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At least 19 recordsLinked to original sources
PubMed1988

Colonization with slime-positive coagulase-negative staphylococci as a risk factor for invasive coagulase-negative staphylococci infections in neonates.

Mucocutaneous cultures obtained at admission and subsequent weekly nasopharyngeal cultures were obtained on 182 infants in the neonatal intensive care unit (NICU) over 3 months to assess whether a relationship existed between colonization with coagulase-negative staphylococci and invasive infection, particularly with respect to slime production. Nasopharyngeal colonization by coagulase-negative staphylococci occurred in a mean of 58% of infants weekly, with an equal prevalence of slime-positive and slime-negative isolates over time. Colonization of the nasopharynx on admission increased from 8.9% of those admitted within the first day of life to 33% of those admitted thereafter (p less than 0.005). The presence of slime-positive coagulase-negative staphylococci on admission was not predictive of later patterns of colonization with respect to slime. Of infants not colonized on admission who had subsequent cultures, 72% became colonized with coagulase-negative staphylococci that were equally likely to be slime-positive or slime-negative. The incidence of invasive infections was 4.4%. Infants with slime-positive mucocutaneous colonization were more likely to develop invasive coagulase-negative staphylococci disease than infants with slime-negative or no colonization (8.4% versus 1.1%; p less than 0.025). The incidence of slime-positive coagulase-negative staphylococci isolates from blood cultures was 6/7 (86%) whereas those from mucocutaneous cultures was 131/260 (50%) (p = 0.06). Colonization with slime-positive coagulase-negative staphylococci is a significant risk factor for developing invasive coagulase-negative staphylococci disease and these organisms are responsible for the majority of coagulase-negative staphylococci invasive infections.

Coagulase↗
PubMed1990

The coagulase of Staphylococcus aureus 8325-4. Sequence analysis and virulence of site-specific coagulase-deficient mutants.

The sequence of the coagulase gene (coa) from Staphylococcus aureus strain 8325-4 is reported. The deduced amino acid sequence of the coagulase protein is compared with previously reported sequences of coagulases from strains 213 and BB. The secreted mature forms of coagulase proteins are composed of three distinct segments: (i) the N-terminal 150-270 residues, which are c. 50% identical, (ii) a central region with high (greater than 90%) residue identities, and (iii) a C-terminal region composed of repeated 27-amino-acid residue sequences. The variable N-terminal sequences are probably responsible for antigenic differences among coagulases of different serotype. The region of coagulase which binds to prothrombin and activates it to form staphylothrombin is also located in the N-terminal half of the protein. A site-specific substitution mutation in the coa gene, which abolished plasma clotting activity, was isolated by recombinational allele-replacement in strains 8325-4 and M60. The Coa- mutants did not show diminished virulence in subcutaneous and intramammary infections of mice. No evidence for a role for coagulase in virulence of toxigenic or nontoxigenic strains was obtained. This contradicts findings of several groups using Coa- mutants generated by chemical mutagenesis and suggests that the earlier results were obtained with strains that had suffered additional mutations in virulence-related genes.

Alleles↗
PubMed2000

Patterns of multidrug resistance among methicillin-resistant hospital isolates of coagulase-positive and coagulase-negative staphylococci collected in the international multicenter study RESIST in 1997 and 1998.

