PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Aerococcus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 73 records · Page 4Linked to original sources

Purification of the viridicin produced by Aerococcus viridans.

A new bacteriocin produced by Aerococcus viridans was purified. Bacteria grown on liquid medium synthesized a bacteriocin, viridicin, which can be extracted from the cells by treatment with 0.86 M NaCl solution. Viridicin production was not induced by ultraviolet irradiation or by treatment with mitomycin C. The bacteriocin was purified by ultrafiltration, gel filtration, and preparative polyacrylamide disc gel electrophoresis. The molecular weight was between 100,000 and 120,000. The purified viridicin was homogeneous on polyacrylamide gel electrophoresis. The viridicin was composed of protein, carbohydrate, and lipid.

Bacteriocins↗

Genetic basis of antibiotic resistance in Aerococcus viridans.

Resistance to at least one of the following antibiotics was found in eight wild-type strains of Aerococcus viridans: erythromycin (six strains), tetracycline and minocycline (five strains), chloramphenicol (one strain), and high levels of streptomycin (one strain). None of the strains transferred any of their antibiotic resistance markers into streptococcal, enterococcal, or A. viridans recipients by conjugation. By DNA-DNA hybridization experiments, the ermB gene of transposon Tn917, of Enterococcus faecalis origin, was detected in five of the six strains resistant to erythromycin and was localized for one strain on the chromosome and for four strains on nonconjugative small (4.7- to 4.9-kilobase) plasmids. The tetM gene of the conjugative transposon Tn916, of E. faecalis origin, was localized on the chromosome of four of the five strains resistant to tetracycline and minocycline; in three of these strains a structure similar to that of Tn916 was found. Homology to the tetO gene of pUA466, of Campylobacter jejuni origin, was detected on the chromosome of the fifth strain. No sequence homology was detected in any strain with probes corresponding to the tetL gene of group B Streptococcus origin, to the ermA gene of the transposon Tn554 of Staphylococcus aureus origin, or to the cat genes of either pC194 or pC221 of S. aureus origin.

Anti-Bacterial Agents↗

Aerococcus viridans in the hospital environment.

Aerococcus viridans has been described as an airborne organism prevalent in occupied rooms. It has also been described as an organism having many characteristics that might cause it to be confused with streptococci or staphylococci, and this may account for the fact that the presence of A. viridans has not been reported in the hospital environment or in clinical specimens. Swab specimens were taken from 47 objects in 11 different areas in a local hospital, cultured overnight in Trypticase Soy Broth, and streaked on blood-agar and on a selective serum agar containing potassium tellurite and crystal violet. Of 85 alpha-hemolytic cultures isolated, 11 proved to be typical A. viridans based on diagnostic tests that also were applied to a collection of gram-positive cocci, including authentic strains of A. viridans. These organisms are gram-positive cocci with a strong tendency toward tetrad formation in broth cultures. They are predominantly aerobic, have a very weak catalase activity, and lack porphyrin respiratory enzymes. Three similar cultures also were obtained from routine clinical specimens.

Air Microbiology↗

Detection of serum thermolabile beta-2 macroglycoprotein (Hakata antigen) by enzyme-linked immunosorbent assay using polysaccharide produced by Aerococcus viridans.

Although a serum thermolabile beta-2 macroglycoprotein (TMG) may play a role in host defense as a lectin, little is known of its related physiological functions, mainly due to a lack of appropriate methods for tracing the functions of TMG. We identified a polysaccharide from Aerococcus viridans, PSA, which reacts with TMG, and based on this finding, we developed an enzyme-linked immunosorbent assay to trace the functions of TMG. Using ethanol precipitation and DEAE-Sepharose and Sephacryl S-400 column chromatographies, we isolated PSA from cultured medium of A. viridans, and it exhibited specific binding against TMG in blood samples. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the isolated PSA showed ladder bands that implied the existence of repeating units composed of D-glucose, N-acetyl-D-glucosamine, D-mannose, and D-xylose, as confirmed by gas chromatography-mass spectrometry. SDS-PAGE and immunochemical analysis, using rabbit anti-TMG antibody, showed that PSA specifically binds solely to intact serum TMG but not to TMG heated at 56 degrees C for 30 min, a condition under which antigenicity is lost. TMG in serum samples bound to PSA in a dose-dependent manner, and this binding was clearly suppressed by addition of PSA. These observations indicate that PSA is a useful adsorbent to TMG and can be used to develop appropriate methods for tracing the functions of TMG.

