and generating empirical treatment guides, the purpose of this study is to analyze trends in antimicrobial susceptibility of BSI from 2010 to 2019 in healthcare institutions from Medellin and nearby towns in Colombia.

Methods

A Whonet database was analyzed from the GERMEN antimicrobial surveillance network; frequency and antibiotic susceptibility trends were calculated on more frequent microorganisms using Mann Kendall and Sen’s Slope Estimator Test.

Results

61,299 isolates were included; the three microorganisms more frequent showed a significant increasing trend through time E. coli (Sen’s Slope estimator = 0.7 p = <0.01) S. aureus (Sen’s Slope estimator = 0.60 p = <0.01) and K. pneumonia (Sen’s Slope estimator = 0.30 p = <0.01). E. coli showed a significant increase trend in cefepime and ceftazidime resistance, while K. pneumoniae showed a significant increase in resistance to cefepime, ciprofloxacin, and gentamicin. P. aeruginosa increases its susceptibility to all analyzed antibiotics and S. aureus to oxacillin. No increasing trend was observed for carbapenem resistance.

Conclusion

An upward trends was observed in more frequent microorganisms and resistance to third and fourth-generation cephalosporins for E. coli and K pneumoniae; in contrast, not increasing trends in antibiotic resistance was observed for P. aeruginosa and S. aureus. The essential role of AMR-surveillance programs is to point out and identify these trends, which should improve antibiotic resistance control.

Prior use of antibiotics and immunosuppression are risk factors for fracture-related infection during the COVID-19 pandemic period: a Brazilian prospective cohort study

Background

Little is known about the role of COVID-19 pandemic period on the epidemiology of fracture-related infection (FRI). The present study summarizes the changes in the prevalence, microbiology, and risk factors of FRI during this period.

Methods

A prospective single-center cohort study assessed in the setting of COVID-19 pandemic (2020–2021), clinical, microbiological aspects, and independent risk factors (RF) of FRI. RFs were estimated by bivariate and multivariable analyses using prevalence ratio (PR) with significance at P < 0.05. Kaplan–Meier analysis was performed to evaluate treatment outcomes.

Results

Overall, 132 patients were analyzed, with patients with age over 65 years accounting 65.1%. FRI was diagnosed in 21(15.9%) patients. Independent RFs for FRI were recent and preoperative use of systemic antibiotics (PR: 7.0, 95% confidence interval (95% CI): 2.2 – 22.4, p = 0.001) and cancer (PR: 9.8, 95% CI: 2.0 – 48.8, p = 0.005). Cultures yielded Gram-negative bacteria in 77.8%, 33.3% were MDR.

Conclusions

We found higher rates of FRI, predominating in the elderly with closed femoral fractures during the COVID-19 pandemic. Prior use of antibiotics and immunosuppression conditions were independent factor for FRI. Our outcomes provide evidence to avoid the empirical use of antibiotics prior to surgery for fracture stabilization.

Non-elective and revision arthroplasty are independently associated with hip and knee prosthetic joint infection caused by Acinetobacter baumannii: a Brazilian single center observational cohort study of 98 patients

BACKGROUND

Prosthetic joint infection (PJI) caused by Acinetobacter baumannii (Ab) has become a growing concern due to its overwhelming ability to express resistance to antibiotics and produce biofilm.

AIM

This study aimed to identify independent risk factors (RFs) associated with Ab-associated PJI and their role in the treatment outcome.

METHODS

This was a single-centre, retrospective cohort study of PJI patients diagnosed between January 2014 and July 2018. A PJI diagnosis was made based upon the MSIS 2018 criteria. To estimate RFs associated with Ab-associated PJI, multivariate analyses with a level of significance of p < 0.05 were performed. To evaluate treatment failure, Kaplan-Meier analysis and log-rank test were performed.