The primary purpose of the multicenter international study "RESIST" was to obtain an update on the degree of multidrug resistance among methicillin-resistant staphylococci collected from a geographically diverse sample. A total of 3,307 staphylococcal isolates were recovered from single patients and primarily from clinical specimens that were collected at 20 collaborating regional health centers located in several countries in Europe, Asia, and Latin America during a 3- to 4-month period each in 1997 and 1998. All strains were deposited at the Laboratory of Molecular Genetics at ITQB/UNL in Oeiras, Portugal, for quality control and for testing by microbiological and molecular typing techniques; the Laboratory of Microbiology at The Rockefeller University serving as organizational center. The majority of strains, 3,100, were methicillin-resistant, of which 1,749 were coagulase positive (methicillin-resistant Staphylococcus aureus, MRSA), and 1,351 were coagulase negative (methicillin-resistant coagulase negative staphylococci, MRCNS). The overall frequency of drug resistance traits among the 1,749 MRSA strains was high (over 70% and up to and over 90% of the strains) to ciprofloxacin, erythromycin, clindamycin, gentamicin, and tetracycline, and was somewhat less frequent to sulfamethoxazole-trimethoprim (45%), chloramphenicol (30%), and rifampin (38%). None of the 3,307 staphylococcal isolates showed reduced susceptibility to vancomycin except for a single methicillin-resistant coagulase-negative isolate. The great majority of staphylococci were also susceptible to the new antimicrobial Synercid. In contrast, resistance to teicoplanin was significant among methicillin-resistant strains of coagulase-negative staphylococci, particularly among Staphylococcus haemolyticus. MRSA isolates showed marked geographic variation in their patterns of multiresistance, most likely reflecting the properties of unique multiresistant MRSA clones dominant in the hospitals that provided the MRSA isolates from the various geographic areas. The multiresistance patterns of MRSA strains and strains of methicillin-resistant coagulase-negative staphylococci originating at the same country source also showed striking differences, suggesting that resistance to antimicrobial agents emerged under different antibiotic pressures in these bacterial species.

Anti-Bacterial Agents↗
PubMed1982

Microtube coagulase test for detection of coagulase-positive staphylococci.

Studies were performed to determine the sensitivity and specificity of a new microtube method for the detection of coagulase production by Staphylococcus aureus. Rabbit plasma containing EDTA was added to and lyophilized in API microtubes. Two standard coagulase plasmas containing EDTA were used in the conventional macrotube test and served as a basis for comparison. No false-positive or false-negative reactions were encountered with the microtube system. With this system, 53% of the coagulase-positive strains tested were detected within 1 h after inoculation, 82% were detected after 2 h, 97% were detected after 3 h, and 99% were detected after 4 h. With the first conventional method, 45, 81, 96, and 98% of the positive strains were detected in 1, 2, 3, and 4 h, respectively, whereas with the second conventional method, only 6% of the positive strains were detected in 1 h, 24% in 2 h, 66% in 3 h, and 81% in 4 h. With the microtube method, 5 of the 139 coagulase-producing strains studied reverted to negative between 5 and 24 h after inoculation, whereas 9 reverted with the more rapid conventional method, and no reversions occurred with the second conventional method. All reversions involved strains which caused gelation of plasma within 1 h after inoculation. The data obtained showed that 99% of the coagulase-positive strains tested could be detected within 4 h by the microtube method. In addition, the microtube method offers a more convenient and economical format for the performance of the coagulase tube test.

Animals↗
PubMed1970

Polymyxin-coagulase-mannitol-agar. I. A selective isolation medium for coagulase-positive Staphylococci.

A selective, differential plating medium was developed for the isolation and identification of coagulase-positive and mannitol-fermenting staphylococci. Coagulase produced by growing Staphylococcus aureus caused an opaque zone of fibrin to form around each colony. Several strains of S. aureus produced a visible coagulase reaction by 8 hr, and all strains gave a positive reaction before 12 hr. Mannitol fermentation was usually observed between 12 and 36 hr. Rabbit serum was filtered through Sephadex G-100 to obtain plasmin- and plasminogen-free coagulase-reacting factor (CRF). False-negative reactions, caused by staphylokinase and staphylococcal Müller factor action on plasminogen, were eliminated when this CRF was used. False-positive reactions by lipolytic, coagulase-negative staphylococci were reduced, since gel filtration removed the serum lipoprotein which served as a primary source of opacity. The addition of 75 mug of polymyxin B per ml selectively retarded the growth of S. epidermidis and minimized false-positive reactions caused by citrate-utilizing gram-negative rods. The preparation, characteristics, and use of the medium are presented.

Agar↗
PubMed1983

Effect of highly purified coagulase and culture filtrate on virulence and immunity of a coagulase-negative mutant of staphylococcus aureus BB.

