Mario Sviben

Seroprevalence of TORCH infections in women of childbearing age in Croatia

During 2005–2009, a seroepidemiological study was carried out in Croatia to define the population susceptible to common TORCH agents among pregnant and non-pregnant women of childbearing age. The IgG seroprevalence was 29.1% forT. gondii, 94.6% for rubella, 75.3% for cytomegalovirus (CMV), 78.7% for herpes simplex virus type 1 (HSV-1), and 6.8% for HSV-2. Acute toxoplasmosis and CMV infection (positive IgM antibodies with low IgG avidity) were documented in 0.25% and 0.09% women, respectively. IgM prevalence was 1.2% for both HSV-1 and HSV-2. None of the participants showed acute rubella infection. Seropositivity to T. gondii and HSV-2 varied significantly between age groups (p = 0.001 and p = 0.036, respectively). Women residing in rural regions showed a significantly higher seroprevalence rate for T. gondii, CMV, and HSV-1 than urban women (T. gondii: 44.0% vs. 25.4%, p < 0.001; CMV: 85.0% vs. 73.1%, p = 0.018; HSV-1: 86.0% vs. 76.4%, p = 0.041).

Seroprevalence of Toxocara canis infection among asymptomatic children with eosinophilia in Croatia.

A total of 142 serum specimens from Croatian children aged 3-18 years, with peripheral eosinophilia and without any clinical symptoms, were tested for the presence of Toxocara canis IgG antibodies using an enzyme-linked immunosorbent assay (ELISA) and Western blot method. The overall T. canis seropositivity rate in the samples tested was 31%. There was no statistical difference in the seroprevalence rate between boys (32.1%) and girls (29.7%, chi2 = 0.092, P = 0.761). The T. canis seropositivity varied significantly between age groups both in boys (Fishers test P < 0.001) and girls (Fishers test P = 0.007). The highest seroprevalence rate was found in boys aged 11-14 (42.9%) and girls aged 7-10 (44.2%). Our results showed a high seroprevalence rate of T. canis infection among children with eosinophilia. It is important that testing for toxocariasis should be included in a differential diagnosis of eosinophilia, especially in children.

Antimicrobial Susceptibility and Beta-Lactamase Production of Selected Gram-Negative Bacilli from Two Croatian Hospitals: MYSTIC Study Results

Abstract The Meropenem yearly Susceptibility test information Collection (MYSTIC) programme is a global, longitudinal resistance surveillance network that monitors the activity of meropenem and compares its activity with other broad-spectrum antimicrobial agents. We now report the antimicrobial efficacy of meropenem compared to other broad-spectrum agents within the selective Gram-negative pathogen groups from two Croatian Hospitals investigated between 2002-2007. A total of 1510 Gram-negative pathogens were tested and the minimum-inhibitory concentrations (MICS) were determined by broth microdilution method according to CLSI. There was no resistance to either imipenem or meropenem observed for Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis in both medical centers. High resistance rates of K. pneumoniae to ceftazidime (18%), cefepime (17%) and gentamicin (39%) are raising concern. Acinetobacter baumannii turned out to be the most resistant Gram-negative bacteria with 81% resistant to ceftazidime, 73% to cefepime, 69% to gentamicin and 71% to ciprofloxacin. Almost 20% of Pseudomonas aeruginosa strains were resistant to imipenem, 13% to meropenem, 69% to gentamicin and 38% to ciprofloxacin. The prevalence of extended-spectrum beta-lactamases (ESBLs) in E. coli was 10% and in K. pneumoniae 49%. PCR and sequencing of the amplicons revealed the presence of SHV-5 in nine E. coli strains and additional TEM-1 β-lactamase five strains. Five K. pneumoniae strains were positive for bla SHV-5 gene. Eight ESBL positive Enterobacter spp. Strains were found to produce tem and CTX-M β-lactamases. Plasmid-mediated AmpC β-lactamases were not found among K. pneumoniae, E. coli and Enterobacter spp. Three A. baumannii strains from Zagreb University Center were identified by multiplex PCR as OXA-58 like producers. Six A. baumannii strains from Split University Center were found to possess an ISAba1 insertion sequence upstream of bla OXA-51 gene. According to our results meropenem remains an appropriate antibiotic for the treatment of severe infections caused by Gramnegative bacteria. These data indicate that despite continued use of meropenem, carbapenem resistance is not increasing among species tested, except for A. baumannii, in the two study hospitals and suggest that clinicians can still administer carbapenems as a reliable and effective choice in managing serious nosocomial infections.

