Deoxyribonucleic acids from Pasteurella multocida and Pasteurella haemolytica]

Pasteurella multocida and P. haemolytica strains contain between 1.5 and three per cent phosphorus, between nine and 14 per cent nitrogen, between two and four per cent DNA, and between five and 18 per cent RNA, the precise figures depending on culturing conditions. High-molecular DNA may be isolated by means of bacteriolysis, using deoxycholate or dodecylsulphate and the usual steps of purification, with yield and purity differing by strains. DNA with sufficient purity can be obtained from Sepharose 2 B by gel chromatography. The isolated DNA yields were characterised, base values being between 37 and 38 per cent GC for P. haemolytica and between 41 and 48 per cent GC for P. multocida. Highly suitable precursors to DNA synthesis for tritium labelling are 3H-thymidine, which is incorporated in excess of 3H-thymine by a factor of 255, as well as 3H-uracil, with its activity being recovered also from the pyrimidine bases of DNA via pyrimidine biosynthesis.     

Long-chain fatty acids of Pasteurella multocida nad Pasteurella haemolytica

The relative contents of long-chain fatty acids in P. multocida and P. haemolytica were investigated. A dependence on the composition of the broth was established. Accordingly, comparative quantitative studies on fatty acid contents have to be conducted using bacteria grown with the same lot of broth medium. As for P. multocida, there were significant differences between the serovars (C14 in TDHM and C16, delta 2C18 in BPL). These differences are, however, not significant to replace serotyping. Highly significant differences were also detected between P. multocida isolates from nasal swabs and pneumonic lungs (interims of C14, delta C16 on BPL and BRU). The largest differences were measured for strains grown on BRU, which is interpreted as an expression of virulence. Significant differences were found between biotypes A and T of P. haemolytica, namely for C14, C16 in TDHM, and C14, delta C16, C16, C18 in BPL medium.     

Investigation of outer membrane proteins of Pasteurella. 2: Iron-regulated outer membrane proteins of Pasteurella multocida and 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.     

Incubation of Pasteurella haemolytica and Pasteurella multocida lipopolysaccharide with sheep lung surfactant

Lipopolysaccharides (LPS) were extracted from a serotype of each of 2 species of Pasteurella isolated from sheep with respiratory tract infections. Lipopolysaccharides from P haemolytica 82-25 (serotype 1A) or P multocida P-1573 (serotype 12) were mixed with sheep lung surfactant and were incubated for 6 hours at 37 C. After incubation, LPS-surfactant mixtures were centrifuged overnight in sucrose density gradients, and fractions were analyzed. Binding occurred between LPS and surfactant vesicles resulting in a stable complex with densities greater than those with the surfactant alone. The surfactant alone had a density of 1.052 to 1.060 g/ml. Diffuse bands of surfactant had a density of 1.075 to 1.092 when incubated with P haemolytica LPS and a density of 1.069 to 1.105 when incubated with P multocida LPS.     

Pulmonary response to intratracheal challenge with Pasteurella haemolytica and Pasteurella multocida.

Calves were inoculated intratracheally with 5 X 10(7), 5 X 10(8), or 5 X 10(9) colony forming units of either 18-hour stationary phase cultures or 4-hour log phase cultures of Pasteurella haemolytica. The log phase culture at all concentrations produced more severe clinical signs, hematological changes and pulmonary lesions at postmortem examination than did the corresponding stationary phase culture. More severe effects were seen with the larger doses especially with the log phase culture. Fibrinous bronchopneumonia with focal or multifocal necrosis was consistently produced by both the stationary and log phase cultures. To determine if this lesion was peculiar to P. haemolytica or whether it could be produced generally by rapidly growing Gram negative organisms, a 4-hour log phase culture of Pasteurella multocida was prepared in an identical manner to that used for the culture of P. haemolytica and given to calves intratracheally at the high bacterial dose (5 X 10(9]. The P. haemolytica produced more severe clinical, hematological and morphological changes than did the P. multocida. The lesions observed with P. multocida differed morphologically from those of P. haemolytica; there was a suppurative exudative component and minimal to no necrosis with P. multocida. It appears that an important pathogenic principle is produced by the rapidly growing P. haemolytica that causes it to produce a more severe clinical disease and more necrotizing pulmonary lesions than P. multocida.     