The virulence of the coagulase-deficient mutant BB-Cgl- 1301 (50% lethal dose [LD50] for mice by the intravenous route) was compared with that of its parental strain, Staphylococcus aureus BB. The BB strain produced free coagulase of serotype I, whereas the mutant 1301 did not. Mice were infected with strain 1301, alone or in combination with a highly purified coagulase type I or type II solution, or with concentrated culture filtrates of parent strain BB or mutant strain 1301. The ratios of the LD50S of 1301 and its combinations to that of BB ranged from 34.9 to 461. Combining strain 1301 with a concentrated culture filtrate of BB (BB-CF2.5) was the most effective for enhancement of its virulence. When mice were infected with a combination of strain 1301 and BB-CF2.5, the LD50 of strain 1301 (1.72 mg of cells [wet weight]) was decreased to 0.13 mg (1.3 x 10(8) CFU). This LD50 yielded the smallest ratio, 34.9, as compared with the LD50 of BB (0.00373 mg). In contrast, when the mice subcutaneously immunized with strain 1301 and BB-CF50 were intravenously challenged by strain BB, the LD50 for the immunized mice was 17.4 times the LD50 for the unimmunized control mice (0.0429 mg as compared with 0.00246 mg), indicating that combination was the most effective for enhancement of mouse immunization with strain 1301. However, combining strain 1301 with the highly purified sample of coagulase increased neither the virulence nor the immunizing power of mutant strain 1301.

Animals↗
PubMed2001

Identification of slide coagulase positive, tube coagulase negative Staphylococcus aureus by 16S ribosomal RNA gene sequencing.

AIMS: To ascertain the clinical importance of a strain of slide coagulase positive but tube coagulase negative Staphylococcus species isolated from the blood culture of a 43 year old patient with refractory anaemia with excessive blasts in transformation who had neutropenic fever. METHODS: The isolate was investigated phenotypically by standard biochemical methods using conventional biochemical tests and two commercially available systems, the Vitek (GPI) and API (Staph) systems. Genotypically, the 16S ribosomal RNA (rRNA) gene of the bacteria was amplified by the polymerase chain reaction (PCR) and sequenced. The sequence of the PCR product was compared with known 16S rRNA gene sequences in the GenBank by multiple sequence alignment. RESULTS: Conventional biochemical tests did not reveal a pattern resembling a known Staphylococcus species. The Vitek system (GPI) showed that it was 94% S. simulans and 3% S. haemolyticus, whereas the API system (Staph) showed that it was 86.8% S. aureus and 5.1% S. warneri. 16S rRNA gene sequencing showed that there was a 0 base difference between the isolate and S. aureus, 28 base difference between the isolate and S. lugdunensis, 39 base difference between the isolate and S. schleiferi, 21 base difference between the isolate and S. haemolyticus, 41 base difference between the isolate and S. simulans, and 23 base difference between the isolate and S. warneri, indicating that the isolate was a strain of S. aureus. Vancomycin was subsequently prescribed and blood cultures taken four days after the start of treatment were negative. CONCLUSIONS: 16S rRNA gene sequencing was useful in ascertaining the clinical importance of the strain of slide coagulase positive but tube coagulase negative Staphylococcus species isolated from blood culture and allowing appropriate management.

Adult↗
PubMed1998

Trends in antibiotic resistance of staphylococci over an eight-year period: differences in the emergence of resistance between coagulase positive and coagulase-negative staphylococci.

The antimicrobial susceptibilities of 1058 Staphylococcus aureus and 2,163 coagulase-negative staphylococci (CNS) isolates obtained from clinical specimen between 1988 and 1995, were determined against 13 anti-staphylococcal antibiotics. During the study period the resistance of Staphylococcus aureus to ciprofloxacin, ceftazidime, and norfloxacin increased significantly by 7%, 4%, and 6%, respectively (p < or = 0.001). By comparison, the antibiotic resistance of CNS to ceftazidime, oxacillin, norfloxacin, ciprofloxacin, fusidic acid, and cefoxitin increased by 20%, 17%, 15%, 14%, 12% and 10%, respectively (p < or = 0.001). Invasive and noninvasive S. aureus had similar antibiotic resistance, whereas CNS invasive isolates were more resistant than noninvasive isolates to every antibiotics, except vancomycin and fusidic acid. These differences were significant (p < 0.001) for oxacillin, cefoxitin, and clindamycin. Our observations confirm that staphylococci and particularly CNS isolates show an important rate of increased resistance to the standard antimicrobials used for therapy, and that the rate of emergence of resistance differ considerably between coagulase-positive and coagulase-negative staphylococci.

