[Microorganism of the Moraxella group].
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Enterobacteriaceae↗
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[The intracellular urease activity of Moraxella Iwoffi (Bacterium anitratum) group].
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Culture Media↗
[The penicillin susceptibility of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus in persons suffering from upper respiratory tract infections].
The susceptibility to penicillin was tested in 293 strains of S. aureus, 162 strains of H. influenzae, 60 strains of M. catarrhalis and 77 strains of S. pneumoniae, isolated from persons suffering from upper respiratory tract infections. Penicillin susceptibility testing has been performed by the disc diffusion technique. Beta-lactamase production in the penicillin-resistant strains of H. influenzae, M. catarrhalis and S. aureus was detected with nitrocefin impregnated disc. In beta-lactamase positive strains, the susceptibility to amoxacillin/clavulanic acid (AMC) was determined. Nearly half (46.3%) of H. influenzae strains was resistan to ampicillin. In the remaining bacteria, the percentage of resistance was 2.6% for S. pneumoniae, 82.4% for M. catarrhalis and 88.1% for S. aureus strains. All strains resistant to penicillin (ampicillin) produced beta-lactamase and were AMC sensitive.
Bacterial Infections↗
Relatedness of three species of "false neisseriae," Neisseria caviae, Neisseria cuniculi, and Neisseria ovis, by DNA-DNA hybridizations and fatty acid analysis.
DNA-DNA hybridization was used to determine the levels of genomic relatedness of the three species of "false neisseriae," Neisseria caviae, Neisseria cuniculi, and Neisseria ovis. The reference strains of these species exhibited high levels of intraspecies relatedness (93 to 100% for N. caviae, 79 to 100% for N. cuniculi, and 68 to 100% for N. ovis) but low levels of interspecific relatedness (less than 34%) to each other and to various species belonging to the beta subclass of the Proteobacteria (Kingella kingae, Neisseria gonorrhoeae, Neisseria meningitidis, and Oligella urethralis) or to the gamma subclass (Branhamella catarrhalis, Kingella indologenes, Moraxella atlantae, Moraxella bovis, Moraxella lacunata subsp. lacunata, Moraxella lacunata subsp. liquefaciens, Moraxella nonliquefaciens, Moraxella osloensis, and Moraxella phenylpyruvica). However, the levels of DNA-DNA hybridization for the three species of "false neisseriae" were significantly higher with the species belonging to the gamma subclass (average, 13.7%) than with the species belonging to the beta subclass (average, 4.5%). These data suggest that N. caviae, N. cuniculi, and N. ovis are three separate genomic species in the gamma subclass. An ascendant hierarchical classification based only on fatty acid profiles distinguished four main classes containing (i) most of the "classical moraxellae," the "false neisseriae," and B. catarrhalis, (ii) only Acinetobacter spp., (iii) M. nonliquefaciens and "misnamed moraxellae" (M. atlantae, M. osloensis, and M. phenylpyruvica), and (iv) the "true neisseriae," the three Kingella species, and O. urethralis. Fatty acids that distinguish these four classes were identified. The fatty acid profiles of the two strains of Psychrobacter immobilis which we studied are not very similar to the profiles of the other taxa. Our results support the hypothesis that the three species of "false neisseriae," B. catarrhalis, the "classical moraxellae," and Acinetobacter spp. should be included in the same family.
Bacterial Typing Techniques↗
Role of nasopharyngeal culture in antibiotic prescription for patients with common cold or acute sinusitis.
