Vaccine Effectiveness against GP-Attended Symptomatic COVID-19 and Hybrid Immunity among Adults in Hungary during the 2022-2023 Respiratory Season Dominated by Different SARS-CoV-2 Omicron Subvariants

Hungary provides the opportunity to evaluate the effectiveness of COVID-19 vaccination in a setting where naturally acquired immunity and hybrid immunity are likely to play a greater role due to suboptimal vaccination coverage.

METHODS

A test-negative study was conducted during the 2022-2023 respiratory season at the primary care level to determine the effectiveness of at least one COVID-19 booster dose in preventing medically attended symptomatic RT-PCR-confirmed SARS-CoV-2 infection in adults. Unvaccinated patients were used as a reference group.

RESULTS

A total of 247 cases and 1073 controls were included in the analysis. CVE was 56.8% (95% CI: 11.9-78.8%) in the population aged 60 years and older and 2.3% (95% CI: -50.0-36.3%) in the younger adults against COVID-19 caused by Omicron subvariants, mainly BA.5, BQ.1, and XBB.1. Self-reported COVID-19 in the 60-365 days prior to the current illness did not confer protection against reinfection without vaccination, but together with booster vaccination, it reduced the risk of COVID-19 by 63.0% (95% CI: -28.0-89.3%) and 87.6% (95% CI: 26.4-97.9%) among the 18-59 and 60+ age groups, respectively.

CONCLUSIONS

CVE against COVID-19 was moderately high in the 60+ age groups. Because of the benefit of hybrid immunity, persons with previous SARS-CoV-2 infection should still be considered for vaccination campaigns.

Enterobacterales carrying chromosomal AmpC β-lactamases in Europe (EuESCPM): Epidemiology and antimicrobial resistance burden from a cohort of 27 hospitals, 2020-2022

INTRODUCTION

The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs.

METHODS

We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated.

RESULTS

Our study comprised 6,774 ESCPM isolates. MALDI-TOF coupled to mass spectrometry was the predominant technique for bacterial identification. Susceptibility to new β-lactam/β-lactamase inhibitor combinations and confirmation of AmpC overproduction were routinely tested in 33.3% and 29.6% of the centres, respectively. The most prevalent species were E. cloacae complex (44.8%) and S. marcescens (22.7%). Overall, third-generation cephalosporins (3GC), combined third- and fourth-generation cephalosporins (3GC + 4GC) and carbapenems resistance phenotypes were observed in 15.7%, 4.6%, and 9.5% of the isolates, respectively. AmpC overproduction was the most prevalent resistance mechanism detected (15.8%). Among carbapenemase-producers, carbapenemase type was provided in 44.4% of the isolates, VIM- (22.9%) and OXA-48-enzyme (16%) being the most frequently detected. E. cloacae complex, K. aerogenes and Providencia species exhibited the most notable cumulative antimicrobial resistance profiles, with the former displaying 3GC, combined 3GC + 4GC and carbapenems resistance phenotypes in 15.2%, 7.4%, and 12.8% of the isolates, respectively. K. aerogenes showed the highest rate of both 3GC resistant phenotype (29.8%) and AmpC overproduction (32.1%), while Providencia species those of both carbapenems resistance phenotype (42.7%) and carbapenemase production (29.4%). ESCPM isolates exhibiting both 3GC and combined 3GC + 4GC resistance phenotypes displayed high susceptibility to ceftazidime/avibactam (98.2% and 95.7%, respectively) and colistin (90.3% and 90.7%, respectively). Colistin emerged as the most active drug against ESCPM species (except those intrinsically resistant) displaying both carbapenems resistance phenotype (85.8%) and carbapenemase production (97.8%).

CONCLUSIONS

This study presented a current analysis of ESCPM species epidemiology in Europe, providing insights to inform current antibiotic treatments and guide strategies for antimicrobial stewardship and diagnostics.

Prevalence, serogroup distribution and risk factors of Neisseria meningitidis carriage in high school and university students in Hungary

Neisseria meningitidis causes life-threatening invasive meningococcal disease (IMD) with high mortality worldwide. Asymptomatic pharyngeal meningococcus colonisation is an important reservoir for the spread of the bacterium. The aim of this study was to determine N. meningitidis colonisation rates in asymptomatic high school and university students and to identify risk factors for carriage. Oropharyngeal swab samples and data from a self-reported questionnaire were obtained from overall 610 students, among them 303 university students and 307 high school students, aged between 15 and 31 years in Budapest, Hungary, between November 2017 and December 2018. Meningococcal carriage and serogroup of N. meningitidis were determined by RT-PCR from DNA extracted directly from the specimen. N. meningitidis was identified in 212 (34.8 %) of the participants. Significantly higher carriage rate was found among high school students (48.9 %) compared to university students (20.5 %). Peak of colonisation rate was among 17-19-year-old students (48.7 %). Most carriage isolates were non-typable (87.3 %). From the 212 meningococcus carriers, 19 were colonised by serogroup B (9 %), 5 by serogroup C (2.4 %), and 1 had serogroup Y (0.5 %). Significantly higher colonisation rate was found among males (42.4 %) than in females (33.1 %). Antibiotic use in the past 2 months has decreased the rate of meningococcal colonisation. Recent respiratory infection, active or passive smoking and attending parties have not influenced meningococcal colonisation rate significantly. In conclusion, we have found high asymptomatic meningococcus carriage rate among high school students and young adults, however, the majority of the colonizing meningococci were non-typable.

The effect of COVID-19 vaccination status on all-cause mortality in patients hospitalised with COVID-19 in Hungary during the delta wave of the pandemic

The high mortality of patients with coronavirus disease 2019 (COVID-19) is effectively reduced by vaccination. However, the effect of vaccination on mortality among hospitalised patients is under-researched. Thus, we investigated the effect of a full primary or an additional booster vaccination on in-hospital mortality among patients hospitalised with COVID-19 during the delta wave of the pandemic. This retrospective cohort included all patients (n = 430) admitted with COVID-19 at Semmelweis University Department of Medicine and Oncology in 01/OCT/2021-15/DEC/2021. Logistic regression models were built with COVID-19-associated in-hospital/30 day-mortality as outcome with hierarchical entry of predictors of vaccination, vaccination status, measures of disease severity, and chronic comorbidities. Deceased COVID-19 patients were older and presented more frequently with cardiac complications, chronic kidney disease, and active malignancy, as well as higher levels of inflammatory markers, serum creatinine, and lower albumin compared to surviving patients (all p < 0.05). However, the rates of vaccination were similar (52-55%) in both groups. Based on the fully adjusted model, there was a linear decrease of mortality from no/incomplete vaccination (ref) through full primary (OR 0.69, 95% CI: 0.39-1.23) to booster vaccination (OR 0.31, 95% CI 0.13-0.72, p = 0.006). Although unadjusted mortality was similar among vaccinated and unvaccinated patients, this was explained by differences in comorbidities and disease severity. In adjusted models, a full primary and especially a booster vaccination improved survival of patients hospitalised with COVID-19 during the delta wave of the pandemic. Our findings may improve the quality of patient provider discussions at the time of admission.

