Authors:Krisztina Laub, Adrienn Tóthpál, Szilvia Kardos, and Orsolya Dobay
The aim of this study was to assess the Staphylococcus aureus nasal carriage rate in healthy children all over Hungary and to specify some risk factors, the antibiotic resistance patterns of the bacteria, and their genetic relatedness. In total, 878 children (aged 3–6 years) were screened at 21 day-care centers in 16 different cities in Hungary, between February 2009 and December 2011. Samples taken from both nostrils were cultured on blood agar, and suspected S. aureus isolates were identified by β-hemolysis, catalase positivity, clump test, and nucA PCR. Methicillin-resistant strains were screened by mecA and mecC PCR. Antibiotic susceptibility was determined by agar dilution or gradient test strips. Pulsed-field gel electrophoresis was used for genotyping. S. aureus carriage rate was found to be 21.3%, which correlates well with international data. We found no statistically significant correlation between the gender or the sibling status and S. aureus carriage. All isolates were sensitive to oxacillin, trimethoprim–sulfamethoxazole, and mupirocin. The resistance rates for erythromycin, ciprofloxacin, clindamycin, gentamicin, and tetracycline were 7.5%, 0.5%, 1.1%, 3.7%, and 4.3%, respectively. The isolates showed very high genetic diversity. In summary, carried S. aureus isolates are more sensitive to antibiotics compared with clinical isolates in Hungary, and methicillin-resistant S. aureus carriage rate is very low yet.
Authors:Krisztina Laub, Szilvia Kardos, K. Nagy, and Orsolya Dobay
Asymptomatic carriage of Staphylococcus aureus in healthy individuals has a high prevalence, especially in children and young adults. Nasal colonisation is a well-known risk factor for subsequent severe infection, or can be the source of transmission of this bacterium to other susceptible persons. In this study, we have surveyed the nasal carriage rate of students of the Semmelweis University, by screening 300 volunteers. We have determined the antibiotic sensitivity of the isolates by Etest, and their genetic relatedness by pulsed-fieled gel electrophoresis. The nasal carriage rate of S. aureus was found to be 29.3%, and that of MRSA only 0.67% (2/300). The isolates were generally sensitive to antibiotics, except for macrolides. We could observe a noticeably great genetic diversity, even among strains deriving from students of the same university group.
Authors:Adrienn Tóthpál, Krisztina Laub, Szilvia Kardos, Károly Nagy, and Orsolya Dobay
Streptococcus pneumoniae is responsible for a high level of morbidity and mortality, especially among children. For a long time, only the polysaccharide vaccine was available against pneumococcal infections, but in the last decade special conjugate vaccines were developed for paediatric use. These vaccines have made a deep impact on serotype distribution all over the world, by suppressing those serotypes included in the vaccines, while new, previously rare types emerged. These changes have been monitored closely in numerous publications all over the world. Nevertheless, data on pneumococcal serotypes in Hungary were mostly published in Hungarian, therefore not available in the international literature. In this meta-analysis, our aim was to collect and summarise all available data, and try to follow the changes observed after the introduction of the conjugate vaccines.
Authors:Adrienn Tóthpál, Anita Ordas, Edit Hajdú, Szilvia Kardos, Erzsébet Nagy, K. Nagy, and Orsolya Dobay
Streptococcus pneumoniae is an important pathogen with significant morbidity and mortality rates worldwide, especially among children <5 years. Healthy carriers are the most important sources of pneumococcal infections, and the nasopharyngeal colonisation is the most prevalent among children attending communities such as day-care centres (DCCs). The conjugate pneumococcal vaccines (PCVs) were shown to have an impact on the colonisation, and so play an important role in inhibiting infections. In this study we compared the nasal carriage of healthy children attending DCCs in Szeged, Hungary in 2003/2004, when nobody was vaccinated, and in 2010, when already 1/5 of the children received PCV-7. Significant differences were observed in the serotype distribution, representing a marked shift from the previously widespread vaccine-types (mostly 6A or 14) to others (11A and 23F). The new serotypes showed higher antibiotic susceptibility. The bacterium exchange between children was clear from the pulsed-field gel electrophoresis (PFGE) patterns, and the circulation of certain international clones plays also a role in these dynamic changes.
Authors:Adrienn Tóthpál, Szilvia Kardos, Edit Hajdú, Károly Nagy, Mark Linden, and Orsolya Dobay
Streptococcus pneumoniae is responsible for a significant amount of morbidity and mortality worldwide, especially among children <5 years. Healthy carriers are the most important sources of infections and the carriage also peaks in the first years of life, especially among children attending communities. In this study, for the first time in Hungary, we surveyed the nasal carriage of healthy children, just before the use of the conjugate vaccine started increasing.Nasal specimens of 358 children were cultured and pneumococci isolated. The strains were serotyped with antisera and PCR, genotyped by PFGE and their antibiotic sensitivity determined by agar dilution method.The carriage rate was 37.71%. The isolates were sensitive to most tested antibiotics, except for macrolides. In this cohort of specimens still the widespread, so-called “pediatric serotypes” dominated (14, 19F, 23F, 6A, 6B in ranking order), but three of the previously rare types: 15B, 11A and 13 were represented already by 21.5% of all strains and also a few other rare non-vaccine types (e.g. 10A or 37) were detected.The calculated vaccine coverage was 55.6% for PCV-7, 69.6% for PCV-13 and 86.7% for Pneumovax. In this cohort, only 15.9% of the children (n = 57) were vaccinated. The carriage rate of PCV-7 vaccinated children was significantly lower (30.4%) than that of the non-vaccinated group (39.2%). The clonality of the isolates was significant within each group, revealing the extensive bacterium exchange among children.
Authors:Krisztina Laub, Adrienn Tóthpál, Eszter Kovács, Judit Sahin-Tóth, Andrea Horváth, Szilvia Kardos, and Orsolya Dobay
We collected nasal samples from 1,390 healthy 3–7 years old children in Szolnok city, Hungary, in 2012. We detected 476 Staphylococcus aureus isolates from 474 children. In two occasions, two different S. aureus were isolated, based on hemolysis type and pulsed-field gel electrophoresis pattern. S. aureus carriage rate was calculated to be 34.1% similar to others studies. Male gender was found to be a risk factor for carriage by statistical analysis. Altogether, four methicillin-resistant S. aureus (MRSA) strains were detected by mecA polymerase chain reaction, which means 0.8% community-acquired MRSA prevalence among the S. aureus isolates. All MRSA strains harbored the SCCmec type IV cassette (typical for CA-MRSA) and belonged to ST45 by multilocus sequence typing. During antibiotic susceptibility testing, we measured the following resistance rates: 0.0% for mupirocin, 0.2% for ciprofloxacin, 0.6% for gentamicin and oxacillin, 3.4% for tetracycline, 9.5% for clindamycin, 10.3% for erythromycin, and 91.4% for penicillin, which are generally lower compared with Hungarian clinical isolates.