Antibodies, Bacterial↗

Identification of monounsaturated fatty acids of Aerococcus viridans with dimethyl disulfide derivatives and combined gas chromatography-mass spectrometry.

Location of the double-bond position of monounsaturated fatty acids of Aerococcus viridans was accomplished by combined gas chromatography (GC)-mass spectrometry analysis of dimethyl disulfide (DMDS) derivatives. The monoenoic fatty acids from whole bacterial cells were converted to methyl esters and then to DMDS adducts and analyzed by capillary GC-mass spectrometry. The mass spectra of DMDS adducts gave an easily recognizable molecular ion (M+) and two major diagnostic ions attributable to fragmentation between the two CH3S groups located at the original site of unsaturation. Two relatively novel acids that distinguish aerococci from bacteria of closely related genera were identified as C16:1 omega 9c and C16:1 omega 9t from their mass spectrometry fragmentation patterns and retention characteristics on nonpolar capillary GC columns.

Disulfides↗

Aerococcus-like organism, a newly recognized potential urinary tract pathogen.

During the last 10 to 15 years, Aerococcus-like organisms have been isolated from urinary tract specimens from hospitalized patients at Bispebjerg Hospital, Copenhagen, Denmark, with signs of urinary tract infection, and a single strain has been deposited at the National Collection of Type Cultures (NCTC 12142). An additional 63 isolates from the urine specimens of as many patients with suspected urinary tract infection have been identified from seven departments of clinical microbiology in Denmark. Clinical information indicates that this organism may be involved in urinary tract infection. These strains and ten previously collected strains, two of which were from blood cultures, were characterized phenotypically. By comparing the results with data on other gram-positive, catalase-negative cocci or coccobacillary organisms, the identified organisms seem to represent a separate taxon.

Adolescent↗

Development of a polymerase chain reaction test for specific identification of the urinary tract pathogen Aerococcus urinae.

A polymerase chain reaction test was developed for identification of the gram-positive urinary tract pathogen Aerococcus urinae. Oligonucleotide primers were based on highly specific sequences within the small-subunit rRNA gene. A confirmatory test based on hybridization of the amplified products to a highly specific internal probe was also developed.

Bacteriological Techniques↗

Aerococcus urinae in urinary tract infections.

Aerococcus urinae is a rarely reported pathogen, possibly due to difficulties in the identification of the organism. A. urinae is a gram-positive coccus that grows in pairs and clusters, produces alpha-hemolysis on blood agar, and is negative for catalase and pyrrolidonyl aminopeptidase. Some of these characteristics and its being absent from the databases of most commercial identification systems could allow A. urinae to be misidentified as a streptococcus, enterococcus, or staphylococcus. We report two cases of urinary tract infection (UTI) caused by A. urinae and characterize these isolates by morphology, biochemical testing, whole-cell fatty acid analysis, 16S rRNA gene sequencing, and antibiotic susceptibilities. Most patients infected with A. urinae are elderly males with predisposing conditions who present initially with UTI. Because A. urinae is resistant to sulfonamides, treatment could be inappropriate, with infections resulting in serious complications, including death. It is important for the clinician and the microbiologist to consider A. urinae a potential pathogen and proceed with thorough microbiological identification.

Aged↗

Septicaemia associated with an Aerococcus viridans infection in immunodeficient mice.

This report describes a case series of septicaemia caused by infection with Aerococcus viridans in immunodeficient NOD/LtSz-Prkdc(scid) (NOD/SCID) mice. During a period of 3 weeks more than 40 animals died or became ill with clinical signs of ruffled coat, weight loss, laboured breeding, and distended abdomen. At necropsy it was found that the animals displayed symptoms of sepsis with widespread abscesses in the liver, heart, lungs or pyogenic peritonitis. A Gram-positive coccus was isolated in pure culture from the abscesses or peritoneum from affected animals. According to phenotypic and phylogenetic characterization, the isolate was identified as A. viridans. This is the first report of a spontaneous outbreak of septicaemia caused by A. viridans infection in immunodeficient laboratory mice and we conclude that A. viridans should be considered as a pathogen in immunodeficient mice.