The aim of the present study was to assess the hypothesis that, when present in nasopharyngeal secretions, Streptococcus pneumoniae. Haemophilus influenzae, and Moraxella catarrhalis play a pathogenic role early in the course of an upper respiratory tract infection. Adults with a clinical diagnosis of acute sinusitis or common cold were enrolled. Participants were randomly assigned in a double-blind manner to receive azithromycin 500 mg daily or placebo for 3 days. The effect of treatment on symptom evolution in the predefined subset of patients with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis in their nasopharyngeal secretions was assessed. Of 265 patients enrolled, 132 received placebo and 133 azithromycin. Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis was identified in nasopharyngeal secretions of 77 patients (29%). In this predefined subgroup of patients with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, resolution of symptoms by day 7 occurred in 73% of those treated with azithromycin compared with 47% of those who received placebo (P=0.007). The median time before resolution of symptoms was 5 days in the azithromycin group compared to 7 days in the placebo group. Respiratory complications requiring antibiotic treatment occurred in 19% of patients in the placebo group and in 3% of the azithromycin group (P=0.025). In the remaining 188 patients without Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, resolution of symptoms by day 7 was similar in both groups (69% in the placebo group vs. 64% in the azithromycin group [P=0.75]). Antibiotic treatment is of clinical benefit for patients with acute sinusitis or common cold when Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis is present in nasopharyngeal secretions. This observation provides new insights into the pathogenic role of these bacteria in the early stage of the common cold.
Acute Disease↗
Taxonomy of pasteurella anatipestifer. 1. DNA base composition and DNA-DNA hybridization analysis.
DNA was isolated from 15 strains of Pasteurella anatipestifer and from one strain each of Moraxella nonliquefaciens, M. bovis, Pasteurella multocida, P. haemolytica, P. gallinarum, P. pneumotropica, and P. ureae. The guanine-plus-cytosine contents of P. anatipestifer ranged from 32 to 35 mole %, whereas those of Moraxella and Pasteurella spp. were much higher, ranging from 40 to 45 mole %. DNA-DNA hybridization analysis revealed that homology of nine P. anatipestifer strains to strains ATCC 11845 and PA 15 was 52 to 100%, whereas homology of Moraxella and Pasteurella strains to these strains was only 3 to 17%. Similarly, homology of P. anatipestifer strains, Moraxella, and Pasteurella species other than P. multocida to P. multocida reference strain P-2192 was low. These results strongly suggest that P. anatipestifer is genetically unrelated to either Pasteurella or Moraxella.
Base Composition↗
Cell surface display of synthetic phytochelatins using ice nucleation protein for enhanced heavy metal bioaccumulation.
Synthetic phytochelatins (ECs) composed of (Glu-Cys)nGly are protein analogs of phytochelatin that exhibit improved metal-binding capacity over metallothioneins (MTs). Expression of EC20 on the surface of E. coli using the Lpp-OmpA anchor resulted in improved bioaccumulation of cadmium and mercury, providing a new method for treating heavy metal contamination. To further improve the whole-cell accumulation of heavy metals, EC20 was expressed on the surface of Moraxella sp., a bacterium known to survive in contaminated environments, using the truncated ice nucleation protein (INPNC) anchor. Production of EC20 was approximately three-fold higher in Moraxella sp. than E. coli. As a consequence, the mercury-binding capacity of the recombinant Moraxella sp. was increased by more than 10-fold. Owing to the very high level of surface expression, the use of Moraxella sp. and INPNC anchor may prove to be useful for the remediation of other environmental contaminants.
Bacterial Outer Membrane Proteins↗
Complement deficiency predisposes for meningitis due to nongroupable meningococci and Neisseria-related bacteria.
Nongroupable meningococci or bacteria related to the genus Neisseria rarely cause meningitis. Complement deficiency has been identified as a major predisposing factor for meningococcal disease. To assess whether patients with meningitis due to such strains have a complement deficiency, we studied 12 persons. Six patients had meningitis due to nongroupable strains of meningococci, and six patients had meningitis due to Moraxella species or Acinetobacter species. Inherited complement component C7 or C8 deficiency was found in two persons who had had meningitis due to nongroupable meningococci, and one C8-deficient person had had meningitis caused by Moraxella osloensis. Hypocomplementemia resulting from CSF drain-associated shunt nephritis was found in one person with meningitis due to Moraxella nonliquefaciens and in one person with meningitis due to Acinetobacter lwoffi. This rather high frequency of inherited or acquired complement deficiencies among patients with meningitis due to nongroupable meningococci, Moraxella species, and Acinetobacter species justifies the recommendation that such patients must be studied for complement deficiency.
Acinetobacter Infections↗
The bacterial biogenesis of isobutyraldoxime O-methyl ether, a novel volatile secondary metabolite.
