Interaction Between Aflatoxicosis and a Natural Infection of Chickens with Salmonella

Broiler chicks with a natural congenital infection of Salmonella worthington required a lower concentration of dietary aflatoxin (0.625 mug/g) to depress growth than uninfected chicks (2.50 mug/g).     

Relation of Salmonella typhi and Salmonella gallinarum auxotrophicity to the ability to grow on Simmons' medium

A total of 9 S. typhi strains and 1 S. gallinarum strain isolated from clinical material are auxotrophic with respect to tryptophan. The growth of S. typhi is accelerated in a glucose- and tryptophan-containing minimal medium with cysteine and methionine added. S. typhi strains are incapable of using sodium citrate as the only source of carbon. S. typhi cannot grow on Simmons citrate agar as these organisms are auxotrophic with respect to tryptophan and incapable of using sodium citrate as the only source of carbon, and S. gallinarum cannot grow on this medium as they are auxotrophic with respect to tryptophan.     

Tetratrichomonas gallinarum in the Blood of Chickens Infected with Spirochetes

SYNOPSIS. Tetratrichomonas gallinarum was found in the blood of 3 chickens experimentally infected with Borrelia anserina . The blood infection was successfully reproduced in healthy chickens and was accompanied by evidence that the trichomonads multiplied in the blood, ingested red blood cells, and were themselves phagocytized by leucocytes. T. gallinarum was maintained in serial passage in chicken embryos as well as in the usual trichomonad culture media.     

Purification and characterization of phospholipase C of Salmonella gallinarum

Phospholipase C was isolated from an outbreak strain of Salmonella gallinarum with ciprofloxacin extraction, dialysis, gel filtration, ion exchange chromatography and chromatofocussing. Purified phospholipase C (mol wt. 65 KDa; isoelectric point, pI 3.5) was resistant to pasteurization, stomach enzyme (pepsin), bacterial protease and lipase but lost its activity on trypsin and chymotrypsin treatment. It was sensitive to pH > or = 8.0. It was haemolytic, embryotoxic, enterohaemorrhagic, lethal to birds, cytotoxic to Vero and MDBK cells, dermonecrotoxic in rabbit and antigenically active protein. Antisera raised against purified phospholipase C neutralized its all biological activities and agglutinated the producer Salmonella strains. Serologically it was proved similar to phospholipase C of Klebsiella pneumoniae and S. weltevreden. Fluorescent antibody technique (FAT) was standardized to detect phospholipase producer strains.     

Pathogenicity of Salmonella gallinarum After Metabolic Injury by Freezing

Freezing (-75 C) and storage (-20 C) of a cell suspension of Salmonella gallinarum resulted in a heterogeneous population of dead, metabolically injured, and unharmed cells. Injured cells constituted as much as 40% of those surviving freezing and storage for 1 day. Replica plating of frozen and thawed cells indicated metabolic injury was repairable and not a stable mutation. Penicillin was used to increase the ratio of injured to uninjured cells from a frozen and thawed cell suspension. Pathogenicity was evaluated by observing per cent mortality after injecting injured or uninjured cells into separate sets of chicks. Mortality differences between wholly uninjured and predominantly injured populations were small and consistent (5% level) with a hypothesis of no difference.     