RESULTS

Overall, 98 PJI cases were assessed, including 33 with Ab-associated PJI and 65 with PJI involving other microorganisms (non-Ab-associated PJI). Independent RFs associated with Ab-associated PJI were revision arthroplasty [odds ratio (OR) = 3.01; 95% confidence interval (CI) = 1.15-7.90; p = 0.025] and nonelective arthroplasty (OR = 2.65; 95% CI = 1.01-7.01; p = 0.049). Ab-associated PJI was also more likely than non-Ab-associated PJI to be classified as a chronic late infection (OR = 5.81; 95% CI = 2.1-16.07; p = 0.001). Ab-associated PJI was not associated with treatment failure (p = 0.557).

CONCLUSIONS

Late chronic infections, surgical revision and nonelective arthroplasty are well-known predictors of PJI but were also independently associated with Ab-associated PJI. Infections caused by Ab and surgical treatment with debridement, antibiotics and implant retention were not associated with PJI treatment failure.

TRIAL REGISTRATION

Study data supporting our results were registered with the Brazilian Registry of Clinical Trials ( https://www.ensaiosclinicos.gov.br/rg/RBR-6ft5yb/ ), an open-access virtual platform for the registration of studies on humans performed in Brazil. Registration no. RBR-6ft5yb .

Beta-Lactamase-Producing Escherichia coli Isolates Recovered from Pig Handlers in Retail Shops and Abattoirs in Selected Localities in Southern Nigeria: Implications for Public Health

Antibiotic resistance evolution among pathogenic microorganisms has become a huge burden globally as it has increased the burden of diseases amongst humans and animals. The prevalence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) and metallo beta-lactamase-producing Escherichia coli (MBL-Ec) isolated from pig abattoir and handlers in retail shops was studied. In addition, the relationship between the isolates' prevalence and the background characteristics of the butchers/retailers was also investigated. Samples from 32 hand swabs of pork sellers at retail shops and 8 butchers at abattoirs, as well as 272 swabs taken from knives, tables, floors, water troughs, and carcasses from both retail shops and abattoirs, were collected. Escherichia coli (E. coli) was isolated from hand swabs, fomites, and carcasses and were identified by standard microbiological procedures. The isolates susceptibility to nitrofurantoin (300 µg), ciprofloxacin (5 µg), ceftazidime (30 µg), cefuroxime (30 µg), gentamicin (10 µg), cefixime (5 µg), ofloxacin (5 µg), amoxicillin/clavulanic acid (30 µg), imipenem (10 µg), and meropenem (10 µg) and their ability to produce ESBL and MBL was determined by phenotypic methods. Demographic information of the handlers was retrieved by means of a structured questionnaire and, in some cases, via face to face interviews. Out of 104 E. coli isolates from both sources, 52 (50.0%) and 8 (7.7%) were ESBL and MBL producers, respectively. ESBL was more prevalent on the hands of the retailers (40.6%) and butchers (75.0%). The isolates were 100% resistant to ceftazidime, cefotaxime, and amoxicillin-clavulanic acid and 4.8% resistant to nitrofurantoin. Diverse resistance patterns were observed among ESBL-Ec and MBL-Ec. It was found that 90% of ESBL-Ec and 100% of MBL-Ec were multidrug-resistant. A possible epidemiological link between the two sources was observed. The prevalence of E. coli ESBL- and MBL-producing isolates was associated with the duty performed by handlers (p = 0.012) and gender (p = 0.012). Our results provide evidence that the handlers' hands and abattoir environment had a great role to play in the high prevalence and resistance profiles of the microorganisms.

Antimicrobial resistance profiles and genes in uropathogenic Enterobacteriaceae in reproductive-age women in St. Petersburg, Russia: implication for treatment of pyelonephritis in pregnancy

