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P Petrás

Publications and source records attributed to P Petrás.

At least 19 recordsLinked to original sources
PubMed2000

[Characteristics of coagulase-negative staphylococci isolated from hemocultures].

The authors investigated 352 strains of coagulase-negative staphylococci isolated from hemo-cultures of patients with assumed bacteraemia who were hospitalized in standard hospital departments and intensive care units. The strains were identified using STAPHYtest 16 and 14 different species and subspecies of coagulase-negative staphylococci were found. Most frequent were strains of Staphylococcus epidermidis (53%), strains of S. hominis subsp. hominis (22%) and S. haemolyticus (13%). In the strains the production of slime and delta-haemolysin was investigated. The formation of these two important factors of virulence was recorded in 95% strains (incl. major slime production in 13.4%), and 50% strains resp. The resistance to 13 antibiotics was also assessed. A total of 91% strains were resistant to penicillin, 63% to oxacillin and amoxicillin with clavulanic acid, 67% to gentamicin and 66% to erythromycin. In the group 15 strains of a recently described subspecies S. hominis subsp. novobiosepticus was identified. These isolates displayed most frequently resistance: they were resistant in 100% to five antibiotics (penicillin, oxacillin, erythromycin, clindamycin and amoxicillin with clavulanic acid) and with a single exception to another three antibiotics (chloramphenicol, gentamicin and ciprofloxacin). In these strains most frequently slime as well as delta-haemolysin was found. The authors assume, consistent with previous work, that it is important to focus attention on the incidence of strains of S. hominis subsp. novobiosepticus which very probably play an important role as agents in hospital infections. The authors describe also detection of one strain of S. cohnii subsp. urealyticum which was resistant to 10 of 13 antibiotics. The authors are convinced that also classical phenotypic analysis can contribute in an effective manner to the solution of the problem of infections caused by coagulase-negative staphylococci.

Bacteremia↗
PubMed1995

[ORIDES--orientational identification of coagulase-negative staphylococci from human clinical material].

In the National reference laboratory for staphylococci in the National Institute of Public Health in Prague a new dichotomic schema ORIDES was elaborated for the preliminary identification of 17 species of coagulase-negative staphylococci which can be isolated from human clinical material. Tests of 986 strains revealed that ORIDES can serve rapid and cheap assessment of these bacteria, the importance of which is increasing.

Coagulase↗
PubMed1992

Epidemiological role of arthropods detectable in health facilities.

A total of 161 arthropod specimens were collected from 55 sites in a health care facility during July and September 1990. Of the 116 bacterial isolates obtained from their body surfaces 6% were from parasites (mosquitoes), 59% from eusynanthropic arthropods (Tenebrionid beetles, flies, German cockroaches, wasps), 16% from hemisynanthropic arthropods (ants, spiders) and 19% from occasionally encountered insects (non-biting midges, moths, beetles). Most (88%) of the isolated bacteria were Gram-negative rods of the species E. coli, Enterobacter, Klebsiella, Citrobacter, Proteus, Serratia, Pseudomonas and Acinetobacter. Gram-positive cocci accounted for 13% of isolates and were primarily represented by coagulase-negative staphylococci. The highest isolation rates were from body surfaces of flies, German cockroaches, non-biting midges (Chironomids) and Tenebrionid beetles. About one third of all isolates were resistant to more than three antimicrobials using a standard disc diffusion assay. The presence of multiple resistance to antibiotics was observed in two thirds of Enterobacter isolates, namely those of Enterobacter cloacae from the body surface of Germany cockroaches, in 13% of Citrobacter spp and in 8% of Klebsiella spp as well as Acinetobacter calcoaceticus strains. Strains of Morganella and Hafnia species were very infrequent but all of them shared resistance to the antibiotics tested. In contrast, strains of Serratia spp were relatively antibiotic-sensitive. The group of isolated Gram-positive organisms was represented by two strains of Staphylococcus hominis and one strain of Enterococcus sp, all of them were multiply-resistant to antimicrobials.

Animals↗
PubMed1992

[Use of markers of hospital strains in studying the occurrence of nosocomial infections].

The submitted paper deals with one of the possible aspects of the investigation of nosocomial infections, i.e. investigations of the properties of hospital strains, their importance and possible use. The incidence of bacterial hospital strains was investigated in a surgical department of a district hospital of the North Bohemian region in October 1990; at the time of the survey 29 nosocomial infections (36.1%) were revealed by the prevalence method. Bacterial hospital strains were isolated from patients with a nosocomial infection, from the attending staff and the hospital environment. The following markers were investigated: biotyping, phagotyping, serotyping, toxin production, sensitivity to antimicrobial substances and sensitivity to disinfectants. Based on results of marking of hospital strains 7 incidences with a possible epidemiological association were detected where the hospital strain of equal or very similar properties dominated. The results of the investigation confirmed the important participation of the attending staff in the spread of nosocomial infections, in particular via contaminated hands, and drew attention to shortcomings as regards adherence to the hygienic and epidemiological regime in the investigated department.

