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Lipoquinones of some spore-forming rods, lactic-acid bacteria and actinomycetes.

The respiratory quinones of 73 strains of Gram-positive bacteria including spore-forming rods, lactic-acid bacteria and actinomyctes were examined. Menaquinones with seven isoprenoid units (MK-7) were the main quinone type found in representatives of the genus Bacillus and in Sporolactobacillus inulinus. However, a strain of B. thuringiensis produced MK-8 in addition to MK-7, and strains of B. lentus and B. pantothenticus appeared to produce MK-9 and MK-8, respectively, with no MK-7. In the clostridia and lactic-acid bacteria, no quinones were found, except in Pediococcus cerevisiae NCTC 8066 and Lactobacillus casei subsp. rhamnosus ATCC 7469, which contained menaquinones, and Streptococcus faecalis NCTC 775 and HIM 478-1, which contained demethylmenaquinones, in relatively low concentrations. Menaquinones were also found in the actinomycetes (except Actinomyces odontolyticus and Bifidobacterium bifidum which did not produce any quinones) and in Protaminobacter alboflavus ATCC 8458, the so-called Actinobacillus actinoides ATCC 15900 and Noguchia granulosis NCTC 10559.

Actinomycetales↗

A microbiological study of normal flora of macropod dental plaque.

The percentage bacterial composition of dental plaques from 12 macropods was determined. The major group of organisms was gram-positive filamentous and pleomorphic rods whose median representation was 92.2%. These were mainly Actinomyces viscosus (median value 62.5%) and Bacterionema matruchotii (median value 23.2%). Streptococci were poorly represented (median value 4.2%) as were anaerobic gram-negative organisms. Aerobic gram-negative bacteria were identified as neisseriae and Moraxella sp. The macropod plaque flora was compared with that of human beings and rodents and the differences discussed in relation to dietary differences and the early externalization of the marsupial young.

Actinomycetaceae↗

[The effect of standardised sodium hypochlorite solution on bacteria pathogenic for the urinary tract (author's transl)].

Stable sodium hypochlorite solution shows excellent disinfectant properties, even in higher dilution. Parallel to clinical tests in vitro experiments were made to show the changes of morphology of bacteria pathogenic for the urinary tract by scanning microscope. Two hours after incubation of the bacteria with sodium hypochlorite solution containing 40 mg available chlorine/1 severe damages of the bacterial morphology up to complete destruction were evident in all cases. Gram-negative rod-shaped bacilli were more, gram-positive cocci were less damaged.

Acids↗

Ultrastructure of the subgingival microflora in juvenile periodontitis.

The ultrastructure of the subgingival deposits on the root surfaces of teeth affected by juvenile periodontitis was studied on 12 teeth from nine individuals, 15--30 years of age. The deposits consisted of either microbial masses associated with a pellicle, or of a cuticular material almost free of bacteria. Gram-negative rods and filaments were the predominant microorganisms. "Corncob" configurations consisting of filamentous bacteria surrounded by Gram-positive cocci, and "bristle brush" formations comprising corncobs surrounded by long rods were observed in the superficial layer of the plaque. Spirochetes and flagellated rods constituted a major segment of the microflora. The present data indicated that the deep pockets in juvenile periodontitis harbor a sparse but relatively characteristic microbial population.

Adolescent↗

Studies on Propionibacterium isolated from paddy soils.

The anaerobic bacteria occurring in paddy soils sampled from fields belonging to the Rice Research Station at Ohmagari in Akita Prefecture, Japan, were surveyed from May to November, 1974. Irregularly shaped rods predominated which were found to be gram-positive, strictly anaerobic, catalase-positive and not heat-resistant; populations were estimated at 10(5)--10(-7) cells/g dry soil throughout the entire survey period. On the basis of their morphological and physiological characteristics these bacteria were identified as Propionibacterium. Most strains belonged to P. lymphophilum and P. granulosum.

Anaerobiosis↗

Rhodoglobus galactosidasius sp. nov., a psychrophilic Actinomycetota producing a cold-active β-galactosidase isolated from Cape Hallett, Antarctica.