Background: Urinary tract infections (UTIs) are common in women, and during pregnancy can cause significant morbidity. Growing and greatly varying antimicrobial resistance (AMR) of Enterobacteriaceae, responsible for most UTIs, necessitates regular local AMR surveillance. In obstetric population, where beta-lactams are the mainstay for treatment of severe UTIs, particular focus should be placed on beta-lactam resistance. This study aimed to evaluate AMR rates and frequency of extended spectrum beta-lactamase (ESBL) and carbapenemase genes in uropathogenic Enterobacteriaceae among reproductive-age women in St. Petersburg, Russia.Materials/methods: Urine samples were collected from consecutive reproductive-age women, who attended the D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology from October 2017 to November 2019, and cultured according to routine procedures. Susceptibility to antibiotics and ESBL production was determined using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. All urine samples and Enterobacteriaceae isolates were tested for ESBL and carbapenemase genes using real-time PCR.Results: Enterobacteriaceae were detected in 91 (56 pregnant and 35 non-pregnant) of 119 (76%) included women. The vast majority of Enterobacteriaceae strains were susceptible to nitrofurantoin, fosfomycin and meropenem (99-100%). The frequency of strains susceptible to penicillins and cephalosporins ranged from 59% to 82%; 78% of strains were susceptible to ciprofloxacin. ESBL production was phenotypically detected in 15 (16%) Enterobacteriaceae strains, with CTX-M genes revealed in all cases. In all corresponding urine samples, CTX-M genes were also detected. The remaining 104 urine samples were negative for CTX-M genes. In none of the isolates and urine samples, carbapenemase genes were present.Conclusions: The frequency of ESBL producing Enterobacteriaceae was relatively high (16%), with CTX-M genes detected in all cases in both urine and urine cultures. Rapid PCR detection of CTX-M genes directly in urine samples from women with pyelonephritis can be valuable for timely informing treatment choices.

Drinking water improvements and rates of urinary and gastrointestinal infections in Galápagos, Ecuador: Assessing household and community factors

OBJECTIVES

The Galápagos provides an important setting to investigate the health impacts of a new drinking water treatment plant (DWTP) in a limited resource environment. We examine how household perceptions and practices affect the relationship between water quality and infections before and after DWTP.

METHODS

Ethnographic data and self-reported infections were collected from 121 mothers and 168 children ages 2 to 10 from Isla San Cristóbal. Household tap water samples were tested for levels of fecal contamination. Community level infection rates were estimated using discharge records from the Ministry of Public Health. The effects of the new DWTP and fecal contamination levels on infections were tested using logistic and Poisson models.

RESULTS

Perceptions of water quality and household practices influenced exposures to contaminated tap water. We found minimal change in drinking water sources with 85% of mothers sampled before the DWTP and 83% sampled after using bottled water, while >85% from the pooled sample used tap water for cooking and hygiene practices. The DWTP opening was associated with lower odds of fecal contamination in tap water, reported urinary infections, and community level rates of urinary and gastrointestinal infections. The household practice of recently washing the cistern contributed to higher contamination levels after the DWTP opened.

CONCLUSIONS

To ensure access to clean water, public health works need to consider how household perceptions and practices influence tap water use and quality, in addition to infrastructure improvements. Exposures to contaminated tap water contribute to the burden of infectious disease in environments with inadequate water infrastructure.

Antimicrobial resistance genes present in the faecal microbiota of free-living Galapagos tortoises (Chelonoidis porteri)

Antimicrobial resistance (AMR), encoded by plasmid-mediated AMR genes (ARGs), is an increasing global public health threat. Wildlife play a fundamental role as sentinels, reservoirs and potential vectors of ARGs. For the first time in Galapagos, we have identified and quantified the presence of ARGs in free-living giant tortoises (Chelonoidis porteri). We performed ARG analyses by quantitative PCR of faeces collected from the cloaca of 30 tortoises widely distributed across Santa Cruz Island. Validated samples (n = 28) were analysed by a panel of up to 21 different ARGs and all 28 tortoise samples were positive to one or more genes encoding resistance. Thirteen of 21 tested ARGs were present in at least one sample, and 10 tortoises (35.7%) had a multi-resistant pattern. We recommend additional research so we may more fully understand resistance patterns across taxa and geographical locations throughout the Galapagos archipelago, and the implications of ARGs for the health of wildlife, domestic animals, and humans. In this study, we found 100% of sampled giant tortoises had ARGs present in their faeces, suggesting a large-scale distribution of these genes within the archipelago.

