Füsun Can

Emerging Escherichia coli O25b/ST131 Clone Predicts Treatment Failure in Urinary Tract Infections

BACKGROUND We described the clinical predictive role of emerging Escherichia coli O25b/sequence type 131 (ST131) in treatment failure of urinary tract infection. METHODS In this prospective observational cohort study, the outpatients with acute cystitis with isolation of E. coli in their urine cultures were assessed. All the patients were followed up for clinical cure after 10 days of treatment. Detection of the E. coli O25:H4/ST131 clone was performed by multiplex polymerase chain reaction (PCR) for phylogroup typing and using PCR with primers for O25b rfb and allele 3 of the pabB gene. RESULTS In a cohort of patients with diagnosis of acute urinary cystitis, 294 patients whose urine cultures were positive with a growth of >10(4) colony-forming units/mL of E. coli were included in the study. In empiric therapy, ciprofloxacin was the first choice of drug (27%), followed by phosphomycin (23%), trimethoprim-sulfamethoxazole (TMP-SMX) (9%), and cefuroxime (7%). The resistance rate was 39% against ciprofloxacin, 44% against TMP-SMX, and 25% against cefuroxime. Thirty-five of 294 (12%) isolates were typed under the O25/ST131 clone. The clinical cure rate was 85% after the treatment. In multivariate analysis, detection of the O25/ST131 clone (odds ratio [OR], 4; 95% confidence interval [CI], 1.51-10.93; P = .005) and diabetes mellitus (OR, 2.1; 95% CI, .99-4.79; P = .05) were found to be significant risk factors for the treatment failure. In another multivariate analysis performed among quinolone-resistant isolates, treatment failure was 3 times more common among the patients who were infected with ST131 E. coli (OR, 3; 95% CI, 1.27-7.4; P = .012). CONCLUSIONS In urinary tract infections, the E. coli ST131 clone seems to be a consistent predictor of treatment failure.

Transmission of methicillin-sensitive Staphylococcus aureus to a preterm infant through breast milk.

Abstract Contrary to traditional belief, breast milk is not a sterile fluid, even in healthy women. Breast milk may contain pathogenic bacteria that could cause serious infections especially in premature infants. There is no recommendation to evaluate breast milk routinely for pathogenic bacteria. However discontinuation of breastfeeding is not recommended even the mother had mastitis, because it is believed this will not pose a risk to infant. This is the report of a premature infant born at the 32nd gestational week who was readmitted to neonatal intensive care unit with late-onset Staphylococcus aureus sepsis. While searching for the transmission route of the infection, the breast milk was assessed. Although the mother did not have any symptoms of breast inflammation, S. aureus isolates, genetically 99% similar to those from the infant blood samples, were documented in the breast milk. Conclusion: Breast milk may contain pathogenic bacteria, even when expressed, stored and transported properly. When evaluating the source of a S. aureus infection in preterm infants, breast milk might be the source of the infection, even if the mother has no sign of mastitis.

Healthcare-associated Gram-negative bloodstream infections: antibiotic resistance and predictors of mortality.

This article describes the prevalence of antibiotic resistance and predictors of mortality for healthcare-associated (HA) Gram-negative bloodstream infections (GN-BSI). In total, 831 cases of HA GN-BSI from 17 intensive care units in different centres in Turkey were included; the all-cause mortality rate was 44%. Carbapenem resistance in Klebsiella pneumoniae was 38%, and the colistin resistance rate was 6%. Multi-variate analysis showed that age >70 years [odds ratio (OR) 2, 95% confidence interval (CI) 1.22-3.51], central venous catheter use (OR 2.1, 95% CI 1.09-4.07), ventilator-associated pneumonia (OR 1.9, 95% CI 1.1-3.16), carbapenem resistance (OR 1.8, 95% CI 1.11-2.95) and APACHE II score (OR 1.1, 95% CI 1.07-1.13) were significantly associated with mortality.

The clinical impact of ST131 H30-Rx subclone in urinary tract infections due to multidrug-resistant Escherichia coli

