SEARCH · Search PubMed

Results for “Staphylococci”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed1988

Laboratory, clinical, and epidemiological aspects of coagulase-negative staphylococci.

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are increasingly important causes of nosocomial infection. Microbiologists and clinicians no longer can afford to disregard clinical isolates of coagulase-negative staphylococci as contaminants. Accurate species identification and antimicrobial susceptibility testing, in a clinically relevant time frame, are important aids in the diagnosis and management of serious coagulase-negative staphylococcal infections. Emphasis in the clinical laboratory should be placed on the routine identification of S. epidermidis and Staphylococcus saprophyticus, with identification of other species of coagulase-negative staphylococci as clinically indicated. The application of newer techniques, such as plasmid analysis and tests for slime production and adherence, contribute to our understanding of the epidemiology and pathogenesis of coagulase-negative staphylococci and may also be helpful in establishing the diagnosis of infection.

Coagulase↗

PubMed2002

Vancomycin resistance in staphylococci.

Vancomycin resistance has been reported in clinical isolates of both coagulase-negative staphylococci and Staphylococcus aureus. The emerging threat of widespread vancomycin resistance poses a serious public health concern given the fact that vancomycin has long been the preferred treatment of antibiotic-resistant gram-positive organisms. Though major efforts are now being focused on improving our understanding of vancomycin resistance, there is much that remains unknown at this time. This article reviews the major epidemiologic, microbiologic, and clinical characteristics of vancomycin resistance in both coagulase-negative staphylococci and S. aureus. The review begins with a discussion of issues common to both coagulase-negative staphylococci and S. aureus, such as definitions, laboratory detection of vancomycin resistance, and infection control issues related to vancomycin-resistant staphylococci. The rest of the article is then devoted to a discussion of issues unique to each organism, including epidemiology, risk factors for infection, mechanisms of resistance, and management options.

Anti-Bacterial Agents↗

PubMed1971

Use of a plating method to estimate extracellular protein production by staphylococci.

Employing 4% NZ-Amine type NAK medium fortified with thiamine and niacin and solidified with 0.75% agar, staphylococci were streaked onto this medium and incubated for 24 hr at 37 C. After the gentle removal of growth with cotton swabs, the plates were flooded with 25% trichloroacetic acid and allowed to stand for about 15 min, after which various degrees of protein precipitate were noted under the areas of growth. Organisms that produced the most intense precipitate or extracellular protein (ECP) were designated 4+, followed by 3+, 2+, and 1+ for those that produced progressively less ECP to 0 for those that produced none. Of 585 strains of coagulase-positive staphylococci tested, 91% produced 3 to 4+ ECP, whereas only 8.9% of 112 coagulase-negative strains produced these amounts. The NZ-Amine media including type A were far superior to five other media in permitting ECP production. Of other organisms examined, only the three salmonellae species tested produced ECP. Maximum visual quantities of ECP were produced between 22 and 24 hr at pH values between 6.6 and 7.0 and in the presence of <3% NaCl. The visual estimation of ECP production correlated well with the production of certain other specific extracellular products of staphylococci. This plate method provides a simple means of characterizing staphylococci on the basis of extracellular protein production.

Journal Article↗

PubMed1963

POSSIBLE SOURCE OF SECONDARY INVADING STAPHYLOCOCCI IN MICE EXPOSED TO ACUTE COLD.

Miraglia, Gennaro J. (Bryn Mawr College, Bryn Mawr, Pa.) and L. Joe Berry. Possible source of secondary invading staphylococci in mice exposed to acute cold. J. Bacteriol. 85:345-348. 1963.-In an effort to determine the origin of the staphylococci known to invade the deep tissues (liver, spleen, kidneys, lungs, and heart) of mice exposed continuously to 5 C in individual compartments without bedding, the intestinal tract was freed of these organisms, as judged by absence of growth when fecal suspensions were inoculated into selective media. Substitution of 0.01 n hydrochloric acid for drinking water eliminated staphylococci within a few days, yet the incidence of tissue invasion was unaltered. The coagulase-negative strains normally present in feces and in tissues persisted in tissues even though the intestine was seeded with a coagulase-positive strain by feeding contaminated food. Cultures from the external nares continued unaltered. This suggests that the respiratory tract is a possible origin of the staphylococci found in tissues of the cold-stressed mice.