Production of the volatile metabolite, isobutyraldoxime O-methyl ether (IBME) by a Moraxella-like organism NCIB 11650 was investigated under a variety of environmental conditions using gas chromatography. Under aerobic conditions up to 10 micrograms IBME ml-1 was produced on mineral salts media containing 0.5% (w/v) glucose or succinate as sole C source with 0.1% (w/v) NH4Cl as sole N source. Exogenous L-valine further stimulated IBME formation up to 25 micrograms ml-1 but supplementation of the medium with D-isomer or other amino acids had little effect on IBME production and did not lead to the appearance of analogues of IBME. Trapping experiments using [14C]valine confirmed that IBME was derived from this amino acid. Several other bacterial species examined, e.g. Alcaligenes sp. NCIB 11652, another Moraxella-like organism NCIB 11651 and Pseudomonas sp. NCIB 11653 also produced IBME under similar conditions. The Alcaligenes strain synthesized up to 20 micrograms ml-1 in the absence of valine and up to 90 micrograms ml-1 in its presence. The product of IBME exhibited many features characteristic of the formation of a secondary metabolite. Thus biosynthesis was confined to a narrower range of temperature than cell division, was almost completely suppressed by 300 mM-phosphate and was inhibited by high concentrations of readily utilizable C sources. Although IBME synthesis in the Moraxella-like organism NCIB 11650 appeared to be growth-related, its formation by both the Alcaligenes sp. and the Moraxella-like organism NCIB 11651 was delayed until the late-exponential and early-stationary phases of growth. The biological significance of this novel class of secondary metabolite is discussed and a possible biosynthetic route proposed.
Alcaligenes↗
Differentiation of some species of Neisseriaceae and other bacterial groups by DNA-DNA hybridization.
DNA-DNA hybridization using total genomic DNA probes may represent a way of differentiating between miscellaneous bacterial species. This was studied with type and reference strains of 20 species in Moraxella, Kingella, and other selected Gram-negative groups. Both radioactive and biotin labelling were employed. Most of the species examined were easily distinguished, such as Moraxella (Branhamella) catarrhalis, M.(B.) ovis, M. atlantae, M. phenylpyruvica, M. osloensis, Neisseria elongata, N. meningitidis, Kingella kingae, K. indologenes, K. dentrificans, Oligella urethralis, Eikenella corrodens, Cardiobacterium hominis, Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Gardnerella vaginalis, and DF-2. This reflected the extent of the genetic distances between them as a basis for identification by hybridization. There was some clustering in the Moraxella group. Especially the closely related Moraxella nonliquefaciens, M. lacunata and M. bovis showed strong hybridization affinities. This leads to potential problems in distinguishing these three species from each other by DNA-DNA hybridization with total genomic probes alone.
DNA Probes↗
Gas chromatography of bacterial whole cell methanolysates. VII. Fatty acid composition of Acinetobacter in relation to the taxonomy of Neisseriaceae.
The cellular fatty acids of seventeen Acinetobacter strains were determined. Most acids identified were previously found in neisseriae and moraxellae. Specific for Acinetobacter was 2-hydroxydodecanoid acid and a few minor unidentified components. The fatty acid data were analysed by numerical methods and compared with previous results obtained for neisseriae and moraxellae. The findings were consistent with genetic evidence for some affinities of genus Acinetobacter to genus Moraxella and "false neisseriae". Occasionally, a high resemblance in fatty acid pattern was demonstrated between a Moraxella strain and certain strains of Acinetobacter, and also between an Acinetobacter strain and certain "true neisseriae". Still, the acinetobacters constituted one single cluster separated from the other genera of Neisseriaceae.
Acinetobacter↗
Evaluation of pyrrolidonyl arylamidase for the identification of nonfermenting Gram-negative rods.
