Novel gyrase mutations and characterization of ciprofloxacin-resistant clinical strains of Enterococcus faecalis isolated in Poland.

The activity of ciprofloxacin, sparfloxacin and moxifloxacin was determined for 205 Enterococcus faecalis isolates from patients of five hospitals (Warsaw, Poland; collected from 2000 to 2002). Ciprofloxacin resistant and intermediate isolates were numerous (53.7%). Among them, highly resistant (MIC > or = 16 mg/l) isolates predominated (98%). Isolates resistant to ciprofloxacin were also resistant to sparfloxacin and moxifloxacin. The parC and gyrA QRDRs (quinolone-resistance-determining region) of 11 isolates with ciprofloxacin MICs from 1 to 256 mg/l were analysed by DNA sequencing. In ParC one kind of amino acid substitution (of Ser-85 to Ile) in 9 E. faecalis strains with MICs from 16 to 256 mg/l was observed. In GyrA Ser-84 was changed to one of four different amino acids: Arg, Ile, Cys or Tyr, however no association between the amino acid type and MIC value was found. The last two substitutions have not been reported to date for E. faecalis. Moreover, our results may suggest that mutations within parC and gyrA are associated with development of a high-level of ciprofloxacin resistance.

Evidence for tetracycline resistance determinant tet(M) allele replacement in a Streptococcus pneumoniae population of limited geographical origin.

A collection of 185 Streptococcus pneumoniae isolates was tested for their susceptibility to antipneumococcal drugs, with a focus on the distribution of tetracycline resistance determinants tet(M) and tet(O). Resistance patterns were compared with established correlates of multidrug resistance, and tetracycline-resistant isolates were tested for clonality and allelic variation within tet(M). Resistance to tetracyclines, penicillins and macrolides were all strongly related to multidrug resistance. Over one-quarter of the strains were tetracycline resistant, all via the tet(M)-mediated mechanism. Restriction fragment length polymorphism analysis revealed a high degree of allelic variation within tet(M) and gave evidence of a clonal and horizontal spread of selected alleles. A tet(M) variant that emerged with the onset of epidemic multidrug-resistant strains was replacing old alleles in the population.

[Enterotoxin genes occurance among S. aureus strains isolated from inpatients and carriers]. / Wystkpowanie enterotoksyn u szczepów Staphylococcus aureus izolowanych od chorych hospitalizowanych i nosicieli.

We examined 44 inpatients and 66 carriers Staphylococcus aureus strains, isolated in years 2002-2005, for the presence of 18 enterotoxin genes (se/sel) (by PCR), the ability for A-D enterotoxin production (by SET-RPLA) and antibiotic resistance distribution (by disc diffusion method). se/sel genes were detected in 90,9% of all strains, sea (70,5%) and selk and selq (52,3%) - among inpatients strains and egc (65,2%) - among carriers strains were the most frequently se/sel genes found. Positive results of SET-RPLA were consistent with PCR results. There was no correlation observed between antibiotic resistance and se/sel genes distribution among tested S. aureus strains.

[Characteristic of clinical fluoroquinolone resistant isolates E. faecalis]. / Charakterystyka opornych na fluorochinolony szczepów Enterococcus faecalis izolowanych z materialu klinicznego.

In presented study we have characterized phenotype of clinical E. faecalis strains, fluoroquinolone susceptibility and the presence of two potential virulence factors--hemolysin/cytolysin and gelatinase. Eighty three of E. faecalis strains were isolated from clinical samples from patients of five Warsaw hospitals. Susceptibility to 18 antibiotics was assessed by the disk diffusion method (ace. NCCLS). The MIC of ciprofloxacin was determineted by agar dilution method and the MIC of sparfloxacin and moxifloxacin by the E-test (AB BIODISK). Hemolysin production was evaluated on Columbia agar medium supplemented with 5% horse blood. Gelatinase production was determinated by using two different methods: I - on the Todd-Hewitt agar containing gelatin (30 g/l) and II--on the trypticase soy agar supplemented with 1,5% skim milk. Fourty nine (59%) of the 83 isolates E. faecalis were ciprofloxacin resistant and 14 (16,9%) were ciprofloxacin intermediate. The majority of E. faecalis strains (57,8%) were higly resistant to ciprofloxacin (MIC > or = 32 microg/ml). All of ciprofloxacin resistant E. faecalis isolates were cross-resistant to the other fluoroquinolones, as well. Production of hemolysin was more frequent among ciprofloxacin resistant E. faecalis strains. The dependence between gelatinase production and fluoroquinolone:resistance was not observed. Both investigated methods of gelatinase activity detection gave the same results and can be used exchangeably. Hemolytic strains were more frequently isolated from urine (47,8%), however gelatinase producing strains were more frequently isolated from wounds (31,6%).