Journal Article↗

PubMed1963

ABSORPTION OF THE ANTIBACTERIAL SERUM FACTOR BY STAPHYLOCOCCI.

Yotis, William W. (Loyola University, Chicago, Ill.). Absorption of the antibacterial serum factor by staphylococci. J. Bacteriol. 85:911-917. 1963.-The absorption of antibacterial serum factor by eight bacterial species and one yeast showed good correlation with the sensitivity of the organisms to the serum factor. The serum factor was removed from aqueous solution by coagulase-positive and coagulase-negative strains of staphylococci and Bacillus subtilis, and the oxygen consumption of the bacteria was inhibited by prior exposure to the serum factor. Escherichia coli, Neisseria catarrhalis, Proteus vulgaris, Bacillus megaterium, Mycobacterium phlei, and Saccharomyces cerevisiae failed to absorb the serum factor, and their respiration was not inhibited by prior exposure to 40 mg or more of the serum factor per ml. Staphylococci treated with 0.25 mg per ml of coagulase were almost completely refractory to the antibacterial action of 2 mg of serum factor per ml, and the serum factor was not absorbed. When the staphylococci were first treated with the serum factor, subsequent treatment with coagulase had no effect. Exposure of staphylocci to heat (70 C for 1 hr), 3.6% formaldehyde, 1 n sodium hydroxide, and 1 n hydrochloric acid did not prevent absorption of the serum factor. However, pretreatment with 88% liquefied phenol partially prevented serum factor absorption. The absorption and antibacterial activity of the serum factor were dependent on the concentration, the time and temperature of exposure, and the nature and concentration of salts present.

Anti-Bacterial Agents↗

PubMed1964

TWO LYTIC FACTORS INVOLVED IN INDUCED SYNERGISTIC HEMOLYSIS IN NORMALLY NONHEMOLYTIC STAPHYLOCOCCI.

Smith, Doyle C. (Kansas State University, Manhattan), V. D. Foltz, and T. H. Lord. Two lytic factors involved in induced synergistic hemolysis in normally nonhemolytic staphylococci. J. Bacteriol. 88:1700-1704. 1964.-Synergistic hemolysis of "normally nonhemolytic" staphylococci results from the combination of two factors: Z, produced by hemolytic staphylococci that elaborate a secondary hemolytic zone on blood-agar, and T, produced by nonhemolytic staphylococci. Factors Z and T are produced in supernatant fluids of broth cultures and are detected by the synergistic hemolysis (SH) test. Complete lysis of sheep red cells is observed in the SH test only when both factors Z and T are present. Production of Z and T is greatly enhanced by the presence of 10 or 20% CO(2) during incubation. Both Z and T are heat-stable, withstanding 100 C for 15 min. Neither factor is precipitated by saturated Na(2)SO(4) or (NH(4))(2)SO(4). Hydrogen ion concentrations between pH 5.0 and 8.5 do not exert any effect on the two factors. Factor Z is produced in greater quantity than factor T. It is suggested that factors Z and T are not proteinaceous, enzymatic, or lipid in nature.

Ammonium Compounds↗

PubMed1966

Induction of penicillinase by staphylococci in vitro and in vivo.

Eyckmans, Luc (Cornell University Medical College, New York, N.Y.), and Edward W. Hook. Induction of penicillinase by staphylococci in vitro and in vivo. J. Bacteriol. 91:997-1003. 1966.-Staphylococci in mice with peritoneal infection showed no significant increase in penicillinase activity 6 hr after administration of penicillin G. In contrast, induction of penicillinase was readily demonstrated in leukopenic animals under similar conditions. Induction of penicillinase by staphylococci in vitro was inhibited by including leukocytes and immune serum in the mixtures. The role of leukocytes in inhibiting induction of penicillinase by staphylococci in response to penicillin was investigated.

Animals↗

PubMed1982

Differentiation of coagulase-positive and coagulase-negative staphylococci by lectins and plant agglutinins.

