Effect of particulate matter less than 10µm (PM10) on mortality in Bogota, Colombia: a time-series analysis, 1998-2006 / Efecto del material particulado menor a 10µm (PM10) sobre la mortalidad en Bogotá, Colombia: un análisis de series de tiempo 1998-2006

Objective. To analyze the association between daily mortality from different causes and acute exposure to particulate matter less than 10 microns in aerodynamic diameter (PM10), in Bogota, Colombia. Materials and methods. A time-series ecological study was conducted from 1998 to 2006. The association between mortality (due to different causes) and exposure was analyzed using single and distributed lag models and adjusting for potential confounders. Results. For all ages, the cumulative effect of acute mortality from all causes and respiratory causes increased 0.71% (95%CI 0.46-0.96) and 1.43% (95%CI 0.85-2.00), respectively, per 10µg/m³ increment in daily average PM10 with a lag of three days before death. Cumulative effect of mortality from cardiovascular causes was -0.03% (95%CI -0.49-0.44%) with the same lag. Conclusions. The results suggest an association between an increase in PM10 concentrations and acute mortality from all causes and respiratory causes.

Objetivo. Analizar la asociación entre la mortalidad diaria debida a distintas causas y la exposición aguda a partículas menores de 10 micras de diámetro aerodinámico (PM10), en Bogotá, Colombia. Material y métodos. Se realizó un estudio ecológico de series de tiempo (1998-2006). La asociación entre mortalidad y exposición se analizó ajustando modelos de retraso simple y retraso distribuido para diferentes causas de mortalidad. Resultados. En todas las edades, el riesgo acumulado en la mortalidad aguda por todas las causas y causa respiratoria aumentó 0.71% (IC95% 0.46-0.96) y 1.43% (IC95% 0.85-2.00), respectivamente, por incremento de 10µg/m³ en el promedio diario de PM10, tomando un retraso de tres días anteriores al deceso, mientras el riesgo acumulado en la mortalidad por causa cardiovascular fue de -0.03% (IC95% -0.49-0.44), para el mismo retraso. Conclusiones. Los resultados sugieren asociación entre el incremento de las concentraciones de PM10 y la mortalidad aguda por todas las causas y causa respiratoria.

Experimental infection of Peste des Petit Ruminant virus and Mannheimia haemolytica A2 in goats: immunolocalisation of Mannheimia haemolytica antigens.

Nigerian strain of Peste des Petit Ruminant (PPR) virus and Mannheimia haemolytica (MH) biotype A serotype 2, was used successfully to reproduce a concurrent disease in West African Dwarf goats. The development of the various pathological features were studied at regular intervals following infection. The acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together with a moderate bronchial and bronchiolar epithelial necrosis. This progressed to a milder acute broncho interstitial pneumonia with giant cells. At this stage, the mucosal immunity were well developed especially the aggregate form of NALT and more of nodular forms of BALT. The organisms were demonstrated with strong immunostaining in the necrotic center, necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte in the alveoli and respiratory airways. The bacterial antigens were observed as a strong immunostaining in the blood vessels of the nasal septum, sinusoid in the liver and interstium of the kidney, cytoplasm of alveolar macrophages, pneumocytes, bronchial and bronchiolar epithelium, in the monocytes in the blood vessels. These findings confirmed the enhancement of MH tropism especially in the respiratory tract, liver and kidney. It also showed that West african dwarf goats are highly susceptible to the intratracheal combined infection of PPR virus and MH. The fact that the infection induces strong mucosal responses, this phenomenon can be explored in Africa with the use of combined PPR virus and MH intranasal vaccines to curtail the menace of pneumonia associated with the combined infection on field.

[Fatty acid composition of cells and lipopolysaccliarides of Mannheimia haemolytica, Mannheimia glucosida and Bibersteinia trehalosi strains].

