Riza Durmaz

Introduction: In recent years, the prevalence of multidrug-resistant P. aeruginosa has remarkably increased. Thus, we wanted to investigate the carbapenem resistance mechanisms and clonal relationship among 80 carbapenem-resistant P. aeruginosa strains. Methodology: Carbapenemase production was detected using the Modified Hodge Test (MHT), EDTA combined disc method (ECD), and PCR. Expression levels of efflux and porin genes were mesured by real-time reverse transcription PCR. Clonal relationship of the isolates was investigated by pulsed-field gel electrophoresis (PFGE). Results: Carbapenemase production was detected in 7.5% of the isolates with MHT/ECD tests and in 11.3% of the isolates with PCR. Although the specificity of MHT/ECD was high, the sensitivitivity was low. oprD downregulation and mexB, mexY, and mexD overexpression were demonstrated in 55%, 16.3%, 2.5%, and 2.5% of the isolates, respectively. Multiple carbapenem resistance mechanisms were found in nearly a quarter of the isolates. PFGE typing of the 80 P. aeruginosa isolates yielded 61 different patterns. A total of 29 isolates (36.3%) were classified in 10 clusters, containing 2 to 7 strains. We could not find a strict relationship between PFGE profile and carbapenem resistance mechanisms. Conclusions: Although oprD downregulation and MexAB-OprM overexpression were the most common mechanisms, carbapenem resistance was associated with multiple mechanisms in the study. MHT/ECD tests should not be used alone for investigation of carbapenemase production in P. aeruginosa. Rapid tests with high sensitivity and specificity should be developed for the detection of carbapenemase production in P. aeruginosa.

This study obtained information on the serotypes and molecular typing characteristics of Streptococcus pneumoniae strains causing invasive diseases in Turkey. Sixty-eight S. pneumoniae isolates causing invasive pneumococcal diseases were collected from different regions of Turkey from 2009 to 2011. The isolates were characterized by performing multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and capsular serotyping, and 25 different serotypes were identified. Serotypes 19F, 23F, 1, 14, and 7F were common and accounted for 52.9% of all the serotypes. In addition, 54 different PFGE profiles (pulsotypes) were observed. Twenty-three of the 68 (33.8%) isolates were clustered into 9 pulsotypes. MLST analysis yielded 36 sequence types, of which 12 (33.3%) were novel. A comparison of results with the global pneumococcal MLST database by performing eBURST analysis showed that our strains belonged to 20 different clonal complexes and 5 singletons. In addition, we identified 4 new alleles: 2 gdh, 1 xpt, and 1 ddl. Thus, the results of this study highlighted a high level of diversity among pneumococcal isolates. In addition, the study identified a case of possible capsular switching.

A nosocomial outbreak of Acinetobacter baumannii (AB) infections occurred among intensive care units (ICU) (surgery, medical, cardiovascular surgery, coronary unit) of Recep Tayyip Erdogan University Medical School (Rize, Turkey) between January 2011 and May 2012. The identification of isolates and clonal relation among them were investigated by molecular techniques.

Mycobacteria other than tuberculosis (MOTT) cause increasingly serious infections especially in immunosuppressive patients by direct transmission from the environment or after colonization. However, identification of these species is difficult because of the cost and difficulties in defining to species level. Identification and distribution of these species can help clinician in the choice of treatment. A total of 90 MOTT strains obtained from four different centers were included in the study. These strains were identified by sequence analysis of 16S rRNA and Hsp65 genetic regions. Accordingly, within the 90 MOTT strains, 17 different species were identified. In order of frequency, these species were M. gordonea (n = 21), M. abscessus (n = 13), M. lentiflavum (n = 9), M. fortuitum (n = 8), M. intracellulare (n = 6), M. kumamotonense (n = 6), M. neoaurum (n = 5), M. chimaera (n = 5), M. alvei (n = 5), M. peregrinum (n = 3), M. canariasense (n = 3), M. flavescens (n = 1), M. mucogenicum (n = 1), M. chelona (n = 1), M. elephantis (n = 1), M. terrae (n = 1) and M. xenopi (n = 1). Most frequently identified MOTT species according to the geographical origin were as follows: M. abscessus was the most common species either in Istanbul or Malatya regions (n = 6, n = 6, consequently). While M. kumamotonense was the most frequent species isolated from Ankara region (n = 6), M. gordonea was the most common for Samsun region (n = 14). Our study revealed that frequency of MOTT varies depending on the number of clinical samples and that frequency of these species were affected by the newly identified species as a result of the use of novel molecular methods. In conclusion, when establishing diagnosis and treatment methods, it is important to know that infections caused by unidentified MOTT species may vary according to the regions in Turkey. The results of the study showed that there were differences in the frequency of MOTT species in the different geographical regions of Turkey.

