High prevalence of group B streptococcus ST17 hypervirulent clone among non-pregnant patients from a Hungarian venereology clinic.

BACKGROUND: Although Streptococcus agalactiae is the leading causative agent of neonatal sepsis and meningitis, recently it is increasingly isolated from non-pregnant adults. The relation between its presence in the genitourinary tract and manifested clinical symptoms of STD patients remains an open question. In this study, a complex epidemiological investigation of GBS isolates from a venerology clinic was performed. METHODS: Ninety-six GBS isolates were serotyped and their genetic relatedness determined by PFGE. MLST was also performed for a subset of 20 isolates. The antibiotic susceptibility was tested with agar dilution. Surface proteins and the ST-17 hypervirulent clone was detected by PCR. RESULTS: The serotype prevalence was the following: V (29.2%), III (27.1%), Ia (22.9%), IV (10.4%), II (5.2%) and Ib (4.2%). A strong association was demonstrated between surface protein genes and serotypes. All isolates were fully susceptible to penicillin, but erythromycin and clindamycin resistance was high (41.7 and 35.4%, respectively), and 8 phenotypically macrolide sensitive isolates carried the ermB gene. 21.9% of all strains belonged to the hypervirulent ST17 clone, most being of serotype III and all were rib +. We found a few serotype IV isolates belonging to several STs and one serotype V/ST110 strain, containing a 44-bp deletion in the atr allele. CONCLUSIONS: The presence of silent ermB genes is of worry, as their expression upon macrolide exposure could lead to unforeseen therapeutic failure, while clindamycin is used for intrapartum antibiotic prophylaxis, in case of penicillin allergy. The other alarming result is the high prevalence of ST17 among these strains from STD patients, who could be sources of further infections. This is the first report from Hungary providing both serotyping and genotyping data of GBS isolates. These results could be helpful for vaccine production as the major vaccine candidates are capsular antigens or surface proteins.

Bicarbonate Inhibits Bacterial Growth and Biofilm Formation of Prevalent Cystic Fibrosis Pathogens.

We investigated the effects of bicarbonate on the growth of several different bacteria as well as its effects on biofilm formation and intracellular cAMP concentration in Pseudomonas aeruginosa. Biofilm formation was examined in 96-well plates, with or without bicarbonate. The cAMP production of bacteria was measured by a commercial assay kit. We found that NaHCO3 (100 mmol l-1) significantly inhibited, whereas NaCl (100 mmol l-1) did not influence the growth of planktonic bacteria. MIC and MBC measurements indicated that the effect of HCO 3 - is bacteriostatic rather than bactericidal. Moreover, NaHCO3 prevented biofilm formation as a function of concentration. Bicarbonate and alkalinization of external pH induced a significant increase in intracellular cAMP levels. In conclusion, HCO 3 - impedes the planktonic growth of different bacteria and impedes biofilm formation by P. aeruginosa that is associated with increased intracellular cAMP production. These findings suggest that aerosol inhalation therapy with HCO 3 - solutions may help improve respiratory hygiene in patients with cystic fibrosis and possibly other chronically infected lung diseases.

High prevalence of Staphylococcus aureus nasal carriage among children in Szolnok, Hungary.

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.

First description of a catalase-negative Staphylococcus aureus from a healthy carrier, with a novel nonsense mutation in the katA gene.

We have screened 2568 healthy individuals (mostly children) for Staphylococcus aureus and Streptococcus pneumoniae nasal carriage between 2010 and 2012. Out of the isolated 751 S. aureus strains, we found one methicillin-sensitive catalase-negative S. aureus (CNSA). Our CNSA isolate possessed a novel nonsense point mutation in the katA gene leading to early truncation of the protein product. The strain was resistant to penicillin and erythromycin, but sensitive to all other tested antibiotics and carried the enterotoxin A gene. It belonged to sequence type 5 (ST5), which is a successful, worldwide spread, usually MRSA clone. Catalase has been described as a virulence factor strictly required for nasal colonisation, and this is the first case contradicting this theory, as all previous CNSA isolates derived from infections. This is the first report of a CNSA from a symptomless carrier as well as the first occurrence in Hungary.

Epidemiology and antibiotic sensitivity of Staphylococcus aureus nasal carriage in children in Hungary.

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 ß-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.

Radical serotype rearrangement of carried pneumococci in the first 3 years after intensive vaccination started in Hungary.

UNLABELLED: Streptococcus pneumoniae is responsible for a significant amount of morbidity and mortality worldwide. Healthy carriers, mainly young children, are the most important sources of infections. In the current study, we aimed to determine the changes that have occurred since the introduction of PCV-7 in Hungary. Nasal specimens were collected from 1,022 healthy children aged 3-6 years attending day-care centres. After thorough identification, pneumococcal isolates were serotyped, and their antibiotic sensitivity was determined. The carriage rate was found to be 34.9%. A huge serotype rearrangement was detected compared to earlier results, with the previously leading serotype 14 having completely disappeared. Serotypes 11A, 35F, 19A, 6B, 15B, 3 and 38 were most prevalent, and 29 different types were identified in total. The PCV-7 types were responsible for 16.5% of all serotypes, and 36.0% are not covered by any pneumococcal vaccines. The isolates were sensitive to most tested antibiotics, except erythromycin (resistance was 21.6%). Only one penicillin-resistant strain was found. The newly and rapidly emerging non-vaccine serotypes are much more sensitive, except serotype 19A. CONCLUSION: Due to PCV vaccination, a complete serotype arrangement occurred also in Hungary. The old "paediatric" serotypes were replaced by serotypes 11A, 35F, 19A, 6B, 15B, 3 and 38.