A novel psychrophilic member of the phylum Actinomycetota, designated strain CPHL_1T, was isolated from the shoreline of Cape Hallett, Antarctica. Cells were Gram-positive, aerobic, non-motile, non-spore-forming rods (0.7-1.0 µm in length) with orange to yellow pigmentation. Optimal growth occurred at 15 °C, pH 8.0, with NaCl tolerance up to 3% (w/v). Strain CPHL_1T exhibited cytosolic cold-active β-galactosidase activity, with an optimum at 15 °C and pH 7.0 and formed non-adherent biofilms. Phylogenetic analysis based on 16S rRNA gene sequence placed the strain within the genus Rhodoglobus, showing high similarity to Rhodoglobus vestalii LV3T (99.4%) and Rhodoglobus aureus CMS 81yT (97.6%). Chemotaxonomic characteristics, including the predominance of anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0 fatty acids, the presence of MK-11, MK-10 and MK-12 as the major respiratory quinones, and genomic G+C content of 60%, further supported its assignment to the genus Rhodoglobus. Whole-genome comparisons revealed clear taxonomic distinction, with strain CPHL_1T sharing 88.9% average nucleotide identity (ANI) and 38.3% digital DNA-DNA hybridization (dDDH) values with R. aureus, and 81.7% ANI and 25.1% dDDH with R. vestalii, confirming its status as a novel species. Phylogenetic analysis revealed that the β-galactosidases from these Rhodoglobus strains form a well-supported clade with high sequence similarity. Based on these data, a novel species is proposed: Rhodoglobus galactosidasius sp. nov. (type strain CPHL_1T =ITEM 19986T =KCTC 59592T). Genomic analyses also highlighted its biosynthetic potential for specialized metabolites, consistent with the recognized metabolic diversity of the genus.

Phylogeny↗

Novel microbial and chemical components of a specific black-band region in the cockroach hindgut.

An area of the hindgut of the cockroach, Eublaberus posticus, is characterized by its black color. This area is the site of accumulation of metal sulfides in the lumen next to the gut wall. In addition to the normal hindgut flora, two unusual procaryotic organisms are seen by both scanning and transmission electron microscopy only in this area of the hindgut. They are (i) a large rod (1.2 by 6 micrometers) with a tuft of polar flagella, many inclusion bodies, and a distinctive complex wall and (ii) an apparently flexible rod with a helically ridged wall. In addition, phagelike particles are described which are apparently infecting gram-positive bacteria attached to the gut wall in the black band area.

Animals↗

[Comparison of the antibacterial activity of ticarcillin with other antibacterial agents (author's transl)].

Antibacterial activity of ticarcillin was determined in comparison with that of sulbenicillin, amoxicillin, cefuroxime, clindamycin and metronidazole against anaerobic bacteria which have been isolated from various clinical materials in this hospital. Growth of more than 90% of Gram-negative anaerobic rod bacteria was inhibited by ticarcillin at its concentration of 100 micrograms/ml. Strains resistant to ticarcillin showed cross resistance against both sulbenicillin and amoxicillin. Antibacterial activity of ticarcillin against Gram-positive anaerobic bacteria was found almost equal to sulbenicillin but slightly inferior to amoxicillin. Cefuroxime was found most inferior among the tested six antibiotics when an inoculation level of 10(8)/ml was utilized, but it showed similar activity to ticarcillin when they were tested with 10(6)/ml inoculation. Approximately 10% of bacteroides strains was resistant to clindamycin while all the strains were sensitive to metronidazole.

Amoxicillin↗

Studies on bacterial cell wall inhibitors. VIII. Mode of action of a new antibiotic, azureomycin B, in Bacillus cereus T.

Azureomycin B, a new antibiotic which contains sugar, amino acid and phenol moieties and inhibits Gram-positive bacteria, was found to be a specific inhibitor of peptidoglycan synthesis in bacteria. The antibiotic lysed growing cells of Bacillus cereus T at a concentration of 10 micrograms/ml but did not affect resting cells. Microscopical observation revealed swelling and lysis of the bacterial rods when treated with azureomycin B. The incorporation of [3H]diaminopimelic acid or [14C]glucosamine into acid-insoluble fraction of growing cells of Bacillus cereus T was strongly inhibited in the presence of azureomycin B, but that of [14C]leucine, [3H]thymidine or [3H]uridine were not, at least until 5 minutes after the beginning of the incubation. The antibiotic caused accumulation of a nucleotide precursor in the cells which was identified as UDP-MurNAc-L-Ala-D-Glu-meso-Dpm-D-Ala-D-Ala. Thus the site of action was suggested to lie between this nucleotide and peptidoglycan in the pathway of peptidoglycan synthesis.

Anti-Bacterial Agents↗

A study of the bacteria associated with advancing periodontitis in man.

