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At least 19 recordsLinked to original sources

PubMed1990

Presence of an additional penicillin-binding protein in methicillin-resistant Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, and Staphylococcus simulans with a low affinity for methicillin, cephalothin, and cefamandole.

The presence of an additional penicillin-binding protein (PBP) was demonstrated in methicillin-resistant strains of Staphylococcus epidermidis, S. haemolyticus, S. hominis, and S. simulans. In these four species, the apparent molecular mass of this protein was analogous to that of PBP 2' of methicillin-resistant S. aureus SR 1550-9. It exhibited a low affinity for methicillin, cephalothin, and cefamandole; and its synthesis was methicillin inducible. Peptide mapping of this PBP from the four species yielded identical results that were analogous to those obtained with S. aureus SR 1550-9. These results suggest that this protein is similar to, if not the same as, PBP 2' of S. aureus and that it is involved in methicillin resistance in the four species studied.

Bacterial Proteins↗

PubMed1991

In vitro selection of resistance to vancomycin in bloodstream isolates of Staphylococcus haemolyticus and Staphylococcus epidermidis.

The purpose of the study was to determine whether vancomycin-resistant strains of Staphylococcus haemolyticus could be selected regardless of the initial MIC of vancomycin. Twenty-one bloodstream isolates of Staphylococcus haemolyticus were studied by broth and agar selection methods. The broth method selected strains for which MICs of vancomycin ranged from 4 to 32 micrograms/ml and MBCs from 16 to greater than 128 micrograms/ml. The agar method selected strains for which MICs ranged from 8 to 32 micrograms/ml and MBCs from 8 to greater than 128 micrograms/ml. For comparison, seven strains of Staphylococcus epidermidis were evaluated by the agar selection method. Final MICs of vancomycin ranged from 8 to 16 micrograms/ml; MBCs ranged from 16 to 64 micrograms/ml. Clearly, in vitro exposure to vancomycin can select strains of Staphylococcus haemolyticus and Staphylococcus epidermidis for which MIC values are beyond the susceptible breakpoint.

Bacteremia↗

PubMed1985

Plasmid-mediated resistance to lincomycin by inactivation in Staphylococcus haemolyticus.

Staphylococcus haemolyticus BM4610 was resistant to high levels of lincomycin and susceptible to macrolides, clindamycin, and streptogramins. This resistance phenotype, not previously reported for a human clinical isolate, was due to inactivation of the antibiotic. The gene conferring resistance to lincomycin in strain BM4610 was carried by a 2.5-kilobase plasmid, pIP855, which was cloned in Escherichia coli. Plasmid pIP855 caused inactivation of both lincomycin and clindamycin in S. haemolyticus and in E. coli but conferred detectable resistance to lincomycin only in S. haemolyticus and to clindamycin only in E. coli.

Clindamycin↗

PubMed1989

Antimicrobial resistance in nosocomial isolates of Staphylococcus haemolyticus.

Staphylococcus haemolyticus is frequently cultured from hospitalized patients and is characterized by resistance to multiple antimicrobial agents. We found that S. haemolyticus represented 70 of 524 (13%) coagulase-negative staphylococcal isolates identified by the clinical microbiology laboratories of two hospitals over 2 months. S. haemolyticus isolates were recovered from wounds (44%), urine (26%), blood (10%), and other sources (20%). All S. haemolyticus isolates were tested for susceptibility to six antimicrobial agents; 77% were resistant to three or more agents, and 41% were resistant to five or six agents. In addition, among 47 multiply resistant isolates, high MICs (greater than or equal to 6.25 micrograms/ml) of vancomycin (62% of isolates) and teicoplanin (91% of isolates) were found. DNA probes which were derived from S. epidermidis or S. aureus and which contained sequences associated with resistance to antimicrobial agents were used to detect specific genes in the total cellular and plasmid DNAs of 10 resistant S. haemolyticus isolates. Resistance gene probes and the numbers of resistant isolates hybridizing were as follows: methicillin, 10 of 10; gentamicin, 9 of 10; erythromycin, 7 of 10; and trimethoprim, 0 of 10. Genes for resistance to methicillin were found only in chromosomal locations, genes for resistance to gentamicin were found in both chromosomal and plasmid locations, and genes for resistance to erythromycin were found in plasmid locations only. With the exception of trimethoprim resistance determinants, similar genes were found among concurrently isolated multiply resistant S. epidermidis isolates from our hospitals. S. haemolyticus is a potentially important nosocomial species which readily acquires antimicrobial resistance genes and which shares, to some extent, in a common gene pool with S. epidermidis.