Vaccine effectiveness against influenza hospitalisation in adults during the 2022/2023 mixed season of influenza A(H1N1)pdm09, A(H3N2) and B circulation, Europe: VEBIS SARI VE hospital network

We conducted a multicentre hospital-based test-negative case-control study to measure vaccine effectiveness (VE) against PCR-confirmed influenza in adult patients with severe acute respiratory infection (SARI) during the 2022/2023 influenza season in Europe. Among 5547 SARI patients ≥18 years, 2963 (53%) were vaccinated against influenza. Overall VE against influenza A(H1N1)pdm09 was 11% (95% CI: -23-36); 20% (95% CI: -4-39) against A(H3N2) and 56% (95% CI: 22-75) against B. During the 2022/2023 season, while VE against hospitalisation with influenza B was >55%, it was ≤20% for influenza A subtypes. While influenza vaccination should be a priority for future seasons, improved vaccines against influenza are needed.

Coagulase-negative staphylococcal endophthalmitis: clinical severity and outcomes based on speciation

OBJECTIVE

To identify characteristics and visual outcomes of coagulase-negative staphylococci (CoNS) endophthalmitis in the era after the Endophthalmitis Vitrectomy Study.

DESIGN

Single-centre retrospective analysis.

PARTICIPANTS

Forty-two samples from 40 patients with documented CoNS endophthalmitis.

METHODS

Visual acuity outcomes of patients with CoNS endophthalmitis were assessed in relation to species and type of treatment instituted (e.g., pars plana vitrectomy [PPV] versus tap and injection of intravitreal antibiotics [T&I]). Strains were speciated using Gram and Giemsa staining and were further identified using API Staph and Biolog GEN III microplates. Genetic analysis was performed via polymerase chain reaction. Antibiotic susceptibility was assessed with disk diffusion.

RESULTS

Staphylococcus epidermidis was the most prevalent CoNS in our study. Cataract surgery and intravitreal injections were the most common sources for acute CoNS endophthalmitis. Eyes presenting with hand motion or better vision had similar mean final vision after either intravitreal antibiotics or PPV, whereas those with light perception or worse vision at onset had better outcomes after PPV only. Subanalysis showed that patients with S. epidermidis endophthalmitis (n = 39 eyes) had similar visual outcomes with either intravitreal injections or PPV regardless of visual acuity. Hypopyon and vitritis are not always present.

CONCLUSIONS

Patients with S. epidermidis endophthalmitis may benefit similarly from either early vitrectomy or intravitreal antibiotic injections regardless of visual acuity. This finding complements the management standards set forth by the Endophthalmitis Vitrectomy Study.

Alsó légúti minták molekuláris mikrobiológiai vizsgálata a koronavírus-járvány időszakában

Bevezetés: A BioFire FilmArray Pneumonia plus Panel (bioMérieux) az alsó légúti fertőzések mikrobiológiai diagnosztikájára kidolgozott „real-time” PCR-rendszer, mely 18 baktérium, 9 vírus és 7 antibiotikum-rezisztenciagén kimutatására képes. A két órán belül eredményt adó módszer segíti a pneumonia differenciáldiagnosztikáját, a terápiás döntéshozatalt. Célkitűzés: Laboratóriumunkban pneumonia kivizsgálása érdekében végzett PCR-paneltesztek eredményeinek áttekintése, a hagyományos bakteriológiai feldolgozás eredményeivel való összehasonlítása. Módszerek: A 2020. október és 2021. szeptember közötti időszakban 820, feltételezetten pneumoniás kórházi betegtől származó alsó légúti mintát vizsgáltunk a PCR-panellel. A mintákból a multiplex PCR-vizsgálat mellett tenyésztést is végeztünk. A kiegészítő SARS-CoV-2-PCR-vizsgálatok orr-garat törletből vett mintákból történtek. Eredmények: A minták 40%-a SARS-CoV-2-pozitív betegtől származott. A minták 60%-ánál jelzett patogént vagy rezisztenciagént a PCR-panel. A három leggyakrabban kimutatott kórokozó a Pseudomonas aeruginosa, a Staphylococcus aureus és az Acinetobacter baumannii volt. A PCR-rel detektált baktériumok 44%-a tenyésztéssel nem igazolódott, és viszont: tenyésztéssel számos olyan baktériumot, gombafajt, antibiotikum-rezisztenciamechanizmust igazoltunk, melyet a PCR-panel nem vizsgált, vagy melyre negatív eredményt adott. A SARS-CoV-2-pozitív csoportban a S. aureus adta az azonosított kórokozók 25,8%-át. A leggyakrabban kimutatott rezisztenciagén a mecA/C (MRSA) volt. A SARS-CoV-2-pozitív betegek mintáinak 2%-ában, míg a SARS-CoV-2-negatív betegek mintáinak 13%-ában mutattunk ki egyéb légúti vírusgént is. Következtetés: A kórházi pneumoniák gyakori kórokozóit PCR-vizsgálataink eredményei igazolták. A PCR-panel célspektrumában nem szereplő kórokozók jelentősége és az antibiotikumrezisztenciák multifaktoriális volta miatt a pneumoniaspecifikus multiplex PCR-vizsgálatokat tenyésztéssel együtt javasolt végezni, és ezek eredményét együttesen érdemes értelmezni. Orv Hetil. 2022; 163(33): 1295–1302.

Radiomorphological signs and clinical severity of SARS-CoV-2 lineage B.1.1.7

Objective

We aimed to assess the differences in the severity and chest-CT radiomorphological signs of SARS-CoV-2 B.1.1.7 and non-B.1.1.7 variants.

Methods

We collected clinical data of consecutive patients with laboratory-confirmed COVID-19 and chest-CT imaging who were admitted to the Emergency Department between September 1- November 13, 2020 (non-B.1.1.7 cases) and March 1-March 18, 2021 (B.1.1.7 cases). We also examined the differences in the severity and radiomorphological features associated with COVID-19 pneumonia. Total pneumonia burden (%), mean attenuation of ground-glass opacities and consolidation were quantified using deep-learning research software.

Results

The final population comprised 500 B.1.1.7 and 500 non-B.1.1.7 cases. Patients with B.1.1.7 infection were younger (58.5 ± 15.6 vs 64.8 ± 17.3; p < .001) and had less comorbidities. Total pneumonia burden was higher in the B.1.1.7 patient group (16.1% [interquartile range (IQR):6.0-34.2%] vs 6.6% [IQR:1.2-18.3%]; p < .001). In the age-specific analysis, in patients <60 years B.1.1.7 pneumonia had increased consolidation burden (0.1% [IQR:0.0-0.7%] vs 0.1% [IQR:0.0-0.2%]; p < .001), and severe COVID-19 was more prevalent (11.5% vs  4.9%; p = .032). Mortality rate was similar in all age groups.

Conclusion

Despite B.1.1.7 patients were younger and had fewer comorbidities, they experienced more severe disease than non-B.1.1.7 patients, however, the risk of death was the same between the two groups.

Advances in knowledge

Our study provides data on deep-learning based quantitative lung lesion burden and clinical outcomes of patients infected by B.1.1.7 VOC. Our findings might serve as a model for later investigations, as new variants are emerging across the globe.