Bacteria↗
PubMed1992

[Bacterial contamination of arthropods in a health facility].

At 55 sites of a health institution in July and September 1990 a total of 161 specimens of arthropods were detected, 30 outdoors and 131 on the premises of the health institution. On their bodies 116 bacterial strains were isolated, mostly Gram-negative rods (more than 85%), in particular spp. Enterobacter, Acinetobacter, Klebsiella, Citrobacter and Pseudomonas. Gram-positive cocci accounted for cca 12%, in particular strains of S. haemolyticus and S. hominis. The greatest number of strains was detected on bodies of cockroaches, flies, Chironomus and Tenebrio. In about one third of strains the diffuse disk test revealed resistance to more than three antibiotics. The investigation was supplemented by microbiological examination of strains from a hospital environment (45 smears) and strains from biological material (82 specimens), from patients with nosocomial infections.

Animals↗
PubMed1992

Arthropods in a hospital and their potential significance in the epidemiology of hospital infections.

Synanthropic and other arthropods were collected and examined for microbes in the summer seasons of 1988 and 1990. The collection was performed in a Prague hospital with departments situated in separate buildings, each surrounded by a park. In 1988, the most attention was given to flies (35 species collected) found outside between the buildings. In 1990, all arthropods found inside the buildings (particularly in the departments of dermatology and urology) were studied. A total of 30 taxons were identified. The microbes found on the bodies of arthropods were isolated in both seasons. In 1990, the hospital environment and biological material from patients (urine, pus) were also examined for the presence of microbes. Altogether 108 strains (21 species) and 116 strains (25 species) were isolated from the arthropods' bodies in 1988 and 1990, respectively. The ecological characterization of the arthropods and results of microbiological studies show that synanthropic arthropods play a significant role in the epidemiology of hospital infections.

Animals↗
PubMed1991

[Epidemic occurrence of alimentary bacterial infections in the Czech Republic 1979-1989].

The authors analyze the epidemic incidence of alimentary infections of bacterial origin in two periods: 1979-1983 and 1984-1988 and 1989 resp., where in each period the number of notified epidemics of different infections equals 100%. During the period 1984-1988 as compared with 1979-1983, there was a decline in the number of epidemics of salmonelloses in health institutions from 42% to 14%, whereby almost half these epidemics were caused by Salmonella agona spread via dried milk. Conversely there was an increase in the number of epidemics of salmonelloses in communities from 14% to 23% and in works canteens from 9% to 14%. In 68% of the latter Salmonella enteritidis dominated. In 1989 there was a potent increase epidemics of salmonelloses. In 86% of the notified epidemics Salmonella enteritidis was the aetiological agent. A quarter of these epidemics developed in works canteens and half the affected subjects were ill. The transmission occurred via poultry meat and egg products. The annual incidence of bacillary dysentery after 1985 has a declining trend, the epidemics persist in nursery schools, summer camps for children and are increasing in institutes for social care. The number of alimentary intoxications is rising in recent years, in particular in school and works canteens. The number of 008 epidemics in 1984-1988 declined in health institutions from 52% to 20%. 17% of the epidemics developed in schools and camps for children.

Czechoslovakia↗
PubMed1988

Staphylococcus aureus at a maternity ward. I. Colonization of mothers and neonates and survival of various S. aureus types in colonized individuals.

Colonization by Staphylococcus aureus, characterized by phage type or production of enterotoxins and toxic-shock-syndrome-toxin, was followed in 50 mothers and their babies. Types or groups of staphylococci predominating during the particular period at the maternity department were evaluated according to survival rates in the colonized subjects. S. aureus frequently colonized nipples at the start of lactation and was found regularly on umbilical stump and in eye and mouth corners of the babies. During the second stage of the study phage untypable staphylococci producing enterotoxin C (NT/C) strongly predominated. These microorganisms colonized in the greatest extent both mothers and neonates. The majority of NT/C complex originated probably from one or two clones characterized, among others, by high biological activity.

Bacterial Toxins↗
PubMed1988

A new member of the family Enterobacteriaceae--Pragia fontium.

Twenty isolates of the new genus and species Pragia fontium producing H2S were biochemically characterized: they gave positive gluconate oxidation, utilized Simmons citrate and 14 of them hydrolysed esculin. One of them did not produce hydrogen sulfide. Their biochemical activity was low: they did not ferment lactose, adonitol, arabinose, cellobiose, dextrin, dulcitol, erythritol, inulin, maltose, mannitol, mannose, melezitose, melibiose, raffinose, rhamnose, sorbitol, sorbose, starch, sucrose or trehalose. The habitat of Pragia fontium is drinking water, with an exception: the last strain was found in a stool specimen of a healthy woman. The type culture is the first isolate No. 20125-HG 16. It is deposited in Prague (CNCTC) under the designation Eb 11/82.

