Antibiotska osjetljivost i proizvodnja ß-laktamaza kod izolata Moraxella catarrhalis iz Zagreba, Hrvatska

Moraxella catarrhalis, a commensal of the nasopharynx, has been recognized with increasing frequency as a potential pathogen in respiratory tract infections. The ß-lactamase production in Moraxella catarrhalis, first described in 1977, has been ever more frequently reported in many countries of the world. However, there have no such reports from Croatia so far. The aim of this study was to investigate antibiotic susceptibilities and ß-lactamase production in Moraxella catarrhalis isolates from Croatia. Fifty Moraxella catarrhalis strains were collected from various clinical specimens at Zagreb University Children\u27s Hospital during the 1990-1992 period. Antibiotic susceptibilities to a wide range of antibiotics were determined by the broth microdilution method according to NCCLS. In all strains, ß-lactamases were detected by the disk chromogenic substrate (nitrocefin) test. The prevalence of ß-lactamase positive strains in the study period was 100%. No resistance to amoxicillin/clavulanate, cephalexin, ceftibuten, tetracycline, erythromycin, azithromycin and chloramphenicol was observed. In all strains, the activity of amoxicillin was strongly enhanced in the presence of clavulanic acid. Older cephalosporins were equally active, however, the thirdgeneration cephalosporin ceftibuten showed significantly lower minimal inhibitory concentrations compared with older compounds. Among non ß-lactam antibiotics, tetracycline and erithromycin showed similar activity. Azithromycin had a markedly stronger inhibitory activity in comparison with erythromycin and tetracycline. According to our results, amoxicillin combined with clavulanic acid should be the antibiotic of choice for the treatment of infections caused by ß-lactamase positive isolates of Moraxella catarrhalis. Oral cephalosporins, tetracycline, macrolides or azithromycin could be an option too.Moraxella catarrhalis se je ranije smatrala komenzalom u respiracijskom traktu, ali se danas zna da je ona značajan respiracijski patogen. Proizvodnja ß-laktamaze, prvi puta opisana 1977., javlja se sa sve većom učestalošću u mnogim zemljama svijeta. Dosadnije bilo izvještaja iz Hrvatske. Cilj ovoga istraživanja bio je ispitati osjetljivost na antibiotike i proizvodnju ß-laktamaze u kliničkim izolatima Moraxella catarrhalis iz Hrvatske. Pedeset izolata Moraxella catarrhalis prikupljeno je iz različitih kliničkih uzoraka u Klinici za dječje bolesti Zagreb od 1990. do 1992. godine. Osjetljivost na antibiotike je određivana mikrodilucijskom metodom prema NCCLS. Proizvodnja ß-laktamaza je utvrđivana metodom diska s kromogenim supstratom (nitrocefinski test). Supstratni profil je određivan biološkom metodom. ß-Laktamaze su dokazane pomoću nitrocefinskog testa u svim sojevima. Učestalost ß-laktamaza pozitivnih izolata Moraxella catarrhalis u ispitivanom razdoblju je iznosila 100%. Nije zapažena rezistencija na amoksicilin/klavulanat, cefaleksin, ceftibuten, tetraciklin, eritromicin, azitromicin i kloramfenikol. Aktivnost amoksicilina se je značajno pojačala u prisutnosti klavulanske kiseline u svim sojevima. Stariji cefalosporini su bili podjednako djelatni, dok je ceftibuten kao cefalosporin treće generacije imao značajno niže minimalne inhibicijske koncentracije u odnosu na starije generacije. Među ne ß-laktamskim antibioticima tetraciklini i eritromicin su imali slične minimalne inhibicijske koncentracije. Azitromicin je imao jače inhibicijsko djelovanje od tetraciklina i eritromicina. Prema rezultatima našega istraživanja amoksicilin u kombinaciji s klavulanskom kiselinom bi bio antibiotik izbora za liječenje infekcija uzrokovanih sojevima Moraxella catarrhalis pozitivnim na b-laktamazu. Oralni cefalosporini, eritromicin, tetraciklini i azitromicin bi također mogli predstavljati moguću terapiju

Adhesins of uropathogenic escherichia coli and their role in the pathogenesis of urinary tract infections

