Impact of PCV7 vaccination on nasopharyngeal carriage and antimicrobial resistance among children in Turkey.

INTRODUCTION: We aimed to evaluate the effects of 7-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae and antibiotic resistance in children in a well-child clinic in a tertiary children's hospital in Turkey. METHODOLOGY: We collected nasopharyngeal (NP) specimens from 557 two-month-old babies before vaccination. After the study population had received PCV7, NP samples were obtained from 135 babies. Antimicrobial susceptibility testing and serotyping were performed. RESULTS: S. pneumoniae colonized in 48 (8.6%) of the 557 two-month-old babies before vaccination. The follow-up cohort consisted of 135 subjects. The prevalence of PCV7 strain decreased from 33.3% to 19.3% after vaccination. However, non-PCV7 types increased from 66.6% to 80.6% (p = 0.02). Of PCV7 serotypes, 19F was the most frequent serotype before and after vaccination. There was an increase in 6A and 15 of non-PCV7 serotypes after vaccination. Penicillin non-susceptible increased from 56.3% to 80.6% after vaccination (p =0.03). Serotypes 14, 18C, 9V and 6B, which were identified before vaccination, never colonized afterwards. Number of siblings and having sibling with older age of five were determined to be significant effective factors for SP colonization presence after vaccination and antibiotic use was negatively associated with pneumococcal carriage but associated with penicillin non-susceptibility. CONCLUSIONS: Nasopharyngeal carriage rate of S. pneumoniae dropped after PCV7 vaccination, and replacement by NVT pneumococci were also observed. Risk factors for nasopharyngeal carriage included household crowding and having a sibling age five years or older. Penicillin non-susceptibility increased in both VT and NVT strains.

Role of hygienic factors in the etiology of allergic disorders in children.

BACKGROUND/AIM: We investigated the role of body flora and chronic inflammatory infections in the etiology of allergic disorders in Turkish children. MATERIALS AND METHODS: Forty pediatric asthma patients with positive skin prick tests and 40 age-matched healthy subjects with negative skin prick tests were enrolled in this cross-sectional study. Serum H. pylori IgG, viral hepatitis serology, IL-10, and TGF-beta levels were measured. Stool and throat cultures were taken and tested for occurrence of microorganisms. RESULTS: A significantly higher percentage of nonatopic subjects tested positive for anti-H. pylori antibodies compared to atopic subjects (60% vs. 20%). Serum IL-10 levels were also significantly higher in nonatopic subjects. No significant differences in direct microscopy and culture specimens of stools were observed. Examination of throat flora showed significantly higher occurrences of Neisseria and beta-hemolytic Streptococcus in nonatopic subjects, but higher occurrences of gram-positive bacilli in atopic subjects. CONCLUSION: Higher prevalence of anti-H. pylori antibody and higher serum levels of IL-10 in nonatopic subjects suggest that chronic infection and inflammation may protect against atopic disease. Higher occurrences of Neisseria and beta-hemolytic Streptococcus in throat cultures from nonatopic subjects are novel findings that lend further support to the hygiene hypothesis.

Preliminary results of a novel quorum sensing inhibitor against pneumococcal infection and biofilm formation with special interest to otitis media and cochlear implantation.

The purpose of the study is to assess the effect of a novel quorum sensing inhibitor (QSI), coded as 'yd 47', against otitis media and biofilm formation on Cochlear implants (CIs). Small pieces cut from cochlear implant were implanted under the skin in the retroauricular area on both sides of four guinea pigs. The implant pieces in the study and control sides were implanted in Streptococcus pneumoniae strain solution and saline, respectively. The right and left middle ears were also instilled with a solution containing pneumococci and saline, respectively. The animals were only given an intraperitoneal 'yd 47' twice daily for three months to be assessed later with electron microscopy. Clinical examination with palpation, inspection and otoscopy did not reveal any sign of implant infection or otitis media. In the study and control implant materials, soft tissues around the implant and tympanic membranes, there was no biofilm formation by pneumococci. Contamination by various cells and some rod-shaped bacteria (not diplococcic) were seen in some of the materials. In conclusion, the novel QSI seems promising in the prevention of otitis media and biofilm formation on CIs by pneumococci.

Drug resistance profiles and clonality of sporadic Shigella sonnei isolates in Ankara, Turkey.

