Efficacy of ceftazidime/avibactam and plazomicin on carbapenem-resistant Klebsiella pneumoniae and Escherichia coli.

Carbapenem-resistant Enterobacterales (CRE) have become a major public health problem worldwide. The aim of this study was to investigate efficacy of ceftazidime/avibactam and plazomicin on carbapenem-resistant Klebsiella pneumoniae and Escherichia coli isolates. Susceptibility of imipenem, meropenem, ertapenem, ceftazidime/avibactam and plazomicin was investigated by broth-microdilution method. Major carbapenemases NDM, VIM, IMP, KPC, OXA-48 as well as other ß-lactamases namely, TEM, SHV, OXA-1-like, CTX-M, ACC, FOX, MOX, DHA, CIT, EBC, VEB, GES, PER were investigated by PCR. A total of 120 carbapenem-resistant isolates (60 E. coli and 60 K. pneumoniae) were included in this study and blaOXA-48-like was found in 78.33%, blaNDM in 26.66%, blaKPC in 7.5%, blaIMP in 5.83%, and blaVIM in 5%. Among 94 isolates with the blaOXA-48-like gene, 22.3% were resistant to ceftazidime/avibactam and 51.1% were resistant to plazomicin. Of 32 isolates with blaNDM, 31 (96.9%) were resistant to ceftazidime/avibactam and 30 (93.75%) were resistant to plazomicin, and both antibiotics had limited effects against blaNDM carriers (P < 0.001). Of the 12 isolates with blaNDM+OXA-48 combination, 11 (91.7%) were resistant to ceftazidime/avibactam and plazomicin. The effect of both antibiotics was significantly lower in strains with blaNDM+OXA-48 combination (P < 0.005).The most common carbapenemase genes in this study were blaOXA-48-like and blaNDM. Ceftazidime/avibactam demonstrated a good efficacy among OXA-48 producing K. pneumoniae and E. coli, however, plazomicin had a significantly lower antibacterial effect in our study. Both antimicrobial agents should be considered as an option by evaluating combined susceptibility results and gene patterns obtained by regional and global molecular data in the treatment of CRE infections.

Occupational Risks of Podologists: A Combined Assessment of VOCs, Vibration, Noise Levels and Health Complaints.

Podologists are exposed to many occupational hazards, including volatile organic compounds (VOCs) from insole manufacturing and noise/vibration during nail or tissue grinding. In this study, VOCs, noise, and vibration were measured in five podiatry clinics and three offices. Questionnaires were administered to 23 podologists and 19 office workers to inquire about their pain, ocular, skin and respiratory complaints. The results showed that the podologists' exposure to the total VOC concentrations was approximately twice as high as that of the office workers. The podologists' complaints regarding pain were found to be correlated with ambient noise and hand-arm vibration levels. Ocular, skin, and respiratory complaints were also found to be correlated with total VOC concentrations. These results suggest that VOCs, noise and vibration in the working environment may impair podologists' health and that they have an intensifying effect on each other, increasing the severity of health issues.

Distribution of virulence determinants among Escherichia coli ST131 and its H30/H30-Rx subclones in Turkey.

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading pathogen in urinary tract infection. In recent years multidrug-resistant B2-ST131 E. coli clonal group has disseminated worldwide. The ST131 and its subclones H30 and H30-Rx have been identified only in a few studies from Turkey. The aim of this study is to investigate the presence of ST131 and its subclones and to analyze their adhesin virulence genes and antimicrobial resistance. A total of 250 urinary ExPEC isolates were included in the study. Resistance rates of 16 antimicrobial agents were determined by disk-diffusion. Multidrug-resistance and ESBL production were analyzed. Altogether 8 adhesin genes were investigated namely, papAH, fimH, sfa/focDE, focG, afa/draBC, iha, bmaE and gafD. A total of 39 ST131 isolate were determined and 33 (84.6%) were multidrug-resistant. ESBL production was detected in 34 (87.2%) ST131 and 61 (28.9%) of non-ST131 strains. In our study, we found a strong correlation between ST131 strains and fimH, iha, afa/draBC, papAH virulence determinants. Twenty-nine (85.3%) of 34 ST131-O25b-H30 isolates were identified as H30-Rx. All the papAH gene positive isolates were identified within ST131-O25b-H30-Rx lineage. Non-H30-Rx isolates within H30 isolates were identified as pattern 2. Almost 16% of the isolates were identified as ST131 regardless of clinical syndrome and approximately 34% of the multidrug-resistant isolates were H30-Rx subclone. We report H30-Rx as the dominant subclone of ST131 in our study. Imipenem, fosfomycin and nitrofurantoin proved to be the most effective agents according to antibiotic resistance patterns of both ST131 and non-ST131 E. coli strains.

In-vitro activities of imipenem-colistin, imipenem-tigecycline, and tigecycline-colistin combinations against carbapenem-resistant Enterobacteriaceae.