Cellular Aspects of the Resistance of Chickens to Eimeria tenella Infections*

SYNOPSIS. Sporozoites of Eimeria tenella were injected into the peritoneal cavity of normal chickens and chickens immunized against E. tenella. In some experiments normal scrum and serum from resistant chickens were injected prior to the injection of sporozoites. After 15 or 30 minute periods of intraperitoneal incubation, exudates were harvested and the occurrence of intracellular sporozoites was determined. Only macrophages and degranulated granulocytes were observed to contain sporozoites. There was no significant difference between the number of macrophages obtained from normal chickens (normal macrophages) which contained sporozoites and the number of macrophages obtained from immune chickens (immune macrophages) which contained sporozoites. Significantly fewer immune macrophages treated with immune serum contained sporozoites than untreated normal or immune cells, normal macrophages treated with either serum, or immune macrophages treated with normal scrum. Sporozoites in untreated normal macrophages did not appear to be harmed by the intracellular environment, based on structural observations. The majority of sporozoites in macrophages from all other groups were difficult to distinguish within the cytoplasm and were visibly distorted. It is hypothesized that the presence of fewer infected macrophages in exudates of immune chickens and serum-treated normal chickens was caused by an enhanced ability of these cells to destroy the parasite. Similar observations were noted in the case of sporozoites within degranulated granulocytes of experimental groups. The lack of understanding of the degranulation phenomenon makes it difficult to interpret these findings.     

Characterization of a T7-like lytic bacteriophage (phiSG-JL2) of Salmonella enterica serovar gallinarum biovar gallinarum

PhiSG-JL2 is a newly discovered lytic bacteriophage infecting Salmonella enterica serovar Gallinarum biovar Gallinarum but is nonlytic to a rough vaccine strain of serovar Gallinarum biovar Gallinarum (SG-9R), S. enterica serovar Enteritidis, S. enterica serovar Typhimurium, and S. enterica serovar Gallinarum biovar Pullorum. The phiSG-JL2 genome is 38,815 bp in length (GC content, 50.9%; 230-bp-long direct terminal repeats), and 55 putative genes may be transcribed from the same strand. Functions were assigned to 30 genes based on high amino acid similarity to known proteins. Most of the expected proteins except tail fiber (31.9%) and the overall organization of the genomes were similar to those of yersiniophage phiYeO3-12. phiSG-JL2 could be classified as a new T7-like virus and represents the first serovar Gallinarum biovar Gallinarum phage genome to be sequenced. On the basis of intraspecific ratios of nonsynonymous to synonymous nucleotide changes (Pi[a]/Pi[s]), gene 2 encoding the host RNA polymerase inhibitor displayed Darwinian positive selection. Pretreatment of chickens with phiSG-JL2 before intratracheal challenge with wild-type serovar Gallinarum biovar Gallinarum protected most birds from fowl typhoid. Therefore, phiSG-JL2 may be useful for the differentiation of serovar Gallinarum biovar Gallinarum from other Salmonella serotypes, prophylactic application in fowl typhoid control, and understanding of the vertical evolution of T7-like viruses.     

禽大肠杆菌、肠炎、鼠伤寒、鸡白痢及鸡伤寒沙门菌多重PCR方法的建立及应用

【背景】大肠杆菌病和沙门菌病是最常见的家禽细菌性疾病,给养禽业造成严重经济损失。另外,禽大肠杆菌和沙门菌也是重要的人畜共患病原菌,可通过禽类及其产品传播给人类,对人类健康造成严重威胁。加强禽大肠杆菌和沙门菌的快速鉴别检测,对养禽业和公共卫生都具有重要意义。【目的】建立禽大肠杆菌、肠炎沙门菌、鼠伤寒沙门菌、鸡白痢沙门菌和鸡伤寒沙门菌的多重PCR检测方法。【方法】通过比较分析确定禽致病性大肠杆菌、肠炎沙门菌、鼠伤寒沙门菌、鸡白痢沙门菌和鸡伤寒沙门菌的特异靶标基因,设计5对特异性引物,通过条件优化建立多重PCR方法,分析该多重PCR方法的特异性、敏感性及可靠性。【结果】该方法能特异性地鉴定禽致病性大肠杆菌、肠炎沙门菌、鼠伤寒沙门菌、鸡白痢沙门菌和鸡伤寒沙门菌,每个PCR反应的最低检出限分别为103 CFU细菌和100 pg基因组DNA。临床分离菌株检测显示,多重PCR与传统血清学方法结果一致。【结论】建立的多重PCR方法能够快速鉴别禽致病性大肠杆菌和不同血清型沙门菌,对禽大肠杆菌病和沙门菌病的流行病学调查及临床检测具有重要意义。