The aims of this study were to investigate drug resistance rates, types of extended spectrum beta lactamases (ESBLs), and molecular epidemiological characteristics of 43 Shigella sonnei isolates. Ampicillin-sulbactam, amoxicillin-clavulanate, chloramphenicol, and ciprofloxacin were the most active antibiotics. Five isolates harbored bla SHV-12, bla(TEM-1) and bla(CTX-M-15). More than 90% of the isolates had an indistinguishable pulsotype.

Drug resistance profiles and clonality of sporadic Shigella sonnei isolates in Ankara, Turkey

The aims of this study were to investigate drug resistance rates, types of extended spectrum beta lactamases (ESBLs), and molecular epidemiological characteristics of 43 Shigella sonnei isolates. Ampicillin-sulbactam, amoxicillin-clavulanate, chloramphenicol, and ciprofloxacin were the most active antibiotics. Five isolates harbored blaSHV-12, blaTEM-1 and blaCTX-M-15. More than 90% of the isolates had an indistinguishable pulsotype.

[Investigation of the Presence of Disinfectant Resistance Genes qacA/B in Nosocomial Methicillin-Resistant Staphylococcus aureus Isolates and Evaluation of Their In Vitro Disinfectant Susceptibilities]. / Hastane Enfeksiyonu Etkeni Olan Metisiline Dirençli Staphylococcus aureus Suslarinda qacA/B Dezenfektan Direnç Genlerinin Varligi ve Dezenfektanlara In Vitro Duyarliliklarinin Arastirilmasi

Development of resistance to disinfectant substances in nosocomial microorganisms is an important problem encountered during disinfectant practices. Methicillin-resistant Staphylococcus aureus (MRSA) remains a significant cause of hospital-acquired infections. Besides being resistant to several antimicrobial agents, MRSA strains can also become resistant to some disinfectant substances. Resistance to disinfectant substances may develop due to the misuse of disinfectants. This may either be due to the frequent use of disinfectant substances or use in lower concentrations than recommended. MRSA strains may harbour the qacA/B disinfectant resistance genes that may cause resistance to quarternary ammonium compounds and some cationic disinfectants. These resistance genes are found in plasmids and are responsible for decreased susceptibility or resistance. In this study, a total of 69 nosocomial MRSA strains isolated from clinical specimens in our hospital were tested for disinfectant activity and the presence of qacA/B disinfectant resistance genes in these isolates was investigated by polymerase chain reaction. We determined whether the presence of these genes caused phenotypic resistance to chlorhexidine and benzalkonium chloride by the use of bactericidal and bacteriostatic tests. For this purpose, the minimum inhibitory concentration (MIC) values of these disinfectants against MRSA isolates were detected by microdilution method with the proposals of CLSI, and bactericidal effects of these disinfectants were also detected by using quantitative suspension test according to EN13727:2003 European Standard. It has been found that 11.6% (8/69) of the isolates harbored qacA/B resistance genes. MIC values for chlorhexidine and benzalkonium chloride were found in the range of 2-8 µg/ml. Although it was observed that MIC values were higher in five of the qacA/B gene positive isolates, statistically significant difference was not found between gene positive and gene negative groups. Both 1% chlorhexidine and 1% benzalkonium chloride were found bactericidal against the isolates including the ones carrying the qacA/B resistance genes. It was concluded that the presence of the qacA/B disinfectant resistance genes did not lead to resistance to the disinfectant substances at the concentrations used in clinical practices. Furthermore, tested disinfectants still exhibited bactericidal activity even with high MIC values.

Evaluation of DNA extraction kits for molecular diagnosis of human Blastocystis subtypes from fecal samples.