EDTA-Induced Pseudothrombocytopenia up to 9 Months after Initial COVID-19 Infection Associated with Persistent Anti-SARS-CoV-2 IgM/IgG Seropositivity

Platelets have a role in vascular complications of COVID-19-related viral coagulopathy. Although immune-induced thrombocytopenia has been described mostly in moderate-to-severe COVID-19, the prognostic role of platelet count in COVID-19 is still controversial. Pseudothrombocytopenia has been reported to represent COVID-19-associated coagulopathy in critical illness, and transient EDTA-dependent pseudothrombocytopenia lasting less than 3 weeks was described in a patient with severe acute COVID-19 pneumonia. In our case study, EDTA-induced pseudothrombocytopenia was still present at 9 months after an initial SARS-CoV-2 virus infection in an apparently recovered 60 year old man. The persistence of antinucleocapside and antispike antibodies 9 months after the initial infection suggests that EDTA-induced pseudothrombocytopenia may be related to anti-SARS-CoV-2 IgG or IgM antibodies. We should acknowledge the possibility that pseudothrombocytopenia may also appear in some patients after seroconversion after the launch of large-scale vaccination programs.

In vitro activity of ceftazidime-avibactam and comparators against Enterobacterales and Pseudomonas aeruginosa isolates from Central Europe and Israel, 2014-2017 and 2018

Between 2014 and 2017, 6,662 Enterobacterales and 1,953 P. aeruginosa isolates were collected by 19 centers in four central European countries and Israel. A further 2,585 Enterobacterales and 707 P. aeruginosa isolates were collected in 2018 by 28 centers in seven European countries and Israel as part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) study. A central laboratory performed antimicrobial susceptibility testing using broth microdilution panels according to Clinical Laboratory Standards Institute (CLSI) guidelines. Susceptibility rates among Enterobacterales were highest to ceftazidime-avibactam (≥98.5%), colistin (≥97.3%), and meropenem (≥95.8%). Ceftazidime-resistant and multidrug-resistant (MDR) Enterobacterales subsets were highly susceptible to ceftazidime-avibactam (≥94.9%) and colistin (≥94.7%). Susceptibility rates to colistin among all P. aeruginosa were ≥97.4% and were ≥96.3% among ceftazidime-resistant and MDR subsets. Susceptibility rates to ceftazidime-avibactam were 91.9% (2014-2017), 86.3% (2018) and, in common with comparator agents, were lower among ceftazidime-resistant (≥51.7%) and MDR isolates (≥57.1%).

Comparison of virus neutralization activity and results of 10 different anti-SARS-CoV-2 serological tests in COVID-19 recovered plasma donors

Serological testing is a tool to predict protection against later infection. This potential heavily relies on antibody levels showing acceptable agreement with gold standard virus neutralization tests. The aim of our study was to investigate diagnostic value of the available serological tests in terms of predicting virus neutralizing activity of serum samples drawn 5–7 weeks after onset of symptoms from 101 donors with a history of COVID-19.

Immune responses against Receptor Binding Domain (RBD), Spike1 and 2 proteins and Nucleocapsid antigens were measured by various ELISA tests. Neutralizing antibody activity in serum samples was assessed by a cell-based virus neutralization test.

Spearman correlation coefficients between serological and neutralization results ranged from 0.41 to 0.91 indicating moderate to strong correlation between ELISA test results and virus neutralization. The sensitivity and specificity of ELISA tests in the prediction of neutralization were 35–100% and 35–90% respectively. No clear cut off levels can be established that would reliably indicate neutralization activity. For some tests, however, a value below which the sample is not expected to neutralize can be established. Our data suggests that several of the ELISA kits tested may be suitable for epidemiological surveys 1–2 months after the infection, estimating whether a person may have recently exposed to the virus. Sensitivities considerably superseding specificity at the cut-off values proposed by the manufacturers suggest greater potential in the identification of insufficient antibody responses than in confirming protection. Nevertheless, the former might be important in assessing response to vaccination and characterizing therapeutic plasma preparations.

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SARS-CoV-2 antibody levels 5-7 weeks after the onset of COVID show moderate to strong correlation with virus neutralization.

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Tests based on the use of S1, nucleocapsid or RBD antigens performed similarly in predicting antibody neutralization.

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None of the examined serological tests could safely identify individuals protected against a later SARS-CoV-2 infection.

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The products assessed might still provide important epidemiological information.

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Serological tests might still have potential in screening donors for therapeutic plasma products or vaccinated individuals.

The diagnostic value of rapid anti IgM and IgG detecting tests in the identification of patients with SARS CoV-2 virus infection

Introduction: At the end of March, 2020, rapid tests detecting the presence of antiviral IgM and IgG antibodies against SARS-CoV-2 virus were introduced in Hungary for the identification of SARS-CoV-2 infection (COVID-19 disease). Aim: We evaluated two rapid tests (Anhui and Clungene) in comparison with those of real-time PCR tests considered as the gold standard in the detection of infection. Method: Between 16, March and 14, April, 2020, we performed rapid IgM and IgG detecting tests without PCR; PCR without rapid tests; and PCR WITH rapid tests in 4140, 3210 and 1654 patients, respectively. (Out of these 1654 patients, Anhui and Clungene tests were used for testing in 625 and 1029 patients, respectively.) Patients were considered as positive in PCR and rapid tests when PCR positivity and IgM or IgG positivity occurred at any time, respectively. (Note: Clungene test is also marketed as 'Lungene'.) Results: The prevalence of PCR positivity in 4864 patients tested with PCR was 6.3%. The sensitivity and specificity of Anhui and Clungene tests were 33.3% and 72.85%, and 35.48% and 85.02%, respectively. At 6% PCR positivity, the positive and negative predictive values of Anhui and Clungene were 7.28%, 94.48%, 13.13%, and 95.38%, respectively. Conclusion: The low positive predictive values indicate that Anhui and Clungene rapid tests detecting the presence of anti-IgM and anti-IgG against SARS-CoV-2 virus infection are not suitable for screening SARS-CoV-2 vírus infection in the general population. These results strongly support that Anhui and Clungene rapid tests detecting IgM and IgG antibodies against SARS-CoV-2 virus should not be used in the differential diagnosis of infection. Orv Hetil. 2020; 161(20): 807-812.

Ceftazidime-avibactam and ceftolozane-tazobactam susceptibility of multidrug resistant Pseudomonas aeruginosa strains in Hungary

Our objective was to compare the activity ceftazidime-avibactam (C/A) and ceftolozane-tazobactam (C/T) against multidrug (including carbapenem) resistant Pseudomonas aeruginosa clinical isolates collected from six diagnostic centers in Hungary and to reveal the genetic background of their carbapenem resistance. Two hundred and fifty consecutive, non-duplicate, carbapenem-resistant multidrug resistant (MDR) P. aeruginosa isolates were collected in 2017. Minimal inhibitory concentration values of ceftazidime, cefepime, piperacillin/tazobactam, C/A and C/T were determined by broth microdilution method and gradient diffusion test. Carbapenem inactivation method (CIM) test was performed on all isolates. Carbapenemase-encoding blaVIM, blaIMP, blaKPC, blaOXA-48-like and blaNDM genes were identified by multiplex PCR. Of the isolates tested, 33.6% and 32.4% showed resistance to C/A and C/T, respectively. According to the CIM test results, 26% of the isolates were classified as carbapenemase producers. The susceptibility of P. aeruginosa isolates to C/A and C/T without carbapenemase production was 89% and 91%, respectively. Of the CIM-positive isolates, 80% were positive for blaVIM and 11% for blaNDM. The prevalence of Verona integron-encoded metallo-beta-lactamase (VIM)-type carbapenemase was 20.8%. NDM was present in 2.8% of the isolates. Although the rate of carbapenemase-producing P. aeruginosa strains is high, a negative CIM result indicates that either C/A or C/T could be effective even if carbapenem resistance has been observed.

