Mycobacterium tuberculosis infection in two East African oryxes.

Tuberculous lesions were observed at necropsy of 2 East African oryxes (Oryx gazella beisa) at a municipal zoological park in Jackson, Ms. Microscopic examination revealed granulomas containing acid-fast bacilli in the lungs and liver of both animals, as well as in the uterus and mediastinal lymph nodes of 1 animal. Mycobacterium tuberculosis was isolated from the tissues of both oryxes and from fluid aspirated from the mammary gland of 1 oryx; the organism was pathogenic for guinea pigs but not for rabbits.

In vitro cultivation of the rickettsial agent of trench fever.

Although trench fever appears to be endemic in many areas of the world, recognition of the disease has been handicapped by the difficulties of making a clinical diagnosis and the unavailability of a simple laboratory procedure to establish the etiology. The author describes a method for the in vitro cultivation of Rickettsia quintana that provides a relatively simple means for the laboratory diagnosis of trench fever. R. quintana can be propagated with ease from the blood of patients directly on blood agar incubated at 37 degrees C for 12-14 days under a gas tension of 5% CO(2) in air. The number of rickettsiae circulating in the patient's peripheral blood can be quantitated. The protracted rickettsiaemia in trench fever makes for a relatively long period during which blood culture can be usefully employed.In the course of studies with the method described, it was found that erythrocytes contain a factor (or, possibly, factors) essential for multiplication of R. quintana; this factor is cryostable and thermostable and may be haemoglobin. Blood serum also promotes multiplication.

Chicken embryo as an animal model for gonorrhea.

Parameters of infection of the chicken embryo with Neisseria gonorrhoeae were defined in order to standardize infectious and lethal doses. Virulent (T1) and avirulent (T3) gonococci from two strains were used to infect 7- to 12-day-old White Leghorn chicken embryos via the yolk sac (YS) or chorioallantoic membrane (CAM) route. Infection of embryos was established following YS inoculation of 1 to 10 viable gonococci. Although 8- to 10-day-old embryos were the most susceptible, an inoculum of less than 100 gonococci was sufficient to kill any age embryo via this route. Embryos were less susceptible to infection via the CAM, where an inoculum of from 10(5) to 10(6) colony-forming units was lethal by 42 h. Strain and morphological type had a variable influence on the ability of the gonococcus to infect and kill the chicken embryo by either route; however, agar-grown and broth-grown organisms produced consistently similar mean lethal dose (LD(50)) and mean infective dose (ID(50)) values. LD(50) and ID(50) differences between T1 and T3 gonococci from strain 72H641 were not apparent after either YS or CAM inoculation of 8- or 10-day chicken embryos, respectively. YS and CAM LD(50) values for strain 72H641 T1 and T3 and CDC 9 T3 were also similar; however, these values were slightly lower for CDC 9 T1. In terms of infectivity or colonization, CDC 9 T1 and T3 had higher ID(50) values via the YS and lower ID(50) values via the CAM than 72H641. CDC 9 T1 was slightly more infective via the YS and less infective via the CAM than its T3 counterpart. Although the gonococcal strain used will influence interpretation of results, infection of both YS and CAM was highly reproducible in terms of gross pathology and of LD(50) and ID(50) data for a particular strain and colony type.

Immunochemical and biological properties of the outer membrane-associated lipopolysaccharide and protein of Rochalimaea quintana.

The outer membrane complex of Rochalimaea quintana was isolated by use of ethylene-eiaminetetraacetate and was compared biochemically and biologically both with lipopolysaccharide (LPS) isolated by phenol-water extraction of whole organisms and with lipids isolated by chloroform-methanol extractions of the phenol-water insoluble residues. The outer membrane consisted of protein and LPS components, as distinguished by precipitin tests with sera from patients with trench fever or tests with hyperimmune animal sera. The outer membrane protein component, but not LPS, also reacted with sera from infections with Rickettsia tsutsugamushi. The LPS contained 2-keto-3-deoxy-octonate and heptose. The outer membrane and phenol-extracted LPS were reactive in the chick embryo lethality test, limulus assay, and complement activation. Outer-membrane activity was confined to the LPS component. The lipid extracts were reactive in chick embryo lethality and limulus assays, but did not activate complement.

Enzyme immunoassay of antibody to Rochalimaea quintana: diagnosis of trench fever and serologic cross-reactions among other rickettsiae.

Enzyme immunoassay (EIA) tests were used to diagnose trench fever and to determine cross-reactions of Rochalimaea quintana with other rickettsiae. The results were compared with those obtained by counterimmunoelectrophoresis (CIE). All sera from cases of primary or relapsed forms of trench fever were positive both in EIA, with serum antibody titers of 1:20-1:640, and in CIE, giving one to three precipitin lines. Sera from patients with other rickettsial infections were also tested for reactivity with R. quintana antigen: typhus group (Rickettsia prowazekii, Ricketsia mooseri), 15 sera; spotted fever group (Ricketsia ricketsii, Rickettsia akari), eight sera; and scrub typhus (Rickettsia tsutsugamushi), six sera. Strong reactions occurred with four sera from patients with scrub typhus, giving one or two lines in CIE and EIA titers of 1:40-1:160; these results were extended to guinea pig antisera to R. tsutsugamushi. About 50% of typhus group sera reacted with a single line in CIE and had antibody titers of 1:20-1:80 by EIA. The results show that EIA is accurate for the diagnosis of trench fever and, with the results obtained by CIE, suggest that R. quintana is antigenically related to R. tsutsugamushi and possibly to rickettsiae in the typhus group as well.

A passive hemagglutination test for diagnosis of trench fever due to Rochalimaea quintana.

A passive hemagglutination test devised for diagnosis of trench fever was easily performed and highly sensitive and specific. Tanned sheep erythrocytes were sensitized with soluble antigen from Rochalimaea quintana. The test detected antibody in six of seven cases of primary infection and in four cases of late, relapsed trench fever. Titers of antibody ranged from 1:20 to 1:640. Although both IgM and IgG antibody to R. quintana were detected by passive hemagglutination, IgG appeared to be the major reactive antibody. Antigens involved in the reaction were two types of proteins, one inactivated at 50 C and 60 C and the other at 80 C and 100 C. Of 322 control samples of sera that were tested, only one reacted positively; thus, the test had a specificity of greater than 99%. The single positive reaction was in serum from a patient with Q fever. This finding suggests that, in an area where Q fever is endemic, this disease must be ruled out in the interpretation of a positive passive hemagglutination test. Sera should be tested routinely against tanned, unsensitized erythrocytes, since an occassional sample of serum may agglutinate unsensitized cells. Because of its sensitivity and specificity, as well as its simplicity of performance, the passive hemagglutination test shows promise as a useful procedure for serologic identification of both acute and past infection with R. quintana.