Parental Antibiotic Use in Urban and Peri-Urban Health Care Centers in Lima: A Cross-Sectional Study of Knowledge, Attitudes, and Practices

In pediatric patients, the antibiotic use is affected by parental beliefs and practices; especially in countries where it is possible to acquire them without prescription. This study aims to describe the knowledge, attitudes, and practices on antibiotic use among parents of children from urban and peri-urban health care centers in Lima. A cross-sectional study was performed at 1 urban and 2 peri-urban health care centers selected in Lima, Perú. Parents of children below the age of 3 years answered a knowledge-attitudes-practices-validated questionnaire about antibiotic use and were categorized as high, moderate, and low knowledge regarding antibiotics. We analyzed potential determinants for low knowledge and having medicated their children with unprescribed antibiotics using bivariate and multivariate analyses. A total of 224 parents were enrolled, and 8% were categorized as low knowledge. Half of the parents could not recognize that antibiotics cannot cure viral infections, 59.4% disagreed with "antibiotics speed up recovery from a cold," and 53.2% stored antibiotics at home. Remarkably 23.5% of parents reported having medicated their children with antibiotics without prescription, which was associated with belonging to the peri-urban health care center, use of antibiotics by their children in the last 12 months, and having purchased antibiotics without physicians' prescription. An alarming overuse of antibiotics without prescription was described among children below the age of 3 years. Educational interventions, addressing parental attitudes and practices, and health policies should be developed to limit inappropriate antibiotic use especially in peri-urban communities.

Colorimetric microdilution assay: Validation of a standard method for determination of MIC, IC50%, and IC90% of antimicrobial compounds

The emergence of multiresistant bacteria directly impacts on the search for new compounds with antimicrobial activity, and it is important the improvement of new techniques are able to determine the minimum inhibitory concentration (MIC) of antimicrobial compounds. The microdilution technique is widely used for saving culture media, reagents and compounds to be tested. However, the literature does not describe a colorimetric method capable of correlating absorbance with concentration of viable microorganisms (CFU mL^-1). Therefore, the novelty of this work was the standardization and validation of a colorimetric and quantitative method capable of determining the MIC of several compounds with antimicrobial activity and the conversion of absorbance values to CFU mL^-1. The conditions carried out for the method were: the use of 0.125% (w/v) 2,3,5-triphenyltetrazolium chloride (TTC) solution added after 22 h of incubation at 35 °C, followed by 2 more hours of incubation and subsequent reading in a spectrophotometer. The tested microorganisms were: Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027) and Candida albicans (ATCC 10231). The method was validated and showed linearity (R² > 0.95), precision (RSD <26%), accuracy (75% to 122%) and robustness (p > 0.05). The validated parameters ensured the harmonization of methodology to determine not only MIC as well as inhibitory concentrations of 50% (IC_50%) and 90% (IC_90%) of the antimicrobial compounds.

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.

Extensively-drug-resistant bacteria carriers among overseas travellers: one-third had not been hospitalized previously

BACKGROUND

Extensively-drug-resistant bacteria (XDRB) have emerged as a major source of resistance. Hospitalization abroad seems to be the major risk factor associated with carriage, and numerous reports have warned about the risk of in-hospital transmission. However, little is known regarding possible community transmission.

METHODS

A retrospective matched case-control study was conducted in a Parisian teaching hospital, which included patients admitted to hospital with a history of travel abroad over the preceding 12 months. Each XDRB carrier at admission (case) was matched with two non-carriers (controls) hospitalized in the same ward and admitted during the same month.

AIM

To describe and identify risk factors associated with XDRB carriage at admission.

FINDINGS

Forty-six cases and 92 controls were enrolled. The results of univariate and multi-variate analyses showed that health repatriation was the only factor associated with a higher risk of carrying XDRB (odds ratio 3.22, 95% confidence interval 1.23-7.84; P=0.01). Surprisingly, one-third of the study population had not been hospitalized abroad within the preceding 12 months. The most frequently identified XDRB species were Escherichia coli (36%), Enterococcus spp. (17%) and Klebsiella pneumoniae (9%), and the most frequently identified enzyme was OXA-48 (36%).

