Trends in the Minimum Inhibitory Concentrations of Erythromycin, Clarithromycin, Azithromycin, Ciprofloxacin, and Trimethoprim/Sulfamethoxazole for Strains of Bordetella pertussis isolated in the Czech Republic in 1967-2015.

OBJECTIVE: The aim of the study was to determine trends in the minimum inhibitory concentrations (MICs) of erythromycin used as first-line therapy and alternative antibiotics against Bordetella pertussis (B. pertussis) strains isolated from patients with whooping cough in the Czech Republic (CR) in three periods from 1967 to 2015. METHODS: In total, 135 isolates from the years 1967­2015 were analysed. The strains were divided into three groups by the year of isolation: 1967­1999 (42 strains), 2004­2010 (43 strains), and 2011­2015 (50 strains). MIC of selected antibiotics (erythromycin, clarithromycin, azithromycin, ciprofloxacin, and trimethoprim/sulfamethoxazole) were obtained by the reference agar dilution method on Bordet Gengou Agar with 15% defibrinated sheep blood. RESULTS: The study set included 70 strains previously tested for MICs of erythromycin and four other antibiotics. In the three study periods, the MICs of the tested antibiotics for B. pertussis were nearly identical. All but a single strain, inhibited by erythromycin at a concentration of 0.03 mg/l, were inhibited by two concentrations of erythromycin and azithromycin (0.06 and 0.125 mg/l). Clarithromycin inhibited the strains from all three study periods at the following concentrations: 0.03, 0.06, and 0.125 mg/l. Any of the 135 strains was inhibited by ciprofloxacin at a single concentration of 0.06 mg/l and by trimethoprim/sulfamethoxazole at three concentrations (0.125, 0.25, and 0.5 mg/l). CONCLUSION: The study set of 135 Czech strains of B. pertussis isolated in 1967­2015 appears to be homogeneous in terms of the MICs for five antimicrobials. The MICs remained in a narrow range of two to three low concentrations; the unimodal distribution of the MICs suggests the absence of resistance mechanisms. The highest MICs of erythromycin, clarithromycin, and azithromycin were equally 0.125 mg/l, that of ciprofloxacin was 0.06 mg/l, and that of trimethoprim/sulfamethoxazole was 0.5 mg/l. Over the study period of 55 years, the MICs of the study antibiotics remained in the same ranges.

High prevalence of ST131 among CTX-M-producing Escherichia coli from community-acquired infections, in the Czech Republic.

A total of 2,683 nonrepetitive Escherichia coli isolates were collected from microbiological laboratories covering all regions of the Czech Republic, during April 2011. Antimicrobial susceptibility patterns of E. coli were assessed. All 38 cefotaxime-resistant (CTX-R) isolates were found to be extended-spectrum ß-lactamase (ESBL)-positive by the double-disc synergy test. Thirty-two of those isolates produced enzymes of CTX-M-1 family, five of CTX-M-9 family, and one isolate both CTX-M types. Genotyping by multilocus sequence typing classified all ESBL-producing isolates into 13 sequence types (STs). ST131 was the most prevalent and was exclusively correlated with E. coli belonging to the more-virulent phylogroup B2. blaCTX-M-15 and blaCTX-M-9-like genes were mainly carried by plasmids belonging to the IncF group, while replicon I1 was predominant among CTX-M-1-encoding plasmids. Additionally, 63% of the ESBL-producing isolates were also resistant to ciprofloxacin. Sequence analysis of quinolone resistance-determining regions of gyrA and parC revealed the presence of amino acid substitutions in 22 out of 23 ciprofloxacin-resistant isolates. The acc(6')-Ib-cr and qnrB1 plasmid-mediated quinolone resistance genes were also detected in some of the isolates. This is the first report on the emergence and spread of CTX-M-producing E. coli in the community of the Czech Republic, indicating the high prevalence of ST131 clone among CTX-M producers.

Enteric fever imported to the Czech Republic: epidemiology, clinical characteristics and antimicrobial susceptibility.