The aim of the study is to determine in-vitro effects of imipenem-tigecycline, imipenem-colistin and tigecycline-colistin against carbapenem-resistant Enterobacteriaceae (CRE) isolates. A total of 25 CRE isolates were included to the study. The minimum inhibition concentrations of imipenem, colistin-sulphate and tigecycline were determined with broth dilution method. Synergistic effects of imipenem-tigecycline, imipenem-colistin and tigecycline-colistin were investigated by microdilution checkerboard technique. All of the isolates were resistant to imipenem, whereas 25% of the isolates were resistant to colistin and tigecycline. Imipenem-colistin, imipenem-tigecycline and tigecycline-colistin combinations were synergistic against 40% (10/25), 24% (6/25), and 36% (9/25) of the isolates, respectively. Antagonism was observed in 8% (2/25) of the isolates in tigecycline-colistin combination. Tigecycline-colistin was the most effective (70% synergy) combination in Klebsiella spp. strains; whereas imipenem-colistin was the most effective (75% synergy) combination in Escherichia coli strains. Synergistic effect was variable and strain-depended against CRE isolates that have been tested.

Comparative Analysis of Proteome Patterns of Francisella tularensis Isolates from Patients and the Environment.

Francisella tularensis is the causative agent of tularemia. Although major contributors and the main mechanism of the virulence are well known, some of the molecular details are still missing. Proteomics studies regarding F. tularensis have provided snapshot pictures of the organism grown under different culture conditions to understand the mechanism of virulence. In general, such studies were carried out with standard strains e.g., LVS and did not involve comparisons of F. tularensis isolates from either clinical or environmental sources. In this study, we performed two-dimensional gel electrophoresis (2DE)-based proteomic analysis and compared the protein profiles of the F. tularensis subsp. holarctica strains isolated from the clinical and the environmental samples. Regulations were detected in 14 spots when twofold regulation criteria were applied. The regulated protein spots were subjected to MALDI-TOF/TOF analysis and identified. Classification of the identified proteins based on metabolic functions revealed that the translation machinery was the most varying metabolic processes among the isolates. Using normalized protein spot intensities, PCA analysis was also performed. The results indicated that the strain isolated from water source was different then the strains isolated from the patients. Most interestingly, the isolates were strikingly distinguishable from the standard NCTC 10857 strain.

Relationship between phylogenetic groups, antibiotic resistance and patient characteristics in terms of adhesin genes in cystitis and pyelonephritis isolates of Escherichia coli.

Extraintestinal pathogenic Escherichia coli (E. coli) is considered as the main causative agent of urinary tract infections worldwide. The relationship between antimicrobial resistance, phylogenetic groups, patient characteristics and adhesin virulence genes are complex and not fully understood. In this study, among 146 urinary isolates of E. coli, phylogenetic groups and various adhesin virulence genes were examined with multiplex Polymerase Chain Reaction methods. Patient characteristics divided into sex, cystitis and pyelonephritis; community-acquired and hospital-acquired; complicated and uncomplicated infection. Antimicrobial resistance was also determined. The papAH gene was seen more often in pyelonephritis than cystitis and female than male patients. iha gene was more frequent in hospital-acquired infections than in community-acquired infections. sfa/focDE was more frequent in ampicillin, amikacin, gentamicin, nalidixic acid, norfloxacin, cefuroxime, ceftriaxone, cefazolin, cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole susceptible and extended-spectrum ß-lactamase (ESBL) and multi-drug resistance (MDR) negative isolates. focG was seen more often in nalidixic acid, norfloxacin, cefuroxime, ceftriaxone, ciprofloxacin susceptible and MDR negative isolates. fimH and papAH were more commonly observed in amoxicillin/clavulanic acid and cefotaxime susceptible isolates, respectively. iha and afa/draBC genes were more frequent in resistant isolates than the susceptible ones; for iha, in ampicillin, amoxicillin/clavulanic acid, nalidixic acid, cefuroxime, ceftriaxone resistant and ESBL and MDR positive isolates; for afa/draBC, in cefotaxime, cefuroxime, ciprofloxacin, trimethoprim/sulfamethoxazole resistant and ESBL and MDR positive isolates, this trend was observed. ST 131 E. coli virulence gene pattern has a direct effect on resistance profile. Isolates belong to that clonal group has MDR and commonly harbour afa/draBC and iha genes. Our findings may provide new insights into the relationships between pathogenesis, patient characteristics and resistance of E. coli UTI.

Genotyping and phylogenetic analysis of Giardia duodenalis isolates from Turkish children.

BACKGROUND: Giardiasis is caused by the intestinal protozoan parasite Giardia duodenalis (synonyms: G. lamblia, G. intestinalis), which is one of the most frequent parasites that infect Turkish children. However, molecular characterization of G. duodenalis in Turkey is relatively scarce. The present work aimed at genotyping G. duodenalis isolates from Turkey using molecular techniques. MATERIAL AND METHODS: In the present study, 145 fecal samples from children were collected to search for the presence of Giardia by microscopy and PCR screening. PCR generated a 384 bp fragment for ß-giardin. The PCR products were sequenced and the sequences were subjected to phylogenetic analysis by using PHYLIP. RESULTS: Based on the phylogenetic analysis of the sequences, assemblage A, B, and mixed subtypes were determined. Of 22 isolates, 11 were identified as assemblage A (50%), 7 were assemblage B (31.8%), and 4 were assemblage AB (18.2%). Association between G. duodenalis assemblages and the epidemiological data was analyzed. No correlation was found between symptoms and infection with specific assemblages (P>0.05), but we found statistically significant association between age and the assemblage AB (P=0.001). CONCLUSIONS: The association between G. duodenalis and the epidemiologic data were analyzed. Since assemblage A is the more prevalent subgroup compared with assemblage B, this subgroup might be responsible for common Giardia infections in Turkey. This is the first study that included a detailed phylogenetic analysis of Giardia strains from Turkey.