Sensitivity and Specificity of Various β-Lactam Antibiotics and Phenotypical Methods for Detection of TEM, SHV and CTX-M Extended-Spectrum β-Lactamases

Abstract The aim of this study was to compare the sensitivity and specificity of six different β-lactam antibiotics using five phenotypical tests for detection of extended spectrum beta-lactamases (ESBLs) based on synergism of β-lactam antibiotics and clavulanate. Experiments were performed on a set of 80 Klebsiella pneumoniae strains and 105 Escherichia coli strains with previously characterized ESBLs (SHV, TEM and CTX-M). ESBLs were detected by five different phenotypical methods: MIC (minimum inhibitory concentration) determination of β-lactam antibiotics with and without clavulanate, double-disk synergy test (DDST), inhibitor-potentiated disk-diffusion test (IPDDT), CLSI-Clinical and Laboratory Standard Institution (former NCCLS) combined- disk-test, and modified MAST-disk-diffusion test (MAST-DD-test). Seven antibiotics were tested as indicators of ESBL production: ceftazidime, cefotaxime, ceftriaxone, aztreonam, ceftibuten, cefpodoxime and cefepime. Ceftazidime and aztreonam were the best indicators for SHV-5, SHV-12 and TEM β-lactamases whereas cefotaxime and ceftriaxone were the most sensitive in detection of SHV-2 and CTX-M β-lactamases in DDST, IPDDT and CLSI test. MIC determination of β-lactam antibiotics with and without clavulanate was the most sensitive method. DDST was the least sensitive test. Double-disk synergy test, which is the most frequently used test for detection of ESBLs in routine laboratories, was the least sensitive independently of the indicator antibiotic. Since MIC determination is a very laborious and time consuming method, we would recommend the NCCLS combined disk test or IPDD test for detection of ESBLs in routine laboratories with 5 mm zone augmentation breakpoint.

Postantibiotic and Post-Beta-Lactamase Inhibitor Effect of Carbapenems Combined with EDTA against Pseudomonas aeruginosa Strains Producing VIM-Metallo Beta-Lactamases

Background and Aim: Postantibiotic effect (PAE) is a delay of bacterial growth after short exposure to antibiotics. The phenomenon of continuing suppression of bacterial growth after removal of β-lactamase inhibitors is termed post-β-lactamase inhibitor effect (PLIE). Recently, Pseudomonas aeruginosa strains producing metallo-β-lactamases were described in many countries of the world. The aim of the study was to investigate the PLIE of carbapenems in combinations with EDTA against VIM-MBL-positive strains of P. aeruginosa. Methods: The experiments were performed on two Pseudomonas aeruginosa isolates, one producing VIM-1 and the other producing VIM-2 metallo-β-lactamase. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBC) of imipenem and meropenem alone and combined with EDTA, time-kill curves, PAE and PLIE were performed as described previously. Results: The duration of PAE with meropenem combined with EDTA at 8 × MIC was longer against both VIM-1 and VIM-2 producer than that of imipenem with EDTA on VIM-1- and VIM-2-positive strains. The duration of PLIE was similar on both strains of P. aeruginosa regardless of the sort of carbapenem. At lower concentrations, meropenem with EDTA induced slightly longer PAE and PLIE than imipenem with EDTA. Conclusions: This study has shown that EDTA combined with carbapenems produced a significant PLIE on VIM-MBL-positive P. aeruginosa strains. The results do not have any clinical relevance so far since metal chelators such as EDTA are not used as therapeutic agents due to their toxicity.

Epidemiology and laboratory characteristics of Trichomonas vaginalis infection in Croatian men with and without urethritis syndrome: a case–control study

Objectives The main objective of this study is to determine the prevalence of trichomoniasis in men with and without symptoms of urethritis, with concomitant analysis of sociodemographic and behavioural specificities of both groups. Also, the objective is to evaluate laboratory methods used in the diagnostics of this parasitic disease. Methods A total of 500 men with and 200 without urethritis symptoms were included in the study. Every respondent filled out a questionnaire asking for some general data, specific information about habits, sexual behaviour and symptoms. Sediment of first void urine was analysed by wet mount microscopy, cultivation in Diamonds medium and real-time PCR. Results In the symptomatic group, Trichomonas vaginalis infection was documented in 2.4% of respondents by wet mount microscopy, in 4.8% by cultivation and in 8.2% by real-time PCR. In the asymptomatic group, infection was proven using the same methods in 1.0%, 1.5% and 2.0% of the respondents, respectively. Trichomoniasis prevalence was statistically significantly higher in the respondents manifesting urethritis symptoms when cultivation (χ2=4.20, p=0.041) and real-time PCR (χ2=9.20, p=0.002) were used. Several epidemiological risk factors were identified, and greater sensitivity of real-time PCR was found in comparison with microscopy and culture. Conclusions Trichomonas infection was statistically more frequent in men with urethritis syndrome. Assuming that the samples found positive by any laboratory technique are truly positive, it can be concluded that the real-time PCR showed the greatest sensitivity of all the methods used in this study.

Seroepidemiology of Hepatitis E in Selected Population Groups in Croatia: A Prospective Pilot Study.