The Mannheimia haemolytica, Mannheimia glucosida and Bibersteinia trehalosi strains and the similar fatty acid composition of cells with domination of C(16:1) and C(16:0), which were in almost equal quantities, C(14:0 and C(18:1) + C(18:2). The fatty acid composition of lipopolysaccharides (LPS) of the studied bacteria had no essential differences too. It was mainly represented by C(14:0) and 3-OH-C(14:0) which consisted of more than 80% of all LPS fatty acids. C(12:0), C(16:1) and C(16:0) were presented in LPS in small quantities. The M. haemolytica, M. glucosida and B. trehalosi strains did not differ essentially by fatty acid compositions of cells and LPS from earlier studied strains of genera Pasteurella (P. multocida), Haemophilus (H. influenzae and other species), Actinobacillus (A. pleuropneumoniae). This shows the close phylogenetic relationship of the mentioned bacteria and significance of investigated signs as chemotaxonomic markers for differentiation of taxons of the above genus level. The paper is presented in Russian.

Phenotypic characterisation of Australian sheep and cattle isolates of Mannheimia haemolytica, Mannheimia granulomatis and Mannheimia varigena.

OBJECTIVE: To perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic Pasteurella-Actinobacillus and obtained from cattle and sheep. DESIGN: The 35 isolates that had been obtained from Australian animals, 30 from cattle and five from sheep, were compared with reference strains of the five recognised species of the genus Mannheimia--M. haemolytica, M. glucosida, M. granulomatis, M. ruminalis and M. varigena. RESULTS: Thirty-four of the isolates could be confidently assigned to three species of the genus Mannheimia. Twenty-nine were M. haemolytica, with 25 being isolated from cattle and four from sheep. All but three of the bovine M. haemolytica were isolated from pneumonic lungs. Of the three remaining bovine M. haemolytica isolates, one was obtained in pure culture from a bovine milk sample and the other two as part of a mixed flora associated with a middle ear infection of a calf suffering mucosal disease. Of the four ovine M. haemolytica isolates, two were isolated in pure culture from milk and two, also in pure culture, from pneumonic lungs. Three bovine isolates were identified as M. granulomatis--one from a tongue abscess, one from a jaw abscess and one from a lung showing suppurative bronchopneumonia. Two bovine isolates were identified as M. varigena--one coming from an udder and the other from a spleen. The available diagnostic records provided no information on whether these isolates were associated with a disease process. The remaining isolate was obtained from an ovine tongue abscess and could not be assigned to a recognised species within the genus Mannheimia. CONCLUSION: The study represents the first time that M. haemolytica, M. granulomatis and M. varigena have been recognised as being present in cattle and sheep in Australia. Veterinary laboratories that encounter Pasteurella-Actinobacillus-like organisms from cattle and sheep should attempt as complete a characterisation as possible to help improve our knowledge of the disease potential of these organsims.

Phenotypic and genotypic characterization of Mannheimia (Pasteurella) haemolytica-like strains isolated from diseased animals in Denmark.

Trehalose-negative strains of the Pasteurella haemolytica complex have recently been transferred to a new genus, Mannheimia. This genus presently consists of five named species: M. haemolytica, M. glucosida, M. granulomatis, M. ruminalis and M. varigena. The purpose of this study was to investigate the occurrence of these species and lesions associated with these isolates in Denmark. In all 106 M. haemolytica-like strains isolated from pathological material from cattle, sheep, pigs and hares submitted to the Danish Veterinary Laboratory between 1994 and 1998 were investigated. Phenotypic characterization and ribotyping were used for identification in addition to sequencing of the 16S rRNA genes for selected strains. The species allocation was determined by comparison to results from a previous polyphasic taxonomic study. Seventy-one percent of the strains belonged to M. haemolytica, 18% to M. varigena and 8% to unnamed groups within the genus Mannheimia. Single isolates identified as M. glucosida and P. trehalosi, respectively, were detected. Two isolates belonged to M. granulomatis. Forty-three percent of the strains belonged to serotype 1, 41% were untypeable, while the rest belonged to serotypes 2, 7, 9, and 16. The present investigation also showed that a simplified phenotypic characterization using Diatabs Diagnostic Tablets (Rosco, Denmark) represents a useful method for obtaining a quick and reliable species identification. Finally, the investigation confirmed that serotyping does not represent a reliable method for species identification. The heterogeneity of species associated with bovine "pasteurellosis" should be considered in future studies to improve our understanding of the pathogenesis of pneumonic disease.

