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PubMed2001

Identification of clinical staphylococcal isolates from humans by internal transcribed spacer PCR.

The emergence of coagulase-negative staphylococci not only as human pathogens but also as reservoirs of antibiotic resistance determinants requires the deployment and development of methods for their rapid and reliable identification. Internal transcribed spacer-PCR (ITS-PCR) was used to identify a collection of 617 clinical staphylococcal isolates. The amplicons were resolved in high-resolution agarose gels and visually compared with the patterns obtained for the control strains of 29 staphylococcal species. Of the 617 isolates studied, 592 (95.95%) were identified by ITS-PCR and included 11 species: 302 isolates of Staphylococcus epidermidis, 157 of S. haemolyticus, 79 of S. aureus, 21 of S. hominis, 14 of S. saprophyticus, 8 of S. warneri, 6 of S. simulans, 2 of S. lugdunensis, and 1 each of S. caprae, S. carnosus, and S. cohnii. All species analyzed had unique ITS-PCR patterns, although some were very similar, namely, the group S. saprophyticus, S. cohnii, S. gallinarum, S. xylosus, S. lentus, S. equorum, and S. chromogenes, the pair S. schleiferi and S. vitulus, and the pair S. piscifermentans and S. carnosus. Four species, S. aureus, S. caprae, S. haemolyticus, and S. lugdunensis, showed polymorphisms on their ITS-PCR patterns. ITS-PCR proved to be a valuable alternative for the identification of staphylococci, offering, within the same response time and at lower cost, higher reliability than the currently available commercial systems.

DNA, Bacterial↗

PubMedDate not supplied

Treatment of posttraumatic osteitis with intravenous ofloxacin.

The subjects were 25 patients with osteomyelitis (n = 17) or other bone or joint infections, scheduled for surgical procedures, including debridement, sequestrectomy, and bone resection and reconstruction. Staphylococcus aureus was isolated in 22 patients, Staphylococcus epidermidis in one, Streptococcus haemolyticus in one, Pseudomonas aeruginosa in one, and a Pasteurella species in one. During surgery and for a mean of four days after surgery, each patient received 200 mg of ofloxacin intravenously twice daily (one patient received 300 mg and another received 400 mg twice daily). The patients were then given 200 mg of ofloxacin orally twice daily until the wound was healed (after a mean of 18 days). The wound was healed in all patients and no cases of reinfection occurred. It is concluded that intravenous ofloxacin given perioperatively may be more effective than oral ofloxacin in the management of osteomyelitis.

Acute Disease↗

PubMed1990

Correlations between consumption of antibiotics and methicillin resistance in coagulase negative staphylococci.

The correlation between antibiotic consumption, expressed in defined daily doses (DDD), and antibiotic resistance rates was studied, using 976 isolates of coagulase negative staphylococci (CNS) from human pathological material. Data from four hospitals, including 14 participating departments, were analysed for this purpose. Susceptibility tests were performed according to Dutch national standards, except for methicillin, which for the majority of isolates was tested according to adapted NCCLS standards. Resistance to methicillin was most frequent in Staphylococcus epidermidis (29%) and S. haemolyticus (16%). Among the departments, thoracic surgery (29-47%), surgical intensive care (68%) and neonatology (32%) scored highest. Significant correlations were found between percentages of methicillin resistance in CNS and consumption (DDD/month/bed) of (flu)cloxacillin (P0.008), of cephalosporins (P0.01) and of gentamicin (P0.005). (Flu)cloxacillin was used mainly prophylactically, cephalosporins and gentamicin therapeutically. Results were similar for S. epidermidis (n = 639) alone. There was no significant correlation between consumption and resistance to trimethoprim, erythromycin (P0.08) or gentamicin (P0.09). Analysis of data from individual patients showed significant differences in proportions of methicillin resistance rates in CNS, between use and non-use of penicillinase resistant beta-lactams or gentamicin. It is concluded that clinical use of both (flu)cloxacillin and cephalosporins selects for methicillin resistant CNS.

