Epidemic spread of OXA-48 beta-lactamase in Croatia.

PURPOSE: A dramatic increase in OXA-48 ß-lactamase was observed recently not only in large hospital centres, but also in smaller suburban hospital centres in geographic areas bordering Croatia. The aim of the study was to analyse the epidemiology, the mechanisms of antibiotic resistance and the routes of spread of OXA-48 carbapenemase in Croatia. METHODS: Carbapenemase and other ß-lactamase and fluoroquinolone resistance genes were detected by PCR and sequencing. Whole-genome sequencing (WGS) was performed on five representative isolates. The isolates were genotyped by PFGE. RESULTS: Forty-eight isolates positive for OXA-48, collected from seven hospital centres in Croatia from May 2016 to May 2017, were analysed (40 Klebsiella pneumoniae, 5 Enterobacter cloacae, 2 Escherichia coli and one Citrobacter freundii). Thirty-three isolates were ESBL positive and harboured group 1 CTX-M 1 ß-lactamases. In addition to the ß-lactam resistance genes detected by PCR (blaSHV-1, blaOXA-48 and blaOXA-1), WGS of five representative isolates revealed the presence of genes encoding aminoglycoside resistance, aadA2 and aph3-Ia, fluoroquinolone resistance determinants aac(6)Ib-c, oqxA and oqxB, the sulfonamide resistance gene sul1, and fosA (fosfomycin resistance). IncL plasmid was found in all isolates. Two K. pneumoniae isolates belonged to ST16, two E. cloacae to ST66 and E. coli to ST354. K. pneumoniae isolates were allocated to five clusters by PFGE which occured in different hospitals, indicating epidemic spread. CONCLUSIONS: The OXA-48-positive organisms found in this study showed wide variability in antibiotic susceptibility, ß-lactamase content and PFGE banding patterns. This study revealed a switch from the predominance of VIM-1 in 2012-2013 to that of OXA-48 in the 2015 to 2017.

In vitro effect of subminimal inhibitory concentrations of antibiotics on the biofilm formation ability of Acinetobacter baumannii clinical isolates.

The ability of A cinetobacter baumannii strains to form biofilm is one of the most important virulence factor which enables bacterial survival in a harsh environment and decreases antibiotic concentration as well. Subminimal inhibitory concentrations (subMICs) of antibiotics may change bacterial ultrastructure or have an influence on some different molecular mechanisms resulting in morphological or physiological changes in bacteria itself. The aim of this study was to determine effects of 1/2, 1/4, 1/8 and 1/16 minimal inhibitory concentrationsof imipenem, ampicillin-sulbactam, azithromycin, rifampicin and colistin on biofilm formation ability of 22 biofilm non-producing and 46 biofilm producing A. baumannii strains (30 weak producing strains and 16 moderate producing strains). Results of this study indicate that 1/2-1/16 MICs of imipenem, azithromycin, and rifampicin can reduce bacterial biofilm formation ability in moderate producing strains (p < 0.05), whereas 1/16 MIC of imipenem and 1/4-1/8 MICs of rifampicin reduce the biofilm formation in weak producing strains (p < 0.05). Statisticaly significant effect was detected among biofilm non-producing strains after their exposure to 1/16 MIC of azithromycin (p = 0.039). SubMICs of ampicillin-sulbactam and colistin did not have any significant effect on biofilm formation among tested A. baumannii strains.

Brain abscess due to Aggregatibacter aphrophilus and Bacteroides uniformis.

OBJECTIVE: The aim of this report was to describe the occurrence of a bacterial brain abscess in a healthy individual, without any predisposing condition. CASE REPORT: A thirteen-year old boy was admitted to the Department of Neurosurgery after the onset of vomiting, headache and dizziness. A neurological deficit was detected during the physical examination so urgent magnetic resonance imaging of the brain was performed, revealing an intrahemispheric, right positioned solitary expansive mass with ring enhancement. Purulent material was obtained during osteoplastic craniotomy with total extirpation of the brain abscess. Aggregatibacter aphrophilus and Bacteroides uniformis were isolated. The patient's general condition improved and the neurological deficit subsided as a result of the prompt recognition and treatment of this life threatening condition. CONCLUSION: To achieve a favourable clinical outcome, prompt recognition and surgical treatment of a brain abscess are of primary importance,followed by administration of appropriate antimicrobial therapy. To our best knowledge, this is the first report of this combination of microorganisms as the cause of a brain abscess.