CONCLUSION

In this retrospective study, health repatriation was the only risk factor for XDRB carriage identified at admission. Furthermore, the data suggest community-onset transmission. Therefore, there is an urgent need to conduct studies in high-risk countries to identify the risk factors associated with community carriage.

Clinical characterization and antimicrobial resistance of Escherichia coli in pediatric patients with urinary tract infection at a third level hospital of Quito, Ecuador

BACKGROUND

Urinary tract infections (UTI) are among the most common infections in pediatric patients. The main etiopathogenic agent is Escherichia coli. The purpose of this study was to determine the antimicrobial resistance pattern of E. coli in pediatric patients and to understand their main clinical and laboratory manifestations.

METHODS

Fifty-nine patients were included in the study and classified into two groups: hospitalization (H) and external consultation (EC). Every patient presented urine cultures with the isolation of E. coli that included an antibiogram. Clinical signs and symptoms, urinalysis, complete blood count (CBC) and serum inflammatory markers were analyzed.

RESULTS

The most common clinical manifestations were fever (H: 76.5%; EC: 88%), vomiting (H: 32.4%; EC: 32%), hyporexia (H: 20.6%; EC: 16%), abdominal pain (H: 20.6%: EC: 28%), and dysuria (H: 14.7%; EC: 32%). Ten patients (16.95%) presented UTI for extended spectrum beta-lactamase (ESBL) E. coli. Ampicillin, nalidixic acid, and trimethoprim-sulfamethoxazole showed a higher resistance rate, being ampicillin the most significant (H: 88.2%; EC: 92%). Leukocyturia, bacteriuria and urine nitrites were frequent alterations in urinalysis (H: 52.9%; EC: 92%). In ESBL E. coli patients, a positive correlation was found between leukocytes in CBC and C-reactive protein (r = 0.9, p < 0.01). Diarrhea and foul-smelling urine were associated with E. coli resistance.

CONCLUSIONS

The presence of leukocytes, bacteria, nitrites and the Gram stain are the most common indicators. Nitrofurantoin and phosphomycin are good therapeutic options. However, an antibiogram must be conducted to determine the best therapeutic agent.

Carbapenem-resistant Enterobacteriaceae in the community: a scoping review

Carbapenem antibiotics are used as a last resort to treat serious Gram-negative bacteria (GNB) infections; however, carbapenemase-producing strains of GNB have emerged as a major source of resistance. Owing to the highly transmissible nature of plasmid-borne carbapenemases, numerous reports have warned about the likely spread into the community from healthcare settings. Since the prevalence of carbapenem-resistant Enterobacteriaceae (CRE) in the community is largely unknown, we conducted a scoping review of the literature to assess the percentage of CRE isolates that could be associated with the community. Initially, 361 studies were assessed and 15 met the inclusion criteria. Although 5 studies (33.3%) found no community-associated CRE, the remaining 10 studies identified percentages ranging from 0.04% to 29.5% of either community-associated or community-onset CRE among their samples, with US-based studies alone ranging from 5.6 to 10.8%. The presence of CRE in the community poses an urgent public health threat.

First Report of Group CTX-M-9 Extended Spectrum Beta-Lactamases in Escherichia coli Isolates from Pediatric Patients in Mexico

The aim of this study was to identify the presence of group CTX-M-9 extended spectrum beta-lactamases (ESBL) in clinical Escherichia coli isolates from pediatric patients. A total of 404 non-repeated positive ESBL E. coli isolates were collected from documented clinical infections in pediatric patients over a 2-year period. The identification and susceptibility profiles were determined using an automated system. Isolates that suggested ESBL production based on their resistance profiles to third and fourth generation cephalosporin and monobactam were selected. ESBL production was phenotypically confirmed using a diffusion method with cefotaxime and ceftazidime discs alone and in combination with clavulanic acid. blaESBL gene identification was performed through PCR amplification and sequencing. Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) were performed to establish the clonal relationships of the E. coli isolates. CTX-M-9-type ESBLs were detected in 2.5% of the isolates. The subtypes corresponded to blaCTX-M-14 (n = 4) and blaCTX-M-27 (n = 6). Additionally, coexistence with other beta-lactamases was observed. A clonal relationship was established in three isolates; the rest were classified as non-related. We found seven different sequence type (ST) in CTX-M-9- producing E. coli isolates. ST38 was the most frequent. This study is the first report in Mexico to document the presence of group CTX-M-9 ESBLs in E. coli isolates from pediatric patients.