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.

Bacterial Contamination of ePTFE Membranes Following Regenerative Surgery of Intrabony Defects Treated with Platelet-rich Plasma and Natural Bone Mineral

PURPOSE

The rationale of using platelet-rich plasma (PRP) in reconstructive periodontal surgery is to amplify or accelerate the wound healing through the growth factors contained in platelets. On the other hand, bacterial colonisation of membranes may negatively affect the healing process. The aim of this study was to evaluate bacterial contamination of non-bio-resorbable membranes (ePTFE) used for regenerative periodontal therapy of intrabony defects and the clinical attachment level (CAL) gain with or without PRP.

MATERIALS AND METHODS

Seventeen patients were treated with a natural bone mineral (NBM) and guided tissue regeneration (GTR) with an ePTFE membrane (NBM + GTR group; ie, control group), while in another 17 patients PRP was additionally applied (NBM + PRP + GTR group; ie, test group). Furthermore, the retrieved membranes were analysed for the presence of periodontopathogens and data were related to the gain of clinical attachment. In addition, the in vitro sensitivity of selected microbes to PRP was checked by using agar diffusion test.

RESULTS

Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were not detected in the PRP group whereas in the controls A. actinomycetemcomitans was detected in five patients (p = 0.022) and P. gingivalis in two cases (difference not statistically significant, p = 0.242). Detection of A. actinomycetemcomitans was not associated with less CAL gain. If the samples were positively tested for Prevotella intermedia/nigrescens and/or P. gingivalis, the CAL gains were lower compared with the negative samples (p = 0.002). PRP did not show any inhibitory effect on bacterial growth in vitro.

CONCLUSION

Within their limits, the present results appear to suggest that the presence of P. intermedia/nigrescens and/or P. gingivalis at the regenerated site may negatively influence the clinical outcomes. However, the potential influence of PRP on bacterial colonisation and the impact on the clinical outcome is still unclear and remains to be elucidated.

Ciprofloxacin Promoted qnrD Expression and Phylogenetic Analysis of qnrD Harboring Plasmids

Morganella morganii SE10MM harboring quinolone resistance determinant qnrD was investigated in our study. An entirely sequenced novel 2,662 bp qnrD-plasmid pSE10MM was identified and deposited at GenBank under accession number KU160530. Nucleic acid sequence of pSE10MM showed 94-97% similarity to previously detected qnrD-plasmids of Proteus mirabilis strains. Phylogenetic analysis by Geneious 9.0.5 showed clusters of plasmids with possible common origin. Initial expression of qnrD gene was found 12.5 normalized to rpoB housekeeping gene. Subsequently, a sub-minimum inhibitory concentration (1 mg/L) ciprofloxacin exposure resulted in a fold change of 30.06 at 24 hours. In contrast, qnrD-plasmid pSE10MM copy number increased in time from 1.1 to 6.63. Chromosomal mutations of gyrA with S83I, gyrB with S463A, and parC with S80I amino acid substitutions were detected, but no other mutations have occurred as a consequence of ciprofloxacin exposure. Elevated expression of qnrD correlated with that of recA in M. morganii during ciprofloxacin exposure, which indicates SOS-dependent regulation of qnrD. Protective effect of QnrD plays a role in fluoroquinolone-resistant strain even in the presence of chromosomal mutations in gyrase and topoisomerase IV.

Plasmid-mediated quinolone resistance determinants in Enterobacteriaceae from urine clinical samples

Plasmid-mediated quinolone resistance (PMQR) determinants including, qnrA, qnrB, qnrC, qnrD, qnrS, aac(6')-Ib-cr, oqxAB, and qepA, were investigated in 214 Enterobacteriaceae strains from urine clinical samples. Antimicrobial susceptibility testing for ciprofloxacin, ceftriaxone, and imipenem was performed by broth microdilution method. All strains were screened for PMQR genes by PCR. Virulence determinants, namely afa, pap, pil, sfa/foc, and kpsMT of eight Escherichia coli strains proven positive for at least one qnr gene, were investigated by PCR. All of the eight investigated strains carried the pil gene, showing that P fimbria is a common virulence determinant among qnr positive E. coli. Out of 214 tested strains, 38 yielded any PMQR determinant, altogether 45 genes were detected namely, 6 qnrA, 1 qnrB, 2 qnrD and 8 qnrS, 9 aac(6')-Ib-cr, and 19 oqxAB; however, neither qepA nor qnrC were detected. Notably, 18 Klebsiella spp., harbored oqxAB, nine E. coli were positive for qnrS and two Morganella morganii yielded qnrD resistance determinant. In this study, we demonstrated 17.7% prevalence of PMQR-positive Enterobacteriaceae and first reported qnrD-resistance determinant in Hungary. Altogether, 25 PMQR-positive strains were susceptible or low-level resistant to ciprofloxacin with minimum inhibitory concentration (MIC) between 0.06 and 1 mg/L, suggesting that prevalence of PMQR determinants is underestimated and screening among clinical isolates exhibiting reduced susceptibility is necessary. Fluoroquinolone resistance breakpoints of Enterobacteriaceae were revised in 2017 by European Committee of Antimicrobial Susceptibility Testing indicating ciprofloxacin susceptibility only until 0.25 mg/L MIC value.

[Uncommon non-fermenting Gram-negative rods as pathogens of lower respiratory tract infection]

INTRODUCTION

Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet.

AIM

The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options.

METHOD

Lower respiratory tract samples of 3589 patients collected in a four-year period (2013-2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method.

RESULTS

Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also.

CONCLUSIONS

Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23-30.

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.

Colistin resistance among blood culture isolates at a tertiary care centre in Hungary

OBJECTIVES

The emergence of colistin resistance has been detected worldwide in recent years. Whilst colistin susceptibility has been tested in carbapenem resistant Enterobacteriaceae as well as multidrug-resistant Pseudomonas spp. and Acinetobacter spp. during routine laboratory practice, the overall rate of colistin resistance was unknown in our centre. The aim of this retrospective study was to reveal the prevalence of colistin resistance among clinically significant blood culture isolates in two different periods (2010-2011 and 2016) in our laboratory.

METHODS

Consecutive non-duplicate strains (n=776) were screened for colistin resistance using agar plates containing 4mg/L colistin. Strains cultured on colistin-containing plates were further examined. Minimum inhibitory concentrations (MICs) of colistin-tolerant subcultures and original cultures were determined in parallel by the broth microdilution method. Screening for mcr-1-mediated colistin resistance was performed by PCR.

RESULTS

The rate of colistin resistance was 0.6%, 1.3% and 2.6% in Enterobacteriaceae, Pseudomonas spp. and Acinetobacter spp., respectively; colistin-resistant subpopulations were found in 17%, 27% and 20% of isolates, respectively, with low frequency. Seven colistin-resistant strains were found, among which was an mcr-1-positive Escherichia coli isolated from a blood sample of a haemato-oncology patient in 2011. All Stenotrophomonas maltophilia isolates were resistant to colistin.

CONCLUSIONS

The low prevalence of colistin resistance was in accordance with European data. The prevalence of heteroresistance was significantly higher, but the clinical significance of the phenomenon is unclear. We have identified the first mcr-1-positive E. coli strain in Hungary. mcr-1 has been in Hungary since 2011 but has not yet expanded.