In this study, risk factors for ST131 H30 and H30-Rx subclones among urinary tract infections (UTIs) caused by multidrug-resistant (MDR) Escherichia coli were described. Urine samples were collected from consecutive outpatients registered to the outpatient clinics of Başkent University Hospital (Ankara, Turkey) with complaints of acute cystitis in 2011. A total of 107 MDR E. coli isolates were included in the study. Of the 107 isolates studied, 26 (24.3%) were typed as ST131 clone. Extended-spectrum β-lactamase (ESBL)-producers accounted for 59 (55.1%) of the 107 isolates. Among the 59 ESBL-positive isolates, 18 (31%) were found to belong to the ST131 clone. Of the 18 ESBL-positive ST131 isolates, 17 (94%) were defined as H30 subclone, among which 16 (94%) represented the H30-Rx subclone. Among the 48 ESBL-negative isolates, 8 (17%) ST131 isolates were detected, 7 (88%) of which belonged to H30 subclone; 5 (71%) of the H30 subclone isolates were classified under H30-Rx subclone. In multivariate analysis, hospitalisation within last year was the only host risk factor associated with MDR E. coli ST131 H30-Rx subclone UTI (OR=3.5, 95% CI 1.04-12.17; P=0.042). CTX-M-15 production was found to be highly associated with the presence of ST131 H30-Rx subclone (OR=4.8, 95% CI 1.54-15.32; P=0.007). In conclusion, urinary MDR E. coli ST131 H30-Rx subclone was found to be important in the dissemination of MDR UTIs in the community. Approximately 20% of the MDR isolates were H30-Rx subclone. Infection with this subclone was found to be healthcare-associated.

Cytokine response in crimean‐congo hemorrhagic fever virus infection

We described the predictive role of cytokines in fatality of Crimean Congo Hemorrhagic Fever Virus (CCHFV) infection by using daily clinical sera samples. Consequent serum samples of the selected patients in different severity groups and healthy controls were examined by using human cytokine 17‐plex assay. We included 12 (23%) mild, 30 (58%) moderate, 10 (19%) severe patients, and 10 healthy volunteers. The mean age of the patients was 52 (sd 15), 52% were female. Forty‐six patients (88%) received ribavirin. During disease course, the median levels of IL‐6, IL‐8, IL‐10, IL‐10/12, IFN‐γ, MCP‐1, and MIP‐1b were found to be significantly higher among CCHF patients than the healthy controls. Within the first 5 days after onset of disease, among the fatal cases, the median levels of IL‐6 and IL‐8 were found to be significantly higher than the survived ones (Fig. 3), and MCP‐1 was elevated among fatal cases, but statistical significance was not detected. In receiver operating characteristic (ROC) analysis, IL‐8 (92%), IL‐6 (92%), MCP‐1 (79%) were found to be the most significant cytokines in predicting the fatality rates in the early period of the disease (5 days). IL‐6 and IL‐8 can predict the poor outcome, within the first 5 days of disease course. Elevated IL‐6 and IL‐8 levels within first 5 days could be used as prognostic markers.

Molecular Epidemiology of Bloodstream Associated E. coli ST131 H30-Rx Subclone Infection in a Region with High Quinolone Resistance.

Bloodstream infections caused by Escherichia coli ST131 and ST131 H30-Rx subclones have emerged worldwide. This study was carried out to evaluate the prevalence of the ST131-Rx subclone and characterize the virulence properties of the Rx isolates among the bloodstream E. coli isolates. A total of 297 non-duplicated E. coli bloodstream isolates were studied. Antibiotic susceptibilities were tested using the disc diffusion method. PCR amplification and sequencing was used to identify ST131 and H30-Rx, the virulence gene, the β-lactamase and virotype. Quinolone resistance among bacteraemic E. coli strains was 51 %, and it was 98 % among E. coli ST131 isolates. The ST131 isolates accounted for 16 % (49) of all isolates and all ST131 isolates belonged to the extraintestinal pathogenic E. coli. The proportion of H30 subclone among the ST131 isolates was 98 %, and 75 % of H30 isolates belonged to the H30-Rx subclone. The prevalence of ST131 increased from 13 to 23 % in 4 years; however, there was a decrease in the ratio of H30-Rx infections. CTX-M-15 was detected in 85 % of ST131 and all of the H30-Rx isolates. The virulence genes associated with adhesion, cell protection, iron uptake and toxins (papA, iha, kpsMTII, iut and sat) were more common in ST131 than in non-ST131 isolates. Most of the ST131 and H30-Rx isolates were of the C virotype. All papA-positive isolates were in virotype C. The E. coli ST131 clone has increased rapidly among bloodstream isolates. However, a decrease in the proportion of the H30-Rx subclone in the quinolone-resistant population suggests the possibility of dissemination of other virulent and quinolone-resistant subclones in hospital settings.

Rapid Molecular Detection of Gastrointestinal Pathogens and Its Role in Antimicrobial Stewardship