Anti-Bacterial Agents↗

PubMedDate not supplied

[Physico-chemical properties of staphylococci of different species in resistance to human thrombodefensins].

Testing 54 strains of staphylococci (Staphylococcus aureus, S. epidermidis, S. haemolyticus, S. warneri, S. hominis, S. capitis) revealed that S. aureus in contrast to coagulase-negative staphylococci (CNS) is more resistant to bactoriocidal action of human thrombodefensins (resistance index: 60.3 vs 25.6%), less hydrophilicolipophilic balance-HLB: -0.42 vs -0.64) and less charged (x-potential: -32.4 vs -35.6 mV). In groups of staphylococci (S. aureus and CNS) correlation links of bacterial resistance to human thrombodefensins with their HLB and x-potential (r=-0.32...-0.36). By In vitro experiments, it was shown that 5 passages of staphylococci in meat-peptonic broth with human thrombodefensins (50 mkg protein/ml) lead to adaptation of bacteria followed by the formation of resistance to cationic peptides from thrombocytes, a decrease of hydrophobicity and x-potencial. The role of physico-chemical properties in providing thrombodefensin-resistance of staphylococci as a developmental factor of infectious-and-inflammatory process and persistence of bacteria was confirmed with Salmonella infection.

Adaptation, Physiological↗

PubMed1997

Epidemiological typing of coagulase-negative staphylococci from nosocomial infections.

Biotyping, antibiograms, bacteriophage typing, plasmid profile analysis and SDS-PAGE protein profiles were used to determine the relatedness of 44 Staphylococcus epidermidis and four S. haemolyticus isolates from 14 patients. A selection of these were further characterised by ribotyping. Biotyping classified the isolates into three major groups but was considered a poor strain marker. Although antibiograms classified the S. epidermidis isolates into 20 groups, some changes in the susceptibility patterns of related isolates from a single patient were demonstrated. Bacteriophage typing was the least discriminatory of the methods used. SDS-PAGE gave highly related patterns for the majority of S. epidermidis isolates. Plasmid profile analysis and ribotyping, with a minimum of two restriction endonucleases, were the most discriminatory methods for typing S. epidermidis. Nonetheless, some isolates from the same patient - probably representing a single strain - varied in plasmid profile indicating plasmid instability. One of six related isolates from a single patient lacked two bands from the ribotyping pattern of the other isolates. Although no single method proved entirely satisfactory on all occasions, the combination of typing methods was sufficient to provide evidence of the relatedness of S. epidermidis isolates from individual patients.

Adult↗

PubMed1996

Does the appearance of drug resistance during therapy alter bacterial susceptibility to opsonophagocytosis?

Coagulase-negative staphylococci (CNS) are common causes of infection in patients undergoing chronic ambulatory peritoneal dialysis (CAPD). Their ability to survive intracellularly within peritoneal macrophages and to persist within the peritoneum during antibiotic therapy has led to the development of drug resistance during treatment. Strains of Staphylococcus epidermidis (SE) and Staphytococcus haemolyticus (SH) have been isolated from patients with CAPD during treatment with ciprofloxacin. The respective MIC values pre-and post-therapy were SE-0.25 and 128 mg/L and SH-0.50 and 64 mg/L. The susceptibility of each isolate to opsonophagocytosis was measured in vitro using isolated polymorphonuclear leucocytes (PMN) derived from fresh human blood donations. The bacteria were radiolabelled during growth, opsonised in either 1 or 10% serum and their uptake measured No differences were seen between the pre- and post therapy isolates when using 10% serum as opsonic source (18 vs. 21%); with 1% serum the corresponding values were lower (5 and 8% respectively). Similarly their ability to generate a respiratory burst as measured by chemiluminescence (CL) in the phagocytic cells was not diminished in the strains which had developed resistance to ciprofloxacin. The mean CL response to the strains isolated at outset of therapy ranged from 0.35-0.45 cpsc, and to the resistant strains following therapy from 0.36-0.50 cpsc. It is clear from the present investigation that although the bacterial strain became at least 10 times more resistant to ciprofloxacin during therapy, no change in their susceptibility to phagocytosis occurred refuting the idea that the emergence of drug resistant strains during therapy results in "super-bugs" of greater virulence.