[Periprosthetic joint infection caused by Rhodococcus equi. Case report]

Rhodococcus equi is a rare pathogen in humans causing infections mostly in immunocompromised hosts. We present the first case of periprosthetic joint infection caused by Rhodococcus equi. An 88-year-old male patient was referred to our clinic with a history of fever and right hip pain. The patient had multiple hip surgeries including total joint arthroplasty and revision for aseptic loosening on the right side. He was immunocompetent, but his additional medical history was remarkable for diabetes mellitus, diabetic nephropathy and stroke with hemiplegia resulting in immobilization. Radiography showed stable components, joint aspirate yielded Rhodococcus equi. Irrigation and debridement was proposed, but the patient refused any surgical intervention. Therefore antibiotic therapy was administered. At the last follow-up the patient is free of complaints but the C-reactive protein level is still elevated. This case illustrates the possible role of Rhodococcus equi in medical device-associated infections. Orv Hetil. 2017; 158(27): 1071-1074.

Colistin resistance associated with outer membrane protein change in Klebsiella pneumoniae and Enterobacter asburiae

In this study, outer membrane proteins (OMPs) of colistin-resistant Klebsiella pneumoniae and Enterobacter asburiae were analyzed. One colistin-susceptible and three colistin-resistant K. pneumoniae sequence type 258 strains as well as one colistin-susceptible E. asburiae and its colistin-heteroresistant counterpart strain were involved in the study. OMP analysis of each strain was performed by microchip method. Matrix-assisted laser desorption ionization time of flight/mass spectrometry (MALDI-TOF/MS) investigation was carried out after separation of OMPs by two-dimensional gel electrophoresis and in-gel digestion. The MALDI-TOF/MS analysis of OMPs in the colistin-susceptible K. pneumoniae found 16 kDa proteins belonging to the LysM domain/BON superfamily, as well as DNA starvation proteins, whereas OmpX and OmpW were detected in the colistin-resistant counterpart strains. OmpC and OmpW were detected in the colistin-susceptible E. asburiae, whereas OmpA and OmpX were identified in the colistin-resistant counterpart. This study demonstrated that OMP differences were between colistin-susceptible and -resistant counterpart strains. The altered Gram-negative cell wall may contribute to acquired colistin resistance in Enterobacteriaceae.

[Relationship of consequences of anastomotic insufficiency and bacterial flora of oral cavity in patients with esophageal and cardia cancer]

INTRODUCTION

In the course of anastomotic insufficiency following resection of esophageal cancers the bacterial compound of the esophageal substance has a remarkable, presumable role in the outcome of complications.

AIM

The purpose of this study is to compare the consequences of the anastomotic leak with the bacterial flora of patients' oral cavity.

METHOD

In this prospective study a total of 131 patients were investigated directly before the surgical intervention taking a bacterial sample. Bacterial flora of patients' oral cavity was analysed; and the correlation between the consequences of the anastomotic leak and the content of the bacterial flora was examined.

RESULTS

Pathogenic bacteria in the oral microflora in 50 cases (38.2%) was found. Statistically significant, moderate correlation was found between the severity of the complication and the incidence of pathogenic bacteria (r_s = 0.553; p≤0.05).

CONCLUSIONS

Pathogenic agent in the microbial flora might induce higher risk and more severe outcome in case of anastomotic leakage and it might be evaluated as a determinative factor. Consideration of the bacterial flora of the oral cavity requires more attention in the preoperative preparation than before and it demands the change of the current practice. Orv. Hetil., 2017, 158(1), 25-30.

Plasmid-mediated quinolone resistance among extended spectrum beta lactase producing Enterobacteriaceae from bloodstream infections

The purpose of this study was to determine prevalence and molecular characterization of plasmid-mediated quinolone resistance (PMQR) genes [qnrA, qnrB, qnrC, qnrD, qnrS, aac(6')-Ib-cr, qepA, and oqxAB] among extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella spp. isolates from bloodcultures in Hungary. A total of 103 isolates were tested for quinolone susceptibility by microdilution method and PMQR genes were detected by polymerase chain reaction. About 40 ESBL-producing E. coli (39%) and 50 ESBL-producing Klebsiella spp. strains (48%) were resistant to ciprofloxacin; 40 ESBL-producing E. coli (39%) and 47 ESBL-producing Klebsiella spp. strains (45%) were resistant to levofloxacin; and 88 strains including 40 ESBL-producing E. coli (39%) and 48 (47%) ESBL-producing Klebsiella spp. were resistant to moxifloxacin. Among the 103 ESBL-producing isolates, 77 (75%) isolates (30 E. coli and 47 Klebsiella spp.) harbored PMQR genes. The most commonly detected gene was aac(6')-Ib-cr (65%). The occurrence of qnrS gene was 6%. Interestingly, qnrA, qnrB, qnrC, qnrD, and qepA were not found in any isolates. Among 77 PMQR-positive isolates, 27 (35.1%) and 1 (1.3%) carried two and three different PMQR genes, respectively. Only Klebsiella spp. harbored more than one PMQR genes. Observing prevalence of PMQR genes in the last 8 years, the increasing incidence of aac(6')-Ib-cr and oqxAB can be seen. Our results highlight high frequency of PMQR genes among ESBL-producing Klebsiella pneumoniae and E. coli isolates with an increasing dynamics in Hungary.

Interpretation of Blood Microbiology Results - Function of the Clinical Microbiologist

The proper use and interpretation of blood microbiology results may be one of the most challenging and one of the most important functions of clinical microbiology laboratories. Effective implementation of this function requires careful consideration of specimen collection and processing, pathogen detection techniques, and prompt and precise reporting of identification and susceptibility results. The responsibility of the treating physician is proper formulation of the analytical request and to provide the laboratory with complete and precise patient information, which are inevitable prerequisites of a proper testing and interpretation. The clinical microbiologist can offer advice concerning the differential diagnosis, sampling techniques and detection methods to facilitate diagnosis. Rapid detection methods are essential, since the sooner a pathogen is detected, the better chance the patient has of getting cured. Besides the gold-standard blood culture technique, microbiologic methods that decrease the time in obtaining a relevant result are more and more utilized today. In the case of certain pathogens, the pathogen can be identified directly from the blood culture bottle after propagation with serological or automated/semi-automated systems or molecular methods or with MALDI-TOF MS (matrix-assisted laser desorption-ionization time of flight mass spectrometry). Molecular biology methods are also suitable for the rapid detection and identification of pathogens from aseptically collected blood samples. Another important duty of the microbiology laboratory is to notify the treating physician immediately about all relevant information if a positive sample is detected. The clinical microbiologist may provide important guidance regarding the clinical significance of blood isolates, since one-third to one-half of blood culture isolates are contaminants or isolates of unknown clinical significance. To fully exploit the benefits of blood culture and other (non- culture based) diagnoses, the microbiologist and the clinician should interact directly.