Bakterijska adherencija je stereospecifična reakcija između molekula adhezina na površini bakterijske stanice i komplementarnih receptorskih molekula na stanicama makroorganizama. Bakterije adheriraju na stanice uroepitela na visoko selektivan način, pa ne mogu biti odstranjene nespecifičnim obrambenim mehanizmom čišćenja mokraćnog sustava. Stoga je adherencija važan prvi korak u patogenezi infekcija mokraćnog sustava. Adhezini uropatogenih sojeva Escherichia coli (UPEC) ubrajaju se među najbolje istražene bakterijske adhezine, a važnost adherencije UPEC u nekompliciranim infekcijama mokraćnog sustava je dobro poznata. U ovom pregledu razmatra se priroda, organizacija i značenje u patogenezi infekcija mokraćnog sustava pojedinih adhezina UPEC.Bacterial adherence is a stereospecific interaction between adhesin molecules on the bacterial cell surface and complementary receptor molecules on the host cell surface. Bacteria adhere to uroepithelial cells in highly selective manner, thus cannot be removed by unspecific cleansing mechanism of urinary tract. Therefore, adherence is an important first step in the pathogenesis of urinary tract infections. Adhesins of uropathogenic Escherichia coli (UPEC) are among the best studied bacterial adhesins, and importance of UPEC adherence in uncomplicated urinary tract infections is well known. In this review the nature, organization, and the role in pathogenesis of urinary tract infections of different UPEC adhesins are considered

Razlike u antigenoj strukturi i stvaranju hemolizina među sojevima pseudomonas aeruginosa izoliranim iz različitih materijala

Pseudomonas (P.) aeruginosa produces a number of exoenzymes, which have been implicated as virulence factors in infections caused by this organism. One of these exoenzymes is phospholipase C or heat labile hemolysin (HE) or P. aeruginosa. The aim of the study was to establish differences in HE production of 100 P. aeruginosa strains in dependence of their antigenic structure and type of specimens from which they were isolated. Isolates were serotyped by agglutination with commercial antisera according to the International Antigenic Typing System. A microtiter HE assay was used to quantitate the hemolytic activity of the strains investigated. The most commonly detected O-serogroup was O11, found in 34% of strains, followed by O6 (16%), O3 (9%), O4 (8%), O2 (7%) and O1 (6%) serogroups. Serogroups O7, O10, O13, O14, O15 and O17 were not detected. Serogroup O11 was found in 11 out of 16 strains isolated from bronchial secretion, and in 2 of 15 strains isolated from urine (p<0.01). HE production was detected in 88% of all isolates. The O1, O2, O3 and O16 strains mostly produced a large quantity of HE, while the epidemic O11 strains produced a small amount of HE. Urine and pharyngeal isolates produced the highest levels of HE.Pseudomonas (P.) aeruginosa stvara brojne egzoenzime koji se drže činiteljima virulencije u infekcijama koje izaziva ovaj mikroorganizam. Jedan od njih je fosfolipaza C ili termolabilni hemolizin P. aeruginosa. Svrha ovoga istraživanja bila je utvrditi razlike u stvaranju hemolizina 100 sojeva P. aeruginosa u ovisnosti o antigenoj strukturi soja i vrsti materijala iz kojega je soj izoliran. Izolati su serotipizirani pomoću aglutinacije s komercijalnim antiserumima prema Internacionalnoj shemi za antigeno tipiziranje. Metoda mikrotitracije rabljena je za kvantificiranje hemolitičke aktivnosti istraživanih sojeva. Najčešće je utvrđena serogrupa O11, tj. u 34% sojeva, potom serogrupe O6 (16%), O3 (9%), O4 (8%), O2 (7%) i O1 (6%). Serogrupe O7, O10, O13, O14, O15 i O17 nisu utvrđene među istraživanim sojevima. Od 16 sojeva izoliranih iz sekreta bronha, serogrupa O11 nađena je u 11 sojeva, dok je od 15 sojeva izoliranih iz mokraće ista serogrupa nađena u dva soja (p<0,01). Stvaranje hemolizina utvrđeno je u 88% svih izolata. Sojevi O1, O2, O3 i O16 stvarali su veliku količinu hemolizina, dok su epidemični sojevi O11 stvarali malu količinu hemolizina. Izolati iz mokraće i ždrijela stvarali su najviše hemolizina