Anti-Infective Agents↗

PubMed1999

Outbreak of mupirocin-resistant staphylococci in a hospital in Warsaw, Poland, due to plasmid transmission and clonal spread of several strains.

An outbreak of mupirocin-resistant (MuR) staphylococci was investigated in two wards of a large hospital in Warsaw, Poland. Fifty-three MuR isolates of Staphylococcus aureus, S. epidermidis, S. haemolyticus, S. xylosus, and S. capitis were identified over a 17-month survey which was carried out after introduction of the drug for the treatment of skin infections. The isolates were collected from patients with infections, environmental samples, and carriers; they constituted 19.5% of all staphylococcal isolates identified in the two wards during that time. Almost all the MuR isolates were also resistant to methicillin (methicillin-resistant S. aureus and methicillin-resistant coagulase-negative staphylococci). Seven of the outbreak isolates expressed a low-level-resistance phenotype (MuL), whereas the remaining majority of isolates were found to be highly resistant to mupirocin (MuH). The mupA gene, responsible for the MuH phenotype, has been assigned to three different polymorphic loci among the strains in the collection analyzed. The predominant polymorph, polymorph I (characterized by a mupA-containing EcoRI DNA fragment of about 16 kb), was located on a specific plasmid which was widely distributed among the entire staphylococcal population. All MuR S. aureus isolates were found to represent a single epidemic strain, which was clonally disseminated in both wards. The S. epidermidis population was much more diverse; however, at least four clusters of closely related isolates were identified, which suggested that some strains of this species were also clonally spread in the hospital environment. Six isolates of S. epidermidis were demonstrated to express the MuL and MuH resistance mechanisms simultaneously, and this is the first identification of such dual MuR phenotype-bearing strains. The outbreak was attributed to a high level and inappropriate use of mupirocin, and as a result the dermatological formulation of the drug has been removed from the hospital formulary.

Anti-Bacterial Agents↗

PubMed1996

Antibacterial activity of quinupristin/dalfopristin. Rationale for clinical use.

Most Gram-positive organisms are highly susceptible to the streptogramin, quinupristin/dalfopristin (RP 59500; Synercid). Minimum inhibitory concentrations for 90% of isolates (MIC90) were < or = 1 mg/L for Staphylococcus aureus, S. epidermidis, S. haemolyticus, Streptococcus pneumoniae, S. pyogenes and Listeria monocytogenes. Importantly, quinupristin/dalfopristin shows similar activity against methicillin-susceptible and -resistant strains of S. aureus, and streptococci with benzylpenicillin (penicillin G)- or erythromycin-acquired resistance. Enterococci have varying susceptibility to quinupristin /dalfopristin, although most isolates tested are susceptible to the drug, including vancomycin-resistant and multiresistant Enterococcus faecium. E. faecalis are generally the least susceptible. Among the Gram-negative respiratory pathogens Moraxella catarrhalis is susceptible and Haemophilus influenzae is moderately susceptible to quinupristin/ dalfopristin; however, Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp. are resistant. The drug is active against anaerobic organisms tested, including Clostridium perfringens, Lactobacillus spp., Bacteroides fragilis and Peptostreptococcus. Synergy has been demonstrated in vancomycin-resistant and multiresistant E. faecium, and methicillin-sensitive and -resistant S. aureus with the combination of vancomycin and quinupristin/ dalfopristin. Quinupristin/dalfopristin shows antibacterial activity in vivo in animal models of infection, including methicillin-sensitive and -resistant S. aureus infection in rabbits, S. aureus and S. pneumoniae in mice, and erythromycin-sensitive and -resistant viridans group streptococci infections in rats. The drug is rapidly bactericidal against Gram-positive organisms (with the exception of enterococci) at concentrations similar to or within 4-fold of the MIC, and it has a long postantibiotic effect both in vitro and in vivo.