To evaluate the activity of pyrrolidonyl arylamidase (PYR) for the differentiation and identification of nonfermenting gram negative rods (NFGNR), 293 isolates were tested. A 24 h culture of each test organism was prepared. From this a 108-109 cfu/mL suspension was added to 0.25 mL of sterile physiologic solution. A PYR disk was then added and the test was incubated for 30 minutes at 35-37 degrees C, at environmental atmosphere. Reading was done by adding 1 drop of cinnamaldehyde reagent. Strains of Acinetobacter baumannii, Acinetobacter haemolyticus, Alcaligenes faecalis, Bergeyella zoohelcum, Bordetella bronchiseptica, Bordetella hinzii, Brevundimonas diminuta, Brevundimonas vesicularis, Brucella ovis, Brucella spp., Brucella suis, Burkholderia cepacia complex, Moraxella catarrhalis, Moraxella lacunata, Moraxella nonliquefaciens, Moraxella osloensis, Oligella ureolytica, Pseudomonas alcaligenes, Pseudomonas mendocina, Pseudomonas pseudoalcaligenes, Pseudomonas putida, Pseudomonas stutzeri, Pseudomonas Vb3, Psychrobacter phenylpyruvicus, and Stenotrophomonas maltophilia were PYR negative. On the other hand Achromobacter piechaudii, Achromobacter denitrificans, Achromobacter xylosoxidans, Burkholderia gladioli, Chryseobacterium gleum-indologenes, Comamonas testosroni, Cupriavidus pauculus, Delftia acidovorans, Elizabethkingia meningoseptica, Myroides spp., Ochrobactrum anthropi, Pseudomonas oryzihabitans, Ralstonia pickettii, Rhizobium radiobacter, Shewanella spp., Sphingobacterium multivorum, Sphingobacterium spiritivorum, and Weeksella virosa were PYR positive. Finally, Acinetobacter lwoffii, Pseudomonas aeruginosa, Pseudomonas fluorescens, Roseomonas spp., and Sphingomonas paucimobilis-parapaucimobilis were PYR variable. PYR testing should be considered as a useful tool to facilitate the identification of NFGNR.
Aminopeptidases↗
Occurrence and patterns of waxes in Neisseriaceae.
Forty-five strains classified in the family Neisseriaceae were analysed for wax esters by gas-liquid chromatography. The amounts and types of waxes varied between the taxa. Waxes were not detected in 16 strains of 'true neisseriae' (genus Neisseria) or in two strains of Kingella, but they were found in all 'false neisseriae', in all species of Moraxella except Moraxella phenylpyrouvica, in five out of 10 strains of Acintobacter, and in all strains of a group of psychrophilic, oxidase-positive organisms. The chain lengths of the wax esters ranged from C24 to C42, with C36 predominating. In all taxa, esters with even numbers of carbon atoms constituted 70 to 100% of the total. Saturated, mono-unsaturated and diunsaturated waxes were found. Acinetobacter strains were characterized by large amounts (30 to 98%) of di-unsaturated wax esters; such waxes did not exceed 8% in the 'false neisseriae' or Moraxella spp. Waxes of strains belonging to the psychrophilic, oxidase-positive group generally resembled those found in Moraxella. Wax esters with odd numbers of carbon atoms were abundant in M. lacunata (29%), M. atlantae (15%) and in the psychorophilic group (19 to 28%); long-chain esters (C40 or above) were characteristic of M. atlantae (30%) and one strain of M. osloensis (26%).
Chromatography, Gas↗
Quantitative and qualitative aspects of bacterial flora of Karachi coastal water shrimp (Penaeus merguiensis and Metapenaeus monoceros).