The aim of this study was to describe epidemiological and clinical characteristics of imported enteric fever in Czech travellers and to determine the antimicrobial susceptibility of isolated strains. Retrospective descriptive study included adult patients treated with enteric fever at Hospital Na Bulovce during January 2004-December 2012. A case of typhoid or paratyphoid fever was defined as isolation of Salmonella Typhi or Paratyphi from blood or stool. During the study period, there have been diagnosed 19 cases of enteric fever (12 males and 7 females) with age median of 30 years; 14 cases were caused by Salmonella Typhi and 5 cases by S. Paratyphi A. The infection has been acquired in South Asia (16 patients; 84.2 %), in Africa (Egypt, Angola) in two cases (10.5 %), and in Mexico (1; 5.3 %). Symptoms included fever (all patients), diarrhoea (16 cases; 84.2 %), headache (9; 47.4 %), and abdominal pain (7; 36.8 %). Seventeen patients (89.5 %) were treated with fluoroquinolones; however, the treatment failure was observed in seven of them (41.2 %). Decreased ciprofloxacin susceptibility was detected in eight strains (66.7 %), and one strain (8.3 %) was multidrug resistant. Sequence analysis of quinolone resistance-determining regions (QRDR) of the gyrA gene revealed the presence of amino acid substitutions in all tested isolates with decreased ciprofloxacin susceptibility. Typhoid and paratyphoid fevers represent epidemiologically important diseases that may lead to potentially life-threatening complications. Major issue in the management of enteric fever represents the non-susceptibility of Salmonella strains to fluoroquinolones and other antimicrobials.

[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:-.

KPC-2-producing Klebsiella pneumoniae isolated from a Czech patient previously hospitalized in Greece and in vivo selection of colistin resistance.

Carbapenemase-producing Gram-negative bacteria peak clinical interest due to their ability to hydrolyze most ß-lactams, including carbapenems; moreover, their genes spread through bacterial populations by horizontal transfer. Bacteria with acquired carbapenemase have sporadically been reported in the Czech Republic, so far only in Enterobacteriaceae and Pseudomonas aeruginosa. In this study, we described the first finding of a KPC-2-producing strain of Klebsiella pneumoniae, which was isolated from a surgical wound swab, decubitus ulcer, and urine of a patient previously hospitalized in Greece. The patient underwent various antibiotic therapies including a colistin treatment. However, after approximately 20 days of the colistin therapy, the strain developed a high-level resistance to this drug. All the isolates were indistinguishable by pulsed field gel electrophoretic analysis and belonged to the international clone ST258, which is typical of KPC-producing K. pneumoniae isolates. The bla (KPC-2) gene was located on a Tn4401a transposon variant. The OmpK35 and OmpK36 genes analysis performed due to the high resistance level of the strains to ß-lactams exhibited no changes in their sequence or in their expression when compared with carbapenem-susceptible isolates.

DHA-1-producing Klebsiella pneumoniae in a teaching hospital in the Czech Republic.

Thirty-eight AmpC-producing Klebsiella pneumoniae isolates identified from January to October 2006 in a large teaching hospital in the Czech Republic were analyzed. The AmpC cephalosporinase was identified as DHA-1, encoded by a plasmid-located complex class 1 integron, previously observed in a K. pneumoniae isolate from the Parisian region. The DHA-1 expression was inducible, and although in two isolates with higher resistance, the induction effect was masked at the phenotypic level. All of the isolates belonged to the international K. pneumoniae clone sequence type 11, split into two disseminated pulsed-field gel electrophoresis types. This is the first report on enterobacteriaceae with acquired AmpCs in the Czech Republic and possibly the first description of organisms with DHA-1 in the Central and Eastern Europe.

Carbapenem-nonsusceptible strains of Klebsiella pneumoniae producing SHV-5 and/or DHA-1 beta-lactamases in a Czech hospital.

Resistance to carbapenems in enterobacteria is mediated by the production of several types of carbapenemases or by the decreased permeability of the outer membrane, combined with the expression of extended-spectrum beta-lactamases (ESBLs) or AmpC-like cephalosporinases. The objective of this study was to characterize carbapenem-nonsusceptible (C-NS) isolates of Klebsiella pneumoniae in the University Hospital in Plzen (Czech Republic) and compare them with carbapenem-susceptible (C-S) K. pneumoniae isolates from the same patients. Six C-NS K pneumoniae isolates from different patients were collected between January 2007 and June 2008, and from three of these patients, C-S isolates were available for the study as well. The isolates were typed by pulsed-field gel electrophoresis and multilocus sequence typing. beta-Lactamases were analyzed by isoelectric focusing, bioassay, and PCR and sequencing of bla genes. Major porin channels, OmpK35 and OmpK36, were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot; porin genes were amplified and sequenced, and their expression was assessed by reverse transcriptase-PCR. The C-NS isolates belonged to three pulsotypes and to the clone ST11, produced the SHV-5 ESBL and/or DHA-1 AmpC-type cephalosporinase, did not express OmpK36, and had a reduced expression of OmpK35. The C-S isolates differed from their C-NS counterparts only by porin expression profiles.

