Norovirus infections in the Czech Republic in 2008-2020.

INTRODUCTION: Noroviruses, together with rotaviruses, are the most common cause of viral gastroenteritis in the Czech Republic (CR). The aim of this study was to analyse data on the incidence of norovirus gastroenteritis in the CR and thus to add to the body of knowledge about its significance. MATERIAL AND METHODS: A descriptive analysis was performed of the basic characteristics of norovirus gastroenteritis reported under ICD-10 code A08.1 to the Epidat or ISIN electronic infectious diseases information system between 2008 and 2020. On the basis of reports from five microbiological laboratories, weekly data on confirmed cases of norovirus infection from 2010-2020 were analysed. Databases of microbiology laboratories from across the Czech Republic were searched to determine the number of the laboratories where norovirus infections were diagnosed and the methods used for this purpose in 2008-2020. RESULTS: From 2008 to 2020, 33,575 cases of norovirus gastroenteritis were reported to the infectious diseases information systems, which equates to an annual incidence of 24.5/100,000 population, varying between years from 8.2 to 77.1/100,000. Men accounted for 40.2% of cases with an incidence of 20.1/100,000 compared to 28.8/100,000 recorded in women. Of the total of reported cases, 14,282 patients (42.5%) required hospital admission. Over the whole study period, 7,431 cases of norovirus gastroenteritis were recorded in children under 5 years of age. This age category accounted for 13.7-38.9% of the annual totals of reported cases. The incidences were 101.8/100,000 in children under 5 years of age, 40.1/100,000 in 5-14-year-olds, 12.7/100,000 in 15-64-year-olds, and 38.2/100,000 in the age group 65 years and over. Twenty-four deaths (case fatality rate of 0.07%) were reported as associated with norovirus gastroenteritis at the ages 42-94. In the age categories 15-64 years and 65 years and over, the case fatality rates were 0.02% and 0.24%, respectively. Over the study period, 274 epidemics occurred, during which 16,893 (50.3%) of the total of 33,575 cases were reported. In the epidemic outbreaks, 1,694 (10.0%) patients required hospital admission. The largest outbreak with 5,248 reported cases in 2015 was associated with contamination of the Prague water supply system. Norovirus infections were laboratory diagnosed year-round, peaking in the autumn and winter months. They are currently diagnosed by 81 laboratories in the Czech Republic, 90.1% of which use immunochromatographic tests. CONCLUSION: The study confirmed the highest incidence of norovirus gastroenteritis among children under 5 years of age and the highest case fatality rate in the age group 65 years and over. Over half of the reported cases were outbreak associated. Most laboratories use immunochromatographic tests. The use of more sensitive laboratory methods would improve diagnosis.

Nosocomial candidemia in the Czech Republic in 2012-2015: results of a microbiological multicentre study.

  Background: Candidemia is a severe and often life-threatening infection frequently occurring in critically ill patients. During the last decade, new therapeutic and prophylactic strategies influenced (at least in some patient subgroups) the epidemiological situation and the spectrum of causative Candida strains. The present multicentre study aimed to assess the current epidemiological situation of Candida strains causing invasive candidiasis (IC) in patients of tertiary care hospitals in the Czech Republic. MATERIAL AND METHODS: Clinical and microbiological data on patients with bloodstream yeast isolates collected in 11 tertiary care hospitals in the Czech Republic between 2012 and 2015 were analysed. The incidence of cases and species distribution were assessed by study year, age, and specialty. Moreover, an association with the Candida colonization and presence of toxigenic strains of Clostridium difficile in stool prior to blood culture positivity was analysed. For some of the strains, minimum inhibitory concentrations (MICs) of systemic antifungals were determined using standard methods. RESULTS: A total of 886 episodes of candidemia (921 yeast strains) were identified during the study period. The overall incidence per 1000 admissions was 0.40 (range 0.21-1.22 depending on the hospital). Almost half of the isolates belonged to the species Candida albicans (49.7 %), followed by Candida glabrata (15.3 %) and Candida parapsilosis (11.2 %). Non-albicans species of Candida significantly predominated in oncology wards (71.6 %) as compared to surgery (40.4 %) or internal medicine (52.0 %) departments. More than 70.0 % of patients stayed in intensive care units at the time of positive culture; in 65.0 % of patients, colonization with the same yeast species preceded blood culture positivity. In only 5.1 % of all patients, the previous presence of toxigenic strains of Clostridium difficile in stool was found. Fifty-six of the 921 yeast strains were tested for antifungal susceptibility, with an increase in MICs to azoles being observed for C. glabrata. CONCLUSION: The incidence of candidemia in the Czech Republic did not vary significantly between 2012 and 2015, and C. glabrata was the second most common yeast species after C. albicans isolated from blood.