Methicillin-resistant Staphylococcus aureus in North-east Croatia.

OBJECTIVE: The aim of this 5-year study was to determine the frequency and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA)-related infections at Osijek Clinical Hospital. MATERIALS AND METHODS: A total of 1987 staphylococci-infected clinical isolates were collected and analysed at the Microbiology Department of the Public Health Institute of Osijek-Baranja County. RESULTS: Between 2008 and 2012, the average rate of MRSA-related infections in staphylococci-infected patients was 27.4%. The proportion of MRSA-related infections on all Staphylococcus aureus (S. aureus) isolates from clinical specimens showed a decreasing trend, from 32.6% in 2008 to 25.5% in 2012. MRSA-related infections were mostly detected in wound swabs (50.6%) and aspirates (28.8%) of patients hospitalized in the surgical (49.8%) and intensive care units (27.9%). MRSA-related infection showed an increase compared to S. aureus-infections in samples of wounds and aspirates in 2011 and 2012 (57.9%/34.9% and 35.2%/16.3%, respectively). The majority of strains of MRSA-related infections were resistant to several antibiotics, including erythromycin and clindamycin, where susceptibility were less than 10%. All MRSA isolates were susceptible to vancomycin, teicoplanin and linezolid. Therefore, antibiotic therapies for MRSA infections include vancomycin, teicoplanin and linezolid, but microbiological diagnostics need to be performed in order to know when the use of glycopeptides and oxazolidinones is indicated. CONCLUSION: Our results suggest that appropriate prevention measures, combined with the more rational use of antibiotics are crucial to reduce the spread of MRSA-related infection in healthcare settings. Further monitoring is necessary of the incidence and antibiotic susceptibility of MRSA-related infections in our community.

[First report of carbapenemases in Osijek-Baranja County in imported Enterobacter cloacae isolate in vitro susceptible to carbapenems]. / Prvi opis karbapenemaze u osjecko-baranjskoj zupaniji u unesenom izolatu Enterobactera cloacae in vitro osjetljivom na karbapeneme.

Carbapenems are often the only therapeutic option to treat infections caused by multidrug-resistant Gram-negative bacteria. Emergence of carbapenemases in the isolates of Enterobacteriaceae limits therapeutic options. Carbapenem-resistant Enterobacteriaceae have emerged since 2008 throughout Croatia. In Osijek-Baranja County carbapenem-resistant strains of Enterobacteriaceae were not reported until 2013. The first carbapenem-resistant strain (Enterobacter cloacae) was identified in August 2013 in a patient previously hospitalized at University Hospital Center Zagreb for the treatment of acute lymphoblastic leukemia. Molecular analysis revealed the production of VIM-1 metallo-beta-lactamase (MBL). In spite of the metallo-beta-lactamase production the strain was not resistant to imipenem and meropenem in disk-diffusion and microdilution test. This report shows that routine susceptibility testing carried out in most laboratories does not necessarily detect carbapenemase production in Enterobacteriaceae. Since these enzymes are encoded on mobile genetic elements there is a risk of horizontal spread to other enterobacterial isolates and the development of hospital outbreaks.

Antibiotic susceptibility of isolates from paediatric intensive care units in Zagreb.