Does Staphylococcus Saprophyticus Cause Acute Cystitis only in Young Females, or is there more to the Story? A One-Year Comprehensive Study Done in Budapest, Hungary

Staphylococcus saprophyticus is a well-known urinary pathogen in acute cystitis in young females. We completed a retrospective overview of the distribution of urinary tract infections (UTIs) occurring in 2014, at Semmelweis University hospitals and at Heim Pál Children's Hospital. Six age-groups (ages 0-100) were examined, with the frequency of S. saprophyticus in females being: 0.1% (0-4), 0.7%, (5-15), 7.4% (16-24), 1.2% (25-39), 0.4% (40-59) and 0.1% (60-100), and S. saprophyticus being the 3(rd) most common pathogen in females aged 16-24. In males, S. saprophyticus was only isolated from those aged 5-15. Seasonal distribution of UTIs caused by S. saprophyticus showed that most infections occurred during the months of January, June, August and November. Antibiotic-resistance rates of amoxicillin, clindamycin, doxycycline, erythromycin, gentamicin and sulfamethoxazole- trimethoprim varied as follows: 0.9%, 32.7%, 19.6%, 34.6%, 0.9% and 0.9%, respectively. Thirty randomly selected samples were analysed by pulsed-field gelelectrophoresis, and 28 different genotypes were identified. S. saprophyticus is involved in the pathogenesis of acute cystitis not only in young females, but also in other age-groups, and in young males as well. We did not find any significant seasonal occurrence in S. saprophyticus-caused UTIs. The infective strains were genetically diverse. Antibiotic-resistance does not pose any issue as of yet.

Significance of yeasts in bloodstream infection: Epidemiology and predisposing factors of Candidaemia in adult patients at a university hospital (2010-2014)

The incidence of Candida bloodstream infection (BSI) has increased during the past decades. Species distribution is changing worldwide, and non-albicans Candida spp. are becoming more prevalent. Acquired resistance to antifungal agents has been documented in several reports. The aim of our study was to assess the epidemiology and antifungal susceptibility of Candida isolates from BSI at our institute. The incidence of Candida BSI increased during the first four years of our investigation, from 1.7 to 3.5 episodes / 10 000 admissions, then dropped to 2.66 episodes / 10 000 admissions in the last year. The most frequently isolated species was C. albicans (63%), followed by C. glabrata (13%), C. parapsilosis (10.2%), C. tropicalis (9.3%), and C. krusei (3.7%). One isolate each of C. kefyr, C. fabianii and C. inconspicua were detected. The percentage of C. albicans remained stable throughout the study period. The most frequent risk factors of Candida BSI in our patient population were intensive care treatment (60.4%), abdominal surgery (52.5%), and solid malignancy (30.7%). All isolates were wild-type organisms, no acquired antifungal resistance was detected.

Antibiotic susceptibility of sulfamethoxazole-trimethoprim resistant Stenotrophomonas maltophilia strains isolated at a tertiary care centre in Hungary

Sulfamethoxazole-trimethoprim (SXT) is the drug-of-choice in Stenotrophomonas maltophilia caused infections. There has been an increase in resistance to SXT of S. maltophilia over recent years. In this study 30 S. maltophilia clinical isolates resistant to SXT were investigated. Antibiotic susceptibilities for ciprofloxacin, moxifloxacin, levofloxacin, doxycycline, tigecycline, ceftazidime, colistin and chloramphenicol were determined by broth microdilution method. None of the strains were susceptible to ciprofloxacin, tigecycline, ceftazidime or colistin. Only 37% of the isolates were susceptible to levofloxacin or moxifloxacin. Two isolates resistant to all tested antibiotic agents and two others susceptible only to doxycycline were further investigated: susceptibility for combinations of antibiotics was analyzed by checkerboard technique. According to the fractional inhibitory concentration indices calculated, moxifloxacin plus ceftazidime combination was found to be synergistic in each case. Genetic testing revealed the predominance of sul1 gene. Our study concluded that the range of effective antibiotic agents is even more limited in infections caused by SXT-resistant S. maltophilia. In these cases, in vitro synergistic antibiotic combinations could be potential therapeutic options.

Infection and colonization by Stenotrophomonas maltophilia: antimicrobial susceptibility and clinical background of strains isolated at a tertiary care centre in Hungary

BACKGROUND

Stenotrophomonas maltophilia is an important opportunistic, mainly nosocomial pathogen that emerged in the last decades worldwide. Due to its inherent extended antibiotic resistance, therapeutic options are strongly limited. New resistance mechanisms in S. maltophilia make antibiotic therapy even more difficult. The aim of our study was to investigate the antimicrobial resistance of S. maltophilia isolates collected in our laboratory and to reveal related clinical background.

METHOD

Consecutive non-duplicate S. maltophilia isolates (n = 160) were collected in a three-year period. Conventional methods, automated identification system and MALDI-TOF MS was used for identification, ERIC-PCR for genetic relationship analysis and broth microdilution method to determine the susceptibility for trimethoprim/sulfamethoxazole (SXT), ciprofloxacin, levofloxacin, moxifloxacin, colistin, doxycycline and tigecycline. Clinical final reports were used retrospectively to collect clinical information.

RESULTS

ERIC-PCR revealed large heterogeneity. Trimethoprim/sulfamethoxazole, moxifloxacin and levofloxacin were found to be the most effective agents with MIC50/MIC90 0.5/1, 0.25/1, 1/2 mg/l, respectively. Seventy percent of patients with S. maltophilia infection were treated in intensive care units. All-cause mortality rate was 45%. Nearly 70% of the isolates were collected from polymicrobial infections/colonizations.

CONCLUSIONS

Trimethoprim/sulfamethoxazole is the most potent antibiotic agent against S. maltophilia. In case of SXT hypersensitivity, intolerance or resistance, fluoroquinolones are alternative therapeutic options. Missing clinical breakpoints, consensus antibiotic susceptibility testing guidelines and clinical trials make the interpretation of antibiotic susceptibility testing results difficult. The indirect pathogenicity of S. maltophilia in polymicrobial infections or colonizations has to be taken into consideration.

Special application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in clinical microbiological diagnostics

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry as a new possibility for rapid identification of bacteria and fungi revolutionized the clinical microbiological diagnostics. It has an extreme importance in the routine microbiological laboratories, as identification of the pathogenic species rapidly will influence antibiotic selection before the final determination of antibiotic resistance of the isolate. The classical methods for identification of bacteria or fungi, based on biochemical tests, are influenced by many environmental factors. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry is a rapid method which is able to identify a great variety of the isolated bacteria and fungi based on the composition of conserved ribosomal proteins. Recently several other applications of the method have also been investigated such as direct identification of pathogens from the positive blood cultures. There are possibilities to identify bacteria from the urine samples in urinary tract infection or from other sterile body fluids. Using selective enrichment broth Salmonella sp from the stool samples can be identified more rapidly, too. The extended spectrum beta-lactamase or carbapenemase production of the isolated bacteria can be also detected by this method helping the antibiotic selection in some cases. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry based methods are suitable to investigate changes in deoxyribonucleic acid or ribonucleic acid, to carry out rapid antibiotic resistance determination or other proteomic analysis. The aim of this paper is to give an overview about present possibilities of using this technique in the clinical microbiological routine procedures. Orv. Hetil., 2014, 155(38), 1495–1503.

Candida bloodstream infection: a clinical microbiology laboratory perspective

The incidence of Candida bloodstream infection (BSI) has been on the rise in several countries worldwide. Species distribution is changing; an increase in the percentage of non-albicans species, mainly fluconazole non-susceptible C. glabrata was reported. Existing microbiology diagnostic methods lack sensitivity, and new methods need to be developed or further evaluation for routine application is necessary. Although reliable, standardized methods for antifungal susceptibility testing are available, the determination of clinical breakpoints remains challenging. Correct species identification is important and provides information on the intrinsic susceptibility profile of the isolate. Currently, acquired resistance in clinical Candida isolates is rare, but reports indicate that it could be an issue in the future. The role of the clinical microbiology laboratory is to isolate and correctly identify the infective agent and provide relevant and reliable susceptibility data as soon as possible to guide antifungal therapy.