Anti-Bacterial Agents↗

PubMed2006

Heterogeneous resistance to vancomycin in Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains: characterisation of glycopeptide susceptibility profiles and cell wall thickening.

The population analysis profile (PAP) method as well as analysis of autolytic activity and cellular ultrastructure by transmission electron microscopy (TEM) were used to characterise Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus warneri clinical strains with reduced susceptibility to glycopeptides. All strains showed heterogeneous profiles to vancomycin and teicoplanin by the PAP method. Subpopulations that grew in the presence of high concentrations of each drug were selected from the PAP as derivative strains. Their glycopeptide minimal inhibitory concentrations (MICs) were determined and subsequently all parental and derivative strains were grown in one-half of the MIC of vancomycin or teicoplanin. An increase in cell wall thickness of all derivative strains was seen by TEM, with statistically significant values (P<0.01) compared with their respective parental strains. In general, variable rates of autolysis among the strains were observed. Cell wall thickness is an important factor involved in glycopeptide resistance and, in association with PAP results, confirmed the Brazilian coagulase-negative staphylococci clinical isolates as being heteroresistant to glycopeptides. Detection of these heteroresistant organisms is important in order to achieve more judicious use of vancomycin and teicoplanin in hospitals.

Anti-Bacterial Agents↗

PubMed1990

Homology of mecA gene in methicillin-resistant Staphylococcus haemolyticus and Staphylococcus simulans to that of Staphylococcus aureus.

A penicillin-binding protein of molecular weight 76,000 inducible by beta-lactams was detected in methicillin-resistant Staphylococcus haemolyticus and Staphylococcus simulans. DNA from these strains hybridized to the mecA gene from Staphylococcus aureus; however, the chromosomal HindIII fragments containing the mecA genes were 3.4 kilobases in S. haemolyticus and 4.3 kilobases in S. simulans.

Bacterial Proteins↗

PubMed1992

In vitro adherence of Staphylococcus saprophyticus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus aureus to human ureter.

Staphylococcus saprophyticus adhered to human ureteral epithelium in vitro. The levels of adherence, which were determined quantitatively with the scanning electron microscope, correlated well with bacterial hemagglutinating activities with sheep erythrocytes (r = 0.9459, P < 0.01). Transmission electron microscopy revealed that the adhering bacteria and the hemagglutinating bacteria possessed similar pili-like structures on their cell surfaces. Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus aureus did not adhere to the epithelium. Only S. aureus adhered markedly to the connective tissue of the ureter, and adhesion of this organism was direct via its cell wall. This adherence test system clearly showed up differences in the abilities of these staphylococcal species to adhere to the urinary tract.

Bacterial Adhesion↗

PubMed1989

Activities of daptomycin and teicoplanin against Staphylococcus haemolyticus and Staphylococcus epidermidis, including evaluation of susceptibility testing recommendations.

The in vitro activities of daptomycin, teicoplanin, and three other antimicrobial agents were determined against 105 strains of Staphylococcus haemolyticus and 92 strains of Staphylococcus epidermidis. The MICs for 90% of strains tested (MIC90s) of fusidic acid and rifampin were less than or equal to 0.25 microgram/ml. The MIC90s of daptomycin and vancomycin were less than or equal to 4 micrograms/ml. Teicoplanin had a comparable MIC90 of less than or equal to 4 micrograms/ml for isolates of S. epidermidis. However, MIC90s were 8 and 16 micrograms/ml for oxacillin-susceptible and oxacillin-resistant S. haemolyticus, respectively. Disk diffusion tests were evaluated for daptomycin and teicoplanin. Disks with 30 micrograms of teicoplanin performed satisfactorily when S. epidermidis was tested, but when S. haemolyticus was tested, there was a very major error rate of 10% and a minor error rate of 38%.

Anti-Bacterial Agents↗

PubMed2005

The discovery of a multi-resistant Staphylococcus haemolyticus clone in the hospital and community environment in south western Nigeria.