AIM: Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program is a longitudinal global surveillance study to monitor in vitro data on microbial susceptibility in centers that prescribe meropenem. Results of the six years period (2002-2007) for the antimicrobial efficacy of meropenem compared to other broad-spectrum agents against Gram-negative and Gram-positive isolates collected at pediatric intensive care units of the University Hospital Center Zagreb in Croatia were reported. METHODS: A total of 110 Gram-negative and 43 Gram-positive pathogens from pediatric specimens were tested. The minimum-inhibitory concentrations (MICs) were determined by broth microdilution method according to CLSI. RESULTS: There was no resistance to either imipenem or meropenem observed for Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. High resistance rates of K. pneumoniae to ceftazidime and gentamicin (50%) are a raising concern. Pseudomonas aeruginosa was the most resistant Gram-negative species with two (12%) of the strains resistant to meropenem, three (18%) to imipenem, 10 (47%) to gentamicin and six (35%) to piperacillin/tazobactam and ciprofloxacin. According to our results meropenem remains an appropriate antibiotic for the treatment of severe infections caused by Gram-negative bacteria in pediatric population. CONCLUSIONS: The results indicate that meropenem has excellent potency and spectrum of activity despite being prescribed for a long time for the treatment of seriously ill patients, and still appears to be a reliable option for the initial empirical therapy of serious nosocomial infections in children. However, later studies have shown the emergence of carbapenem-resistant Gram-negative bacteria after 2008.

Red and processed meat and cardiovascular risk factors.

AIMS: The British National Diet and Nutrition 2000/1 Survey data set records on 1,724 respondents (766 males and 958 females) were analyzed in order to assess the potential influences of red and processed meat intakes on cardiovascular risk factors. METHODS: Linear regression of the associations of the red, processed, combination of red and processed, and total meat intakes with body mass index (BMI), systolic blood pressure and plasma total cholesterol as cardiovascular risk factors was conducted, paying due attention to the subject age and sex as potential confounders. RESULTS: Linear analyses showed the total meat intake and combined red and processed meat intake to cause a 1.03 kg/m2 rise in BMI each, while the red and processed meat intakes analyzed as separate categories caused 1.02 kg/m2 rise each. The greatest effects were observed on the systolic blood pressure with a 1.7 mm Hg rise for the total and the red and processed meat intakes, 1.5 mm Hg rise for the red meat intake, and 1.02 mm Hg rise for the processed meat intake. There were no associations between different meat intakes and plasma total cholesterol. DISCUSSION AND CONCLUSION: Study results revealed the interquartile ranges of the mentioned meat type intakes to increase BMI by around 1 kg/m2 and systolic blood pressure by around 1.5 mm Hg, while they had no influence on plasma total cholesterol.

Distribution of genital human papillomavirus (HPV) genotypes in Croatian women with cervical intraepithelial neoplasia (CIN)--a pilot study.

Genital infection with high-risk human papillomavirus (HR HPV) associates with increased risk of developing precancerous lesions, such as cervical intraepithelial neoplasia (CIN). The objective of this pilot study conducted in north-east Croatia was to determine the prevalence of HPV genital infection in women with abnormal cervical cytology and to determine its association with their age and HPV genotype(s). From March 2009 to December 2011, cervical swabs from 100 women were analysed for HR HPV infection (AMPLICOR HPV Test, Roche Diagnostics) and genotyped for high risk (HR), intermediate (IR) and low risk (LR) HPVs (Linear Array HPV Genotyping Test, Roche Diagnostics). The most prevalent HR genotypes in women with CIN were HPV 16 (27.6%), HPV 31 (11.8%), HPV 51 and HPV 52 (10.2% each). The most prevalent IR genotypes were HPV 66 (30%) and HPV 62 (23.3%). The most prevalent LR genotype was HPV 6 (20.3%). Women between 21 and 25 years of age showed the highest rate of HPV infection (44.2%). Moreover, women younger than 35 years showed a significant association (p < 0.01) and positive correlation (r = 0.67; p < 0.05) between HR HPV infection and CIN stages 1 and 2. Multiple HPV infections were found in almost half of the women. This is the first study that analysed the prevalence of genital infection with HR/IR/LR HPVs in women with CIN from north-east Croatia. Despite the preliminary nature of this pilot study, the lower prevalence of some HR HPVs (HPV18) and the higher prevalence of other HR HPVs (HPVs 51, 52 and 31) may imply the necessity for the development of more targeted anti-HPV vaccines or other strategies for more efficient protection against oncogenic HPV infection in women from our region.