Serotype distribution of Streptococcus pneumonia in children with invasive disease in Turkey: 2015-2018.

Objectives: To determine the serotype distribution of pneumococcus causing invasive pneumococcal disease (meningitidis, bacteremia and empyema) in children in Turkey, and to observe potential changes in this distribution in time to guide effective vaccine strategies. Methods: We surveyed S. pneumoniae with conventional bacteriological techniques and with real-time polymerase chain reaction (RT-PCR) in samples of cerebrospinal fluid (CSF), blood and pleural fluid. S. pneumoniae strains were isolated from 33 different hospitals in Turkey, which are giving health services to approximately 60% of the Turkish population. Results: A total of 167 cases were diagnosed with invasive pneumococcal disease between 2015 and 2018. We diagnosed 52 (31.1%) patients with meningitis, 104 (62.2%) patients with bacteremia, and 11 (6.6%) patients with empyema. Thirty-three percent of them were less than 2 years old and 56% less than 5 years old. Overall PCV13 serotypes accounted for 56.2% (94/167). The most common serotypes were 19 F (11.9%), 1 (10.7%) and 3 (10.1%). Conclusions: Besides the increasing frequency of non-vaccine serotypes, vaccine serotypes continue to be a problem for Turkey despite routine and high-rate vaccination with PCV13 and significant reduction reported for the incidence of IPD in young children. Since new candidate pneumococcal conjugate vaccines with more serotype antigens are being developed, continuing IPD surveillance is a significant source of information for decision-making processes on pneumococcal vaccination.

Evaluation of a chromogenic medium for detection of extended-spectrum-beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae strains.

BACKGROUND: Because of the emergence and spread of extended-spectrum-beta-lactamase (ESBL)-producing strains which are resistant to many antibiotics, reliable detection of ESBL is very important for infection control. Several chromogenic media have been proposed for the detection of ESBL producers in addition to the conventional phenotypic and genotyping methods. The aim of the present study was to evaluate the performance of Brilliance ESBL agar (Oxoid; Thermo Fisher Scientific, UK), a selective chromogenic agar for the detection of ESBL-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) strains. METHODS: A total of 237 strains (143 ESBL producers (76 isolates of E. coli and 67 isolates of K. pneumoniae) and 94 non-ESBL producers (44 isolates of E. coli and 50 isolates of K. pneumoniae)) isolated from various clinical specimens were included in the study. Isolates were identified by conventional methods, Phoenix system (Becton Dickinson, USA), and mass spectrometry. ESBL confirmation was performed by phenotypical tests. A 10 microL aliquot of each isolate's 0.5 McFarland suspension was streaked onto Brilliance ESBL agar. All plates were incubated at 37 degrees C for 24 hours and then were interpreted for growth and colony color according to the manufacturer's recommendations. Identification and ESBL test results were used to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the medium evaluated at 24 hours. RESULTS: The sensitivity, specificity, PPV, and NPV of the medium were 97.9%, 100%, 100%, and 96.9%, respectively, when considering only species specific colored colonies of the isolates. CONCLUSIONS: Brilliance ESBL agar could provide a practical alternative to the traditional methods for the identification of ESBL producers.

Evaluation of the BD Phoenix system for detection of methicilin resistance in Staphylococcus aureus isolates in comparison to BD GeneOhm MRSA assay.

BACKGROUND: In order to identify methicillin-resistant Staphylococcus aureus isolates quickly, automated and semiautomated systems, commercial media, and identification kits are widely used. The Phoenix system (BD, Sparks, MD, USA) has been available since 2004 in our laboratory. This study evaluated the reliability of the Phoenix system for the detection of methicillin resistance in Staphylococcus aureus isolates in comparison to BD GeneOhm MRSA assay (Becton Dickinson Diagnostics GeneOhm, CA, USA). METHODS: A total of 206 clinically significant Staphylococcus aureus isolates, submitted to the clinical microbiology laboratory between March 2011 and May 2013, were included in the study. Phoenix panels were studied for identification and susceptibility testing according to manufacturers' instructions. The detection of MRSA was performed using the BD GeneOhm MRSA assay (Becton Dickinson Diagnostics GeneOhm, CA, USA). The assay is a qualitative real-time PCR method. RESULTS: The Phoenix system results and mecA gene pozitivity were concordant for 134 methicillin-resistant and 71 methicillin-susceptible strains. One discordant isolate, identified as mecA negative by the PCR method, was methicillin-resistant Staphylococcus aureus positive by the Phoenix system (oxacilline MIC = 2 microg/mL; cefoxitin MIC = 8 microg/mL). In this study, Phoenix automated system's sensitivity, specificity, negative predictive value, and positive predictive value are found as 100%, 100%, 100%, and 100%, respectively. CONCLUSIONS: As a result of our study, use of the Phoenix automated identification method for the detection of methicillin-resistant Staphylococcus aureus isolates is a practical and reliable approach for daily clinical laboratory procedures.