Blastocystis sp. is now recognized as one of the most common intestinal parasite in human fecal examinations. Recently, PCR-based diagnostic methods of Blastocystis infection using direct DNA extraction from fresh fecal samples with commercially available kits are reported. Several kits have been developed, but little has been done in comparing the detective sensitivity between PCR methods using the commercial kits. In this study, we compared the detective sensitivity among five commercially available kits (MagNA Pure LC DNA Isolation Kit I, Roche; QuickGene SP Kit DNA, FujiFilm; NucleoSpin Plant II, Macherey-Nagel; QIAamp DNA Stool Mini Kit, Qiagen; ZR Fecal DNA Kit, Zymo Research) and fecal culture method. In a preliminary test, the DNA isolated with two kits (FujiFilm and Macherey-Nagel) showed negative PCR, while the other three kits showed positive PCR. Then, DNA from 50 clinical samples that was Blastocystis-positive in the examination of fecal culture method were isolated with the three kits and 1.1 kbp SSU rRNA gene was detected with PCR. The positive rates of the three kits (Roche, Qiagen, and Zymo Research) were 10, 48 and 94%, respectively. The present study indicated that there is different detective sensitivity among the commercial kits, and fecal culture method is superior in detection rate and cost performance than DNA-elution kits for diagnosis of Blastocystis sp. subtypes.

A microbiological assessment of polymer and conventional carbide burs in caries removal.

PURPOSE: The purpose of this study was to compare the caries removal efficiency of polymer burs (Smartburs) and conventional carbide burs microbiologically. METHODS: Twenty-four patients participated, each presenting 2 active carious lesions on the occlusal surfaces of primary molars. Sample-taking and caries-removal were done in the following order: (1) first sample (from the carious dentin); (2) caries removal (with a Smartbur or carbide bur); and (3) second sample (from the caries-free dentin), respectively. The samples were processed in a laboratory and spread on various media. The colonies on the agar plates were counted, and then numbers of CFU/ml were calculated. RESULTS: There were no statistically significant differences between the numbers of CFU/ml in the carious dentin before preparation, comparing the Smartbur group and carbide bur group for all the media used (P>.05). There were statistically significant differences in the numbers of CFU/ml before and after preparation comparing both types of burs for all the media used (P<.05). There were no statistically significant differences in the reductions of the numbers of CFU/ml, comparing the 2 preparation instruments (P>.05). CONCLUSION: The polymer burs were found as effective as the conventional carbide burs microbiologically in caries removal.

Nasopharyngeal carriage of Streptococcus pneumoniae in healthy Turkish infants.

OBJECTIVES: The aims of this study were to determine nasopharyngeal carriage rates, serotype distribution and antimicrobial resistance patterns of Streptococcus pneumoniae in healthy 0 to 2 year-old infants who live within a rural or urban locale and not attending daycare centers. In order to evaluate the possible impact of pneumococcal conjugate vaccine in this population, coverage of the isolated serotypes by the vaccine was also calculated. METHODS: The study was conducted on 564 healthy infants attending 2 different well child clinics, one of which is located in an urban region and the other in a rural region. Specimens were collected with nasopharyngeal swabs. Serotyping was performed with standard antisera. Penicillin susceptibility was determined with E-test. Chi-square tests and logistic regression were used for data analysis. RESULTS: The pneumococcal carriage rate was 22.5%. Age (>2 months age) [2.98 (1.41-6.29) p=0.004] and presence of another child within the house who attends school [1.72 (1.13-2.62) p=0.01] increased the carriage rate. The most frequently isolated serotypes were 11 (11.8%), 23 (7.9%), 19F (7.1%), 22 (6.3%), 9 (5.5%), 19 (5.5%) and 23B (5.5%). The total coverage of vaccine and vaccine-related serotypes by 7, 11 and 13 valent pneumococcal conjugate vaccines were 51.2, 59.0 and 59.0%, respectively. Of the isolated pneumococci, 10 (8.5%) were intermediately resistant and 8 (6.8%) were highly resistant to penicillin. CONCLUSION: This study provides data about the local carriage rate and serotype distribution of S. pneumoniae strains in Turkish children, which is important in predicting the possible effects of different valent pneumococcal conjugate vaccines in this population.

Consistent intrafamilial transmission of Actinobacillus actinomycetemcomitans despite clonal diversity.