Hepatitis E has become an emerging infection in many European countries. We analysed the prevalence of hepatitis E virus (HEV) infection in selected population groups in Croatia. Overall HEV IgG seropositivity was 5.6%, while 1.9% participants showed IgM antibodies suggestive of recent infection. No IgM‐positive sample was positive for HEV RNA. HEV IgG antibodies were most prevalent in alcohol abusers (8.9%) and war veterans (8.6%), compared with 6.1% among injecting drug users and 2.7% in healthcare professionals. No individual with high‐risk sexual behaviour tested HEV seropositive. HEV IgG positivity increased significantly with age from 1.8% to 2.3% in individuals younger than 40 years to 11.3% in individuals older than 50 years (P = 0.023). The mean age of HEV‐positive participants was significantly higher than that of HEV‐negative participants (50.9 ± 11.8 years versus 41.2 ± 11.8 years, P = 0.008). Seroprevalence rates were significantly higher in residents of suburban and rural areas compared with residents of urban areas (14.5% versus 2.5%, P = 0.003). Additionally, an increasing prevalence of HEV IgG antibodies was observed from 1.8% in participants living in families with two household members to 12.1% in those living with more than four members (P = 0.046). Gender, marital status, educational level, sexual orientation, source of drinking water, history of blood transfusions, surgical procedures, tattooing and travelling were not associated with HEV seroprevalence. Logistic regression showed that living in suburban/rural areas was the main risk factor for HEV seropositivity (OR = 6.67; 95%CI = 1.89–25.0; AOR = 7.14, 95%CI = 1.89–25.0).

Seroprevalence of Taenia solium infections in Croatian patients presenting with epilepsy

Epilepsy is one of the most common neurological disorders, while neurocysticercosis caused by Taenia solium infection of the central nervous system currently represents the leading cause of secondary epilepsy in Central and South America, East and South Asia, and sub-Saharan Africa. As a result of increased migration from these endemic regions, neurocysticercosis and subsequent epilepsy are becoming a growing public health problem in developed countries as well. In order to determine the prevalence of T. solium infection in patients with epilepsy in Croatia, a retrospective serological study was conducted. A total of 770 serum samples were tested for the presence of T. solium IgG antibodies using a commercial qualitative enzyme immunoassay. The Western blot technique was used as a confirmatory test for the diagnosis. The overall seroprevalence rate of T. solium infection in patients with clinically proven epilepsy was 1.5%. Although the results have shown that infection with this tapeworm is rare in Croatia, this study hopes to increase awareness about the importance of preventive measures and benefits of accurate and timely diagnosis. Intervention measures for infection control are crucial, namely sanitation improvement, control of domestic pig-breeding, detailed meat inspection, detection and treatment of tapeworm carriers, hand washing and health education.

Seroprevalence of Echinococcus granulosus infection in Croatian patients with cystic liver disease

Cystic liver disease (CLD), presenting with solitary or multiple cysts in the liver, is a common diagnosis today, primarily due to the frequent application of modern radiological methods. There is a wide range of possible causes. CLD of infective origin is usually caused by an echinococcal species. During the past three decades a number of cystic echinococcosis (CE) control programmes have led to a significant decrease in the incidence of human hydatidosis in some endemic areas. The aim of this study was to determine the seroprevalence of E. granulosus infection in Croatian patients with CLD. A total of 540 serum samples from patients with hepatic cysts detected by imaging methods were screened for the presence of E. granulosus IgG antibodies using semiquantitative enzyme-linked immunosorbent assay. The Western blot technique was used as a confirmatory test for the CE diagnosis. The overall E. granulosus seroprevalence rate in patients with CLD was 3.9%. There was no significant difference in seroprevalence rate between male and female patients (P = 0.541). According to age groups, there was a significant difference in seropositivity among age groups (P = 0.002). The highest seroprevalence rate was detected in the youngest age group (up to 18 years), both in males and females (20% and 13%, respectively). This study indicates that CE still represents a public health problem in Croatia. Preventive measures should be used to control Echinococcus infections, including avoidance of contact with infected dogs, egg-contaminated soil or plants; control and treatment of dogs with antihelmintics; hand washing, improved sanitation and health education.

Potential role of enterohepatic Helicobacter species as a facilitating factor in the development of Chlamydia trachomatis proctitis

Gastrointestinal manifestations of chlamydial infection are frequent, yet not always recognised. One of the common entities is proctitis, especially prevalent amongst men who have sex with men (MSM). Likewise, some enterohepatic Helicobacter species have also been associated with proctitis, namely Helicobacter (H.) cinaedi and H. fennelliae. It is well established that Helicobacter species have general and specific mechanisms for innate immune evasion and suppression, and can affect intestinal homeostasis. Here it is proposed that their presence in the rectum might facilitate the development of Chlamydia trachomatis proctitis, where they could act as cofactors in initial infection and progression of the disease.