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Seven strains belonging to the family Micrococcaceae and possessing strong antagonistic properties against Staph. aureus and several other Gram-positive bacteria, have been isolated. The strains were characterized and identified, phage typed, tested for antibiotic-sensitivity and antagonistic activities. Two patients of inhibition were noted.
Materials from 1134 patients with various surgical infections were tested. From the materials collected from purulent inflammatory foci 2137 cultures were isolated. Many of them belonged to Micrococcaceae (63.7 per cent). Cultures belonging to Enterobacteriaceae and Streptococcaceae were isolated from 50.9 and 25.2 per cent of the patients respectively. Isolates belonging to other families were less frequent: diphtheroids were isolated from 13.3 per cent of the patients and Pseudomonas spp. were isolated from 10.6 per cent of the patients. The majority of the isolates of diverse taxons were sensitive to gentamicin (73 to 98.4 per cent). As the second active antibiotic the following should be indicated: fusidin, active against staphylococci (S. epidermidis and S. aureus, 70.5 and 83.3 per cent respectively); ristomycin, active against micrococci and diphtheroids (75.3 and 79.1 per cent respectively); ampicillin, active against S. faecalis (61.3 per cent); polymyxin, active against the trib microbes Escherichia, Klebsiella and Pseudomonas (75.5, 64.3 and 71.4 per cent respectively). No second antibiotic active against a significant percentage of various species of Proteus, fecal alkali forming bacteria, and A. calcoaceticus was stated. Sporulating aerobes were sensitive to the majority of the antibiotics.
Seven strains belonging to the Micrococcaceae family and excreting substances with antibiotic activity, were grown in submerged cultures on technical scale for isolation, purification and identification of biologically active compounds. Two basic substances were isolated and classified to the micrococcin antibiotics family. The naturally occurring mixture of micrococcin M1 and M3 was called micrococcin M. This antibiotic has the formula C48H50O11N12S6 and a molecular weight of about 1160, melting point 221--224 degrees C, and optical rotation [a]20/D = + 66.6. Other antibiotically active substances produced by seven investigated strains were identified as micrococcin M or as separate compounds. Comparison with previously described micrococcin and micrococcin P has been made.
It has been valued a new quick latex method (Staphaurex Wellcome) for the identification of the aureus Staphylococcus. This shown simultaneously the Clumping Factor (CF) and the A protein; the production of the free Coagulase (CL) and the Thermonuclease (TNase), has been utilized as methods of remarking. On 120 bacterial stocks isolated by many biological materials, belonging to the family of the Micrococcaceae, 56 stocks was identified as aureus. St. and 64 as not aureus St. For what concerns the quick Staphaurex method, it has shown a sensitivity of 83.4, with 8 false negatives on 120 cases, while it proved very satisfactory as specification with one false positive.
During 1983, the antibacterial activity of ceftizoxime has been tested in vitro against 325 strains of Enterobacteriaceae, Streptococcaceae, Micrococcaceae, Pseudomonaceae and Acinetobacter sp. isolated from material of human origin (blood, urine, faeces, sputum, various exudates). Except for S. faecalis and some strains of P. rettgeri, P. aeruginosa, A. calcoaceticus, Staphylococcus spp. all the strains examined were found to be sensitive to the antibiotic, whose MIC was 0.05-1.5 micrograms/ml in the great majority of cases. For 72 ceftizoxime-sensitive strains the MBC/MIC ratio was nearly always under 4:1, confirming the drug's bactericidal activity. On strains of Enterobacteriaceae (E. coli, K. pneumoniae, S. marcescens, S. typhimurium) MIC of ceftizoxime achieved a minimum bactericidal time (MBT) between 3 and 4 hours of bacteria-antibiotic contact, and bacterial survival percentages were, in any case, very low as early as the 1st hour.
The antigenic features of S. aureus peptidoglycan (PG) were studied in the reaction of stimulation of oxygen-dependent neutrophil metabolism, mediated by the IgG opsonins of normal human serum. The study was carried out at different taxonomic levels: the species (S. aureus), the genus (Staphylococcus), the family (Micrococcaceae), as well as in relation to remote taxons (organisms belonging to the families Streptococcaceae, Enterobacteriaceae, Neisseriaceae, to the genus Corynebacterium). All S. aureus strains were identical with respect to the specificity of their PG, essentially differing from other bacteria in this regard. After the removal of antibodies to different PG the effectiveness of PG opsonization decreased by 10.4-44.7%. Such decrease was most pronounced in experiments with the PG of streptococci (S. pyogenes, S. faecalis, S. salivarius) and Micrococcus luteus.