Suppression of Mannheimia (Pasteurella) haemolytica serovar 1 infection in lambs by intrapulmonary administration of ovine antimicrobial anionic peptide.

In this study, the efficacy of ovine antimicrobial anionic peptide (AP) was assessed in a lamb model of acute pneumonia. A single intratracheal dose of the peptide, H-DDDDDDD-OH (0.5 mg) reduced pulmonary inflammation and the concentration of Mannheimia (Pasteurella) haemolytica in infected lung tissue. Administration of H-DDDDDDD-OH after infection was more effective in reducing the consolidation and lesion scores at the deposition site than its administration prior to infection. Hence, the in vivo effectiveness of AP suggests that it may have applications in the treatment of pulmonary infections. Further studies are needed to confirm these findings and also to determine the optimal doses and intervals of H-DDDDDDD-OH therapy.

Taxonomic relationships of the [Pasteurella] haemolytica complex as evaluated by DNA-DNA hybridizations and 16S rRNA sequencing with proposal of Mannheimia haemolytica gen. nov., comb. nov., Mannheimia granulomatis comb. nov., Mannheimia glucosida sp. nov., Mannheimia ruminalis sp. nov. and Mannheimia varigena sp. nov.

The present paper presents the conclusions of a polyphasic investigation of the taxonomy of the trehalose-negative [Pasteurella] haemolytica complex. Clusters previously identified by ribotyping and multilocus enzyme electrophoresis (MEE) have been evaluated by 16S rRNA sequencing and DNA-DNA hybridizations. Results obtained by the different techniques were highly related and indicated that the [P.] haemolytica complex contains distinct genetic and phenotypic groups. At least seven species were outlined, five of which were named. We refrained in formal naming of more groups until additional strains are characterized. Five 16S rRNA clusters were identified corresponding to distinct lineages previously outlined by MEE. Within 16S rRNA cluster I two distinct genotypic groups have been outlined in addition to [P.] haemolytica sensu stricto (biogroup 1). Each of the clusters II, III, IV and V represent at least one new species. The investigations underline that [P.] haemolytica sensu stricto only contains strains that do not ferment L-arabinose even though they are referred to as 'biotype A' of [P.] haemolytica. The five 16S rRNA clusters identified had a common root relative to the other species within the family Pasteurellaceae, and the overall sequence similarity among these five clusters was higher than what is observed within the existing genera of the family. The allocation of the trehalose-negative [P.] haemolytica complex to a new genus seems to be indicated. Based on the polyphasic investigation performed a new genus Mannheimia is proposed for the trehalose-negative [P.] haemolytica complex. At the present stage two previously named species are transferred to this new genus and three new species are described. [P.] haemolytica is reclassified as Mannheimia haemolytica comb. nov., whereas Pasteurella granulomatis, Bisgaard taxon 20 and [P.] haemolytica biovar 3J are reclassified and combined in the species Mannheimia granulomatis comb. nov. Mannheimia glucosida sp. nov. corresponds to [P.] haemolytica biogroups 3A-3H and the beta-glucosidase and meso-inositol-positive strains of [P.] haemolytica biogroup 9. All typable strains within M. glucosida belong to serotype 11. Mannheimia ruminalis sp. nov. consists of strains previously classified as Bisgaard taxon 18 and [P.] haemolytica biogroup 8D. Finally, Mannheimia varigena sp. nov. includes [P.] haemolytica biogroup 6 as well as Bisgaard taxon 15 and Bisgaard taxon 36. The type strains are NCTC 9380T (M. haemolytica), ATCC 49244T (M. granulomatis), CCUG 38457T = P925T (M. glucosida), CCUG 38470T = HPA92T (M. ruminalis) and CCUG 38462T = 177T (M. varigena).