Antibiotska osjetljivost i proizvodnja ß-laktamaza kod izolata Moraxella catarrhalis iz Zagreba, Hrvatska

Moraxella catarrhalis, a commensal of the nasopharynx, has been recognized with increasing frequency as a potential pathogen in respiratory tract infections. The ß-lactamase production in Moraxella catarrhalis, first described in 1977, has been ever more frequently reported in many countries of the world. However, there have no such reports from Croatia so far. The aim of this study was to investigate antibiotic susceptibilities and ß-lactamase production in Moraxella catarrhalis isolates from Croatia. Fifty Moraxella catarrhalis strains were collected from various clinical specimens at Zagreb University Children\u27s Hospital during the 1990-1992 period. Antibiotic susceptibilities to a wide range of antibiotics were determined by the broth microdilution method according to NCCLS. In all strains, ß-lactamases were detected by the disk chromogenic substrate (nitrocefin) test. The prevalence of ß-lactamase positive strains in the study period was 100%. No resistance to amoxicillin/clavulanate, cephalexin, ceftibuten, tetracycline, erythromycin, azithromycin and chloramphenicol was observed. In all strains, the activity of amoxicillin was strongly enhanced in the presence of clavulanic acid. Older cephalosporins were equally active, however, the thirdgeneration cephalosporin ceftibuten showed significantly lower minimal inhibitory concentrations compared with older compounds. Among non ß-lactam antibiotics, tetracycline and erithromycin showed similar activity. Azithromycin had a markedly stronger inhibitory activity in comparison with erythromycin and tetracycline. According to our results, amoxicillin combined with clavulanic acid should be the antibiotic of choice for the treatment of infections caused by ß-lactamase positive isolates of Moraxella catarrhalis. Oral cephalosporins, tetracycline, macrolides or azithromycin could be an option too.Moraxella catarrhalis se je ranije smatrala komenzalom u respiracijskom traktu, ali se danas zna da je ona značajan respiracijski patogen. Proizvodnja ß-laktamaze, prvi puta opisana 1977., javlja se sa sve većom učestalošću u mnogim zemljama svijeta. Dosadnije bilo izvještaja iz Hrvatske. Cilj ovoga istraživanja bio je ispitati osjetljivost na antibiotike i proizvodnju ß-laktamaze u kliničkim izolatima Moraxella catarrhalis iz Hrvatske. Pedeset izolata Moraxella catarrhalis prikupljeno je iz različitih kliničkih uzoraka u Klinici za dječje bolesti Zagreb od 1990. do 1992. godine. Osjetljivost na antibiotike je određivana mikrodilucijskom metodom prema NCCLS. Proizvodnja ß-laktamaza je utvrđivana metodom diska s kromogenim supstratom (nitrocefinski test). Supstratni profil je određivan biološkom metodom. ß-Laktamaze su dokazane pomoću nitrocefinskog testa u svim sojevima. Učestalost ß-laktamaza pozitivnih izolata Moraxella catarrhalis u ispitivanom razdoblju je iznosila 100%. Nije zapažena rezistencija na amoksicilin/klavulanat, cefaleksin, ceftibuten, tetraciklin, eritromicin, azitromicin i kloramfenikol. Aktivnost amoksicilina se je značajno pojačala u prisutnosti klavulanske kiseline u svim sojevima. Stariji cefalosporini su bili podjednako djelatni, dok je ceftibuten kao cefalosporin treće generacije imao značajno niže minimalne inhibicijske koncentracije u odnosu na starije generacije. Među ne ß-laktamskim antibioticima tetraciklini i eritromicin su imali slične minimalne inhibicijske koncentracije. Azitromicin je imao jače inhibicijsko djelovanje od tetraciklina i eritromicina. Prema rezultatima našega istraživanja amoksicilin u kombinaciji s klavulanskom kiselinom bi bio antibiotik izbora za liječenje infekcija uzrokovanih sojevima Moraxella catarrhalis pozitivnim na b-laktamazu. Oralni cefalosporini, eritromicin, tetraciklini i azitromicin bi također mogli predstavljati moguću terapiju

Sociodemographic, sexual behaviour and microbiological profiles of men attending public health laboratory for testing for sexually transmitted diseases