Animals↗

Septicaemia due to Aerococcus urinae.

In a case of septicaemia, Aerococcus urinae was isolated from the blood. The patient had undergone operation on the prostate gland. The urine was sterile.

Aged↗

Penicillin-resistant Aerococcus viridans bacteremia associated with granulocytopenia.

Aerococcus viridans, a catalase-negative gram-positive coccus rarely causing bacteremia, was isolated from blood cultures of a 52-yr-old man under the granulocytopenic condition. The isolate showed the typical characteristics of A. viridans, i.e., tetrad arrangements in gram stain, positive pyrrolidonyl aminopeptidase (PYR) and negative leucine aminopeptidase (LAP) reactions, and no growth at 45 degrees C. The isolate was revealed to be highly resistant to penicillin, erythromycin, clindamycin, and ceftriaxone, although most strains of A. viridans isolated from the previously reported patients were susceptible to penicillin and other commonly used antibiotics. Even though A. viridans is rarely associated with human infections, it could be a potential causative agent of bacteremia, especially in immunocompromised patients.

Agranulocytosis↗

Estimated prevalence of Aerococcus viridans and Anophryoides haemophila in American lobsters Homarus americanus freshly captured in the waters of Prince Edward Island, Canada.

The Canadian lobster industry holds lobsters Homarus americanus in captivity for various periods to supply markets with live product year-round. Mortality during holding results in considerable losses, estimated at 10 to 15 % yr(-1) by the industry. This study examined the prevalence of Anophryoides haemophila and Aerococcus viridans, causative agents of 'bumper car' disease and gaffkemia, respectively, in lobsters freshly captured in the waters of Prince Edward Island during the spring and fall fishing seasons of 1997. A total of 116 lobsters were sampled in the spring, and 138 in the fall. A. haemophila was not detected in the spring, while the prevalence was 0.72 % in the fall with a 95% confidence interval (CI) of 0.02 to 3.97% and an overall prevalence of 0.39% (95% CI: 0.01 to 2.17%). The prevalence of A. viridans was estimated at 6.9% (95% CI: 3.0 to 13.14%) in the spring, 5.8% in the fall (95% CI: 2.54 to 11.10%), and 6.30% overall (95% CI: 3.64 to 10.03%). Because of the reduced interest in food of diseased lobsters, and compromised metabolism in the case of gaffkemia, these prevalence estimates are likely underestimates of the true prevalence of gaffkemia and 'bumper car' disease in the wild populations of lobster around Prince Edward Island.

Animals↗

Studies on the virulence of Aerococcus viridans (var.) homari, the causative agent of gaffkemia, a fatal disease of homarid lobsters.

Virulent and avirulent strains of Aerococcus viridans (var.) homari were used to extend previous studies to determine and confirm differences between the 2 types. Virulent strains possessed polysaccharide capsules and were not agglutinated by lobster hemolymph serum; avirulent strains did not have capsules, were agglutinated by the lobster hemolymph serum, and most did not grow well in lobster hemolymph serum. Growth of the avirulent strains in sterile lobster hemolymph serum induced the production of capsules (which reached a maximum after 5 to 7 d incubation), eliminated susceptibility of the strains to the lobster serum agglutinin, and restored their virulence against lobsters. The factor(s) in lobster hemolymph serum inducing the long-lasting phenotypic response of virulence was (were) heat labile.

Agglutination Tests↗

Response of American lobsters Homarus americanus to infection with a field isolate of Aerococcus viridans var. homari (Gaffkemia): survival and haematology.