The life-threatening illnesses caused by Streptococcus pneumoniae have been declined significantly after the use of pneumococcal conjugate vaccines. Continuous monitoring of the vaccine serogroups/types is necessary to follow the changing epidemiology of invasive pneumococcal diseases. Recently, the sequential multiplex PCR approach, which uses several different sets of reactions, has been commonly adopted for determining capsular serogroups/types of S. pneumoniae isolates. In our study, we focused on development of a one-step multiplex PCR assay detecting all 1, 3, 4, 5, 6A/B, 7F, 9V, 14, 18C, 19A, 19F and 23F serogroups/types targeted by PCV13. The content of multiplex PCR mix and the cycling conditions were optimized in a manner that allowed rapid and accurate serotyping of a pneumococcal isolate by performing only a single amplification reaction. In our study of 182 clinical isolates, the one-step multiplex PCR assay exhibited 100% sensitivity and specificity, suggesting that its utilization can significantly reduce the use of traditional antiserum method requiring expensive reagents.

The main perspective of this study was to determine cross-transmissions amongst anthrax cases and provide detailed information regarding the genotypes of Bacillus anthracis isolates circulating in Turkey. A total of 251 B. anthracis isolates were obtained from human (93 isolates), animal (155 isolates), and environmental (three isolates) samples in various provinces of Turkey. All isolates were susceptible to quinolones, vancomycin, tigecycline, and linezolid, but not to ceftriaxone. Excluding human isolates, one of the animal isolates was found to be resistant to penicillin, erythromycin, and doxycycline. Multiple-locus variable-number tandem repeats analysis including 8 loci (MLVA8) revealed 12 genotypes, in which genotype 43 was observed at the highest frequency (41.8 %), followed by genotype 35 (25.5 %) and genotype 27 (10.4 %). Major subtype A3.a was the predominant cluster, including 86.8 % of the isolates. The MLVA25 analysis for the 251 isolates yielded 62 different genotypes, 33 of which had only one isolate, while the remaining 29 genotypes had 2 to 43 isolates, with a total of 218 isolates (86.9 %). These findings indicate very high cross-transmission rates within anthrax cases in Turkey. The genotypes diagnosed in Turkey are populated in the A major cluster. Penicillin prescribed as the first-choice antibiotic for the treatment of anthrax is still effective.

We characterized an outbreak of acute diarrheal disease caused by group A rotavirus that occurred during the Autumn of 2005 in Malatya City, Turkey. A total 9907 patients between 0 to 91 years old (mean age: 25.05�19.67) were included in the epidemic. The patients� data were prospectively collected and statistically analyzed. Microbiologic analyses were performed to determine the etiologic agent. Rapid onset diarrhea (98.36%), abdominal cramps (69%), fever (44.4%) and vomiting (69.6%) were the most common symptoms observed in patients. Rotavirus antigen was detected in 52.7% of the studied patients. RT-PCR analysis led to identification of Group A rotavirus as the causative agent of this epidemic. Simultaneous measurements of the drinking water samples yielded very low chlorine levels; as low as 0 to 0.05 mg/L. The outbreak investigation team indicated possible contamination of a large water depository from a water well, which supplies drinking water to two major districts of the city. Effective chlorination and blockage of the passage between the well and the water depository stopped the outbreak. This outbreak shows the high epidemic potency of rotavirus in large human populations, including all age groups, and underlines the importance of water safety in pipeline systems.