Intra-abdominal Infections: The Role of Anaerobes, Enterococci, Fungi, and Multidrug-Resistant Organisms

BACKGROUND

Intra-abdominal infections (IAI) constitute a common reason for hospitalization. However, there is lack of standardization in empiric management of (1) anaerobes, (2) enterococci, (3) fungi, and (4) multidrug-resistant organisms (MDRO). The recommendation is to institute empiric coverage for some of these organisms in "high-risk community-acquired" or in "healthcare-associated" infections (HCAI), but exact definitions are not provided.

METHODS

Epidemiological study of IAI was conducted at Assaf Harofeh Medical Center (May-November 2013). Logistic and Cox regressions were used to analyze predictors and outcomes of IAI, respectively. The performances of established HCAI definitions to predict MDRO-IAI upon admission were calculated by receiver operating characteristic (ROC) curve analyses.

RESULTS

After reviewing 8219 discharge notes, 253 consecutive patients were enrolled (43 [17%] children). There were 116 patients with appendicitis, 93 biliary infections, and 17 with diverticulitis. Cultures were obtained from 88 patients (35%), and 44 of them (50%) yielded a microbiologically confirmed IAI: 9% fungal, 11% enterococcal, 25% anaerobic, and 34% MDRO. Eighty percent of MDRO-IAIs were present upon admission, but the area under the ROC curve of predicting MDRO-IAI upon admission by the commonly used HCAI definitions were low (0.73 and 0.69). Independent predictors for MDRO-IAI were advanced age and active malignancy.

CONCLUSIONS

Multidrug-resistant organism-IAIs are common, and empiric broad-spectrum coverage is important among elderly patients with active malignancy, even if the infection onset was outside the hospital setting, regardless of current HCAI definitions. Outcomes analyses suggest that empiric regimens should routinely contain antianaerobes (except for biliary IAI); however, empiric antienterococcal or antifungals regimens are seldom needed.

Infecções comunitárias do trato urinário: prevalência e susceptibilidade aos antimicrobianos na cidade de Florianópolis

Objetivo: Determinar a frequência de isolamento dos uropatógenos e avaliar o perfil de sensibilidade antimicrobiana in vitro das bactérias isoladas em uroculturas de pacientes ambulatoriais atendidos em Florianópolis no ano de 2014, correlacionando tais dados com sexo e idade do paciente. Métodos: Estudo observacional, descritivo do tipo transversal, que incluiu uroculturas positivas de pacientes ambulatoriais realizadas em um único laboratório seguindo a mesma metodologia. Realizaram-se análises de estatísticas descritivas e testes de associação entre as variáveis classificatórias: sexo, idade, agente etiológico e sensibilidade aos antimicrobianos. Resultados: Foram registradas 1035 uroculturas positivas, das quais 89,66% de pacientes femininas. Microrganismos Gram-negativos foram os patógenos mais isolados, com destaque para a Escherichia coli (77,10%), principal agente causal. Proteus mirabilis foi significativamente mais prevalente no sexo masculino e o principal microrganismo isolado nas uroculturas dos meninos de 1 a 5 anos. A E. coli foi significativamente mais prevalente no sexo feminino e apresentou o perfil mais amplo de resistência. Evidenciaram-se diferenças estatisticamente significativas nas resistências às fluoroquinolonas entre os gêneros, com maiores prevalências de resistência em homens e entre as faixas etárias, com maior resistência entre idosos. Conclusões: Idade e sexo são variáveis determinantes na frequência de isolamento dos uropatógenos e na prevalência da susceptibilidade antimicrobiana; e os microrganismos mais prevalentes já não respondem satisfatoriamente a parte dos antimicrobianos amplamente utilizados. É fundamental que o médico considere tais informações no momento da decisão terapêutica e preze pelo uso racional dos antimicrobianos, sobretudo aqueles de largo espectro como as fluoroquinolonas.