Among clinically significant isolates of coagulase negative staphylococci, Staphylococcus haemolyticus is ranked second after Staphylococcus epidermidis. It has been associated with septicemia in newborns and various infections in persons with compromised host defenses and implanted foreign bodies. The existence of a multi-resistant Staphylococcus haemolyticus clone was discovered during a study on patients with skin and soft tissue infections at two local health clinics and in a referral hospital in South Western Nigeria. The clonal nature of these strains was determined by antibiotic susceptibility profile and pulsed field gel electrophoresis. This represents the first report of what appears to be a hospital-acquired and transmitted Staphylococcus haemolyticus clone in South Western Nigeria. Careful infection control measures and strain typing are urgently needed to understand species epidemiology and to limit the spread of multi-resistant strains within and beyond healthcare facilities.

Academic Medical Centers↗

PubMed2001

Glycopeptide susceptibility profiles of nosocomial multiresistant Staphylococcus haemolyticus isolates.

We investigated 48 Staphylococcus haemolyticus isolates from patients and medical staff in terms of susceptibility to and in-vitro selection for vancomycin and teicoplanin in regard to their antibiotypes. On comparison of multiresistant S. haemolyticus isolates with non-multiresistant isolates, the geometric mean minimum inhibitory concentration (MIC) of vancomycin for multiresistant S. haemolyticus was 2.9 microg/ml, and that of teicoplanin was 18.0 microg/ml, both of which values were significantly greater than the corresponding mean MICs of vancomycin (2.0 microg/ml) and teicoplanin (4.7 microg/ml) for nonmultiresistant isolates. After agar selection, the mean of the highest teicoplanin concentration of selected plates for multiresistant S. haemolyticus was 97.1 microg/ml, which was significantly higher than that for nonmultiresistant isolates (57.8 microg/ml). However, the means' of the highest vancomycin concentrations after agar selection for multiresistant and nonmulti-resistant isolates were the same, at 7.4 microg/ml, with no colonies capable of growing in 32 microg/ml of vancomycin. There was no significant difference in glycopeptide susceptibility between oxacillin-resistant and oxacillin-susceptible isolates among nonmultiresistant S. haemolyticus. The geometric mean MICs of vancomycin for oxacillin-resistant and oxacillin-susceptible isolates were 2.1 microg/ml and 1.6 microg/ml, and those of teicoplanin were 4.4 microg/ml and 5.6 microg/ml, while the means of the highest concentrations of the selected plates of vancomycin were 8.6 microg/ml and 3.3 microg/ml, and those of teicoplanin were 52.8 microg/ml and 74.7 microg/ml, respectively. Multiresistant isolates showed significantly greater mean MICs of vancomycin and teicoplanin and higher teicoplanin concentration of the selected plates than nonmultiresistant isolates, irrespective of oxacillin resistance. These results indicate that methicillin resistance may not be related to reduced susceptibility to glycopeptide in S. haemolyticus, and that a multiresistant profile is associated more with a decreasing susceptibility to glycopeptides then with resistance to oxacillin. In this study, antibiotypes showed good concordance with pulsed-field gel electrophoresis typing results, with a sufficiently high discriminatory ability index, of 0.912. We consider that primary screening with antimicrobial susceptibility testing and antibiotyping, with attention to the multiresistant profile, would be useful for monitoring nosocomial S. haemolyticus colonization and infection.

Anti-Bacterial Agents↗

PubMed1998

Molecular characterization of epidemic multiresistant Staphylococcus haemolyticus isolates.

Fifty-five Staphylococcus haemolyticus specimens isolated from patients and neonatal intensive care unit staff were tested for susceptibility to 12 antimicrobial agents. There were 34 multidrug-resistant isolates which were resistant to oxacillin, ampicillin, cefazolin, cefmetazole, imipenem, and gentamicin. These isolates had a higher frequency of resistance to tobramicin and ofloxacin, and relatively high MICs (2 to 4 micrograms/mL) for vancomycin, although none of the isolates were vancomycin resistant. To investigate hospital-acquired colonization and infection by multiresistant S. haemolyticus, we examined all isolates by pulsed-field gel electrophoresis (PFGE) after SmaI and SstII digestion, and detected an endemic PFGE pattern in multiresistant isolates. The results suggested that local spread of multiresistant S. haemolyticus was hospital acquired, and that the hospital staffs functioned as a reservoir.

Ampicillin↗

PubMed1996

Characterization of IS1272, an insertion sequence-like element from Staphylococcus haemolyticus.