Animals↗

PubMed2005

[Review on the etiology and treatment of bacterial pneumonias].

The bacterial pneumoniae are the significant factor of morbidity and mortality all over the world. So USA are at the sixth place per mortality cause. The bacteria are in 60-80% of cases the causes of pneumonia in the communities. Therefore this is the review on the ethiology of the verification and treatment of pneumonias in the 17-month period in the General hospital "Sarajevo". In the period of the 1st January 2002 till the 31st May 2003 year, it was examined 105 sputa on the antibiogram, and in 12 cases (11.4%) was found the positive bacterial finding. Most often were gram negative bacteria in 7 cases (58.3%), while were found the gram positive in 5 patients (41.7%). Therefore that the majority of the examinees belonged to the risk group, and that were the patients with over 50 years of age 11 (78.6%), with the chronic obstructive lung disease 5 (35.7%), with the malignant disease 1 (7.1%) and with the coinfection of the urinary tract. E. coli was found in 3 patient (25.0%), Kl. Pneumoniae in 2 (16.7%), Ps. aeruginosis in 1 (8.3%), Citrobacter freundi in 1 (8.3%), and in 2 cases (16.7%) were isolated. Staphylococcus intermedius and Streptococcus beta haemolyticus gr. A and Str. Pneumoniae in 1 case (8.3%). To the patients with the positive finding of sputum on antibiogram were most often administered empirically cefalosporia of the third generation because it was about the more severe patients, then the combination of ampicillin with gentamicin. All were dismissed as recovered or in better condition. Pneumonias is in the risk groups are possible to prevent to the five-years pneumococcus vaccine when is indicated or by influenza vaccine when simultaneously was prevented the viral, that is the possible bacterially superinfected pneumonia.

Anti-Bacterial Agents↗

PubMed1981

[Clinical studies on cefroxadine in the field of pediatrics (author's transl)].

Cefroxadine dry syrup was administered to 57 children with acute febrile respiratory tract infections and 2 children with scarlet fever in the dose of 40 mg/kg/day q.i.d. for 2 approximately 7 days. 65 strains of organism were isolated as pathogen from the 59 patients, and 50 of the 65 strains (76.9%) showed bacteriologically good responses. Clinically, 55 children (93.2%) had good response. Out of 63 strains isolated from the 57 cases with respiratory infections, 48 strains (76.2%) showed good bacteriological response. As for the type of pathogen, all strains of Staphylococcus aureus, 86.4% of Streptococcus haemolyticus and 90.0% of Streptococcus pneumoniae had good response, but as for Haemophilus influenzae it was only 47.6%. In one child, Streptococcus pneumoniae appeared during cefroxadine treatment in addition to the preexisting Haemophilus influenza. From the 4 children having no response for their respiratory infections, H. influenzae were isolated in 3 cases and Streptococcus haemolyticus was isolated in 1 case, before starting the treatment. As for side effects, mild diarrhea developed in only 3 children.

Cephalosporins↗

PubMed1995

Bacterial flora of semen collected from Danish warmblood stallions by artificial vagina.

Semen samples were collected from 21 Danish Warmblood stallions by the Colorado artificial vagina (Colorado AV, 14 samples) or by the Missouri artificial vagina (Missouri AV, 7 samples). The semen was examined bacteriologically by direct plating (DP) on blood agar plates, and by plating of semen swabs stored in Stuart's transport media (TM) at 4 degrees C for 1-4 days. No significant differences were observed between results obtained by DP and cultures of identical TM samples. Of the 21 samples examined, only 1 TM (4.8%) and 2 DP samples (9.5%) were sterile, while the rest yielded a predominantly mixed flora comprising 1 to 4 bacterial genera. The natural flora was dominated by coagulase-negative staphylococci (Staphylococcus lentus, S. capitis, S. haemolyticus, S. xylosus) (16/21 = 76%), coryneforms (11/21 = 52%) and alpha-hemolytic streptococci and lactobacilli (7/21 = 33%). Potential venereal pathogens were isolated from 7 stallions (33%). Beta-hemolytic streptococci were found in 4 stallions used for natural service, whereas Pseudomonas aeruginosa serotype 6 (2 samples) and Klebsiella pneumoniae subsp. pneumoniae capsule type K5 (1 sample) were isolated from 3 stallions used exclusively for artificial insemination. The role of the stallion as a carrier of potential venereal pathogens, and the artificial vagina as a source of contamination, is discussed in the context of mare endometritis.