[Susceptibility of the bacteria isolated from samples of clinical material in Poland in 1998 to selected chemotherapeutics and antibiotics--the analysis of the questionnaire findings. I. Susceptibility of staphylococci]. / Wrazliwosc na wybrane antybiotyki bakterii izolowanych z próbek materialu klinicznego w Polsce w 1998 roku-- analiza wyników badan ankietowych Cz. I. Lekowrazliwosc gronkowców.

The work has been undertaken in order to attain detailed information on the antibiotic sensitivity of the identified microorganisms from different clinical material derived from inpatients, outpatients and healthy people, on various regions of Poland in 1998. Approprite questionnaires (cards) were sent to each sanitary-epidemiological stations throughout Poland. Received 28619 cards, from 44 Public Health Service laboratories, allowed to create a computerized data base in Department of Bacteriology in National Institute of Hygiene in Warsaw. Staphylococci were the most frequent etiologic pathogen isolated from the clinical material--24,7%. Among them, there were: S. aureus--75,8%, S. epidermidis--9,7%, unidentified coagulase negative staphylococci (CNS)--9,2% and S. saprophyticus--5,1%. 71,6% of staphylococci strains derived from non-hospital material and 26,7% from hospital material. Staphylococci strains isolated from inpatients specimens were more resistant to antibiotics than those from outpatients specimens. The highest resistance, among both hospital and non-hospital strains, was exhibited to penicillin (70-100%) and tetracycline (approximately 50%); the lowest to: glycopeptides, ciprofloxacin, trimethoprim/sulfametoxazole, nitrofurantoin and gentamicin. Staphylococci isolated from various clinical specimens differed in their antibiotic resistance. The percentages of coagulase-negative staphylococci strains resistant to the antibiotics used were higher than of S. aureus strains. On the average 34% of S. aureus strains were methicillin-resistant (MRSA); but depending on specimens were isolated from, it ranged from 24% of MRSA strains for ear and nose swabs to 70% of MRSA strains for feaces samples. Among MRSA strains the percentage of resistance to other antibiotics was a few time higher than among MSSA strains. The territorial distribution of staphylococci strains resistance to various antibiotics in Poland is not uniform.

[The characteristic of Staphylococcus aureus strains isolated from food's samples]. / Charakterystyka szczepów Staphylococcus aureus izolowanych z próbek zywnosci.

The study was carried out of 22 isolates of S. aureus isolated from 7 different incriminated food's samples from foodborne-disease outbreaks. The possibility of these isolates to producing of enterotoxins by commercial test SET-RPLA (Oxoid) was tested. The genotyping of these isolates was done by pulse-filed gel electrophoresis, acc. to Pfaller in own modification. On the basis of the DNA restriction patterns of the 22 isolates--5 strains were singled out, one of these strains--strain V (isolat nr 7) was not relationship to others. It was found that this strain V was one enterotoxin produced. Additionaly, all tested strains, in spite of the strain nr V, were isolated from the 2 or 3 samples of different kinds of foods. In the present study it has been shown too, that several similar colonies should be isolated for farther studies to assess microbiological contamination of the food products properly.

[Microbiological external quality assurance program (MEQAP)--evaluation of results obtained in sanitary epidemiological laboratories in 2002]. / Program Zewnetrznej Oceny Jakosci Badan Mikrobiologicznych--ocena wyników sprawdzianu przeprowadzonego w 2002 roku w laboratoriach stacji sanitarno-epidemiologicznych.

