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Background: As prisons have a high prevalence of tuberculosis and HIV infection, we studied the possibility of multiple tuberculosis infections in a selected population of HIV-infected inmates. Methods: Two groups of patients with special characteristics were selected from 226 HIV-infected inmates diagnosed with tuberculosis in the prisons of Madrid (Spain) between 1993 and 1994. The first group contained nine patients who remained culture positive 4 months after the initiation of therapy and the second group contained 28 patients with Mycobacterium tuberculosis isolated from different anatomical sites. DNA typing with 156110 was performed on all isolates from these patients. In some patients a secondary DNA typing with the plasmid pTBN12 was performed. Results: Two patients from group A had a second M. tuberculosis strain obtained 4 and 18 months after the initial isolate, with different IS6110 and pTBN12 patterns. In one patient the second strain was multidrug resistant and in the other patient both strains had the same drug-susceptible pattern. The clinical and microbiologic evidence in both patients was consistent with the presence of active tuberculosis caused by a new strain of M. tuberculosis. In group B, the isolates from 27 patients shared similar fingerprint pattern; however, in one patient isolates from sputum and urine showed different IS6110 and pTBN12 patterns, although both strains showed the same drug-susceptible phenotype. Conclusion: This study provides evidence that HIV-infected inmates living under conditions of high environmental infectivity can be infected with two different strains of M. tuberculosis. This finding has implications for the tuberculosis-control programs in prison.

We used a test based on the polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis DNA in 11 CSF samples from 10 HIV-seropositive patients in whom tuberculous meningitis was suspected. PCR was positive in nine samples from eight patients in whom clinical data, CSF findings, evidence of tuberculosis at an extraneural site, and response to antituberculous drug therapy supported the diagnosis, whereas cultures were positive in five of these nine samples and staining in only one. The PCR was negative in 14 CSF samples from the control group.

Summary Studies of the skin reactions produced by formalin-killed suspensions of Rickettsia mooseri and Rickettsia prowazekii in normal human subjects and in subjects with various kinds of previous experience with typhus organisms have yielded the following observations: Relatively concentrated rickettsial suspensions produce local “toxic” reactions in the skin of normal subjects which are compatible with an endotoxic component in the organisms.Subjects with previous typhus experience exhibit a markedly enhanced local and systemic reactivity to the typhus antigens. Thir reaction is compatible with a delayed type hypersensitivity to typhus antigens.Histologic studies of skin biopsies taken from different subjects at various times after injection of test material revealed an early inflammatory response in normal subjects compatible with that induced by endotoxins and a delayed inflammatory response in hypersensitive subjects compatible with a reaction of delayed type hypersensitivity.The skin reaction did not distinguish between murine and epidemic typhus, suggesting that the major antigen(s) involved is common to both species of organism.The delayed type hypersensitivity to typhus antigens developed with regularity following vaccination with the attenuated living E strain of R. prowazekii, a positive reaction often appearing as early as 7 to 10 days following vaccination.

Forty-six strains of Staphylococcus aureus and 47 strains of unspeciated coagulase-negative staphylococci were inoculated in tubes containing a cation-supplemented Mueller-Hinton broth with 4% (wt/vol) NaCl. A critical concentration of methicillin (10 micrograms/ml) or oxacillin (6 micrograms/ml) was achieved in each tube by adding the appropriate number of antibiotic disks. Growth was interpreted as resistance. Results obtained with fully resistant or fully sensitive strains showed complete agreement with the reference method. Four strains with intermediate sensitivity (two S. aureus and two coagulase-negative staphylococci) were classified as resistant by the broth-disk elution test.

A simple method for carrying out the Coombs test with U-shaped microtiter plates instead of tubes is described. This technique provides reliable and more rapid testing of large numbers of sera in suspected cases of human brucellosis.

Excerpt Insecticides, rodenticides, immunoprophylactic measures, and chemotherapeutic agents have combined to minimize the present-day importance of typhus fevers as a cause of death or incapacitat...