Bacterial counts were made over a period of two years of two important commercial shrimp varieties of Karachi coastal waters. Bacteria were also isolated and identified. Total number of bacteria were found to be remarkably equal at 37 degrees, 30 degrees and 25 degrees C. Aerobic plate count of Penaeus merguiensis at 37 degrees C ranged from 1.2 X 10(5) to 6.0 X 10(7) CFU/g (Median 1.8 X 10(6) CFU/g), and were predominantly Vibrio, Micrococcus, Pseudomonas, Staphylococcus, Bacillus, and Flavobacterium. The corresponding count at 30 degrees C ranged from 3.2 X 10(5) to 4.7 X 10(7) CFU/g (Median 2.6 X 10(6) CFU/g). The bacterial flora in order of predominance were Vibrio, Micrococcus, Pseudomonas, Moraxella, Flavobacterium, Bacillus, Alteromonas, and Acinetobacter. The 25 degrees C counts ranged from 5.3 X 10(5) to 8.5 X 10(7) CFU/g (Median 3.1 X 10(6) CFU/g), the flora was composed of Vibrio, Moraxella, Micrococcus, Pseudomonas, Flavobacterium, Bacillus, Alteromonas, and Acinetobacter in order of predominance. The aerobic plate count of Metapenaeus monoceros at 30 degrees C ranged from 8.4 x 10(5) to 3.8 x 10(7) CFU/g (Median 2.9 x 10(6) CFU/g). The bacterial flora in order of predominance were Vibrio, Micrococcus, Moraxella, Pseudomonas, Alteromonas, Flavobacterium and Staphylococcus. No significant qualitative or quantitative difference was obtained between the two shrimp species. The presence of Staphylococcus at 37 degrees C was attributed to favourable incubation temperature as well as to excessive unsanitary handling while the absence of Moraxella and Alteromonas putrefaciens at this temperature was considered due to the psychotrophic nature of these organisms.
Animals↗
The envelope structure of Branhamella catarrhalis as studied by transmission electron microscopy.
The envelope structure of Branhamella catarrhalis was studied by electron microscopy and compared with that of other bacteria of the family Neisseriaceae, such as Moraxella lacunata subsp. liquefaciens and Neisseria gonorrhoeae. Negative staining of B. catarrhalis showed a mamilliform surface similar to that of Moraxella. On thin sections, the cell wall appeared to be made up of a wavy outer membrane tightly linked to a straight peptidoglycan layer. Spicule-like structures protruded from the cell surface. Ruthenium red staining revealed that they contained polysaccharides. While the outer polysaccharide layer of N. gonorrhoeae was unstable after repeated subcultures in vitro, this layer remained stable in B. catarrhalis and in Moraxella lacunata subsp. liquefaciens.
Cell Wall↗
Cloning and overexpression of the triosephosphate isomerase genes from psychrophilic and thermophilic bacteria. Structural comparison of the predicted protein sequences.
We focused on the temperature adaptation of triosephosphate isomerase (TIM; E.C. 5.3.1.1.) by comparing the structure of TIMs isolated from bacterial organisms living in either cold or hot environments. The TIM gene from psychrophilic bacteria Moraxella sp. TA137 was cloned and its nucleotide sequence determined. Its deduced amino acid sequence revealed 34% identity with the thermophilic bacteria Bacillus stearothermophilus TIM. Expression vectors were constructed and recombinant Moraxella TA137 and Bacillus stearothermophilus TIMs were overproduced and purified to homogeneity. Recombinant TIM inactivation constants (Ki), measured at various temperatures, compared to those of the mesophilic Escherichia coli recombinant TIM clearly show that Moraxella TA137 and B. stearothermophilus TIMs have respectively psychrophilic and thermophilic characteristics. To try to elucidate the structure-thermolability and structure-thermostability relationship, factors affecting the overall stability of these two TIMs were examined, based on the alignment with the mesophilic chicken TIM, the three-dimensional structure of which is already known. From this comparison, it appears that the adaptability of TIM to high temperature is favored by better stabilizing residues for the helix dipole as well as better helix-forming residues whereas the adaptability of TIM to low temperature seems to reside in the nature of helix-capping residues.
Amino Acid Sequence↗
Risk assessment of opportunistic bacterial pathogens in drinking water.