Serotype-specific invasive disease potential of Streptococcus pneumoniae in Czech children.

To estimate the invasive disease potential of Streptococcus pneumoniae serotypes, invasive isolates (n=138) were compared with nasopharyngeal isolates (n=153) from children under 6 years of age in the Czech Republic. Odds ratios (ORs) based on a comparison of the distribution of S. pneumoniae serotypes amongst invasive and carriage isolates were calculated for individual serotypes and 172 strains were characterized using multilocus sequence typing. The ORs of serotypes 9V and 14 were significantly greater than 1, suggesting an association with invasive disease, while serotypes 6A and 23F were significantly associated with carriage (ORs less than 1). A single predominant clone with high invasive disease potential was found in each of the 9V, 7F, 14 and 1 serotypes while carriage-associated serotypes were highly heterogeneous.

Clonal distribution of invasive pneumococci, Czech Republic, 1996-2003.

We conducted surveillance on invasive pneumococci isolated from adults in the Czech Republic during 1996-2003. The 7 most prevalent serotypes were characterized. Coverage with the 7-valent pneumococcal conjugate vaccine was low. Our observations confirm that detection methods may have modified the expected effect of this vaccine.

International clones of Klebsiella pneumoniae and Escherichia coli with extended-spectrum beta-lactamases in a Czech hospital.

A 2-month survey of extended-spectrum beta-lactamase (ESBL) producers was performed in a Czech hospital. Klebsiella pneumoniae produced SHV-2, -5, or -12, Escherichia coli produced CTX-M-9 or -15, and other species produced TEM-92 or -132. All K. pneumoniae and E. coli isolates belonged to sequence types (STs) or clonal complexes (CCs) spread across the world (K. pneumoniae clonal complex 11 [CC11], CC14, and sequence type 101 [ST101] and E. coli CC31, CC73, CC131, and CC405) and carried various plasmids (mainly with A/C- and FII-type replicons).

Hospital antibiotic management in the Czech Republic--results of the ABS maturity survey of the ABS International group.

BACKGROUND: Hospital antibiotic stewardship (ABS) programs are essential for ensuring long-lasting quality of antibiotic usage and for controlling antimicrobial resistance in the hospital setting. METHODS: A questionnaire for self-assessment of a hospital's ABS maturity was sent to 80 Czech hospitals in May 2007. The survey was focused on diagnostic issues, control of antibiotic consumption, antibiotic-related organization and tools, antibiotic-related personnel development and antibiotic-related relationships to relevant environments. RESULTS: Of 80 addressed hospitals, 45 sent back processed questionnaires (response rate 56.3%). These 80 hospitals cover about 85% of the Czech population. All Czech university hospitals were included in the replying group. The listed diagnostic tools were declared available by all hospitals; 44 of 45 hospitals have surveillance systems for antibiotic resistance rates. Control of antibiotic consumption was available only partially in 42 of 45 hospitals. Some antibiotic tools need to be improved and must be used more frequently. Official recognition, job descriptions and better funding of antibiotic personnel are needed, as well as support for further development of ABS structures and functions. DISCUSSION: The basic structure of ABS is well developed in the Czech hospitals. A network of antibiotic centers focusing their services on optimization of antibiotic usage has been in place in the Czech Republic since the 1970s. Nevertheless, the survey revealed a clear need and many opportunities for further improvement. Control of antibiotic consumption is not implemented in all Czech hospitals and some of the essential antibiotic tools should be used more widely.

High genotypic diversity of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis in the Czech Republic.

Over the last decade, epidemic and frequently multidrug-resistant Pseudomonas aeruginosa has increasingly been found among European cystic fibrosis (CF) patients. In the Czech Republic, more than half of the registered CF patients attend the Prague CF centre. At this centre, a Burkholderia cenocepacia strain was recently found to have spread among the patients. The aim of the present study was to assess whether P. aeruginosa isolates from patients at this centre were also genetically related and, if so, whether they were multidrug-resistant. We investigated a collection of 69 isolates from as many patients who represented 80% of the total number of P. aeruginosa-positive patients in 2004. The organisms were typed by AFLP and SpeI macrorestriction analyses (PFGE). Using these methods, 44 unique strains and nine groups of two to five isolates each were distinguished. Among these groups, two each had a prevalence of 7% in the patient population, while others had a prevalence of < or =3%. The diversity observed with PFGE was largely in agreement with the diversity found by AFLP analysis. All isolates were susceptible to colistin; 94-96% were susceptible to piperacillin, ceftazidime, cefepime, meropenem, amikacin or tobramycin; and 84-87% were susceptible to ciprofloxacin, gentamicin or netilmicin. In conclusion, the organisms recovered from Czech CF patients showed high genotypic diversity and good susceptibility to antipseudomonal agents. The absence of highly epidemic P. aeruginosa strains may result from infection control measures taken upon recognition of the epidemic B. cenocepacia.