Animals↗

PubMedDate not supplied

Bacterial and Ureaplasma colonization of the airway: radiologic findings in infants with bronchopulmonary dysplasia.

OBJECTIVE: We designed this retrospective study to compare radiologic findings in premature infants with bronchopulmonary dysplasia (BPD) in whom gram-positive cocci (GPC), gram-negative bacilli (GNB), or Ureaplasma urealyticum were colonized. Another objective was to correlate the radiologic findings of these patients with the clinical severity of BPD. STUDY DESIGN: We correlated serial tracheal aspirates with radiographic findings from 183 infants whose birth weight was < or = 1250 gm. BPD severity was assessed by oxygen dependency at 36 weeks of postconceptional age (36 w PCA) and at the time of discharge. Two radiologists independently scored films taken at birth and 1, 7, 14, 21, 28, and 35 days of life. RESULTS: Of the study population, 55% were male and 35% were black; 80% received surfactant and 69% received dexamethasone; 91% survived. GPC isolates from throat cultures were mainly Staphylococcus [corrected] epidermidis and Streptococcus haemolyticus. A superimposed GNB colonization was present in 37% of these infants. Most common isolates were Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. Sepsis caused by GPC developed in 16% of all patients; 7% had sepsis caused by GNB. Infants infected with GNB remained receiving oxygen at 36 w PCA and at the time of discharge twice as often as those noninfected. RADIOLOGIC FINDINGS: Hyperinflation, interstitial changes, and generalized or localized emphysema were prominent features throughout. Mean radiologic scores increased over time in a pattern similar among GPC, GNB, and U. urealyticum infected and noninfected infants. High radiologic scores were not predictive at any time of infants who needed supplemental oxygen at 28 days and at 36 w PCA. Infants infected with U. urealyticum were neither clinically nor radiologically different than noncolonized neonates. CONCLUSION: GPC, GNB, and U. urealyticum airway colonization is not associated with particular radiographic changes at any time. GNB-infected infants had the most severe BPD course, and yet they were radiologically indistinguishable from the other patients. U. urealyticum colonization does not result in more clinically severe BPD or demonstrate a unique radiologic course.

Bacterial Infections↗

PubMed1996

Alkaline-fermented foods: a review with emphasis on pidan fermentation.

Alkaline-fermented foods constitute a group of less-known food products that are widely consumed in Southeast Asia and African countries. They can be made from different raw ingredients. For instance, Japanese natto, Thai thua-nao, and kinema are made from cooked soybeans, dawadawa from African locust beans, ogiri from melon seeds, ugba from African oil beans, kawal from fresh legale leaves, owoh from cotton seeds, and pidan from fresh poultry eggs. In alkaline-fermented foods, the protein of the raw materials is broken down into amino acids and peptides; ammonia is released during the fermentation, raising the pH of the final products and giving the food a strong ammoniacal smell. Most alkaline fermentations are achieved spontaneously by mixed bacteria cultures, principally dominated by Bacillus subtilis. In other cases, pure cultures can be used. For example, Japanese natto is inoculated with a pure culture of B. subtilis var natto. Pidan is a special example of alkaline fermentation. Instead of using microorganisms, pidan is made using an alkali-treated fermentation. Sodium hydroxide (NaOH) is produced from the reaction of sodium carbonate (Na2CO3), water (H2O), and calcium oxide (CaO) of pickle or coating mud. NaOH penetrates into the eggs, causing the physicochemical changes, color changes, and gelation. The appearance of pidan differs from fresh eggs in that the white becomes a semitransparent tea-brown color, and the yolk is solid or semisolid with a dark-green color. The nutritional value of pidan is slightly decreased compared with fresh eggs, but pidan has an extremely long shelf life and a pleasant, fragrant taste that is preferred by most people in Southeast Asian countries. In a small-scale laboratory study conducted by the authors, B. subtilis was not found in pidan. Four Staphylococcus spp. (S. cohnii, S. epidermidis, S. haemolyticus, and S. warneri) and two strains of Bacillus spp. (B. cereus and B. macerans) were isolated from pidan. Staphylococcus spp. did not contribute to the fermentation and were considered contaminants.