This study was undertaken to examine quantitatively the risks to human health posed by heterotrophic plate count (HPC) bacteria found naturally in ambient and potable waters. There is no clear-cut evidence that the HPC bacteria as a whole pose a public health risk. Only certain members are opportunistic pathogens. Using the four-tiered approach for risk assessment from the National Academy of Sciences, hazard identification, dose-response modeling, and exposure through ingestion of drinking water were evaluated to develop a risk characterization, which estimates the probability of infection for individuals consuming various levels of specific HPC bacteria. HPC bacteria in drinking water often include isolates from the following genera: Pseudomonas, Acinetobacter, Moraxella, Aeromonas, and Xanthomonas. Other bacteria that are commonly found are Legionella and Mycobacterium. All these genera contain species that are opportunistic pathogens which may cause serious diseases. For example, the three nonfermentative gram-negative rods most frequently isolated in the clinical laboratory are (1) Pseudomonas aeruginosa, (2) Acinetobacter, and (3) Xanthomonas maltophilia. P. aeruginosa is a major cause of hospital-acquired infections with a high mortality rate. Aeromonas is sometimes associated with wound infections and suspected to be a causative agent of diarrhea. Legionella pneumophila causes 4%-20% of cases of community-acquired pneumonia and has been ranked as the second or third most frequent cause of pneumonia requiring hospitalization. The number of cases of pulmonary disease associated with Mycobacterium avian is rapidly increasing and is approaching the incidence of M. tuberculosis in some areas. Moraxella can cause infections of the eye and upper respiratory tract. The oral infectious doses are as follows in animal and human test subjects: P. aeruginosa, 10(8)-10(9); A, hydrophila, > 10(10); M. avium, 10(4)-10(7); and X. maltophilia, 10(6)-10(9). The infectious dose for an opportunistic pathogen is lower for immunocompromised subjects or those on antibiotic treatment. These bacteria have been found in drinking water at the following frequencies: P. aeruginosa, < 1%-24%; Acinetobacter, 5%-38%; X. maltophilia, < 1%-2%; Aeromonas, 1%-27%; Moraxella, 10%-80%; M. avium, < 1%-50%; and L. pneumophila, 3%-33%. These data suggest that drinking water could be a source of infection for some of these bacteria. The risk characterization showed that risks of infection from oral ingestion ranged from a low of 7.3 x 10(-9) (7.3/billion) for low exposures to Aeromonas to higher risks predicted at high levels of exposure to Pseudomonas of 9 x 10(-2) (98/100). This higher risk was only predicted for individuals on antibiotics. Overall, the evidence suggests that specific members of HPC bacteria found in drinking water may be causative agents of both hospital- and community-acquired infections. However, the case numbers may be very low and the risks represent levels generally less than 1/10,000 for a single exposure to the bacterial agent. Future research needs include (1) determining the seasonal concentrations of these bacteria in drinking water, (2) conducting adequate dose-response studies in animal subjects or human volunteers, (3) determining the health risks for an individual with multiple exposures to the opportunistic pathogens, and (4) evaluating the increase in host susceptibility conferred by antibiotic use or immunosuppression.
Acinetobacter↗
Induction of degranulation and lysis of haemocytes in the freshwater crayfish, Astacus astacus by components of the prophenoloxidase activating system in vitro.
To study the role of the prophenoloxidase activating system, an enzyme cascade located in the haemocytes of crustaceans, in the cellular defences of the freshwater crayfish, Astacus astacus in vitro, monolayer cultures of mixed or separated haemocyte populations, isolated by density gradient centrifugation, were challenged with the bacterium, Moraxella sp. pre-coated with phenoloxidase and the other attaching proteins in crayfish haemocyte lysate (HLS), or in the case of controls, with saline or Moraxella sp. pre-incubated in saline alone. Examination of the coverslips 1 h after inoculation revealed that, in the mixed haemocyte cultures, most of the cells had undergone profound degranulation and lysis following exposure to the HLS-coated bacteria. Cell lysis was also evident in the experimental semigranular cell monolayers, but not in the controls, although in those controls treated with the saline-incubated bacteria, the semigranular haemocytes had undergone degranulation without lysis. In contrast, the granular cells appeared to be unaffected by the saline-incubated Moraxella sp., and with the HLS-coated bacteria displayed only marked degranulation. Greater numbers of bacteria were always associated with the cells or cell remnants in the experimental cultures compared to the controls. We suggest that the attaching proteins of the prophenoloxidase cascade are strong nonself signals for the haemocytes, causing them to degranulate and release previously cell-bound recognition factors into the haemolymph, where they are free to trigger activation of adjacent haemocytes.
Animals↗