The role of Bifidobacterium lactis B94 plus inulin in the treatment of acute infectious diarrhea in children.

BACKGROUND/AIMS: In contrast to many other studies of probiotic species, the number of publications evaluating Bifidobacterium lactis and its combinations with prebiotics as treatments for acute infectious diarrhea is limited. We investigated the synbiotic effects of B. lactis B94 plus inulin on acute infectious diarrhea. MATERIALS AND METHODS: The study was conducted on children with acute diarrhea between the ages of 2 and 60 months. The patients were administered 5×1010 colony-forming units (CFU) of B. lactis B94 plus 900 mg inulin or placebo, once a day for five days. Stools were examined for Rotavirus, Adenovirus, Entamoeba histolytica, Salmonella, Shigella, Campylobacter, Clostridium difficile, Cryptosporidium, and parasites. RESULTS: We examined 79 patients in the synbiotic group and 77 patients in the placebo group. The duration of diarrhea was significantly reduced in the synbiotic group in comparison with the placebo group (3.9±1.2 days vs. 5.2±1.3 days, respectively; p<0.001). Moreover, the number of diarrheal stools on the third day was significantly lower in the synbiotic group than in the placebo group (5.5±2.9 vs. 8.3±3.01, respectively; p<0.001). Diarrhea in the synbiotic-group patients with rotavirus infection was of a significantly shorter duration (3.2±1.3 days vs. 5.2±1.3 days, respectively; p=0.001). Duration of diarrhea in patients who started the synbiotic treatment within the first 24 h was shorter than that in the patients who started the treatment later (3.9±1.1 days vs. 4.8±1.8 days, respectively; p=0.002). CONCLUSION: Treatment with 5 × 1010 CFU of B. lactis B94 plus 900 mg inulin shortened the duration of acute watery diarrhea by an average of 31 h. This decrease was most pronounced in cases of Rotavirus diarrhea.

[Evaluation of antibiotic susceptibilities and VISA-VRSA rates among MRSA strains isolated from hospitalized patients in intensive care units of hospitals in seven provinces of Turkey]. / Türkiye'de Yedi Ildeki Hastanelerin Yogun Bakim Ünitelerinden Izole Edilen MRSA Suslarinda VISA-VRSA Arastirilmasi ve Antibiyotik Duyarlilik Durumlarinin Saptanmasi

The aim of this study was to determine whether vancomycin resistant Staphylococcus aureus (VRSA) and vancomycin intermediate susceptible S.aureus (VISA) strains were present among methicillin-resistant S.aureus (MRSA) strains isolated from patients hospitalised at intensive care units (ICU) of hospitals located at different regions of Turkey and to determine the minimum inhibitory concentration (MIC) values of teicoplanin, linezolid, tigecycline, quinupristin-dalfopristin and daptomycin, which are alternative drugs for the treatment of MRSA infections. A total of 260 MRSA clinical strains (isolated from 113 lower respiratory tract, 90 blood, 24 wound, 17 catheter, 13 nasal swabs, two urine and one CSF sample) were collected from nine health-care centers in eight provinces [Ankara (n= 52), Konya (n= 49), Antalya (n= 40), Istanbul (n= 7), Izmir (37), Diyarbakir (n= 15), Van (n= 12), Trabzon (n= 48)] selected as representatives of the seven different geographical regions of Turkey. Methicillin resistance was determined by cefoxitin disk diffusion in the hospitals where the strains were isolated and confirmed by oxacillin salt agar screening at the Refik Saydam National Public Health Agency. Screening for VISA and VRSA was conducted using the agar screening test and E-test. Susceptibility of the MRSA strains to other antibiotics was also determined by E-test method. None of the 260 MRSA strains were determined to be VRSA or VISA. All were susceptible to teicoplanin and linezolid, and susceptibility rates to daptomycin, tigecycline and quinupristin-dalfopristin were 99.6%, 96.9%, and 95%, respectively. Absence of VISA and VRSA among the MRSA strains surveyed currently seemed hopeful, however, continuous surveillance is necessary. In order to prevent the development of VISA and VRSA strains the use of linezolid, tigecycline, quinupristin-dalfopristin and daptomycin should be encouraged as alternative agents of treatment of MRSA infections.