In order to identify the groups at risk of sexually transmitted diseases (STDs), we assessed the sociodemographic profiles of men testing for STD, their sexual habits, and the results of microbiological analysis. During a three-year period, a total of 700 men older than 18 years of age completed the questionnaire regarding sociodemographic and sexual behavior. Urethral swabs were taken for microbiological analysis. Thirty-three percent of respondents reported not using condoms. Those that do not use condoms were predominantly less educated, unmarried but in steady relationships, employed, with children, and smokers. Alcohol or drug usage before sexual intercourse was disclosed by 21.4% of respondents, and 10.3% respondents reported sexual intercourses with commercial sex workers. Finally, 24.0% respondents reported sexual relations abroad. In 28.1% of subjects, one or more pathogens were observed in urethral swabs. The most commonly diagnosed microorganism was Ureaplasma urealyticum, followed by Chlamydia trachomatis, Mycoplasma hominis, Trichomonas vaginalis, and Neisseria gonorrhoeae. This study identified several factors that may contribute to the general risk of STD transmission, which will serve to better understand the transmission dynamics and implementation of adequate prevention programs. </p

Estimating Clinical Outcome of HPV Induced Cervical Lesions by Combination of Capsid Protein L1 and p16INK4a Protein Detection

The aim of this study was to investigate whether is possible to predict clinical outcome of cervical lesion by immunoassaying performed on cervical smears. During the two year study period the cervical smears of 81 patients were collected. All patients were tested for human papillomavirus (HPV) infections using Amplycor HPV test. Sixty-six of them were tested as positive for high risk types (hrHPV) and squamous intraepithelial lesion, and in those patients repeated cervical smears were taken every six months. The rest were hrHPV negative patients with normal smears which were used as a negative control in immunoassays with HPV L1 and p16INK4a antibodies. The results of p16INK4a staining in 66 hrHPV positive patients showed impairment of the cervical lesion in 22 (33.3%) and unchanged cytological finding in 21 (31.9%) p16INK4a positive patients, respectively, while improving of cytological finding was seen only in three (4.5%) p16INK4a positive patients. On the contrary, impairment of cytological finding was not seen in p16INK4a negative patients, while in 17 out of 20 patients from that group improving or normalisation of cytological finding were detected (p<0.01). Correlation between L1/p16 pattern and cytological finding showed that only in L1–/p16+ cervical lesions was detected impairment of cytological finding during the study period. In L1+/p16+ group the cytological finding was the same during the follow up in all 11 patients, while in L1+/p16– group in most patients (9/11) downgrading or normalisation of Pap test were detected. The usage of p16 and HPV L1 markers can be useful in estimation of biologic potentiality and clinical outcome of cervical lesions

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p&lt;0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line

Epidemiology of hepatitis C in Croatia in the European context

We analyzed prevalence, risk factors and hepatitis C virus (HCV) genotype distribution in different population groups in Croatia in the context of HCV epidemiology in Europe, with the aim to gather all existing information on HCV infection in Croatia which will be used to advise upon preventive measures. It is estimated that 35000-45000 of the Croatian population is chronically infected with HCV. Like in other European countries, there have been changes in the HCV epidemiology in Croatia over the past few decades. In some risk groups (polytransfused and hemodialysis patients), a significant decrease in the HCV prevalence was observed after the introduction of routine HCV screening of blood/blood products in 1992. Injecting drug users (IDUs) still represent a group with the highest risk for HCV infection with prevalence ranging from 29% to 65%. Compared to the prevalence in the Croatian general population (0.9%), higher prevalence rates were found in prison populations (8.3%-44%), human immunodeficiency virus-infected patients (15%), persons with high-risk sexual behavior (4.6%) and alcohol abusers (2.4%). Low/very low prevalence was reported in children and adolescents (0.3%) as well as in blood donors (0%-0.009%). In addition, distribution of HCV genotypes has changed due to different routes of transmission. In the general population, genotypes 1 and 3 are most widely distributed (60.4%-79.8% and 12.9%-47.9%, respectively). The similar genotype distribution is found in groups with high-risk sexual behavior. Genotype 3 is predominant in Croatian IDUs (60.5%-83.9%) while in the prison population genotypes 3 and 1 are equally distributed (52.4% and 47.6%). Data on HCV prevalence and risk factors for transmission are useful for implementation of preventive measures and HCV screening