The screening of staphylococci with a panel of 14 lectins and extracts demonstrating lectin-like activity led to the development of a rapid agglutination slide test for the differentiation of certain coagulase-negative staphylococci and human strains of Staphylococcus aureus. The coagulase-negative staphylococci were agglutinated by agglutinins from Mangifera indica, Triticum vulgaris, and crude Limulus polyphemus. The test is rapid, requiring only 5 to 15 min to identify an unknown strain of staphylococci, as opposed to the 4 to 16 h required to perform the conventional tube coagulase test.

Agglutination Tests↗

PubMed1983

Detection of oxacillin-resistant staphylococci by the AutoMicrobic system.

The AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) is an automated instrument designed for rapid microbiological identification and susceptibility reporting in the clinical laboratory. The reliability of a rapid, automated approach to testing methicillin-resistant staphylococci was evaluated. To determine the accuracy in detecting oxacillin-methicillin resistance by the AutoMicrobic system, 746 staphylococci from seven different geographical areas were tested. Results were compared with the Bauer-Kirby agar disk diffusion technique as the reference method. Of the 304 staphylococci, 209 coagulase-positive and 95 coagulase-negative strains were resistant to oxacillin-methicillin. These organisms fell into three categories of resistance detection. The first category had resistance levels high enough for initial detection, the second category had low resistance levels requiring modified data analysis techniques for detection, and the third category had resistance levels too low for detection. Of the resistant strains tested, 21% showed a category two resistant growth pattern. Major errors, as a result of hetero-resistant growth patterns of the tested strains, were resolved by computer analysis of growth curves. These data analysis applications enabled detection of 96% of the oxacillin-methicillin-resistant organisms. Results for all resistant staphylococci tested were available in an average time of 5.5 h.

Autoanalysis↗

PubMed1984

Comparison of various methods for differentiation of staphylococci and micrococci.

A modified oxidase test (Remel, Lenexa, Kans.) and susceptibility to furazolidone and lysostaphin (Remel) were evaluated in conjunction with the Staph-Ident strip (Analytab Products, Plainview, N.Y.) to accurately differentiate between staphylococci and micrococci. A total of 414 clinical isolates of catalase-positive, gram-positive cocci were each tested with the Staph-Ident strip and by glucose fermentation, acid production from glycerol, susceptibility to furazolidone and lysostaphin, and the oxidase test. Based on the reference methods of glucose fermentation and acid production from glycerol, 396 (95.6%) of the organisms were classified as Staphylococcus species and 18 (4.4%) were classified as Micrococcus species. Of the staphylococci, 99% were oxidase negative and susceptible to furazolidone; 82% were susceptible to lysostaphin. All of the micrococci were oxidase-positive and resistant to furazolidone and lysostaphin. Of the staphylococci, 99% were identified to species by the Staph-Ident strip. However, six (33%) of the micrococci were incorrectly identified as Staphylococcus species (three each of Staphylococcus hominis and Staphylococcus saprophyticus). Because of the demonstrated sensitivity and specificity of the oxidase and furazolidone susceptibility tests, it is suggested that either of these methods be used in the clinical laboratory to accurately differentiate between staphylococci and micrococci. It is also suggested that when working with the Staph-Ident strip, additional testing such as furazolidone susceptibility or oxidase activity should be performed to provide increased accuracy in the differentiation and characterization of members of the family Micrococcaceae.

Bacteriological Techniques↗

PubMed1986

Involvement of coagulase-negative staphylococci in toxic shock syndrome.

Coagulase-negative staphylococci that produce toxic shock syndrome toxin 1 (TSST-1) or a staphylococcal enterotoxin or both were isolated from various sources. Coagulase-negative strains that produce TSST-1 alone or with enterotoxin A were the only staphylococci isolated from seven patients with toxic shock syndrome. Two other toxic shock syndrome patients had coagulase-positive staphylococci also, but only the coagulase-negative strains produced TSST-1. Coagulase-positive and coagulase-negative strains that produced TSST-1 were isolated from two other toxic shock syndrome patients. In addition, coagulase-negative staphylococci that produced toxins were isolated from patients with other staphylococcal infections and from food implicated in a case of food poisoning.