American lobsters Homarus americanus were inoculated with a field isolate of the Gram-positive bacterium Aerococcus viridans var. homari, causative agent of gaffkemia, at 1 x 10(6), 1 x 10(4) or 1 x 10(2) colony forming units (CFU) kg(-1) or with sterile 3% NaCl and maintained at 10 or 15 degrees C until they died or were euthanised. Progression of disease in individual animals was monitored daily by total haemocyte count (THC) and haemolymph culture. Post-mortem examinations were performed on all lobsters. Effects of both ambient temperature and infective dose on survival time were observed. Marked bacteraemia occurred in all mortalities. Haemocytopenia (THC < 10 x 10(9) cells l(-1)) preceded death in most, but not all, mortalities.

Animals↗

Induced resistance to infection of lobsters Homarus americanus by Aerococcus viridans (var.) homari, the bacterium causing gaffkemia.

A vaccine composed of steam sterilized (autoclaved) cells of a virulent strain of Aerococcus viridans (var.) homari was effective in protecting lobsters Homarus americanus against gaffkemia. At 15 degrees C the heat-killed vaccines (HKV) at concentrations between 1 and 5 x 10(7) particles kg(-1) lobster body wt induced maximal protection in induction periods ranging from 7 to 11 d. Protection was substantial over the course of a 30 d post-induction trial period. Spring-caught lobsters (i.e. those more fully rehabilitated following ecdysis) gained more protection (LD50 = 1.9 x 10(4)) from the vaccination than did those caught in the late fall-early winter period (lobsters that were not yet fully recovered from ecdysis) (LD50 = 3.2 x 10(3)). The protection offered by the HK vaccine was comparable to that induced by a vaccine produced by incubating the pathogen with low concentrations (2 pg ml(-1)) of the antibiotic vancomycin. The bacterins produced by both methods exhibited similar new properties: (1) agglutination at low titres by lobster hemolymph serum, suggesting an impaired capsule layer, and (2) increased permeability to the large Alcian Blue molecule. With both vaccines, the protection may be a direct result of increased exposure to intact bacterial cell structures by the lobster defences, an exposure which otherwise would be prevented by an intact capsule.

Agglutination Tests↗

Genetic characterization of the lobster pathogen Aerococcus viridans var. homari by 16S rRNA gene sequence and RAPD.

A combination of 16S rRNA sequencing and random amplified polymorphic DNA (RAPD) analysis was used to evaluate the genetic diversity within Aerococcus viridans var. homari, the causative agent of gaffkemia in lobsters. A collection of 7 A. viridans var. homari strains and 2 avirulent A. viridans-like cocci isolated from homarid lobsters harvested from different regions on the Atlantic Coast of North America were analyzed. The isolates are separated geographically and temporally between the years 1947 and 2000. Sequencing of 16S rRNA genes confirmed the inclusion of all 9 isolates in the monophyletic A. viridans clade (99.8 to 100% similarity). RAPD analysis revealed that the 9 A. viridans var. homari isolates could be separated into 2 distinct subtypes. Subtype 1 included the 7 pathogenic lobster isolates and constituted a homogeneous group regardless of their geographical, temporal or virulence differences. Subtype 2 contained the 2 avirulent A. viridans-like cocci that had distinct RAPD patterns and clustered separately with the non-marine A. viridans. RAPD analysis represented a useful method for determining molecular subtyping for the intraspecific classification and epidemiological investigations of A. viridans var. homari.

Animals↗

Esophageal diverticulum associated with Aerococcus viridans infection in a loggerhead sea turtle (Caretta caretta).

A juvenile loggerhead sea turtle (Caretta caretta) stranded in Gran Canaria, Spain was necropsied. The turtle was underweight, had sunken eyes, and small amounts of crude oil were in the oral cavity. The most significant lesion was a large esophageal diverticulum at the junction of the esophagus and stomach. The diverticulum was full of gas and green mucoid fluid and a diffuse thick yellow fibrinonecrotic membrane covered the mucosa. The lumen of the diverticulum also contained moderate numbers of cephalopods, crustaceans, and anthropogenic debris including crude oil balls, plastics, and fishing lines. Histologically there was a severe diffuse fibrinonecrotic esophagitis. Aerococcus viridans was isolated from the diverticulum. This is the first report of an esophageal diverticulum in a sea turtle. Although A. viridans is a known pathogen of lobsters and fishes, there are no reports of A. viridans infection in sea turtles.

Animals↗