Epidemiological relationships among penicillin non-susceptible Streptococcus pneumoniae strains recovered in the Czech Republic.

Since 1986, penicillin non-susceptible pneumococci (PNSP) have been found in the Czech Republic. As documented by a nationwide study, the proportion of invasive strains with reduced susceptibility to penicillin has fluctuated around 5 % in the past decade. Although the level of resistance to penicillin remains stable, the contribution of different capsular serotypes among the PNSP population varies. Whereas serotype 19A was predominantly associated with penicillin resistance until 1997, serotype 9V became most common among PNSP strains in 1998. In a collection of PNSP strains (n=225) isolated from 2000 to 2002, the most frequent serotype was 9V (n=91, 40.4 %), followed by 19F (n=30, 13.3 %) and 14 (n=25, 11.5 %). PFGE and multilocus sequence typing were used to characterize a set of PNSP of the currently predominant serotypes 9V (n=42), 14 (n=15) and 19F (n=14). The Spain(9V)-3 clone [sequence type (ST) 156] was responsible for a large proportion (100 % of serotype 9V strains, n=42; 93.3 % of serotype 14 strains, n=14) of the analysed strains. A representative of the Taiwan(19F)-14 clone (ST 236) was also recovered in the Czech Republic (a single isolate of serotype 19F). These findings confirm the spread of the major penicillin-resistant clones in the Czech Republic.

Susceptibilities to telithromycin and six other agents and prevalence of macrolide resistance due to L4 ribosomal protein mutation among 992 Pneumococci from 10 central and Eastern European countries.

The macrolide and levofloxacin susceptibilities of 992 isolates of Streptococcus pneumoniae from clinical specimens collected in 1999 and 2000 were determined in 10 centers in Central and Eastern European countries. The prevalences of penicillin G-intermediate (MICs, 0.125 to 1 microg/ml) and penicillin-resistant (MICs, < or =2 microg/ml) Streptococcus pneumoniae isolates were 14.3 and 16.6%, respectively. The MICs at which 50% of isolates are inhibited (MIC(50)s) and the MIC(90)s of telithromycin were 0.016 and 0.06 microg/ml, respectively; those of erythromycin were 0.06 and >64 microg/ml, respectively; those of azithromycin were 0.125 and >64 microg/ml, respectively; those of clarithromycin were 0.03 and >64 microg/ml, respectively; and those of clindamycin were 0.06 and >64 microg/ml, respectively. Erythromycin resistance was found in 180 S. pneumoniae isolates (18.1%); the highest prevalence of erythromycin-resistant S. pneumoniae was observed in Hungary (35.5%). Among erythromycin-resistant S. pneumoniae isolates, strains harboring erm(B) genes (125 strains [69.4%]) were found to be predominant over strains with mef(E) genes (25 strains [13.4%]), L4 protein mutations (28 strains [15.6%]), and erm(A) genes (2 strains [1.1%]). Similar pulsed-field gel electrophoresis patterns suggested that some strains containing L4 mutations from the Slovak Republic, Bulgaria, and Latvia were clonally related. Of nine strains highly resistant to levofloxacin (MICs, >8 microg/ml) six were isolated from Zagreb, Croatia. Telithromycin at < or =0.5 microg/ml was active against 99.8% of S. pneumoniae isolates tested and may be useful for the treatment of respiratory tract infections caused by macrolide-resistant S. pneumoniae isolates.

Susceptibility to telithromycin in 1,011 Streptococcus pyogenes isolates from 10 central and Eastern European countries.

Among 1,011 recently isolated Streptococcus pyogenes isolates from 10 Central and Eastern European centers, the MICs at which 50% of isolates are inhibited (MIC(50)s) and the MIC(90)s were as follows: for telithromycin, 0.03 and 0.06 microg/ml, respectively; for erythromycin, azithromycin, and clarithromycin, 0.06 to 0.125 and 1 to 8 microg/ml, respectively; and for clindamycin, 0.125 and 0.125 microg/ml, respectively. Erythromycin resistance occurred in 12.3% of strains. Erm(A) [subclass erm(TR)] was most commonly encountered (60.5%), followed by mef(A) (23.4%) and erm(B) (14.5%). At <0.5 microg/ml, telithromycin was active against 98.5% of the strains tested.