Bacterial Toxins↗

PubMed1989

Effect of milk on fibronectin and collagen type I binding to Staphylococcus aureus and coagulase-negative staphylococci isolated from bovine mastitis.

Tryptic soy broth (TSB)-grown cells of Staphylococcus aureus isolated from acute and chronic bovine mastitis bound mainly 125I-fibronectin (Fn) [corrected], whereas strains of nine species of coagulase-negative staphylococci showed a predominant interaction with 125I-collagen (Cn) [corrected] type I. A particle agglutination assay (PAA) was used to examine the interaction of coagulase-negative staphylococci with 125I-Fn and 125I-Cn immobilized on latex. All 368 coagulase-negative staphylococci demonstrated high 125I-Cn and moderate to low 125I-Fn interactions in the PAA. Cn-PAA reactivity was high among strains of Staphylococcus xylosus (84.2%), Staphylococcus simulans (77.8%), Staphylococcus epidermidis (76.7%), and Staphylococcus hyicus (74.3%), whereas all six Staphylococcus capitis strains clumped Cn-PAA reagent. Incubating TSB-grown cells in 10% skim milk for 1 h decreased the 125I-Fn- and 125I-Cn-binding affinity in most of the S. aureus and coagulase-negative staphylococci, while growth in 10% skim milk for 18 h resulted in more than 90% decrease or complete loss of interaction with these proteins. Decreased 125I-Fn binding in the presence of milk was correlated with protease production but not with 125I-Cn binding.

Acute Disease↗

PubMed1992

Detection of methicillin-resistant staphylococci by using the polymerase chain reaction.

A polymerase chain reaction (PCR)-based test was developed for the detection of mecA in staphylococci. To facilitate this process, a rapid cell lysis procedure was established for the release of DNA from staphylococcal strains. Primers based on the DNA sequence of the mecA gene from Staphylococcus aureus were used in PCRs to screen for the presence of this gene in a total of 98 staphylococcal isolates. Fifty-one isolates were mecA positive (17 S. aureus strains and 34 coagulase-negative staphylococci including S. epidermidis, S. haemolyticus, and S. simulans). Results obtained with PCRs were generally consistent with those of standard microbiological assays. PCRs designed to detect the femA gene (factor essential for methicillin resistance) revealed the presence of the gene in all S. aureus strains examined regardless of the susceptibility profiles of the strains to methicillin. In contrast, femA could not be detected in coagulase-negative staphylococci by PCR with the same primers. Low-stringency hybridization suggested the presence of a gene structurally related to femA in S. epidermidis and other coagulase-negative staphylococci examined.

Base Sequence↗

PubMed1992

Rapid detection of the mecA gene in methicillin-resistant staphylococci by enzymatic detection of polymerase chain reaction products.

In order to identify methicillin-resistant staphylococci from clinical sources with ease and reliability, enzymatic detection of polymerase chain reaction (ED-PCR) was applied. ED-PCR is based on the capture of amplified products via biotin-streptavidin affinity and the detection of an incorporated hapten in amplified products with an enzyme-linked antibody. In order to identify methicillin-resistant staphylococci of all species, a 150-bp fragment of the mecA gene was targeted for ED-PCR. After PCR was performed with a pair of biotin and dinitrophenol 5'-labeled primers, the reaction mixture was applied to a microtiter well precoated with streptavidin. Thereafter, bound PCR products were detected colorimetrically with alkaline phosphatase-conjugated anti-dinitrophenol antibody. The extraction of DNA from staphylococcal cells for PCR was simplified so that it could be performed within one tube. The total assay, including PCR, took less than 3 h. The sensitivity of mecA gene detection ranged from greater than 5 x 10(2) CFU per tube for Staphylococcus aureus to greater than 5 x 10(3) CFU per tube for Staphylococcus epidermidis. Genotyping results obtained by ED-PCR of 161 tested strains from the colonies (97 strains of S. aureus and 64 strains of coagulase-negative staphylococci) were compared with the phenotypic susceptibilities of the strains to oxacillin. The results of ED-PCR showed excellent agreement with the MICs of oxacillin with very few exceptions; only one strain of S. aureus and two strains of coagulase-negative staphylococci were found to possess the mecA gene, which was discrepant with their phenotypes. Fifty-five blood culture samples were also tested by ED-PCR. For staphylococcal isolates in 33 of the cultures, oxacillin MICs were >4 microgram/ml; 31 of the 33 staphylococcal isolates were determined by ED-PCR to be mecA gene positive. These results suggest that ED-PCR can be used with reasonable confidence in the clinical microbiological laboratory.