In vitro efficiency of vancomycin containing experimental drug delivery systems

Biofilm-forming Staphylococcus epidermidis strains are common cause of the periprosthetic infection. The treatment of the periprosthetic infection is very problematic, so the prevention of these infections by an antibiotic containing prothesis could be an option for prevention.The purpose of the present study was to examine the in vitro effects of drug delivery systems (DDSs), namely Wax 1 and Wax 2 with different vancomycin content: 0.5, 1, 2 and 4 mg. In order to control the antibacterial activity of DDSs killing curve study was performed and in order to determine the antibiotic release and the antibiotic peak concentration from the DDSs biological assay was carried out.The time kill curve studies showed, that both DDSs with all vancomycin concentration decreased significantly the bacterial counts, however, Wax 2 with 4 mg vancomycin significantly decreased the bacterial count than all the other groups.The vancomycin release was the best with the highest peak concentration from DDSs with 4 mg vancomycin contain; it was significantly better than in the other groups, however, no significant difference was observed between Wax 1 and Wax 2 in this respect.These findings suggest that Wax 2 with 4 mg vancomycin content could be a potential agent for clinical use.

Synergistic antibiotic combinations for colistin-resistant Klebsiella pneumoniae

In this study antibiotic combinations for multidrug-resistant Klebsiella pneumoniae strains were investigated. The study included a colistin-susceptible and a colistin-resistant KPC-2 producing K. pneumoniae ST258 strains isolated in 2008 and 2009 during an outbreak in Hungary. Antibiotic combinations were analyzed by checkerboard technique and fractional inhibitory concentration indices were calculated. The following antibiotics were tested: ceftazidime, cefotaxime, ceftriaxone, ampicillin, imipenem, ertapenem, amikacin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, rifampicin, polymyxin B and colistin. Combinations including 0.25 μg/ml colistin plus 1 μg/ml rifampicin, 0.25 μg/ml polymyxin B plus 1 μg/ml rifampicin, 1 μg/ml imipenem plus 2 μg/ml tobramycin, were found synergistic.These in vitro synergistic combinations suggest potential therapeutical options against infections caused by KPC-2 producing, multidrug-resistant K. pneumoniae ST258.

Impact of molecular mimicry on the clinical course and outcome of sepsis syndrome

We investigated the impact of molecular mimicry between pathogenic microbes and their antigenic surrounding on the clinical course and outcome of pneumonia induced sepsis. Using mathematical prediction, we estimated the mimicry tendency of the identified pathogenic flora of patients with the human proteome as well as intestinal microbes. Since gut bacteria become invasive and hostile in critical illness, mimicry between these organisms and the infectious flora is expected to be rather hyperinflammatory type, in contrast to the expectedly tolerogenic self versus pathogen cross-reactions. Differential effects of these two kinds of cross-reactions were studied. The predicted similarity of the identified pathogenic flora and intestinal microbes was higher in non-survivor patients compared to survivors (P=0.019). Higher values of "pathogen versus intestinal flora/pathogen versus human proteome" mimicry ratios (inflammatory quotients) were associated with mortality at a higher extent of significance (P<0.01), and correlated with admission APACHE II disease severity scores (R=0.311; P=0.017). We also found a correlation between the previously reported sepsis mortality rates by causative agent and the corresponding inflammatory quotients of these pathogens (R=0.738; P<0.05). Gram negative species showed higher similarity to intestinal bacteria and reached higher inflammatory quotients compared to Gram positives (P=0.01 and P<0.01, respectively). The disadvantageous effect of "pathogen versus intestinal flora" mimicry - presumably due to the extension of inflammation from the infectious focus to the already injured gut - is in accordance with the gut-lymph hypothesis, assessing that the destruction of the intestinal symbiosis culminates in the formation of damageous gut origin lymph. Our results raise the idea that molecular mimicry between pathogenic microbes and their antigenic surrounding might be a contributing factor behind the clinically and experimentally observed differences in microbiologically distinct forms of sepsis syndrome.

Changes in the incidence of multiresistant pathogens and its consequences in intensive care unit

Incidence of nosocomial infections and antibiotics resistance in intensive care units is increasing worldwide. Blood-stream infections of Gram-negative non-fermentive bacteria are associated with higher mortality. Aim and methods: The aim of this study was to compare the antibiotic sensitivity of nosocomial blood-stream infections between years 2008–2010. Results: There was no difference in the sensitivity of methycillin-resistant Staphylococcus aureus and extended-spectrum beta lactamase producing Klebsiella spp. and Escherichia coli infections between the two years examined. Antibiotic resistance of Acinetobacter baumannii and Pseudomonas infections showed a marked increase in 2010 when compared to that found in 2008: there was no multiresistant Acinetobacter infection in samples obtained in 2008, but all these infections were found to be sensitive only to colistin in samples investigated in 2010. Sensitivity of Pseudomonas infections to carbapenems and piperacillin/tazobactam decreased significantly during this time. In addition, the authors found that the mortality of multiresistant Gram-negative blood-stream infections was higher compared to that caused by non-multiresistant bacteria. Conclusions: These results emphasize the importance of infection control, adequate dosing and timing of antibiotics, and an appropriate number of nurses in intensive care unit. Orv. Hetil., 2011, 152, 1486–1491.

Curiosities of the methicillin-resistant Staphylococcus aureus survey - possibility of pseudo-outbreak and transmission to household contacts

Methicillin-resistant Staphylococcus aureus (MRSA) is currently one of the most prevalent antibiotic-resistant pathogens in hospitals, but it is also emerging as a community-acquired pathogen. We analysed the clinical and microbiological data of the patients in a county teaching hospital regarding MRSA. During the examination period (1996-2010), four outbreaks and one pseudo-outbreak occurred. It also became evident that health care workers and their families are possibly at risk of becoming carriers of MRSA. The importance of the molecular epidemiological investigation (pulsed-field gel-electrophoresis (PFGE)) typing and hygienic measures in order to detect and control MRSA outbreaks must be emphasised. Following infection control guidelines seems to be cost-effective method of controlling the nosocomial transmission of MRSA.

Clinical microbiology of neonatal candidiasis in Hungary

The occurrence of Candida spp. was investigated during a three-year period in two neonatal intensive care units, Budapest, Hungary. The species distribution among the 41 analysed cases was the following: C. albicans (30/41, 73%), C. parapsilosis (10/41, 24%) and C. glabrata (1/41, 3%). All of the isolates were susceptible to the tested drugs. There was a significant difference in the birth weight, the gestational age <30 weeks and the occurrence of caesarean section between the C. albicans and the C. parapsilosis groups of the cases. Respiratory tract colonization was the same (76-77%) in the extremely low birth weight (ELBW) and the very low birth weight (VLBW) groups. Comparing the ELBW, VLBW, and >1500 g birth weight groups, significant difference was found in the parenteral nutrition, the gestation weeks <36 or <30, the polymicrobial infection and the transfusion. The ratio of C. albicans, C. parapsilosis and C. glabrata was 9:7:1 in ELBW group; 6:3:0 in VLBW group and 15:1:0 in >1500 g group. The mortality rate for C. parapsilosis was higher than for C. albicans.