Anti-Bacterial Agents↗
PubMed2001

Relatedness between the coagulase gene 3'-end region and coagulase serotypes among Staphylococcus aureus strains.

The 3'-end region of the coagulase gene from 22 strains of Staphylococcus aureus including 10 standard serotype strains was sequenced, and five subgroups with 4-8 tandem repeating units were distinguished among the tested strains. Phylogenetic analysis of the 3'-end region of the coagulase gene indicated that strains belonging to the same serotype were clustered in the same branch. A phylogenetic tree of the deduced amino acid sequences revealed that the C-terminal region might not be responsible for the epitope of the coagulase protein.

Bacteriological Techniques↗
PubMed1983

Polymyxin susceptibility in staphylococci differentiating coagulase-positive and coagulase-negative strains.

47 staphylococcal reference strains representing 13 species were tested for polymyxin sensitivity using tablet and disc diffusion methods. Corresponding MIC and IC50 values were determined with a plate dilution assay. Coagulase-positive strains were found to be more resistant towards polymyxin, and could thereby be separated from coagulase-negative strains. Furthermore, 100 recently isolated staphylococci from clinical specimens were tested, and again the coagulase-positive strains could be identified by their smaller tablet inhibition zones. We conclude that the polymyxin test is an aid in the fast differentiation of staphylococci in laboratories performing primary sensitivity tests.

Coagulase↗
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↗
PubMed1981

Transfer of gentamicin resistance between coagulase-negative and coagulase-positive staphylococci on skin.

The transfer of gentamicin resistance between a coagulase-negative S. hominis strain and various coagulase-positive S. aureus strains on human and murine skin in the absence of a selective agent is described. Transfer occurs at higher frequency on skin than in broth. Skin transfer may account for the apparently explosive occurrence of gentamicin resistant staphylococci in hospitals.

Animals↗
PubMed1996

Different susceptibility of coagulase-positive and coagulase-negative staphylococci to ciprofloxacin.

Ciprofloxacin susceptibility was evaluated in 573 clinical staphylococcal isolates (Staphylococcus aureus 230, methicillin-resistant (MR) 36%; coagulase-negative strains 343, MR 66%) collected from 1989 to 1995. Resistance to ciprofloxacin for MR Staphylococcus aureus was 25% until 1991 when ciprofloxacin was introduced into the hospital formulary, and rose progressively to 90% in 1994-1995. MR Staphylococcus haemolyticus showed a ciprofloxacin resistance of 46% until 1991 and of 73% from 1992 to 1995. In contrast MR Staphylococcus epidermidis and other coagulase-negative strains showed a constant susceptibility to this agent (80%). Ciprofloxacin has limited usefulness against MR Staphylococcus aureus but can be still used to treat Staphylococcus epidermidis infections.

Ciprofloxacin↗
PubMed1997

Incidence of methicillin resistant coagulase positive & coagulase negative staphylococci in blood cultures.

Isolates of Staphylococcus aureus and coagulase negative staphylococci (CONS) from blood culture of bacteraemic patients were studied for methicillin resistance is 1993 and 1996. An increase in methicillin resistance among these isolates was observed in 1996. In 1993, 32.6 per cent isolates of S. aureus were methicillin resistant, this increased to 45.7 per cent in 1996. Methicillin resistance in CONS were 1.6 and 14.6 per cent respectively in 1993 and 1996. This increase in methicillin resistance may pose therapeutic problems and requires more effective drugs based on susceptibility testing of such isolates.

Bacteremia↗