Bovine pneumonic pasteurellosis: model for Pasteurella haemolytica- and Pasteurella multocida-induced pneumonia in cattle

Pneumonic lesions in calves were induced with Pasteurella haemolytica or P multocida. The inoculum, consisting of a suspension of either organism, was administered by transthoracic intrapulmonic injection to 23 calves. Three died of septicemia; the 20 remaining, killed 96 hours after inoculation, had an expanding unifocal pneumonia qualitatively comparable with that of acute pneumonic pasteurellosis (shipping fever). The concentration of bacteria that consistently produced a lesion was a 5-ml volume containing 10(9) colony-forming units of bacteria; a concentration of 10(6) colony-forming units inconsistently produced lesions. Bacteria, except in calves that developed septicemia and died, remained localized at the injection site. The inflammatory process spread within the lungs, not only through airways, but through the interlobular and interalveolar septa as well.     

产毒素多杀性巴氏杆菌的鉴定

采用菌落多重PCR方法对分离保存的28株多杀性巴氏杆菌进行种型和毒素基因的检测,结果表明,菌株C51-6、M-4和P-2237为产毒素多杀性巴氏杆菌,菌株C51-6和P-2237为荚膜血清D型,菌株M-4为荚膜血清A型。同时用金黄色葡萄球菌抑制试验、中性吖啶黄沉淀试验和豚鼠皮肤坏死试验对PCR方法进行了验证。基于对甘露醇、卫茅醇、山梨醇、海藻糖的发酵能力和产生鸟氨酸脱羧酶的特性,3株菌株鉴定为多杀性巴氏杆菌多杀亚种。     

Serotypes of Pasteurella haemolytica and Pasteurella trehalosi isolated from farm animals in Hungary.

The biochemical and serological characteristics of 486 P. haemolytica and 31 P. trehalosi strains (517 in total) isolated from different lesions of cattle, sheep, goats, pigs and poultry were examined. A total of 476 P. haemolytica strains (97.9%) showed the characteristics typical of the former biotype A of P. haemolytica, while 10 isolates (2.1%), all from poultry, could not be biotyped. A total of 481 strains (93.0%) could be assigned to one of the 17 serotypes of P. haemolytica-P. trehalosi and 36 strains (7.0%) could not. The majority (83.6%) of the cattle isolates were serotypes A1 and A2. Among strains isolated from sheep all serotypes of P. haemolytica could be identified with the exception of A14, but serotypes A1, A2, A6, A8 and A5 were the most frequent. The overwhelming majority (94%) of the caprine isolates were A2, other serotypes occurred only sporadically. The pig isolates, which could be isolated only very rarely, represented different serotypes, while none of the 10 strains isolated from poultry could be biotyped or serotyped.     

Multiple drug resistance in Pasteurella multocida and Pasteurella haemolytica from cattle and swine.

The results of antimicrobial susceptibility testing on 262 strains of Pasteurella multocida and 141 strains of Pasteurella haemolytica isolated from cattle and swine from 1971 to 1974 were analyzed for patterns of resistance to streptomycin, penicillin, tetracycline, and chloramphenicol, using a modified Kirby-Bauer procedure. Resistance was recorded for 80.5% of the isolants of P multocida and 92.2% of those of P haemolytica. Resistance to streptomycin was most frequent, followed by resistance to penicillin and tetracycline. Most cultures of P multocida and P haemolytica were susceptible to chloramphenicol. There were 9 patterns of resistance with the aforementioned antibiotics. The combinations, streptomycin and penicillin and streptomycin and tetracycline, each accounted for approximately 10% of the resistance patterns of P multocida. Approximately half of the 14 isolants of P haemolytica were resistant to the combination of streptomycin, penicillin, and tetracycline. These observations underscore the need for antimicrobial susceptibility testing of clinical isolants of P multocida and P haemolytica.