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.

Rapid identification of pathogens in blood culture with fluorescent in situ hybridization (FISH)

Rapid identification of pathogens in bloodstream infections is of utmost importance to improve survival of septic patients. Fluorescent in situ hybridization (FISH) accelerates the identification of most frequent bacterial and yeast pathogens of sepsis. In this study, 210 positive blood cultures were tested with FISH method and the results were evaluated comparing to the traditional cultivation based results. Overall agreement between FISH and conventional identification was 91.4%, with better results for Gram-negative bacteria than for Gram-positives (100% and 89.5%, respectively). FISH results were obtained within 1 hour. FISH may serve as a useful tool to supplement traditional microbiological methods for rapid, provisional identification of sepsis pathogens.

In vitro activity of clarithromycin in combination with other antimicrobial agents against biofilm-forming Pseudomonas aeruginosa strains

The aim of the study was to investigate the biofilm-production of 60 Pseudomonas aeruginosa strains isolated from clinical samples and to examine the effect of different antimicrobials and their combinations with clarithromycin on biofilm-formation. The minimal inhibitory concentrations (MICs), minimal biofilm inhibitory concentrations (MBICs), and antibiotic synergy by calculating the fractional inhibitory concentration (FIC) index were determined for the following antibiotics: ceftazidime, cefepime, piperacillin/tazobactam, imipenem, meropenem, levofloxacin, ciprofloxacin, gentamicin, amikacin, tobramycin, netilmicin and clarithromycin. A total of 14 (23.3%) isolates out of 60 isolates of P. aeruginosa were biofilm positive. Cefepime, imipenem and meropenem had the lowest MIC 90 values. Piperacillin/tazobactam and clarithromycin had the highest MIC 90 values. Imipenem, meropenem, piperacillin/tazobactam and clarithromycin had the lowest MBIC 90 values. For biofilm-forming P. aeruginosa strains 2-fold to 128-fold higher MBIC values than MIC values were obtained for ceftazidime, cefepime, imipenem, amikacin and netilmicin. The MBIC was 2-fold to 512-fold lower then the MIC values in the case of piperacillin/tazobactam, ciprofloxacin, levofloxacin and clarithromycin. Synergy was generally demonstrated for clarithromycin in combination with aminoglycosides, fluoroquinolones or ceftazidime. However, surprisingly it was found that combinations of clarithromycin with carbapenems or cefepime led to an antagonistic interaction: combination of clarithromycin with imipenem, meropenem or ertapenem showed antagonism in 37.5%, 50% and 62.5% of the strains tested whereas its combination with cefepime expressed antagonism in 75% of the strains, respectively. To the best of our knowledge no one has previously described this phenomenon so far.

Experiences of the Department of Anesthesiology and Intensive Therapy of Semmelweis University during the 2009 pandemic H1N1 (pH1N1) influenza outbreak

Introduction: The 2009 pandemic 2009 H1N1 (pH1N1) influenza A virus shows a markedly different disease pattern than seasonal strains, causing critical illness in relatively young, female, pregnant individuals as well as in comorbid patients. Materials and methods: The Department of Anesthesiology and Intensive Therapy of Semmelweis University served as a regional influenza center for the adult critically ill during the winter of pH1N1 outbreak. We analyzed data collected from 26 suspected pH1N1 critically ill patients treated in our unit during this period. Results: Sixteen cases were confirmed as pH1N1 infection with RT-PCR, while the other 10 patients with influenza like illness showed tendency to a different age and comorbidity, as well as outcome characteristics, suggesting a different pathogenesis. Confirmed pH1N1 patients showed a mean age of 50.5 years (median: 44; range: 20–85), with female predominancy (69%). Comorbidity was present in 69% of cases (chronic heart conditions, chronic pulmonary disease, previous history of malignancy present in 31; 25 and 19%, respectively). Twenty-five percent of the patients were pregnant women. Nineteen percent of the cases received previous pH1N1 vaccination. But two patients were later readmitted for worsening chronic conditions that led to death, which resulted in a total mortality rate of 31%. Mean APACHE II and SOFA scores on admittance were 12.2 and 5.3, respectively. Average length of treatment was 11.5 days (median: 6.5; range 2–50 days). All patients received ventilatory assistance, 69% of patients received invasive, while 31% of patients received non-invasive ventilatory assistance. The average number of days of invasive ventilation was 10.5 days (median: 5.5; range: 2–45). Forty-five percent of ventilated patients required rescue ARDS therapy. Complications included hemodynamic instability (56%); acute renal failure (13%) and pneumothorax (13%). Superinfection with other microbes were observed in 56% of the patients. Conclusions: In our study, pH1N1 infected critically ill patients had a wide age range, but were more commonly female, pregnant, or had a previously described underlying disease. Mortality, length of treatment, need for invasive mechanical ventilation, length of mechanical ventilation, major complication rates were similar to those previously described. A previously not reported relatively high occurrence of pneumothorax was noted, which is possibly a long-term complication of severe viral pneumonitis.

Prevalence and antimicrobial resistance of uropathogens in different inpatient wards

The predominant causative agent of urinary tract infections in children and adults is Escherichia coli , but it is necessary to appreciate the importance of other Gram-negative rods, especially in newborns. Antibiotic resistance rates are also different in children and in adult care units due to many factors and therapeutical guidelines.The aim of this retrospective study was to show the local prevalence and resistance patterns of uropathogens in certain clinics of university and present the distribution of uropathogens in different age groups. Therefore, 4833 positive samples were analysed. E. coli was found to be the highest prevalent causative agent in every adult care unit, but some differences in other causative agents could have been detected. Three types of antimicrobial agents showed decreasing susceptibility rates: trimethoprim/sulfamethoxasole, cephalosporins and quinolones; but there were differences in resistance among the 8 investigated inpatient wards.

Comparison of Austrian, Hungarian and Macedonian methicillin-resistant and methicillin-sensitive Staphylococcus aureus strains in relation to prevalence of cytotoxin genes

Cytotoxin genes in 128 Austrian (AT) MSSA, 48 MRSA, 94 Hungarian (HU) MSSA, 110 MRSA and 67 Macedonian (MK) MSSA, 81 MRSA strains were examined. The presence of alfa-haemolysin gene (hla) was more common in HU MSSA strains compared to AT and MK (99%, 86%, 72%: p<0.001). AT and MK MRSA harboured hlb genes more frequently compared to HU (60%, 62%, 33%: p<0.001). HU and MK MRSA strains carried gamma-haemolysin gene (hlg) in higher percentage in contrast to AT (88%, 83%, 69%: p=0.01). Haemolysin gamma-variant gene (hlgv) was more prevalent in HU MSSA compared to AT and MK (84%, 56%, 69%: p<0.001). Panton-Valentine leukocidin genes were found only in AT, HU, MK MSSA and MK MRSA in 2.3%, 4%, 1.5% (p=0.53) and 1% (p=0.38), respectively. The 3-gene combination pattern comprising of hla, hlg and hld genes showed increased prevalence among AT MSSA compared to HU (27%, 11%: p<0.001). The 4-gene pattern composed of hla, hlg, hlgv and hld genes was significantly characteristic for HU MRSA in contrast to AT and MK MRSA (56%, 12.5%, 27%: p<0.001). Frequency of certain cytotoxin genes and combinations differed significantly in Staphylococcus aureus strains according to geographical origin and methicillin-resistance.