Seventy-two strains of bacteria of the families Bacillaceae, Enterobacteriaceae and Micrococcaceae were investigated for antigens resembling Gm (1), Gm (2) and Inv (1) human immunoglobulin group factors. Antigens similar to these factors were encountered in some strains of the genus Bacillus. Staph. epidermidis strains had antigenic structures resembling Gm (1) and Inv (1) factors, and strains of Enterobacteriaceae structures resembling Gm (2) and Inv (1). Occurrence among various species of bacteria of antigens resembling human gamma-globulin group factors suggests immunization by bacterial infection as one of the causes of presence of anti-Gm and anti-Inv antibodies in human beings.
Fourier transform IR spectroscopy (FTIR) is used to analyze cells of Micrococcus luteus, the type species of the highly heterogeneous genus Micrococcus that belongs to the Micrococcaceae family. The cells of M. luteus, which is a Gram-positive and yellow-pigmented bacterium, are submitted to increasing doses of gamma radiation. Irradiation leads to the generation of reactive oxygen species that induce biochemical changes as shown in spectral profiles. Beyond a dose of 0.70 kGy, significant differences between samples are observed, particularly in the 1485-900 cm(-1) region, which contains information about membrane lipids, cell wall polysaccharides, and nucleic acids. After a dose of 16.50 kGy, M. luteus is reincubated for times ranging from 1 to 24 h. Postirradiation reincubated bacteria are found far from the control and irradiated cells (mainly in the 985-900 cm(-1) range), suggesting that a biomolecular rearrangement occurs as soon as reincubation begins in the growth medium. Thus, FTIR spectroscopy appears to be a very useful technique for the rapid visualization of the alterations induced by both the radiation and mutagenic response during reincubation. The use of mathematical methods gives good insight into the biomolecular compounds involved in these two mechanisms. In view of these preliminary results, we hypothesize that it can be successfully applied to any type of tissue and that it may be a future interesting tool for evaluating the effects of radiation in humans.
To document deodorant efficacy the antimicrobial activity of a gelatinous antiperspirant formulation of aqueous aluminum chloride hexahydrate was investigated. In vitro assays demonstrated highly bactericidal activity on microorganisms comprising the resident axillary skin flora, including micrococcaceae and aerobic diphtheroid bacteria. Gram-negative bacteria and yeast were partially inhibited. In vivo experiments utilizing occlusive patches on forearm skin and bacterial sampling of the axilla showed pronounced bacteriostasis and persistence of aluminum chloride on the skin. Inhibition of microbial growth lasted more than 3 days after a single treatment of the axilla. Following repeated open applications to the volar aspect of the forearm, the skin remained virtually sterile for 3 days.
Among the main aspects to be considered when treating burns, the problem of infection control remains unsolved. Considerable financial resources are needed to prevent the transmission of organisms. To justify such investments in buildings and antiseptic measures, an extensive epidemiological hospital study was carried out from 1970 to 1974, involving 930 patients, and more than 25,000 wound biopsies as well as 10,000 contact cultures and environmental swabs. Bacteria from the environment of severly burned patients were counted every week. Serotyping was used for a specialized study of Pseudomonas aeruginosa. In 200 patients wound organisms were counted. The most important organisms were: Streptococcaceae (pyogenic streptococci, less frequently faecal and salivary streptococci). Pseudomonadaceae, Enterobacteriaceae, and Micrococcaceae (especially Micrococcus aureus). Povidon iodine, gentamicin and silver sulfadiazine were used for local disinfection. Antibiotics used were gentamicin, carbenicillin and polymyxin. Whereas from 1970 to 1972 P. aeruginosa was the predominant organism found in wounds, other gram-positive organisms increased from 1972 on. Wounds were colonized mainly in the course of the first two weeks of treatment. Special studies regarding P. aeruginosa revealed a predominance of serotypes 5 and 13 between 1970 and 1973, whereas types brought into the hospital were dominant from 1973 on. An analysis of furniture and equipment, water faucets and drains showed that Pseudomonas strains found in the water did not coincide with those found in wounds. Therefore, a contamination from this source seems unlikely. Strains found on furniture and equipment, however, also appeared in the wound flora. When the therapeutic routine was changed (to prevent patients passing through common treatment areas such as bathrooms and dressing areas) hospital organisms 5 and 13 could be eliminated almost completely. Thus, it is possible to achieve a considerable reduction in the rate of cross-infection among patients by, for instance, excluding common treatment areas from the therapy programme. Nevertheless, in the majority of cases wounds will still be colonized, in particular by bacteria that were already in the anal region or on the skin before the patient was injured. For this reason, the elimination of such organisms by topical bactericidal agents constitutes an an important factor in efforts to reduce the rate of septicaemic complications. In view of the persisting high mortality due to generalized infections this therapeutic aspect must also be exploited thoroughly in the future. Although in comparative studies of topical therapy using povidon iodine, silver sulfadiazine and gentamicin, organisms did appear in the course of the first two weeks; in the case of the PVP-I the colonization never reached 10(5) organisms per cm2, i.e. the danger threshold for generalized sepsis. There was no evidence of a correlation between number of organisms and depth of burns.