We have previously shown (G. L. Archer, D. M. Niemeyer, J. A. Thanassi, and M. J. Pucci, Antimicrob. Agents Chemother. 38:447-454, 1994) that some methicillin-resistant staphylococcal isolates contain a partial deletion of the genes (mecR1 and mecI) that regulate the transcription of the methicillin resistance structural gene (mecA). When a fragment of DNA inserted at the point of the mecR1 deletion was used as a probe, hybridization with multiple bands was detected for Staphylococcus haemolyticus genomic DNA. In the present study, DNA sequencing of four unique clones recovered from a lambda library of S. haemolyticus revealed identical 1,934-bp elements. Each element, designated IS1272, contained 16-bp terminal inverted repeats (sequence identity, 15 of 16 bp) and two open reading frames of 819 and 687 bp; there were no flanking target site duplications. Database searches yielded amino acid homology with proteins predicted to be encoded by open reading frames from a putative insertion sequence element from Enterococcus hirae. DNA probes from each end and the middle of IS1272 were hybridized with restriction endonuclease-digested genomic DNA from clinical S. haemolyticus, Staphylococcus epidermidis, and Staphylococcus aureus isolates. Each of the 20 or more copies of the element found in S. haemolyticus isolates was intact, and copies were found in most chromosomal SmaI fragments. S. aureus and S. epidermidis isolates contained mostly incomplete fragments of the element, and there were many more hybridizing fragments in methicillin-resistant than in methicillin-susceptible isolates. IS1272, which appears to be primarily resident in S. haemolyticus, has disseminated to multiple staphylococcal species and is prevalent in multiresistant isolates.

Amino Acid Sequence↗

PubMed1988

Site of action of a gonococcal growth inhibitor produced by Staphylococcus haemolyticus.

The inhibitory substance produced by Staphylococcus haemolyticus strain no. 7 acts on growing as well as resting gonococcal cells, as shown by reductions in viable counts. The optical density of these cell suspensions was only slightly reduced. The inhibitor caused lysis of gonococcal spheroplasts at 24 degrees C and 37 degrees C, but was much less active at 4 degrees C. Acting on intact gonococcal cells, the inhibitor caused a temperature-dependent release of radioactive cytoplasmic material. Electronmicroscopy showed that treated suspensions contained ghost cells with the cell envelope relatively intact. Our results suggest that the inhibitor may act on the cytoplasmic membrane of the gonococcal cell causing cytoplasmic leakage and, eventually, death.

Antimicrobial Cationic Peptides↗

PubMed1988

The amino acid sequence of a gonococcal growth inhibitor from Staphylococcus haemolyticus.

A gonococcal inhibitor produced by Staphylococcus haemolyticus was separated into three components by reverse-phase h.p.l.c. The amino acid composition analysis of each of the three components indicated extensive similarities. N-Terminal sequence analysis of all three components allowed the identification of the first 27-30 residues of each. The complete primary structure of each component was determined from the sequence analysis of trypic peptides and peptides generated by mild acid hydrolysis. Each component is composed of 44 amino acid residues, with evidence suggesting the presence of an N-terminal formylmethionine residue in each. The components I, II and III have respectively 33, 29 and 33 identical amino acid residues in their sequences, which represents 75%, 65.9% and 75% homology. These components contain a high proportion of hydrophobic amino acids, and their hydrophobicity profiles are closely related. Also, each of the three components contains a positively charged residue (lysine) as the third residue, followed by a core of hydrophobic residues. These results suggest that the three components are possible signal sequences of one or more secreted or membrane-associated proteins.

Amino Acid Sequence↗

PubMed2000

Glycopeptide susceptibility profiles of Staphylococcus haemolyticus bloodstream isolates.