Alterations in bovine platelet function and acute phase proteins induced by Pasteurella haemolytica A1.

Platelet function was assessed by aggregometry in 10 Holstein calves before and after exposure to Pasteurella haemolytica (biotype A, serotype 1) by intrabronchial challenge. At 24 h after exposure the platelets had become more reactive to stimulation with known platelet agonists such as adenosine diphosphate (ADP) and platelet-activating factor (PAF) and the platelet aggregates that formed were more resistant to disaggregation. The activation of platelets was an early response in the challenged calves as platelet function had returned to pretreatment levels 72 h after exposure to the bacteria while the acute phase reactant proteins, haptoglobin and fibrinogen, were approaching their peak values and alpha 2-macroglobulin levels had also risen significantly (P < 0.05) at this time. The plasma levels of these proteins were still elevated and albumin levels were depressed 6 d post-treatment. At post-mortem all calves exhibited pneumonic tissue damage. When P. haemolytica leukotoxin was added directly to bovine platelet suspensions both spontaneous aggregation and an increase in the aggregation response to ADP and PAF stimulation were observed. The morphological appearance of the platelet aggregates exhibited the typical pattern for bovine platelets with 2 distinct zones of cells being visible within each aggregate. One zone contained platelets in which the cytoplasmic granules were still evident and the other zone contained irregularly shaped platelets devoid of granular content. In the latter zone, discrete gaps, or pores, were evident in the plasma membrane of numerous platelets. This pore formation is characteristic of leukotoxin action and is not observed in ADP or PAF induced aggregates.

The Pasteurella haemolytica 35 kDa iron-regulated protein is an FbpA homologue.

In a previous investigation, a 35 kDa iron-regulated protein was identified from total cellular proteins of Pasteurella haemolytica grown under iron-depleted conditions. This study reports identification of the gene (fbpA) encoding the 35 kDa protein based on complementation of an entA Escherichia coli strain transformed with a plasmid derived from a P. haemolytica lambda ZAP II library. Cross-reactivity was demonstrated between an anti-35 kDa mAb and a 35 kDa protein expressed in this strain. Furthermore, a translated ORF identified on the recombinant plasmid corresponded with the N-terminal amino acid sequence of the intact and a CNBr-cleaved fragment of the 35 kDa iron-regulated protein. Nucleotide sequence analysis of the gene encoding the 35 kDa protein demonstrated homology with the cluster 1 group of extracellular solute-binding proteins, especially to the iron-binding proteins of this family. Complete sequence analysis of the recombinant plasmid insert identified three other predominant ORFs, two of which appeared to be in an operonic organization with fbpA. These latter components (fbpB and fbpC) showed homology to the transmembrane and ATPase components of ATP-binding cassette (ABC)-type uptake systems, respectively. Based on amino acid/DNA sequencing, citrate competition assay of iron affinity and visible wavelength spectra, it was concluded that the P. haemolytica 35 kDa protein functions as an FbpA homologue (referred to as PFbpA) and that the gene encoding this protein is part of an operon comprising a member of the FbpABC family of iron uptake systems. Primary sequence analysis revealed rather surprisingly that PFbpA is more closely related to the intracellular Mn/Fe-binding protein IdiA found in cyanobacteria than to any of the homologous FbpA proteins currently known in commensal or pathogenic members of the Pasteurellaceae or Neisseriaceae.

Further studies of the relationships among strains classified as taxon 15, taxon 18, taxon 20, (Pasteurella) granulomatis or the (Pasteurella) haemolytica-complex in ruminants using quantitative evaluation of phenotypic data.