Samples of apical plaque were taken by means of an anaerobic gas-flushed syringe from 21 sites in eight patients. The samples were anaerobically dispersed, diluted and plated and incubated in an atmosphere of 80% N2, 10% H2 and 10% CO2 for 7-21 days. All colonies on plates containing 20-50 isolates were picked, repeatedly restreaked, characterized and identified where possible by a probabilistic computer identification program. The sites were divided into four groups on the basis of clinical features. The significance of differences between bacterial populations in the groups was determined by the Kruskal Wallis and Mann-Whitney U tests, while the Spearman rank correlation coefficient was used to determine the rank correlation of clinical features of diseases and microbial species. The subgingival microbiota in advanced destructive sites was predominated by Gram-negative rods. The microbiota of two young adult patients with generalized extensive bone loss, extensive clinical inflammation and suppuration was dominated by Bacteroides asaccharolyticus and an organism with characteristics consistent with Actinobacillus actinomycetemcomitans. The predominant cultivable microbiota in two patients with extensive bone loss but minimal clinical inflammation was predominated by Bacteroides melaninogenicus ss intermedius and Eikenella corrodens in one patient and E. corrodens and a slow growing fusiform-shaped Bacteroides in a second patient. A third group of four patients demonstrated moderate levels of clinical inflammation and evidence of continued bone loss in the last year. Predominant organisms in this group were more heterogeneous and included B. asaccharolyticus, Fusobacterium nucleatum, the "fusiform" Bacteroides and anaerobic vibrios. Sites with minimal disease in the patients revealed higher proportions of Gram-positive organisms including Rothia dentocariosa, Actinomyces naeslundii and Actinomyces viscosus. A positive rank correlation could be detected between clinical inflammation including suppuration and B. asaccharolyticus and a negative rank correlation between inflammation and E. corrodens.

Adult↗

Necrotizing fasciitis associated with Acinetobacter lactucae and Bacillus paramobilis infections in 2 dogs.

Two immunocompetent dogs from separate households were presented to a tertiary referral hospital with soft tissue wounds attributable to severe bacterial infection. A 5-y-old, castrated male Golden Retriever dog (case 1) was presented with extensive hemorrhagic cellulitis of the forelimbs and neck that developed over 48-h and was attributable to Acinetobacter lactucae infection. Additionally, an 8-y-old, spayed female Labrador Retriever-mix dog (case 2) sustained a deep penetrating wound over the left hip that progressed over 24 h to necrotizing fasciitis, from which Bacillus paramobilis was isolated. Histopathologic findings in both cases included severe acute, skeletal muscle necrosis and necrosuppurative myofasciitis, dermatitis, and panniculitis with intralesional rod-shaped bacteria. Whole-genome sequencing and phylogenetic analysis of the bacterial isolates revealed numerous cytolytic toxins and other virulence genes carried by the isolates, expanding the profile of these 2 bacteria. To our knowledge, canine cases of A. lactucae and B. paramobilis associated with necrotizing fasciitis have not been reported previously. In both cases, progression from an inciting incident to septic disease was extremely rapid, occurring within 48 h in case 1 and 24 h in case 2, underscoring the fulminant nature of necrotizing fasciitis.

Animals↗

Effect of clays on the microbe adsorption.

The non motile Gram-positive spore-forming bacteria are much more adsorbed on the bentonite than the motile Gram-negative rods. The motile bacteria adjance to clays in the phases of their rapid multiplication only. The dependence of the clay adsorption of motile microbes by the substrate and/or intermediate adsorption has been suggested.

Adsorption↗

SCE-129, antipseudomonal cephalosporin: in vitro and in vivo antibacterial activities.

SCE-129 [3-(4-carbamoyl-1-pyridiniomethyl)-7beta-(d-alpha-sulfophenylacetamido)-ceph-3-em-4-carboxylate monosodium salt], a new semisynthetic cephalosporin, shows potent in vitro antibacterial activities against Pseudomonas aeruginosa and some gram-positive bacteria, whereas it shows lower activity against many gram-negative rods. Against clinical isolates of P. aeruginosa this cephalosporin exhibited higher activity than did carbenicillin, and against the strains of Staphylococcus aureus, SCE-129 had similar activity to carbenicillin. Variations in pH, addition of horse serum, and type of growth medium had no significant effects on the activity of the cephalosporin; however, the inoculum size had some effect on the activity. SCE-129 is an effective bactericidal agent against P. aeruginosa and S. aureus. The protective effects of SCE-129 in mice infected with P. aeruginosa and S. aureus were more potent than those of carbenicillin. The protective effects of SCE-129 on Pseudomonas infection in mice varied according to the dosage schedule and the challenge dose. In a multiple dose schedule, a smaller amount of SCE-129 was necessary than that in a single dose schedule. The effects of SCE-129 after subcutaneous or intraperitoneal administration were more potent than were those by intravenous administration. No protective effect was observed by oral administration.

Animals↗

Adherence of bacteria, yeast, blood cells, and latex spheres to large-porosity membrane filters.