The bacterial flora of minced meat is dominated by Micrococcaceae. In addition lactobacilli, pseudomonads, and enterobacteria are present in high numbers. The most important groups of spoiled meat are lactobacilli and pseudomonads. Enterobacteria develop predominantly at higher spoilage temperatures (15 degrees C). A more detailed study was conducted on 1076 cultures of enterobacteria and 915 cultures of pseudomonads. The main groups of enterobacteria found on minced meat are Enterobacter liquefacines, Erwinia, Citrobacter and Klebsiella. In spoiled meat E. liquefaciens and Erwinia predominate. Basicly, however, the enterobacteria flora of fresh and spoiled meat is rather similar. The same applies to the pseudomonads flora which at a rate of 60-70% consists of Pseudomonads fragi. The total count of minced meat is subject to large variations.
A rapid latex agglutination test, Staphaurex, was tested for its ability to identify Staphylococcus aureus using 72 reference strains and 785 clinical isolates of the family Micrococcaceae. All reference strains of Staphylococcus aureus were Staphaurex-positive. Non-Staphylococcus aureus reference strains were negative. Using clinical strains, the results of the Staphaurex test were compared with the results of other tests commonly used to identify Staphylococcus aureus. A total of 393 clinical isolates were classified as Staphylococcus aureus. The Staphaurex, slide coagulase, tube coagulase/human plasma and tube coagulase/rabbit plasma tests correctly identified 98%, 93.6%, 93.6% and 97.5% of the Staphylococcus aureus strains, respectively. The performance of the Staphaurex test, in terms of sensitivity and specificity, was significantly better than the slide coagulase test. It was as sensitive and almost as specific as the tube coagulase rabbit test and more sensitive than the tube coagulase human test.
From the guts of new and old colonies (female and male) of Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae), we identified a total of 18 different bacterial species belonging to the family Enterobacteriaceae, Pseudomonadaceae, Vibrionaceae, Micrococcaceae, Deinococcacea, Bacillaceae, and the genus Listeria. Enterobacter, Providencia, Serratia, and Staphylococcus spp. were the most frequently isolated genera, with Citrobacter, Streptococcus, Aerococcus, and Listeria found less frequently. We found Bacillus cereus, Enterobacter sakazakii, Providencia stuartii, and Pseudomonas aeruginosa only in the new colony, Aeromonas hydrophila and Klebsiella pneumoniae spp. pneumoniae only in the old colony. We also studied resistance/sensitivity to 12 antibiotics for six bacterial isolates such as Enterobacter cloacae, E. sakazakii, K. pneumoniae spp., Providencia rettgeri, P. aeruginosa, and Bacillus cereus. Isolates on the whole were resistant to penicillin and ampicillin (five of six isolates) and sensitive to rifampin and streptomycin (six of six isolates). Antibiotic resistance profiles might be useful characteristics for distinguishing among species and strains of these bacteria, probably having ecological significance with respect to intra- and inter-specific competition within host cadavers, and could have implications for the utility of these organisms for biological control, including the alternative control strategy, paratransgenesis.