Human orf is a viral zoonotic infection caused by Parapoxvirus. The skin lesions of human orf can be misdiagnosed as cutaneous anthrax leading to overtreatment and also fear. This study was conducted to analyze an outbreak which led to deaths among kids and lambs in the same flock, and skin lesions in some persons who were living on the same farm that were initially diagnosed as cutaneous anthrax by a practitioner. Eight patients with skin lesions and eleven persons who had no skin lesion were considered as patients and control groups, respectively. The cultures obtained from the lesions of all patients were negative for Bacillus anthracis. The diagnosis of skin lesions was done by clinical findings, histopathological examination and PCR as human orf. To be under 20 years of age, direct contact with the animals, and contact with flayed skin of sick animals were the risk factors for human orf (Odds Ratio 7.5; 95% Confidence Interval 1.02-54.54, OR 12.25; 95% CI:1.3-100.9, OR 16.67; 95% CI:1.65-148.20, respectively). Orf should be kept in mind in the differential diagnosis of skin lesions resembling anthrax. For control and prevention of orf, transmission routes should be known; good hand hygiene and other personal protective measures have to be implemented.

S. pneumoniae is a component of normal nasopharyngeal flora in children. Nasopharyngeal colonization in children attending daycare units has an important effect on the spread of S. pneumoniae. In this study, we aimed to investigate colonization status, antimicrobial susceptibility, and clonal relatedness of the S. pneumoniae strains in children attending a daycare unit. One hundred and six nasopharyngeal swabs were collected from 25 children attending a daycare unit in an 8-month period. S. pneumoniae was identified by a conventional method. Antibacterial sensitivities of the strains were tested by disc diffusion method. Pulsed field gel electrophoresis (PFGE) was used to analyze the clonal relationship of the strains. A total of 25 (23.5%) S. pneumoniae strains were identified from 106 nasopharyngeal swaps. S. pneumoniae growth was detected in at least one culture of the 19 children (colonization rate; 76%). Seven of the 25 strains (28%) showed resistance to penicillin, 5 (20%) were resistant to trimethoprim-sulfomethoxsazole. The other tested antibiotics were almost effective. The clonal relationship among strains was found as 54.5%. The highest rate of strain entry was in the winter months with strains of opaque colonies, which are known to be more pathogenic. However, the spreading rate among the children was the highest in the summer months and the strains detected in these months had transparent colonies with more transmitting characteristics. Therefore, to prevent S. pneumoniae infection in closed crowded areas, the summer months should not be overlooked.

The aim of this study was to assess species distribution, antifungal susceptibility and clonal relationships among Candida strains isolated from a group of pediatric/neonatal intensive care (PICU/NICU) patients that had a very high mortality rate (76%). The cases of 21 patients (19 with candidemia, 2 with Candida meningitides) treated over a 1-year period in a Turkish hospital PICU and NICU were retrospectively analyzed. Twenty-eight Candida isolates were detected from blood (20), cerebrospinal fluid (CSF) (2) and other specimens (6). Candida species were identified using the API ID 32C System. Susceptibility testing was done (all 28 isolates) for amphotericin B, fluconazole and itraconazole using the broth microdilution method. Arbitrarily primed polymerase chain reaction (AP-PCR) was used for molecular typing of the 3 most common ones; C. albicans (15), C. parapsilosis (6), and C. pelliculosa (4). Electrophoretic karyotyping (EK) was done to check clonal identity obtained by AP-PCR. Of the 20 blood isolates, 8 (40%) were C. albicans, 12 (60%) were non-albicans Candida, and one of the 2 CSF isolates was C. albicans. The overall species distribution was as follows: 15 C. albicans isolates, 6 C. parapsilosis isolates, 4 C. pelliculosa isolates, 2 C. famata isolates and 1 C tropicalis isolate. Amphotericin B had the best antifungal activity with a MIC90 of 0.125 microg/ml, and the rates of susceptibility to fluconazole and itraconazole were 93% and 82%, respectively. AP-PCR revealed 11 genotypes (4 were identical pairs, 7 were distinct) among the 15 C. albicans isolates, 2 genotypes (5 were classified in the same type) among the 6 C. parapsilosis isolates, and 4 separate genotypes for the 4 C. pelliculosa isolates. Karyotyping results correlated well with the AP-PCR findings. As indicated in the previous research, our results confirmed that non-albicans Candida species have become more frequently causative agents for invasive fungal infections in the ICU. Transmission of C. albicans and C. pelliculosa was relatively low, but transmission of C. parapsilosis was high, suggesting that more effective control and very strict treatment protocols are needed for patients having high mortality and invasive fungal infection in ICU.