Detection and molecular characterization of β-lactamase genes in clinical isolates of Gram-negative bacteria in Southern Ecuador

This work performed a phenotypic and genotypic characterization of 79 clinical isolates of Enterobacteriaceae and Pseudomonadaceae collected in hospitals of Southern Ecuadorin 2013. Our results showed a high incidence of β-lactamases and ESBLs with bla_TEM and bla_CTX-M as the prevalent genes, respectively. By direct sequencing of PCR amplicons, the different β-lactamases and variants of the genes were also distinguished. Our results revealed a predominance of TEM-1 β-lactamase and the presence of different CTX-M variants with a prevalence of CTX-M-15. Two infrequent CTX-M variants in South America were also identified. To the best of our knowledge, this is one of the first studies describing the genetic characteristics of β-lactamases in Ecuador.

Unexpected distribution of the fluoroquinolone-resistance gene qnrB in Escherichia coli isolates from different human and poultry origins in Ecuador

Fluoroquinolone resistance can be conferred through chromosomal mutations or by the acquisition of plasmids carrying genes such as the quinolone resistance gene (qnr). In this study, 3,309 strains of commensal Escherichia coli were isolated in Ecuador from: (i) humans and chickens in a rural northern coastal area (n = 2368, 71.5%) and (ii) chickens from an industrial poultry operation (n = 827, 25%). In addition, 114 fluoroquinolone-resistant strains from patients with urinary tract infections who were treated at three urban hospitals in Quito, Ecuador were analyzed. All of the isolates were subjected to antibiotic susceptibility screening. Fluoroquinolone-resistant isolates (FRIs) were then screened for the presence of qnrB genes. A significantly higher phenotypic resistance to fluoroquinolones was determined in E. coli strains from chickens in both the rural area (22%) and the industrial operation (10%) than in strains isolated from humans in the rural communities (3%). However, the rates of qnrB genes in E. coli isolates from healthy humans in the rural communities (11 of 35 isolates, 31%) was higher than in chickens from either the industrial operations (3 of 81 isolates, 6%) or the rural communities (7 of 251 isolates, 2.8%). The occurrence of qnrB genes in human FRIs obtained from urban hospitals was low (1 of 114 isolates, 0.9%). These results suggested that the qnrB gene is more widely distributed in rural settings, where antibiotic usage is low, than in urban hospitals and industrial poultry operations. The role of qnrB in clinical resistance to fluoroquinolones is thus far unknown.

[Prevalence and risk factors for extended-spectrum β-lactamase-producing Escherichia coli causing community-onset urinary tract infections in Colombia]

INTRODUCTION

Urinary tract infections (UTI) are common in the community. However, information of resistant isolates in this context is limited in Latin America. This study aims to determine the prevalence and risk factors associated with community-onset UTI (CO-UTI) caused by extended-spectrum β-lactamase (ESBL)-Producing Escherichia coli in Colombia.

MATERIALS AND METHODS

A case-control study was conducted between August and December of 2011 in three Colombian tertiary-care institutions. All patients who were admitted to the Emergency Department with a probable diagnosis of CO-UTI were invited to participate. All participating patients were asked for a urine sample. ESBL confirmatory test, antibiotic susceptibility, and molecular epidemiology were performed in these E.coli isolates (Real Time-PCR for bla genes, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] and virulence factors by PCR). Clinical and epidemiological information was recorded, and a statistical analysis was performed.

RESULTS

Of the 2124 recruited patients, 629 had a positive urine culture, 431 of which grew E.coli; 54 were positive for ESBL, of which 29 were CTX-M-15. The majority of ESBL isolates were susceptible to ertapenem, phosphomycin and amikacin. Complicated UTI was strongly associated with ESBL-producing E.coli infections (OR=3.89; 95%CI: 1.10-13.89; P=.03). CTX-M-15-producing E.coli showed 10 different pulsotypes, 65% were PT1 or PT4, and corresponded to ST131. Most of these isolates had 8 out of the 9 analysed virulence factors.