BACKGROUND: Actinobacillus actinomycetemcomitans is a major pathogen in aggressive periodontitis. Our objectives were to determine the periodontal status and occurrence of A. actinomycetemcomitans in family members of subjects with A. actinomycetemcomitans-positive aggressive periodontitis (AgP) and to evaluate the probability of its intrafamilial transmission. METHODS: Of the 300 subjects screened, 66 (22%) had AgP and A. actinomycetemcomitans. Eleven (probands) of these 66 subjects with AgP met the strict inclusion criteria for the study. The study population consisted of 55 subjects, including probands and their family members (N = 44). Two family groups were formed according to whether the proband was a child (N = 7) or a parent (N = 4). Subgingival samples from all subjects were cultured for A. actinomycetemcomitans, and its clonal types were determined by combining serotype and genotype data for each isolate. RESULTS: Among 42 dentate family members, 16 (38%) exhibited periodontitis and eight (50%) had AgP. Periodontitis was found in nine of 12 (75%) of the dentate parents and six of 17 (35%) siblings of the child probands. A. actinomycetemcomitans was detected in 16 of 31 (52%) family members, i.e., one parent and at least one sibling in six families. The child probands shared A. actinomycetemcomitans clonal types with their parents in five of six (83%) families and with their siblings in three of six (50%) families. In the four parent-proband families, A. actinomycetemcomitans occurred in two spouses and all nine children. The parent probands shared A. actinomycetemcomitans clonal types with their spouses in both families and with their children in three of four families. In all families, the likelihood of intrafamilial transmission of A. actinomycetemcomitans was statistically significant. Members of most families (eight of 11, 73%) also harbored additional clonal types of A. actinomycetemcomitans. CONCLUSION: Parents and siblings of an individual with A. actinomycetemcomitans-positive AgP may have an increased susceptibility to periodontitis and shared and/or other clonal types of oral A. actinomycetemcomitans.

In vitro activities of voriconazole as a triazole derivative and caspofungin as an echinocandin were compared with those of some antifungal agents against Candida species isolated from clinical specimens.

We evaluated the in vitro activity of ketoconazole (KET), fluconazole (FLU), amphotericin B (AmpB), and flucytosine (FCU) in comparison to voriconazole (VOR) as a triazole derivative and caspofungin (CAS) as an echinocandin against 114 Candida spp. isolated from different cultures (blood, urine, sputum). The most common species of identified Candida were C. albicans (88), followed by C. parapsilosis (8), C. glabrata (7), C. tropicalis (6), C. famata (2), C. kefyr (2), and C. sake (1). The Clinical and Laboratory Standards Institute M 27-A method was used to evaluate the activity of antifungal agents. The minimal inhibitory concentrations of the strains were evaluated by RPMI 1640 medium using a microdilution method. Of 114 isolates, 100% were sensitive to AmpB, VOR, and CAS, 1.75% showed intermediate resistant to FCU also 0.87% showed intermediate resistant to FLU, and 2.63% were fully resistant to FLU and FCU. These results suggest that KET, AmpB, CAS, and VOR demonstrated excellent activity against all Candida spp. Taken together; these antifungal agents should be effective in the treatment of a broad range of Candida infections.

Effect of timing of glutamine-enriched enteral nutrition on intestinal damage caused by irradiation.

Intestinal mucosal damage and bacterial translocation are clinical problems that may be caused by the use of ionizing radiation. Glutamine (Gln) support reduces the mucosal barrier in several ways. This study was undertaken to investigate the effect of timing of Gln-enriched enteral nutrition (EN) on bacterial translocation and mucosal damage due to radiotherapy (RT). A rat model of whole body irradiation was designed in which a single dose of 485 cGy was given. A total of 50 rats were randomly assigned to the following 5 groups, each of which comprised 10 rats: (1) balanced rat chow given for 8 days without RT (group 1); (2) balanced rat chow given 4 days before and 4 days after RT (group 2); (3) Gln-enriched EN given 4 days before RT (group 3); (4) Gln;enriched EN given 4 days after RT (group 4); and (5) Gln-enriched EN given 4 days before and 4 days after RT (group 5). Mesenteric lymph node and ileum samples were removed for evaluation of bacterial translocation (BT) and histopathologic investigation, respectively. BT and intestinal mucosal injury scores in all rats that received RT were higher than in rats without RT. No difference was seen in parameters between groups 3 and 4 (P>.05, P>.016, respectively); BT and intestinal mucosal injury scores of group 5 were significantly lower than those of groups 3 and 4 (P<.05, P<.016, respectively). Meanwhile, the BT and mesenteric injury scores of group 5 were significantly lower than those of group 2 (P<.05, P<.016, respectively). As a result, intestinal injury due to RT was significantly decreased by Gln-enriched EN support given before and after whole body RT.