Changes in the serotypes of Hungarian pneumococci isolated mainly from invasive infections: a review of all available data between 1988 and 2011.

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.

Nasal carriage of Streptococcus pneumoniae among Hungarian children before the wide use of the conjugate vaccine.

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.

A marked shift in the serotypes of pneumococci isolated from healthy children in Szeged, Hungary, over a 6-year period.

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.

Detection of Staphylococcus aureus nasal carriage in healthy young adults from a Hungarian University.

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.

Genotypic and phenotypic characterisation of invasive Streptococcus pneumoniae isolates from Hungary, and coverage of the conjugate vaccines.

BACKGROUND AND AIMS: The 7-valent conjugate pneumococcal vaccine (Prevenar) was introduced as a recommended (but not yet obligatory) vaccine in Hungary in April 2009 and there was a sharp increase in the number of children vaccinated. Hence there is an urgent need for in-depth epidemiological data on invasive pneumococci before vaccination becomes widespread. Such a study has never been done before in Hungary. METHODS: 144 pneumococcal isolates, obtained from invasive infections or pneumonia, were collected from eight Hungarian diagnostic laboratories between 2000 and 2008. After confirmation of species identity, their susceptibilities to nine antibiotics were determined by Etest and agar dilution method. The serotypes and pulsed-field gel electrophoresis genotypes of the strains were also determined. RESULTS: In this cohort, most of the isolates were from patients at the extreme of life. Only 1.4% of the strains were resistant to penicillin, but nearly 40% were resistant to erythromycin (mainly due to erm(B) gene). Higher incidences of resistance were found in the very young and very old. The most prevalent serotypes in the cohort in descending order were 14, 6A, 6, 6B, 23F, 3, 19F and 11A. CONCLUSIONS: Results showed a similar but not identical profile to previously examined strains causing pulmonary infections in Hungary. The serotypes could be correlated to patient groups. Furthermore, there were examples of serotype switching in strains showing identical genotype but different serotype. The study also shows a good coverage by the conjugate vaccines over the invasive pneumococcal strains in Hungary based on the detected serotypes.

N-glycosylthioureido aglyco-ristocetins without platelet aggregation activity.

The water-soluble N-methoxy-PEG-yl-, N-beta-D-glucopyranosyl- and N-beta-D-maltosylthioureido aglyco-ristocetin were prepared which, in contrast to ristocetin A, did not induce thrombocyte aggregation. The antibacterial activity of N-beta-D-maltosylthioureido aglyco-ristocetin A against MRSA was comparable to that of ristocetin A, while its activity against Enterococcus faecalis (VRE, TSE) is somewhat stronger when compared to those of vancomycin and ristocetin A.

A new series of glycopeptide antibiotics incorporating a squaric acid moiety. Synthesis, structural and antibacterial studies.

The aglycones of the antibiotics eremomycin, vancomycin and ristocetin (3, 4 and 6, respectively) were prepared by deglycosidation of the parent antibiotics with hydrogen fluoride, and complete assignation of their 1H, 13C and 15N spectra was performed. The squaric acid amide esters (11-14), were prepared from dimethyl squarate. The corresponding asymmetric diamides (16-19, 22, 23) were also synthesized using 4-phenylbenzylamine and triglycine. The advantage of the method is the high regioselectivity and that no protecting group strategy is required. Electrospray mass spectroscopic method was elaborated for the determination of the site of substitution of the modified antibiotics. The antibacterial activity of the prepared compounds is discussed in detail.

Cefazolin prophylaxis in neurosurgery monitored by capillary electrophoresis.

Prophylactic use of antibiotics to prevent postoperative infections is a routine method in neurosurgery. Little is known about the period of effectiveness of antibiotics applied only for the purposes of operation. The actual concentration of cefazolin was determined in the serum, in the contents of wound drains, and in the cerebrospinal fluid in a 24-hour postoperative period after the administration of 1 g of cefazolin just prior to skin incision in 8 patients undergoing lumbar discectomy and 11 patients undergoing craniectomy. The concentration of the antibiotic was then compared with the minimal inhibitory concentration values of cefazolin for 10 different bacterial species. For evaluating the concentration of cefazolin, capillary electrophoresis was used, which is a new clinical application of this separation technique. Results showed that the antibiotic was effective against bacterial breeding in the serum and in the drainage up to 12 hours. The drug concentration in the cerebrospinal fluid remained less than the value of the serum, and it exceeded the minimal inhibitory concentration values only for approximately 5 hours.

Application of capillary zone electrophoresis to the analysis and to a stability study of cephalosporins.

The applicability of capillary zone electrophoresis (CZE) for the determination of cephalosporin antibiotics has been studied. In the case of the separation conditions optimised for fourteen cephalosporins, the precision of migration times was smaller than 1.3% RSD, and the values of the limit of detection ranged between 0.42 and 1.62 microg/ml. The proposed CZE method was applied to study the stability of cephalosporins in water at different temperatures (+25, +4 and -18 degrees C). It was established that the degradation of most cephalosporins was not higher than 20% at room temperature within 4 h of dissolution of these antibiotics.