DISCUSSION

E.coli harbouring bla_CTX-M-15 associated with ST131 is still frequent in Colombia. The presence of complicated CO-UTI increases the risk of ESBL-producing E.coli, and must be taken into account in order to provide an adequate empirical therapy.

Antimicrobial susceptibility and emerging resistance determinants (blaCTX-M, rmtB, fosA3) in clinical isolates from urinary tract infections in the Bolivian Chaco

BACKGROUND

Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here.

METHODS

All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed (N=213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers.

RESULTS

Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae, 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected.

CONCLUSIONS

Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines.

Bacteriuria and urinary tract infection after female urodynamic studies: risk factors and microbiological analysis

BACKGROUND

This study was conducted to determine risk factors for infectious complications after urodynamic study (UDS) in women, which can assist clinicians in identifying high-risk subjects who would benefit from antibiotic prophylaxis before UDS.

METHODS

In this prospective cohort study, we studied 232 women who underwent UDS at Santa Casa de São Paulo School of Medical Sciences between June 2013 and June 2014. Women ranging in age from 26 to 84 years who had urinary incontinence, pelvic organ prolapse, or voiding dysfunction were required to collect urine samples at 7 days before, on the day of, and 3-5 days after UDS. Urine cultures with >100,000 CFU/mL were considered positive. Risk factors associated with bacteriuria and urinary tract infection (UTI) after UDS were evaluated using multivariate analysis with multiple logistic regression.

RESULTS

Two hundred thirty-two out of 257 women were subjected to further analysis. The incidence of bacteriuria, transient bacteriuria, and UTI after UDS was 11.6%, 7.3%, and 4.3%, respectively. On multivariate analysis, hypothyroidism (P = .04), body mass index (BMI) >30 (P = .025), and advanced pelvic organ prolapse (P = .021) were associated with a significantly increased risk of bacteriuria; however, only BMI >30 (P = .02) was associated with an increased risk for UTI.

CONCLUSIONS

The rate of infectious complications after UDS was low, and advanced pelvic organ prolapse and hypothyroidism increased the risk for bacteriuria. However, only BMI >30 was associated with bacteriuria and UTI after UDS.

Potential virulence of Klebsiella sp. isolates from enteral diets

We aimed to evaluate the potential virulence of Klebsiella isolates from enteral diets in hospitals, to support nosocomial infection control measures, especially among critical-care patients. Phenotypic determination of virulence factors, such as capsular expression on the external membrane, production of aerobactin siderophore, synthesis of capsular polysaccharide, hemolytic and phospholipase activity, and resistance to antibiotics, which are used therapeutically, were investigated in strains of Klebsiella pneumoniae and K. oxytoca. Modular industrialized enteral diets (30 samples) as used in two public hospitals were analyzed, and Klebsiella isolates were obtained from six (20%) of them. The hypermucoviscous phenotype was observed in one of the K. pneumoniae isolates (6.7%). Capsular serotypes K1 to K6 were present, namely K5 and K4. Under the conditions of this study, no aerobactin production, hemolytic activity or lecithinase activity was observed in the isolates. All isolates were resistant to amoxicillin and ampicillin and sensitive to cefetamet, imipenem, chloramphenicol, gentamicin and sulfamethoxazole-trimethoprim. Most K. pneumoniae isolates (6/7, 85.7%) from hospital B presented with a higher frequency of resistance to the antibiotics tested in this study, and multiple resistance to at least four antibiotics (3/8; 37.5%) compared with isolates from Hospital A. The variations observed in the antibiotic resistance profiles allowed us to classify the Klebsiella isolates as eight antibiotypes. No production of broad-spectrum β-lactamases was observed among the isolates. Our data favor the hypothesis that Klebsiella isolates from enteral diets are potential pathogens for nosocomial infections.