Africa↗

PubMed1988

The in vitro activity of ramoplanin (A-16686/MDL 62,198), vancomycin and teicoplanin against methicillin-susceptible and methicillin-resistant Staphylococcus spp.

Ramoplanin (A-16686/MDL 62,198) is a novel lipoglycopeptide antimicrobial, comprised of three closely related polypeptides containing chlorinated phenyl moieties and D-mannose, isolated from the fermentation products of Actinoplanes sp. ATCC 33076. The antimicrobial activity of ramoplanin is limited to Gram-positive bacteria and its reportedly unacceptable administration side-effects suggest that any potential clinical role will be limited to the topical therapy of superficial skin infections and the eradication of bacteria, representing a possible nosocomial cross-infection source, from carriage sites. In this study the MICs of ramoplanin have been determined for methicillin-susceptible and methicillin-resistant isolates of Staphylococcus aureus, S. epidermidis and S. haemolyticus and compared with those of two glycopeptide antimicrobials, vancomycin and teicoplanin. MICs were determined using an agar incorporation technique in Mueller-Hinton medium with an inoculum of 10(5) cfu. Ramoplanin was 2-8 times more active than either vancomycin or teicoplanin against methicillin-susceptible and methicillin-resistant isolates of S. aureus and methicillin-susceptible isolates of S. epidermidis. Isolates of methicillin-resistant S. epidermidis and both methicillin-susceptible and -resistant isolates of S. haemolyticus were generally less susceptible to teicoplanin than to vancomycin. Ramoplanin was significantly more active than either vancomycin or teicoplanin against these isolates. These results suggest that the clinical evaluation of ramoplanin as a topical antibacterial agent for the control of superficial infections caused by Staphylococcus spp. and for the eradication of methicillin-resistant S. aureus from carriage sites, is justified.

Anti-Bacterial Agents↗

PubMed1993

[Differentiation of staphylococci from sheep and goat milk samples].

A total of 447 micrococcaceae strains isolated from 88 ewe and 359 goat milk samples from cases of chronic mastitis were differentiated by means of the ATB 32 STAPH-test. Of these strains 389 (= 87%) could be identified. Fourteen strains were sensitive in the bacitracin-resistance-test and therefore classified as Micrococcus spp. In ewe milk following Staphylococcus spp. were found: S. epidermidis, S. aureus, S. lentus, S. xylosus, S. warneri, S. equorum, S. haemolyticus, S. simulans, S. hominis and S. saprophyticus. Staphylococcus spp. identified in goat milk samples were: S. epidermidis, S. aureus, S. caprae, S. lentus, S. simulans, S. capitis, S. lugdunensis, S. xylosus, S. chromogenes, S. hominis, S. arlettae, S. warneri, S. sciuri, and S. saprophyticus. Highest cell counts in the milk of both animals species, and the highest incidence of clinical udder alterations were caused by S. aureus. Increases in milk cell counts as well as pathological udder findings were observed in coagulase-negative staphylococcal infections for novobiocin-sensitive Staphylococcus spp. (S. epidermidis, S. warneri, S. simulans, S. lugdunensis, and S. chromogenes) and several S. lentus strains.

Animals↗

PubMed1991

Development of in-vitro resistance to glycopeptide antibiotics: assessment in staphylococci of different species.