Ninety-three trehalose-negative (P.) haemolytica-like strains of ruminant, porcine and leprine origin were investigated. A quantitative evaluation of phenotypic tests was used and the results obtained were compared with those from 246 previously investigated ruminant strains. Cluster analysis of the results obtained displayed most of the taxa as distinct groups which could be related to differences in key characters. Although only minor phenotypic differences were observed between the taxa investigated and the taxa were internally heterogeneous for many of the tests, it was possible to identify characters separating most groups. However, in three instances, taxa isolated from different species could not be separated by any of the tests used or by quantitative evaluation of all 79 tests--the only difference being the species of animals from which they had been isolated. Taxa which could not be separated by phenotypic tests included the ruminant biogroup 6 of (P.) haemolytica and the porcine taxon 15/biovar 1, the ruminant biogroup 7 of (P.) haemolytica and the porcine taxon 15/biovar 2, and ruminant biogroup 31 of (P.) haemolytica and the leprine taxon 20/biovar 1.

Genotypic relationships among strains classified under the (Pasteurella) haemolytica-complex as indicated by ribotyping and multilocus enzyme electrophoresis.

Two-hundred and one strains classified under the (Pasteurella) haemolytica-complex isolated from cattle, sheep, deer, pigs, hares and rabbits were investigated by ribotyping. Fifty-nine of these strains were selected for further studies using multilocus enzyme electrophoresis (MEE). A correlation between the clusters identified by ribotyping and MEE was demonstrated and the results furthermore indicated that a genetic basis exists for most clusters previously outlined by the use of quantitative evaluation of phenotypic data. The taxonomic relevance of ornithine decarboxylase and fermentation of L-arabinose, D-sorbitol and glucosides for taxonomic delineation within the (P.) haemolytica-complex was supported. A taxonomic importance was further indicated for ONPG, ONPX, ONPF, meso-inositol, D-xylose, maltose, dextrine and NPG in relation to some of the taxa. Within the porcine taxon 15, however, differences in ornithine decarboxylase did not correspond to genetic clusters. Six lineages were revealed by MEE. Lineage A contained electrophoretic types (ETs) representing biogroups 1, 3A-3H, 8A and 9, indicating a genetic relationship between these groups--an observation which was supported by ribotyping. Lineage B included biogroup 8D, 3 strains from biogroup 10 and a single strain from biogroup 1 and taxon 18/biovar 1. Lineage C contained strains allocated to biogroup 6 from ruminants and the porcine taxon 15. The similarity between these two groups was accentuated by ribotyping. Lineage D and the single isolate in lineage E contained strains allocated to biogroups 7, 10, 8B and 8C, in addition to single strains from biogroups 6 and 9. The same strains were found in the heterogenous ribotype cluster 17. Lineage F contained strains representing the leprine taxon 20 and the ruminant (P.) granulomatis. Ribotyping indicated that the ruminant biogroup 3J was affiliated with both taxon 20 and (P.) granulomatis.

[Investigation of outer membrane proteins of Pasteurella. 2: Iron-regulated outer membrane proteins of Pasteurella multocida and Pasteurella haemolytica]. / Untersuchungen zu den Proteinen der äusseren Membran von Pasteurellen 2. Mitteilung: Eisenregulierte Proteine der äusseren Membran bei Pasteurella multocida und Pasteurella haemolytica.

Pasteurella multocida and Pasteurella haemolytica produce specific proteins in the outer membrane under iron-depleted conditions. Pasteurella multocida serovar A expresses these proteins of molecular masses of 76 and 96 kDa as determined by electrophoresis. The analogous serovar D produces a further iron-regulated protein of 85 kDa. The Pasteurella haemolytica strains of serovar A1, A6 and T contain iron-regulated outer membrane proteins of molecular masses of 71, 77 and 100 kDa. These proteins possess binding positions for iron ions. Both Pasteurella multocida and Pasteurella haemolytica strains utilize iron from porcine and bovine transferrin, but not from haemin and haemoglobin.

Identification of Pasteurella haemolytica A1 isolates from market-stressed feeder calves by use of enzyme and antimicrobial susceptibility profiles.

An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for alpha-galactosidase, alpha-mannosidase, beta-glucosidase, beta-glucuronidase, cystine aminopeptidase, N-acetyl-beta-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; alpha-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; beta-galactosidase, 2 isolates; and alpha-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P < or = 0.001) than by habitation with calves from other farms while in the feedyard.(ABSTRACT TRUNCATED AT 250 WORDS)