Mycoplasma genitalium – sexually transmitted pathogen that cannot be ignored

Iako je razvoj molekularnih metoda omogućio učinkovitu dijagnostiku infekcije uzrokovane bakterijom Mycoplasma genitalium (M. genitalium), podaci o infekcijama uzrokovanih ovom bakterijom u Hrvatskoj su nedostatni, budući je dijagnostika vrlo zahtjevna te još uvijek nije rutinska metoda u mikrobiološkim laboratorijima. Cilj ovog rada bio je utvrditi učestalost M. genitalium u obriscima cerviksa i obriscima uretre muškaraca zaprimljenih u Službi za kliničku mikrobiologiju Nastavnog zavoda za javno zdravstvo "Dr. Andrija Štampar" radi testiranja na C. trachomatis. Istraživanje je provedeno u razdoblju od sedam mjeseci. Od ukupno 5057 zaprimljenih obrisaka cerviksa koji su bili testirani na C. trachomatis, 195 uzoraka je testirano na M. genitalium (99 C. trachomatis pozitivnih i 96 C. trachomatis negativnih). Testirano je i 52 obrisaka uretre muškaraca s negonokoknim uretritisom (18 C. trachomatis pozitivnih i 34 C. trachomatis negativnih). M. genitalium i C. trachomatis dokazivane su real-time PCR metodama, dok je gonokokna infekcija isključena pregledom izravnog mikroskopskog preparata. U obriscima cerviksa učestalost infekcije uzrokovane C. trachomatis iznosila je 2,04% (103/5057). Od 195 testiranih obrisaka cerviksa, M. genitalium je dokazana u 6 uzoraka (3,08%). Svi obrisci cerviksa pozitivni na M. genitalium bili su istodobno pozitivni i na C. trachomatis (6/99) dok niti jedan C. trachomatis negativan uzorak nije bio pozitivan na M. genitalium (0/96; P < 0,05). U obriscima uretre muškaraca s negonokoknim uretritisom M. genitalium je dokazana u jednom uzorku koji je bio C. trachomatis negativan. M. genitalium je važan, ali u našoj sredini nedovoljno prepoznat i nedovoljno dijagnosticiran uzročnik spolno prenosivih bolesti. Sukladno rezultatima ove studije testiranje na M. genitalium opravdano je izvoditi u sklopu rutinskog testiranja na spolno prenosive bolesti u obriscima cerviksa žena kod kojih je dokazana C. trachomatis infekcija.The development of molecular methods has enabled efficient diagnosis of infections caused by Mycoplasma genitalium (M. genitalium). However, data on M. genitalium infection in Croatia are scarce due to the complexity of detection method for this bacterium which is still not routinely used in clinical laboratories. The aim of this study was to determine the prevalence of M. genitalium in cervical swabs and male urethral swabs referred for C. trachomatis diagnostics to the Clinical Microbiology Department of the Teaching Institute for Public Health "Dr. Andrija Štampar". The study was conducted over a period of seven months. From a total of 5057 received cervical swabs that were tested for C. trachomatis, 195 samples were tested for M. genitalium (99 positive and 96 negative for C. trachomatis). Additionally, 52 urethral swabs collected from men with nongonococcal urethritis were tested for M. genitalium (18 positive and 34 negative for C. trachomatis). Both, C. trachomatis and M. genitalium were detected using realtime PCR methods, while gonococcal infection was excluded by direct microscopy. The incidence of C. trachomatis infection in cervical swabs was 2.04% (103/5057). Out of 195 cervical swabs tested M. genitalium was proved in six samples (3.08%). All samples found positive for M. genitalium were positive for C. trachomatis as well (6/99), while not a single C. trachomatis negative sample was positive for M. genitalium (0/96; P < 0.05). In the urethral swabs of men with NGU, M. genitalium was detected in one sample that was C. trachomatis negative. M. genitalium is important, but in our midst under-recognized and under-diagnosed sexually transmitted pathogen. Based on the results of the study, testing for M. genitalium should become an integral part of routine protocol for diagnosis of sexually transmitted diseases in women with C. trachomatis infection

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p&lt;0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line