The aim of this study was to evaluate reliability of identification and determination of sensitivity to antibiotics and chemotherapeutics of some Gram positive cocci strains in 34 sanitary-epidemiological stations. All laboratories engaged in this study received 3 strains: S. aureus (S. aureus SC+ CF+, resistant to methicillin., or S. aureus SC - CF+, sensitive to methicillin), coagulase-negative staphylococci (S. epidermidis or S. haemolyticus or S. saprophyticus) and Enterococcus sp. (E. faecalis HLAR-positive or E. faecalis HLAR-negative or E. faecium or E. gallinarum). All these strains previously were identified in Department of Bacteriology of National Institute of Hygiene. Of the 68 staphylococci strains tested, 66 isolates were correctly identified. Among the 34 enterococcal strains studied the greatest difficulty in identification was caused by E. gallinarum strain--(8 out of 13 strains were incorrectly recognised). The determination of the sensitivity of the control strains to antibiotics and chemotherapeutic agents, generally was performed correctly in accordance with to the NCCLS and national recommendations. Some incorrect results of the antibiograms were caused by an erroneous interpretation of the zones of inhibition.

[Characteristics of bacteria isolated from body surface of German cockroaches caught in hospitals]. / Charakterystyka bakterii wyizolowanych z powierzchni ciala karaczanów prusaków wystepujacych w srodowisku szpitalnym.

The objective of the study was to identify bacterial flora from external parts of German cockroaches caught in hospitals. The susceptibility of the bacteria to the most important groups of antimicrobial agents was also examined. 80 strains of bacteria were isolated, among them 34 strains of Gram-positive cocci and 31 strains of Gram-negative rods. One of isolated strains of Citrobacter freundii and two strains of Serratia liquefaciens showed ESBL mechanism of resistance and extended level of AmpC--type beta-lactamases. Two Staphylococcus strains (S. epidermidis and S. equorum) were resistant to erythromycin and clindamycin (MLSB mechanism of resistance). Such strains, resistant to antibiotics and chemiotherapeutics may be reservoirs of resistance genes which can be transmitted into other bacteria. Presence of such pathogens on the body surface of German cockroaches, very mobile insects, might create conditions for easy dissemination of them in hospital environment.

[Drug sensitivity of Enterococcus sp. strains isolated from clinical material or from healthy persons]. / Lekowrazliwosc szczepów Enterococcus sp. izolowanych z materialu klinicznego oraz od osób zdrowych.

The aim of this study was to evaluate the drug susceptibility of Enterococcus sp. strains isolated in 2000-2001, from patients of five Warsaw's hospitals (154 strains) and from fecal samples of healthy persons (33 strains). On biochemical reaction profiles species of clinical enterococci were identified as: E. faecalis--66.2%, E. faecium--29.2%, E. hirae--1.9%, E. gallinarum--1.3%, E. casseliflavus--0.6% and E. avium--0.6%. The species of enterococci from stool's samples were identified as: E. faecalis--28 strains, E. durans--2 strains and single strains: E. faecium, E. gallinarum and E. casseliflavus. Susceptibility to 20 antibiotics was tested by disc diffusion method. None of these 187 enterococcal strains was vancomycin resistant; 3 strains of E. gallinarum and 1--E. casseliflavus demonstrated intermediately susceptibility to vancomycin, but they were susceptible to teicoplanin--phenotype Van C. Among clinical strains were resistant to penicillin--33.3% of E. faecalis and 100% of E. faecium, to ampicillin--over 80% of E. faecium and 1 strain of E. faecalis. None of these strains produced beta-lactamase. High-level resistance to aminoglicoside was expressed by 48 strains (47.1%) E. faecalis and 36 (80%) E. faecium isolated from clinical specimens. Both--HLR to streptomycin and gentamycin were found in 28.3% of E. faecalis and 68.9% of E. faecium. Among 33 strains isolated from fecal samples of healthy persons--3 of E. faecalis were resistant to streptomycin and one was resistant to both gentamicin and streptomycin. In general, enterococcal strains isolated from samples of healthy persons were susceptible to the most of used antibiotics. But to rifampicin none of these strains were susceptible. There were about 40% of E. faecalis strains isolated from healthy persons, resistant to tetracyline.