Radiation-resistant microorganisms that survive high doses of ionising radiation serve as valuable models for understanding stress adaptation; however, the genomic determinants underlying extreme radiation tolerance in bacteria from natural environments with high background radiation remain insufficiently characterised. Bacterial isolates from the Chavara-Neendakara HBRA (Kerala, India) were evaluated for desiccation tolerance, and the desiccation-resistant isolates were subsequently exposed to gamma irradiation (1-10 kGy) using a 60Co source. Isolates were identified through 16S rRNA sequencing, morphologically characterised by FE-SEM, and screened for antibiotic susceptibility. The highly radiation-resistant strain underwent whole-genome sequencing via Oxford Nanopore Technology, with De novo assembly, polishing, and genome annotation. Four bacterial isolates (Micrococcaceae and Paenibacillaceae) exhibited D10 values of 1-7 kGy, including one multidrug-resistant strain; no endospores were observed in the Paenibacillus isolate under the tested conditions. Paenibacillus sp. HBRA004 survived 10 kGy gamma radiation, exceeding all previously reported HBRA isolates by over fourfold. Its 5.0 Mbp genome (GC = 48.27%, ≥ 99% completeness) encodes five mechanistically independent DNA repair pathways; homologous recombination (recA, recN, radA), base excision repair (mutM, mutY, mutT), mismatch repair (mutL, mutS), nucleotide excision repair (uvrA, uvrB, uvrD), and non-homologous end joining (ku, ligD), alongside a redundant antioxidant network comprising triple-copy Fe/Mn-family superoxide dismutases and ahpC peroxiredoxin. A thioredoxin system (trxA, trxB, msrA) and manganese uptake via mntH may contribute to further layers of ROS defence. Their specific contribution to the HBRA004 phenotype remains to be experimentally and comparatively validated. These findings represent the first genomically characterised 10 kGy-resistant bacterial isolate from the Chavara-Neendakara HBRA, establishing a new benchmark for radiation tolerance within this ecologically significant environment. Pathway depth, gene copy amplification, and Mn/Fe homeostasis appear to be candidate mechanisms contributing to high-level radiation tolerance, consistent with patterns in other radiation-resistant taxa, though their contribution requires functional validation.
1. Gram-positive bacteria out of the families of Streptococcaceae, Lactobacillaceae, Micrococcaceae and Bacillaceae were investigated with respect to the occurrence and the concentration of phosphoglycolipids. 2. Phosphatidylglycolipids occur exclusively in group D Streptococci and in Streptococcus hemolyticus D-58. Phosphatidyl-alpha-kojibiosyldiacylglycerol, the prevalent species, accounts for up to 28% of the polar lipids. The related glycerophospho-phosphatidyl-alpha-kojibiosyldiacylglycerol is restricted to Streptococcus faecalis. 3. Glycerophosphoglycolipids, usually minor components, comprise thirteen compounds most of which have so far not been described. Except Micrococcus lysodeikticus all examined bacteria contained one or more glycerophosphoglycolipids. Their occurrence parallels, therefore, that of lipoteichoic acids, which supports the hypothesis of a metabolic relationship between these two membrane components.
Sardines from the Adriatic Sea were examined fresh and after 4 and 8 days of storage in ice. A total of 1500 strains isolated were identified from the gills and the surface of the fish. Pseudomonadaceae, Neisseriaceae, Flavobacterium/Cytophaga, Enterobacteriaceae, coryneform bacteria and Micrococcaceae were the most common bacteria in fresh fish. During storage the pseudomonads (mainly the non-fluorescent strains) increased and became the dominating microflora; the Neisseriaceae (Moraxella, Psychrobacter and Acinetobacter) showed a distinct increase during the first 4 days in ice; the percentage of the other bacterial groups clearly decreased. On the gills the quantitative changes in the microflora were less pronounced than on the surface.
The Iberian dry cured ham is an uncooked meat product highly appreciated because of its characteristic flavour. This product is obtained from highly marbled Iberian pig hindlegs after 18-24 months of maturation under natural environmental conditions. The role of Micrococcaceae in the development of the aroma characteristics of this products remains unclear. Identification of Gram-positive, catalase-positive cocci isolated from Mannitol Salt Agar plates showed that Staphylococcus xylosus followed by Staphylococcus equorum are the predominant organisms, even after 16 months of maturing. A remarkable variety of types of both staphylococci and micrococci are detected at any sampling time. The metabolic activities of these organisms could contribute to the characteristics of the final product.
A total of 359 Micrococcaceae strains isolated from goat milk samples were differentiated with the commercially available ATB 32 Staph differentiation system. Of these strains, 303 (84.4%) were identified. Six strains were sensitive in the bacitracin resistance test, and accordingly classified as Micrococcus spp. Staphylococcal species isolated of goat milk 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 somatic cell count (SCC) in milk and the highest prevalence of clinical udder alterations were associated with coagulase-positive S. aureus. Increases in milk SCC as well as pathological udder findings were observed in infections with coagulase-negative staphylococci such as novobiocin-sensitive S. epidermidis, S. simulans, S. lugdunensis, S. chromogenes, and S. warneri.