[Antibiotic resistance in nontyphoidal salmonellae serovars in the Czech Republic]. / Antibiotická rezistence u netyfových sérovaru Salmonella spp. v Ceské republice.

STUDY AIM: To determine antibiotic resistance and incidence of multidrug resistance among Nontyphoidal salmonellae serovars isolated from humans. MATERIAL AND METHODS: Consecutive Salmonella isolates from patients, recovered in 48 microbiology laboratories in May 2012, were analyzed in the respective reference laboratories at the National Institute of Public Health. Strains were re-identified and differentiated into serovars. Their minimum inhibitory concentrations (MICs) to 11 antibiotics were determined by the microdilution method. RESULTS: Of 25 serovars identified among 637 strains of Salmonella enterica, the most frequent were Enteritidis (87.0 %), Typhimurium (4.9 %), and monophasic Typhimurium 4,[5],12:i:- (2.0 %) and Mbandaka (0.6 %); other serovars were rare. Altogether 558 strains (87.6 %) were susceptible to all antibiotics tested and the remaining 79 strains were resistant to one or more antibiotics. The prevalence rates of resistance to individual antibiotics among 637 study strains were as follows: ampicillin 8.5%, tetracycline 5.7%, sulfamethoxazole 5.2%, cipro-floxacin 3.8%, and chloramphenicol 2.5%. Resistance to gentamicin, trimethoprim, and third and fourth generation cephalosporins was rare ( 0.5%) and none of the study strains showed resistance to meropenem. Three producers of extended spectrum beta-lactamase were multidrug resistant and two of them recovered from twins exhibited a different pattern of resistance. Resistant strains were most often assigned to the following serovars: Enteritidis (49.4%), Typhimurium (26.6%), and monophasic Typhimurium (15.2%). While only 7% (39 of 554 strains) of Enteritidis strains were resistant, the serovars Typhimurium and its monophasic variant 4,[5],12:i:- showed high rates of resistance, i.e. 66.7 and 92.3%, respectively. Furthermore, resistance was revealed in all strains of the serovars Virchow (n = 3), Kentucky (n = 1), and Newport (n = 1), in two of three strains of the serovar Infantis, and in one of two strains of the serovar Stanley. All five blood isolates were assigned to the serovar Enteritidis and one of them showed resistance to ciprofloxacin. Of 79 resistant strains, 26.6% showed resistance to ampicillin only and 24.1% to ciprofloxacin only, with multidrug resistance, i.e. resistance to three or more antibiotics, confirmed in 43.0% of strains. CONCLUSION: Despite a relatively low prevalence of resistance to the antibiotics tested among 637 study strains, the following alarming findings were made: Detection of Salmonella enterica strains resistant to ciprofloxacin as the drug of choice or to higher generation cephalosporins and multidrug resistance revealed in two thirds of the strains of the serovar Typhimurium and in all but one strains of its monophasic variant 4,[5],12:i:-.

Prevalence of extended-spectrum beta-lactamase-positive Klebsiella pneumoniae isolates in the Czech Republic.

This study focused on the prevalence and molecular biology of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae isolates collected in the Czech Republic. Clinical material from patients hospitalised in 16 Czech hospitals in September 2004 was used to isolate K. pneumoniae strains. Strains were identified by standard identification procedures. Susceptibility of the strains to antibiotics was tested using a microdilution method. The double-disk synergy test and combination disk method were used to determine ESBL production. Molecular biology characteristics of ESBL-positive isolates were determined using genomic DNA isolation, XbaI restriction digestion and pulsed-field gel electrophoresis differentiation. The acquired restriction maps of individual isolates were compared using GelCompar II software and their relationships were determined. During the 3-week period, 483 K. pneumoniae strains causing clinically detectable diseases were isolated. Of these, 117 (24.2%) were determined to be ESBL-positive. The prevalence of ESBL-positive isolates was 38.9% in Intensive Care Units (ICUs) and 13.1% in standard wards. More than 50% of ESBL-positive isolates were treated effectively only with meropenem (98%), cefoperazone/sulbactam (61%) and amikacin (54%). Conversely, ESBL-negative isolates showed high susceptibility to all tested antibiotics (76-99%). Molecular biology analysis identified 18 clonal types containing two to six identical isolates. Seventeen clones usually contained isolates from only one hospital; isolates from two hospitals were identified only in one clone. Based on the abovementioned results, the prevalence of ESBL-positive K. pneumoniae isolates in the Czech Republic can be perceived as relatively high, especially in ICUs. Extensive spread of 'epidemic clones' within Czech hospitals and, to a limited extent, between them can be demonstrated.