Alkaline Phosphatase↗

PubMed1996

Evaluation of Alamar colorimetric broth microdilution susceptibility testing method for staphylococci and enterococci.

We compared the results of the Alamar broth microdilution susceptibility testing method with the results of the National Committee for Clinical Laboratory Standards reference broth microdilution method for 119 gram-positive organisms. The strains were tested for their susceptibilities to 20 antimicrobial agents. Only appropriate antimicrobial agents were evaluated for each species of bacteria. Absolute categorical agreement between the reference method and the test method was 91.5% for enterococci, 99.8% for oxacillin-susceptible staphylococci, and 97.4% for oxacillin-resistant staphylococci. Essential agreement (percent complete agreement plus percent minor errors) was > 99% for all organisms tested. The results for enterococci showed no very major errors, one major error with ofloxacin, and numerous minor errors with the quinolones. However, all except one of the minor errors were within +/- 1 log2 dilution of the reference result. For staphylococci, only 2 very major errors (one each with chloramphenicol and oxacillin), 1 major error (chloramphenicol), and 15 minor errors (multiple drugs) were observed. The Alamar colorimetric system was easy to use and the results were easy to read. It appears to be an acceptable method for antimicrobial susceptibility testing of staphylococci and enterococci.

Colorimetry↗

PubMed2005

Phenotypic and genotypic mupirocin resistance among Staphylococci causing prosthetic joint infection.

Mupirocin MICs and mupA presence were determined in 108 staphylococci causing prosthetic joint infection. Zero of 35 isolates (0%) of methicillin-susceptible Staphylococcus aureus, 4/15 (27%) methicillin-resistant S. aureus isolates, 3/16 (19%) methicillin-susceptible coagulase-negative staphylococci, and 11/42 (26%) methicillin-resistant coagulase-negative staphylococci were mupirocin resistant. mupA was detected in all five high-level mupirocin-resistant staphylococci and one mupirocin-susceptible staphylococcus.

Adolescent↗

PubMed1962

The dispersal of staphylococci in hospital wards.

The air of three hospital wards was examined frequently for staphylococci for a period of nearly four years using slit samplers. ;Broadcasts' of staphylococci into the air were observed with the air count rising well above the mean of 0.2 staphylococcal particle per cubic foot and these broadcasts often appeared to be due to single patients. Eight of the 3,675 patients admitted to the wards possessed an ability to disperse staphylococci into the air of the wards which was markedly greater than normal. The actual dispersal about the ward appeared to be mediated by the bedclothes, for, when these were disturbed, large numbers of staphylococci were disseminated into the air.

Journal Article↗

PubMed1999

Coagulase-negative staphylococci: role as pathogens.

Coagulase-negative staphylococci have long been regarded as apathogenic but their important role as pathogens and their increasing incidence have been recognized and studied in recent years. Although specific virulence factors are not as clearly established as they are in Staphylococcus aureus, it seems clear that factors such as bacterial polysaccharide components are involved in attachment and/or persistence of bacteria on foreign materials. Coagulase-negative staphylococci are by far the most common cause of bacteremia related to indwelling devices. Most of these infections are hospital-acquired, and studies over the past several years suggest that they are often caused by strains that are transmitted among hospitalized patients. Other important infections due to coagulase-negative staphylococci include central nervous system shunt infections, native or prosthetic valve endocarditis, urinary tract infections, and endophthalmitis. Intravenous treatment of systemic infections is usually required because coagulase-negative staphylococci have become increasingly resistant to multiple antibiotics.

Anti-Bacterial Agents↗