Strong adherence of bacteria, yeast, erythrocytes, leukocytes, platelets, spores, and polystyrene spheres to membrane filter materials was noted during filtration through membranes with pore size diameters much larger than the particles themselves. Quantitative recovery on the membrane filters of these particles from low-concentration suspensions was achieved during gravity- or vacuum-assisted filtration through membranes with pore diameters as much as 30 times that of the filtered particles. Mechanical sieving was not responsible. The phenomenon was judged to be electrostatic. It could be partially blocked by pretreating the filter with a nonionic surfactant (Tween 20), and elution of adherent particles was achieved with 0.05% Tween 20. Gram-positive cocci were removed from suspension more efficiently than gram-negative rods. The commonly used cellulose membranes adsorbed more bacteria, blood cells, and other particles than did polycarbonate filters. Of lesser adsorptive capacity were vinyl acetate, nylon, acrylic, and Teflon membranes. Backwashing with saline, serum, 6% NaCl, dextran solutions, or phosphate buffers of varying molality and pH removed only a fraction of adherent particles. Tween 20 (0.05%) eluted up to 45% of adherent particles in a single back-filtration. Selected filters quantitatively removed the particles tested, which then could be washed and subjected to reagents for a variety of purposes. It is important to anticipate the removal of particles during membrane filtration, since it is not a simple mechanical event.

Adsorption↗

Early neonatal bacteraemia. Comparison of group B streptococcal, other Gram-positive and Gram-negative infections.

All cases of neonatal bacteraemia associated with clinical illness occurring at Hammersmith Hospital, over a 9-year period, 1967-1975 inclusive, have been reviewed. The infants studied were those born in the hospital's maternity unit and those admitted from other hospitals from a wide area round London who were ill or of low birthweight. Positive blood cultures occurred in 91 infants, 47 of them in the first 48 hours of life. These 47 infants were analysed separately and divided into three groups, 13 with group B streptococcal infections, 11 with other Gram-positive infections, and 23 with Gram-negative infections. There were no significant differences in birthweight or gestation, in mortality, in incidence of clinically diagnosed respiratory distress syndrome or recurrent apnoea, or in the need for mechanical ventilation between the three groups. The age at which a diagnosis of infection was suspected, and the age at death were both significantly earlier in the group infected with group B streptococcus than in those obtained with other organisms (P less than 0-01 for both comparisons). There were no significant differences in the incidence of hyaline membrane formation or pneumonia seen at necropsy among the three groups. In some of the earliest deaths in the Gram-negative bacteraemic group, Gram-negative rods comprised the bulk of the hyaline membrane as did cocci in the group B streptoccal group.

Age Factors↗

The clinical importance of anaerobic bacteria in wound infections after gastrointestinal surgery.

Wound cultures from 54 patients with infections after gastrointestinal surgery were examined. Cultures from wounds after surgery on the upper gastrointestinal tract grew few organisms, mainly aerobic gram-positive cocci. Culture from wounds on the lower gastrointestinal tract grew strains of bacteria, aerobic and anaerobic gram-negative rods dominating. Indirect immunofluorescence studies on acute and convalescent phase sera showed significant immune response against Bacteroides fragilis in a majority of cases. Immune response against anaerobic cocci was seldom found. Very high antibody titres against Clostridium perfringens were often found, both in patients' and control sera.

Adolescent↗

Frequency and fate of human renal allografts contaminated prior to transplantation.

Bacterial cultures were done from donor ureter and/or graft perfusion fluid on 92 of 112 patients who had renal transplantations during 1977. Three samples of perfusion fluid and 14 samples of donor ureter contained bacteria. In nine cases there was a gram-positive organism, and in 10 cases a gram-negative rod was (among) the contaminant(s). There was no difference in the rate of graft survival, patient survival, or in the frequency of major postoperative complications between the two groups. Only in two instances could the urinary tract infection following transplanation be traced to the contaminating organism. Except for one case in which a urinary fistula may have been linked to the graft contamination, there were no clinically significant sequelae from the contaminated allografts.

Bacteroides fragilis↗

In vitro synergy of cefamandole-tobramycin combinations.

Twenty-five isolates of Staphylococcus aureus, 24 isolates of Escherichia coli, and 25 isolates of Klebsiella pneumoniae obtained from clinical material were tested in vitro for susceptibility to cefamandole, tobramycin and combinations of the two antibiotics utilizing an automated microdilution system. Synergistic or partially synergistic bactericidal effects of the combination were observed against 15 of the S. aureus isolates (60%), 23 of the E. coli isolates (96%), and 19 of the K. pneumoniae isolates (76%) tested. No antagonistic effects of the combination were noted. This study suggests that cefamandole-tobramycin combinations are capable of acting synergistically in vitro against certain gram-positive and gram-negative organisms and may have potential usefulness in clinical situations such as gram-negative rod and staphylococcal sepsis.

Anti-Bacterial Agents↗