Forty-two clinical isolates belonging to ten species of staphylococci were studied for their ability to develop single-step resistance, in vitro, to glycopeptide antibiotics. Selection was attempted through separate exposure to four glycopeptides (vancomycin, teicoplanin, and two investigational semisynthetic derivatives of the latter, TD-A3 and CTA-A1) on agar containing 10 mg/l of the test drug. No survivors from any test strain were recovered after exposure to TD-A3 or CTA-A1. After exposure to vancomycin or teicoplanin, surviving clones were only recovered from strains of three species, Staphylococcus aureus, S. epidermidis, and S. haemolyticus. Emergence of resistant clones was easier to observe from strains of S. haemolyticus exposed to teicoplanin. When tested for susceptibility, many survivors exhibited vancomycin and teicoplanin MICs below the drug concentration used for in-vitro selection, probably due to an inoculum effect in the plating procedure. In particular, the vancomycin MICs did not exceed 8 mg/l for S. aureus and S. epidermidis clones, and reached 16 mg/l for some clones from a S. haemolyticus strain. Teicoplanin MICs did not exceed 8 mg/l for S. aureus clones, but reached 64 mg/l for some clones of S. epidermidis, and were particularly high (64 to greater than or equal to 128 mg/l) for most clones of S. haemolyticus. In contrast, against all clones selected from all three species, the MICs of TD-A3 and CTA-A1 did not exceed 2 and 4 mg/l, respectively. Morphological investigations indicated that the colonies of a highly resistant S. haemolyticus clone were smaller and more butyraceous in consistency than those of the parent strain. In transmission and scanning electron microscopy studies, this same S. haemolyticus clone showed a more irregular cell wall than the parent strain.

Aminoglycosides↗

PubMed2001

Correlation between genotype and phenotypic categorization of staphylococci based on methicillin susceptibility and resistance.

Positive correlation between methicillin and oxacillin susceptibility test results and the detection of the mecA gene was observed for Staphylococcus aureus, S. epidermidis, and S. haemolyticus as well as among mecA(+) strains of other species of coagulase-negative staphylococci (CNS). However, at least 50% of the mecA-negative strains of these other species of CNS were falsely classified as methicillin and oxacillin resistant.

Genotype↗

PubMedDate not supplied

[A new device for the disinfection of handpieces and turbines].

Dental handpieces are often difficult to disinfect. This is one of the main reasons for the considerable risk of cross-infections in dental offices. The aim of the present study was the evaluation of the disinfectant property of a recent, commercially available, automatic instrument, described as capable to clean, disinfect and lubricate dental handpieces. The following experimental evaluations were made: 1) antimicrobial activity of the disinfectant (glyoxalaldehyde) used. The method described by the European Committee for Standardization was followed. Test microorganisms were Pseudomonas aeruginosa and Staphylococcus aureus. 2) disinfection of dental handpieces (69 contra-angles and 97 turbines of different marks). They were naturally infected using them on patients for 30 minutes at least. 3) disinfection of dental handpieces infected with bacterial suspensions of Staphylococcus aureus, Streptococcus pyogenes (beta-haemolyticus, group A), Candida albicans and Pseudomonas aeruginosa. The results of the first experiment showed a strong bactericidal power of the disinfectant with both the tested strains, after a contact time of only 1 minute. A great proportion of the dental handpieces tested during the second experiment were found disinfected: from 84% through 89% out of the various models of turbine handpieces; from 89% through 100% out of the models of contra-angle handpieces. Even though bacterial contamination level was low (about 10(3) microorganisms per handpiece), a satisfactory disinfectant ability in natural conditions was found. The results of the third experiment were unclear. The tested instrument reduced 10(5)-10(8) times the original bacterial count when the gram positive microorganisms (Staphylococcus aureus, Streptococcus pyogenes) were used. On the other hand, when Pseudomonas aeruginosa and Candida albicans were used, the results were different: the bacterial count was reduced 10(6)-10(7) times in some cases, and only 10(2) times in other cases. This difference was found in the tests made using the same attachment and in those made using various attachments. In conclusion, the tested instrument showed, in most cases, a good disinfectant property, but the presence of unclear results suggests that some technical modifications are required.

Cross Infection↗