Two high-frequency-transduction phage isolates from lysogenic strains of Pseudomonas aeruginosa transducing antibiotic resistance.

Two high frequency transduction (HFT) phage isolates, obtained from seriously ill patients, transducing individual determinants of antibiotic resistance with a frequency of 10(-5) (phage isolate AP-103) and 10(-6) (phage isolate AP-343), are described. The frequency of transduction depended on the transduced determinant(s) of resistance used for the detection of transductants and on the individual recipient antibiotic-susceptible strain of Pseudomonas aeruginosa (PAO and/or ML series). A multiple-antibiotic resistance was transduced by the phage isolate AP-343 to all tested recipient strains. The appearance of such phages in clinical conditions with an unusually high frequency of transduction might contribute to the dissemination of antibiotic resistance genes among nosocomial strains of P. aeruginosa. The existence of HFT phages might reflect an increased efficiency of transduction of antibiotic resistance among P. aeruginosa strains, and thus an increased risk of spread of antibiotic resistance even to recently introduced anti-pseudomonadal antibiotics among pseudomonads with unfavourable and unwanted epidemiological consequences in hospital conditions.

Further studies of transferable antibiotic resistance in strains of Pseudomonas aeruginosa from four clinical settings in three countries.

This paper describes transferability of antibiotic resistance determinants in clinical isolates of Pseudomonas aeruginosa resistant to imipenem, cefotaxime and ceftazidime obtained from different clinical settings in three different countries. Two strains of Enterobacteriaceae (Escherichia coli K-12 and Proteus mirabilis P-38) and two strains of P. aeruginosa (PAO and ML) were used as recipient strains. The conjugative transfer of resistance was very specific, i.e. donor strains of P. aeruginosa transferred individual resistance determinants either to recipient strains E. coli K-12 and P. mirabilis P-38, or to P. aeruginosa PAO or ML. In a case when three different species (P. aeruginosa, Acinetobacter calcoaceticus, Stenotrophomonas maltophilia) were isolated from a single patient, a block of resistance determinants was transferred both to Enterobacteriaceae and P. aeruginosa recipients. A single plasmid with rather specific properties was suspected of being exchanged among strains of these different species. It was recommended to study the overall situation of transferability of individual resistance determinants in bacterial strains belonging to various species of nosocomial bacteria, especially of P. aeruginosa, by using a rather specific methodology.

[Mobilization of genetic determinants of antibiotic resistance in strains of Pseudomonas aeruginosa]. / Mobilizácia genetických determinantov rezistencie na antibiotiká u kmenov Pseudomonas aeruginosa.

The authors describe a phenomenon of mobilisation of antibiotic resistance from non-transferring strains of P. aeruginosa by cultivation with strains of P. aeruginosa capable to transfer determinants of antibiotic resistance to a susceptible recipient strain, by triparental cross. In this report three strains of P. aeruginosa (No. 282, 283 from Bata's Hospital in Zlín and 76 from Frankfurt University Clinics) are described capable to mobilise for transfer the resistance determinants in four strains of P. aeruginosa (No. 76, 229, 47 and 125 from Frankfurt University Clinics) with multiple antibiotic resistance which itself was not transferable to recipient strains. By an indirect selection method it was assessed, that all six antibiotics (cephalotin-cefazoline, carbenicillin, kanamycin, cefotaxime, ceftazidime and aztreonam), present in resistance spectrum of intermediary recipient strains, were mobilised for transfer. Imipenem and ofloxacin were not mobilised for transfer. In the second and third cycles of transfer the authors confirmed the stability and transferability of the block of six antibiotic resistance determinants, which were not previously transferable.

[Helicobacter pylori in patients with diabetes mellitus]. / Helicobacter pylori u nemocných s diabetes mellitus.

The authors assessed the frequency of Helicobacter pylori in diabetic patients with gastroduodenal ulceration and non-ulcerative dyspepsia. They evaluated a group of 91 hospitalized type II diabetics which non-ulcerative dyspepsia, endoscopically confirmed ulceration of the duodenal bulbus and gastric ulceration. The control group was formed by 98 hospitalized non-diabetic subjects. Between the two groups there was no difference in the frequency of Helicobacter pylori in non-ulcerative dyspepsia (61.1% as compared with 56.0% in non-diabetics) and gastric ulceration (75.0% as compared with 77.7% in non-diabetics). There is a significantly (p > 0.005) lower incidence of HP infection in diabetics with active duodenal ulceration (46.6%), as compared with non-diabetics (87.5%). The authors assume that active duodenal ulceration in diabetics could be more frequently caused by other factors than Helicobacter pylori.