ABSTRACT We aimed to detect the etiological agents of acute diarrhea by a molecular gastrointestinal pathogen test (MGPT) and to assess the impact of MGPT on antimicrobial stewardship programs (ASP). This is a prospective observational study and was conducted between 1 January 2015 and 30 June 2017. We included consequent patients who had acute diarrhea. At the end of 2015, we implemented ASP in acute diarrhea cases and compared the outcomes in the pre-ASP and post-ASP periods. An FDA-cleared multiplexed gastrointestinal PCR panel system, the BioFire FilmArray (Idaho Technology, Salt Lake City, UT), which detects 20 pathogens in stool, was used. In 499 out of 699 patients (71%), at least one pathogen was detected. Among 314 adults with positive MGPT, 101 (32%) enteropathogenic Escherichia coli (EPEC), 71 (23%) enteroaggregative E. coli (EAEC), 68 (22%) enterotoxigenic E. coli (ETEC), 55 (18%) Shiga toxin-producing E. coli (STEC) (17%) Norovirus, 48 (15%) Campylobacter, 21 (7%) Salmonella, and 20 (6%) Clostridium difficile strains were detected. Among 185 children, 55 (30%) EPEC, 37 (20%) C. difficile, 32 (17%) Norovirus, 29 (16%) EAEC, 22 (12%) STEC, 21 (11%) ETEC, 21 (11%) Campylobacter, 20 (11%) Salmonella, and 16 (5%) Rotavirus strains were detected. Inappropriate antibiotic use decreased in the post-ASP period compared with the pre-ASP period among inpatients (42.9% and 25.8%, respectively; P = 0.023). Using MGPT in clinical practice significantly decreased the unnecessary use of antibiotics. Detection of high rates of C. difficile in children and Salmonella spp., as well as relatively high rates of Campylobacter spp., which were hard to isolate by routine stool culture, were remarkable.

Impact of the ST101 clone on fatality among patients with colistin-resistant Klebsiella pneumoniae infection

Objectives We describe the molecular characteristics of colistin resistance and its impact on patient mortality. Methods A prospective cohort study was performed in seven different Turkish hospitals. The genotype of each isolate was determined by MLST and repetitive extragenic palindromic PCR (rep-PCR). Alterations in mgrB were detected by sequencing. Upregulation of pmrCAB, phoQ and pmrK was quantified by RT-PCR. mcr-1 and the genes encoding OXA-48, NDM-1 and KPC were amplified by PCR. Results A total of 115 patients diagnosed with colistin-resistant K. pneumoniae (ColR-Kp) infection were included. Patients were predominantly males (55%) with a median age of 63 (IQR 46-74) and the 30 day mortality rate was 61%. ST101 was the most common ST and accounted for 68 (59%) of the ColR-Kp. The 30 day mortality rate in patients with these isolates was 72%. In ST101, 94% (64/68) of the isolates had an altered mgrB gene, whereas the alteration occurred in 40% (19/47) of non-ST101 isolates. The OXA-48 and NDM-1 carbapenemases were found in 93 (81%) and 22 (19%) of the total 115 isolates, respectively. In multivariate analysis for the prediction of 30 day mortality, ST101 (OR 3.4, CI 1.46-8.15, P = 0.005) and ICU stay (OR 7.4, CI 2.23-29.61, P = 0.002) were found to be significantly associated covariates. Conclusions Besides ICU stay, ST101 was found to be a significant independent predictor of patient mortality among those infected with ColR-Kp. A significant association was detected between ST101 and OXA-48. ST101 may become a global threat in the dissemination of colistin resistance and the increased morbidity and mortality of K. pneumoniae infection.

The Role of AcrAB–TolC Efflux Pumps on Quinolone Resistance of E. coli ST131

Escherichia coli ST131 is a cause for global concern because of its high multidrug resistance and several virulence factors. In this study, the contribution of acrAB–TolC efflux system of E. coli ST131 to fluoroquinolone resistance was evaluated. A total of nonrepetitive 111 ciprofloxacin-resistant E. coli isolates were included in the study. Multilocus sequence typing was used for genotyping. Expressions of acrA, acrB, and TolC efflux pump genes were measured by RT-PCR. Mutations in marA, gyrA, parC, and aac(6′)-lb-cr positivity were studied by Sanger sequencing. Sixty-four (57.7%) of the isolates were classified as ST131, and 52 (81.3%) of the ST131 isolates belonged to H30-Rx subclone. In ST131, CTX-M 15 positivity (73%) and aac(6′)-lb-cr carriage (75%) were significantly higher than those in non-ST131 (12.8% and 51%, respectively) (P < 0.05). The ampicillin–sulbactam (83%) resistance was higher, and gentamicin resistance (20%) was lower in ST131 than that in non-ST131 (64% and 55%, respectively) (P = 0.001 and P = 0.0002). Numbers of the isolates with MDR or XDR profiles did not differ in both groups. Multiple in-dels (up to 16) were recorded in all quinolone-resistant isolates. However, marA gene was more overexpressed in ST131 compared to that in non-ST131 (median 5.98 vs. 3.99; P = 0.0007). Belonging to H30-Rx subclone, isolation site, ciprofloxacin MIC values did not correlate with efflux pump expressions. In conclusion, the marA regulatory gene of AcrAB–TolC efflux pump system has a significant impact on quinolone resistance and progression to MDR profile in ST131 clone. Efflux pump inhibitors might be alternative drugs for the treatment of infections caused by E. coli ST131 if used synergistically in combination with antibiotics.