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  • Author or Editor: Orsolya Dobay x
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In this study we summarise the results of the first major epidemiological survey of Streptococcus pneumoniae isolates from Hungary. Neither the incidence nor the level of resistance to penicillin of the strains was high, we observed, however, 40% macrolide resistance. The main underlying mechanism was the presence of the erm(B) gene, but we could find also strains with the mef gene, some of them with unusually high resistance levels. The main serogroups in ranking order were 6, 9, 19, 23 and 14, accounting together for 88.2% of all typed strains. We found a close correlation between serotypes and resistance. As a result of genotyping the penicillin non-susceptible strains, we found that the penicillin resistant isolates all belonged to the same PFGE clone, while in the intermediate group the diversity was greater. We could compare our isolates to the successful international PMEN clones, and proved the presence of some of them in Hungary. In general, we could establish the similarity of Hungarian pneumococci and other international isolates.

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A pneumococcus elleni konjugált védőoltás 2009 áprilisában Magyarországon bekerült az önkéntes oltások közé, és ezzel ugrásszerűen megnőtt az átoltottság. Számolni kell azonban azzal a veszéllyel, hogy az oltás következményeként az eddigi szerotípusok lecserélődnek. Célok: A Semmelweis Egyetem Orvosi Mikrobiológiai Intézetében három éve gyűjtik és vizsgálják az óvodásoktól származó orrmintákat. A dolgozatban az alacsony, illetve magas szintű átoltottsággal rendelkező gyerekcsoportokat hasonlították össze. Anyagok és módszerek: 2009 óta 854 óvodást vizsgáltak az ország különböző területein lévő 20 óvodából. Meghatározták a hordozott törzsek szerotípusait, antibiotikum-érzékenységét és genetikai rokonságukat. Eredmények: A hordozott törzsek száma 324, a hordozási arány 37,94% volt. A törzsek a legtöbb antibiotikumra érzékenynek bizonyultak, kivéve a makrolidokat. Az oltott populációban a vakcinaszerotípusok határozott visszaszorulását tapasztalták a kezdeti 78,85%-ról 35,30%-ra. Következtetések: A szerzők véleménye szerint az eredmények a vakcina hatékonyságát tükrözik, és hangsúlyozzák a pneumococcus elleni oltási program szükségességét, illetve a vakcina kötelező oltások közé történő besorolását. Orv. Hetil., 2012, 153, 1031–1034.

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The effects of bafilomycin A1 and of the reduced level of endosomal epsilon-COP (coatomer protein) on the infectivity of human adenovirus type 5 were investigated in Coxsackie adenovirus receptor- (CAR-) transfected Chinese hamster ovary (CHO) cells. The endosomal proton pump inhibitor bafilomycin A1 was able to cause only partial inhibition. Using ldlF cells (an epsilon-COP thermosensitive mutant CHO cell line) the reduction of epsilon-COP level also had partial inhibitory effect. Based on these results and comparing them to existing models of the adenovirus entry, we propose a refined model in which there are two pathways of adenoviral entry: the first one involves the epsilon-COP as the downstream effector of the acidification and can be blocked by bafilomycin A1 and the second one is a pH-independent pathway.

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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.

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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.

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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.

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The presence of the vanA gene was determined in enterococci from healthy poultry, originating from the Hungarian resistance monitoring system between 2001 and 2004. Enterococci (n = 562) were collected from intestinal samples of slaughtered broiler chickens. The presence of van genes was detected by polymerase chain reaction (PCR). The vancomycin-resistant enterococcus (VRE) strains carried only the vanA gene. Genus- and species-level identification of the vanA gene carrier strains was carried out by PCR using specific primers. In 2001, 25 out of the 289 isolated strains (8.6%) were vanA carriers (1 Enterococcus mundtii , 13 E. durans and 11 E. faecium ). In 2002 (n = 87), 20 (23%) strains were vanA positive (11 E. durans and 9 E. faecium ). In 2003 and 2004, none of the strains (n = 95 and 91, respectively) were positive for the most common van genes. In 2003, there was only one strain for which higher minimum inhibitory concentrations (MIC) of vancomycin (4 mg/L) and teicoplanin (8 mg/L) were found. In 2004 there were three strains for which the MIC of vancomycin was 8 mg/L, and 2 strains and 1 strain with teicoplanin MICs of 4 mg/L and 8 mg/L, respectively. The potential similarity of these strains was studied by pulsed-field gel electrophoresis (PFGE). The VRE strains were not closely related to one another. The annual data of vancomycin resistance indicate an association between the recovery of vancomycin-resistant enterococci and the use of avoparcin in animal feeds. This study indicates that with the reduced use of antibiotics in food animals, it is possible to decrease the rate of resistant bacteria. Although the use of avoparcin had been banned in 1998, the VRE strains disappeared only five years later.

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In this report we examined the glycopeptide susceptibility of enterococci, isolated in 2005, from slaughtered animals, within the confines of Hungarian Antibiotic Resistance Monitoring System. We determined the presence of the van genes as well as their genetic relatedness in enterococci from poultry. Enterococcus sp. strains (n = 175) were collected from intestinal samples of slaughtered poultry in 2005. The origin of the samples was registered at county level. After screening the strains with 30 mg vancomycin disc 19 (86%) intermediate resistant and 4 (3%) fully resistant strains were found. The distribution of minimum inhibitory concentration (MIC)-values among 23 enterococcus strains which were intermediate or resistant to vancomycin were 0.25 mg/L (4.4%), 2 mg/L (8.6%), 4 mg/L (8.6%), 8 mg/L (61%), 16 mg/L (8.6%) and 256 mg/L (8.6%). The MICs of teicoplanin were 0.25 mg/L (4.3%), 1 (8.6%), 4 mg/L (78.3%), 16 mg/L (4.3%) and 256 mg/L (4.3%). The two most vancomycin-resistant strains were vanA carriers (1 E. faecalis and 1 E. faecium ).The farms that produced these strains can be reservoirs of VRE and the affected farms should change the technology of disinfection and breeding in order to prevent the emergence of high numbers of human VRE isolates in Hungary.

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Recently, a PCR-derived method for serotyping Streptococcus pneumoniae has been devised to substitute the conventional antiserum phenotypic method. The method initially used a multiplex PCR reaction, dividing the isolates into 6 different groups based on the detected PCR gel pattern. In order to optimise and refine this crucial step, the Taguchi technique was employed, which can evaluate the individual effect of six parameters (in this case: primers, MgCl 2 , nucleotide mix, polymerase and buffer), with only 18 experiments; varying the parameter levels in an orthogonal matrix which suppresses the interactions between them. With this method, clear and sharp bands were observed in 5 experiments out of the 18, while the PCR did not work reliably in the remaining cases. In addition, the PCR-based technique could be rendered more economic by the 10-fold lowering of the quantities of two primers. The modified reaction yielded identical results to those obtained with the original method.Furthermore, we have designed serotype-specific primers for 11 new serotypes. The most important ones are those that can distinguish the very closely related, but equally important serotypes 6A and 6B.

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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.

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