Cytosine↗
PubMed1988

Staphylococcus aureus at a maternity ward. II. Characterization of isolates by enterotoxigenicity and toxic shock syndrome toxin (TSST-1) production.

Tests for enterotoxins A, B, C, D, E and TSST-1 production were carried out on 775 S. aureus strains isolated from various sources (50 mothers and neonates studied periodically, mothers and infants treated for various acute inflammatory conditions, members of hospital staff, environmental swabs) during the period 1981-1983 at a maternity ward chosen for a 3-year systematic study and on additional 97 isolates obtained in 1985 from another maternity ward. This had contributed to a better classification of strains within certain phage type groups. It was found that the distribution of S. aureus types in the particular sub-sets varied, depending on the source of isolates. At the maternity ward followed for 3 years there was a clear-cut trend towards the spread of phage-untypable isolates producing enterotoxin C whereas at ward examined for comparative purposes B enterotoxin producers of phage type 95 were predominant. The tests for enterotoxigenicity has also proved to be useful as the epidemiological marker characterizing the predominantly circulating S. aureus strain. It has been confirmed that the majority role in the spread of maternity-ward-staphylococci is played by the neonates and the factors of hospital environment.

Bacterial Toxins↗
PubMed1987

Drug resistance and pathogenicity of S. aureus isolated from patients.

Over the period 1983-1985, investigators from the Institute of Hygiene and Epidemiology, Prague, and the Central Research Institute of Epidemiology, USSR Ministry of Public Health, Moscow, carried out a joint study of drug resistance in S. aureus strains in relation to their enterotoxigenic properties and phage group specificity. Altogether 277 strains were explored which had been isolated at random from the clinical material from infant and adult inpatients. Most of the isolated strains featured multiple resistance to antibiotics: PNC (77.9%), CMP (52.7%), TET (21.6%), ERY (17.6%) and LIN (11.9%). The strains isolated from infants were most frequently resistant to TET and ERY. No correlation was found between the incidence of antimicrobial drugs resistance and toxigenic properties of the isolated strains.

Adult↗
PubMed1985

Binding of horse-spleen ferritin to group A streptococci.

Receptors for horse-spleen ferritin were found on group A streptococci. Both electron microscopic and chemical investigation of Streptococcus cells treated with ferritin showed that M + variants of group A streptococci were able to bind substantially more ferritin than M - variants of the same serotypes. Ferritin receptors were located on the tops of filamentous protrusions of Streptococcus cell walls and only on the outer surface of isolated cell walls. Trypsin treatment destroyed the ferritin-binding capacity of streptococci completely, while mild pepsin treatment left the ferritin receptors undisturbed, or uncovered additional ones. The ferritin receptors were not identical with receptors for the Fc-portion of swine IgG. The finding of ferritin receptors on bacteria necessitates careful interpretation of results obtained by immunoferritin localization techniques.

Animals↗
PubMed1984

Detection of staphylococcal enterotoxigenicity IV. Strains isolated in 1981 and 1982.

Enterotoxin A, B, C, D and E detection and typing was undertaken in 807 staphylococcal strains isolated from food, breast milk, clinical material, diarrhoeal stools and hospital-collected swabs in 1981 and 1982. One hundred and sixty-six of the strains produced enterotoxin, most frequently type A or C, less so type D or B. There were single instances of strains with double toxin production: AB, AC or AD. Nine hundred and ten supernatants collected in 1972-1973 were additionally tested (after a lapse of 8 years) for type D enterotoxin; there were 152 positive specimens, predominantly relating to strains isolated from tinned cocoa and delicatessen, with 26 of the supernatants containing AD and BD enterotoxin combinations. For the first time the authors' laboratory detected strains producing enterotoxin F and the combination.

Enterotoxins↗
PubMed1983

A hydrogen sulphide producing Gram-negative rod from water.

The biochemical properties of a hydrogen sulphide-producing Gram-negative rod, provisionally designated HG group, were compared with those of the known H2S-producing and H2S-negative Enterobacteriaceae and related organisms. Sixty-four tests were used as a basis for numerical identification. All these tests demonstrated a distinctness of the HG group from other members of Enterobacteriaceae and related organisms. Results of numerical identification are discussed. According to the guanine-plus-cytosine molar content in DNA the bacterium could belong to the tribe Escherichiae of the family Enterobacteriaceae. Plasmids of different molecular size or linear fragments of DNA were found in 17 of 19 strains which indicates that the H2S production is not in correlation with the occurrence of a plasmid of definite size. So far, the only habitat of the HG group had been water, and it seems to be no rarity. Among 28 HG strains a single isolate HG16 was found which differs from HG group in biochemical properties. The distinctness of this single isolate has been confirmed also by numerical identification. Note: On the basis of DNA-DNA hybridization performed by Dr. P.A.D. Grimont and coworkers the HG group has been established as a new genus and a single species. The authors accordingly propose for the group the generic name Budvicia and the specific epithet aquatica.

Cytosine↗