Twelve clinical strains of Staphylococcus haemolyticus (eight methicillin resistant and three methicillin susceptible), isolated from blood cultures between 1982 and 1997, were investigated for teicoplanin and vancomycin susceptibility profiles. On the basis of conventional MIC tests and breakpoints, four isolates were susceptible (MICs, 1 to 8 microgram/ml) and eight were resistant (MICs, 32 to 64 microgram/ml) to teicoplanin while all were susceptible to vancomycin (MICs, 1 to 2 microgram/ml). All four strains for which the conventional teicoplanin MICs were within the range of susceptibility expressed heterogeneous resistance to teicoplanin and homogeneous vancomycin susceptibility. Of the eight strains for which the conventional teicoplanin MICs were within the range of resistance, six expressed heterogeneous and two expressed homogeneous teicoplanin resistance while seven showed heterogeneous vancomycin resistance profiles (with subpopulations growing on 8 microgram of the drug per ml at frequencies of >/=10(-6) for six strains and 10(-7) for one) and one demonstrated homogeneous vancomycin susceptibility. Of six bloodstream isolates of other staphylococcal species (S. aureus, S. epidermidis, and S. simulans), for all of which the conventional teicoplanin MICs were >/=4 microgram/ml and the vancomycin MICs were </=2 microgram/ml, none exhibited heterogeneous susceptibility profiles for teicoplanin while three showed homogeneous and three showed heterogeneous susceptibility profiles for vancomycin (with subpopulations growing on 8 microgram of the drug per ml found for only one strain). The results of this study indicate that a heterogeneous response to glycopeptides is a common feature of S. haemolyticus isolates and suggest that susceptibility to glycopeptides as determined by conventional MIC tests may not be predictive of the outcome of glycopeptide therapy.

Anti-Bacterial Agents↗

PubMed1990

Selection for vancomycin resistance in clinical isolates of Staphylococcus haemolyticus.

Killing curves were used to characterize Staphylococcus haemolyticus isolates previously reported to contain subpopulations showing increased resistance to vancomycin. Results suggested that vancomycin and teicoplanin were ineffective at a concentration of 8 micrograms/ml and growth was seen between 24 and 48 h. Conversely, the lipopeptide antibiotic daptomycin at the same concentration rapidly killed tested strains by 6 h. Various staphylococcal strains were examined to determine if vancomycin resistance could be selected in all strains of staphylococci, was specie(s) restricted, or was unique to this patient's clinical isolates. About 1 x 10(8) colony-forming units were added to melted brain-heart infusion agar plates containing 12 micrograms/ml of vancomycin. Plates were examined after 48 h for presence of resistant clones. Results indicated that selection for vancomycin resistance was restricted to S. haemolyticus strains. Further, all S. haemolyticus isolates that displayed a double zone of growth around imipenem agar diffusion discs (Impdz) contained stably resistant subpopulations. Vancomycin resistance could not be selected in imipenem-sensitive derivative clones. Impdz isolates that were recovered from geographically distinct locations displayed nearly identical SDS-PAGE protein profiles. It appears that a characteristic susceptibility pattern displayed by clinical isolates of S. haemolyticus may provide a marker for those strains that contain subpopulations having increased resistance to vancomycin.

Bacterial Proteins↗

PubMed1997

Protease-induced multicell formation in Staphylococcus haemolyticus.

Multicellular cells were efficiently induced in Staphylococcus haemolyticus by the addition of protease to exponentially growing cultures at 30 C. Electron microscopy revealed the formation of tetrad-shaped multicells that were septated but not separated from each other. Incubation of the multicells with extract from the cells grown without protease resulted in a fourfold increase in the number of colony-forming units as compared with the untreated control. An electrophoretic analysis showed that protease caused a loss of cell wall-lytic activity of the cell, which possibly led to the formation of multicells through cessation of cross wall separation.

Cell Division↗

PubMed1992

Detection and purification of a potential precursor protein or a prohaemolysin produced by Staphylococcus haemolyticus.

The haemolytic substance H7 produced by Staphylococcus haemolyticus is composed of three peptides out of 44 amino acid residues each having a structure resembling a signal peptide. The cytoplasmic fraction for the presence of a protein precursor containing this signal sequence was investigated. Specific rabbit IgGs to substance H7 were isolated by affinity chromatography on Sepharose-4B-H7. These anti-H7 IgGs recognized mainly a 51 kD protein in the cytoplasmic fraction of S. haemolyticus from 2, 4, 6, 8, 10 and 23 h cultures. These results support the idea that the 51 kD protein could be either a prohaemolysin or else the precursor of a protein of unknown function with a signal sequence showing homology with the haemolytic peptides. After affinity chromatography on Sepharose-4B-anti-H7, the 51 kD protein was shown associated with an RNA-protein complex composed of four or five proteins and an RNA estimated at 300 nt. This complex could be associated with the machinery of protein secretion. The 51 kD protein was finally purified to homogeneity by HPLC on a Protein Pak DEAE-5PW column in the presence of 5 M urea.

Antibodies↗