[Shall we report the carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii strains detected by BD Phoenix system?]. / Pseudomonas aeruginosa ve Acinetobacter baumannii suslarinda BD Phoenix sistemi ile saptanan karbapenem direncini raporlayalim mi?

Imipenem and meropenem are broad spectrum antimicrobial agents that are especially useful in the treatment of nosocomially acquired Pseudomonas aeruginosa and Acinetobacter spp. infections. Previous reports have noted that susceptibility tests could show false resistance to imipenem. For this reason, Centers for Disease Control and Prevention has recommended that all carbapenem resistant or intermediate resistant isolates should be tested with an additional method to verify the results. This study was aimed to evaluate the imipenem and meropenem susceptibilities by disk diffusion, E-test and broth microdilution in P. aeruginosa and Acinetobacter baumannii strains found to be resistant or intermediate to imipenem-meropenem by BD Phoenix automated susceptibility testing system. Between January 2006-January 2007, 85 non-duplicate isolates of A. baumannii and 51 non-duplicate isolates of P. aeruginosa which were determined as resistant or intermediate resistant to imipenem and/or meropenem by BD Phoenix automated identification and susceptibility system (Becton Dickinson, Sparks, MD, USA) were collected in Akdeniz University Hospital Central Laboratory. All strains were tested by E-test (AB Biodisk, Sweden), disk diffusion and reference broth microdilution (BMD) method following CLSI recommendations. All 51 isolates of P. aeruginosa determined as imipenem and/or meropenem resistant or intermediate resistant by BD Phoenix, were found to be imipenem and/or meropenem resistant or intermediate resistant by the reference BMD method. Minor error rates were same for all testing systems (1.9%) except for the meropenem results of BD Phoenix system (5.9%). No major errors were produced by any system. For A. baumannii, only one very major error was detected for meropenem by BD Phoenix system. Number of minor errors determined for meropenem by all testing systems compared to the reference test, ranged from 2 (2.4%) to 3 (3.5%). It was concluded that carbapenem susceptibility test results obtained by BD Phoenix system for P. aeruginosa and A. baumannii isolates, could be reported without an additional susceptibility testing method unless indicated on case basis.

Nosocomial outbreak of vancomycin-resistant Enterococcus faecium in a paediatric unit at a Turkish university hospital.

BACKGROUND: Despite growing concern about vancomycin-resistant enterococci (VRE) as nosocomial pathogens, especially in the USA, they have been rarely isolated in Turkish hospitals. After initial description in 2001 of unrelated VRE isolates, we report now the molecular characterization of a nosocomial outbreak at the Akdeniz University Hospital, Antalya, Turkey. METHODS: VRE isolates were from either clinical or rectal swab specimens. Identification, susceptibility testing and molecular characterization were performed according to standard techniques. Virulence genes (encoding aggregation substance, gelatinase, cytolysin, enterococcal surface protein and hyaluronidase) were sought by PCR. RESULTS: Thirty-six VRE were isolated from 10 patients between June and October 2005 in the Department of Paediatrics. Six patients were only carriers, two had urinary tract infections and two had bloodstream infections. All isolates were Enterococcus faecium, of vanA genotype and belonged either to a main pulsotype (A) or to three minor pulsotypes (B, C and D). The epidemic strain A, found in eight patients, expressed high-level glycopeptide resistance (MIC of vancomycin 256 mg/L and MIC of teicoplanin 64 mg/L) and was of multilocus sequence typing sequence type (ST) 31, whereas the minor strain D, found in two patients, expressed heterogeneous glycopeptide resistance (MIC of vancomycin 8 to 256 mg/L) and was ST18. Strains B and C were only found in single patients either with strain A or alone. The two epidemic strains A and D were esp gene-positive. Their vanA genes were located on transposons similar to Tn1546, except for deletion of the transposition genes and the presence of IS1542, inserted upstream of the vanA operon, and IS1216, inserted at the 3' end of the vanX gene. VRE outbreak was contained by early identification and implementation of measures for patient isolation and of stringent hand and environmental disinfection policies. CONCLUSIONS: This work underlines the emergence in Turkey of epidemic VRE clones that belong to the clonal complex-17 (CC-17) and that are esp-positive.