In vitro susceptibilities of Escherichia coli and Klebsiella spp. to ampicillin-sulbactam and amoxicillin-clavulanic acid.

Ampicillin-sulbactam (A/S) and amoxicillin-clavulanic acid (AUG) are thought to be equally efficacious clinically against the Enterobacteriaceae family. In this study, the in vitro activities of the A/S and AUG were evaluated and compared against Escherichia coli and Klebsiella spp. Antimicrobial susceptibility tests were performed by standard agar dilution and disc diffusion techniques according to the Clinical and Laboratory Standards Institute (CLSI). During the study period, 973 strains were isolated. Of the 973 bacteria isolated, 823 were E. coli and 150 Klebsiella spp. More organisms were found to be susceptible to AUG than A/S, regardless of the susceptibility testing methodology. The agar dilution results of the isolates that were found to be sensitive or resistant were also compatible with the disc diffusion results. However, some differences were seen in the agar dilution results of some isolates that were found to be intermediately resistant with disc diffusion. In E. coli isolates, 17 of the 76 AUG intermediately resistant isolates (by disc diffusion), and 17 of the 63 A/S intermediately resistant isolates (by disc diffusion) showed different resistant patterns by agar dilution. When the CLSI breakpoint criteria are applied it should be considered that AUG and A/S sensitivity in E. coli and Klebsiella spp. strains may show differences.

Efficacy of various disinfecting agents on the reduction of bacteria from the surface of silicone and polyether impression materials.

The aim of the present study was to evaluate the effectiveness of different disinfectants on the reduction of two resistant bacteria from the surface of impression materials. Impressions were made of a sterile metal model of the edentulous maxillary arch which had been contaminated with Staphylococcus aureus and Enterecoccus faecalis. The impressions were cultured before and after disinfection with 0.525% sodium hypochlorite, Gludex and Mikrozid spray disinfectant. For each of the three impression materials and the two microorganisms, spray disinfectant was found to be less effective than either sodium hypochlorite or Gludex.

Preputial bacterial colonisation in preschool and primary school children.

OBJECTIVES: Preputial bacterial colonisation was investigated in preschool and primary school children with and without phimosis before the circumcision procedure. METHOD: The study group consisted of 32 boys admitted to our clinic consecutively between June 2003 and September 2003 for circumcision. The indication for surgery was religious belief in all patients. Immediately before the procedure, a swab was swept circumferentially once around the surface of the glans starting just proximal to the urethral meatus. In case of phimosis the same procedure was performed after complete retraction of the foreskin avoiding external contamination. The cultures were repeated in all patients after cleansing the glans and nearby preputium with polyvidon-iodine solution. RESULTS: The mean age of the patients' was 6 (4-12) years. All 5 (100%) patients with phimosis had clinically significant (> or =100,000 cfu/ml) uropathogenic bacterial colonisation. In 27 (84.3%) patients without phimosis culture reports revealed the absence of growth in 8 (29.6%) patients while 3 (11.1%) had Diphteroids and 1 (3.7%) had alpha-haemolytic Streptococci isolated from their preputial swabs which were accepted as harmless skin commensals. The rest of the boys (55.5%) had uropathogenic species in their preputium and all except 2 (7.4%) cases had counts exceeding 100,000 cfu/ml. The overall rates for individual species including any count were found as E. coli 3.1%, Klebsiella 18.8%, coagulase-negative Staphylococci12.5% and Enterococcus 43.8%. Cleansing of perimeatal and periurethral region with 10% polyvidon-iodine solution markedly decreased the bacterial count in 80% of the patients with phimosis. Including eight patients with no growth before cleansing 88.9% of the patients in the non-phimosis group were free of preputial bacteria after cleansing with iodine solution. CONCLUSION: Significant preputial colonisation with uropathogens might still be present in preschool and primary school children.

An investigation of the bactericidal effect of certain antiseptics and disinfectants on some hospital isolates of gram-negative bacteria.

The effect of widely used antiseptics and disinfectants on some hospital isolates of gram-negative bacteria was assessed by the quantitative suspension test Chlorhexidine gluconate (4%), savlon (1:100), and 5.25% sodium hypochlorite were tested. Savlon and chlorhexidine gluconate were effective at in-use concentrations and sodium hypochlorite was effective at 1:50 dilution.