Showing papers by "Centers for Disease Control and Prevention published in 1972"
TL;DR: Ninety-eight percent of the 262 strains of group D streptococci isolated from human sources were speciated by a spectrum of tests that allowed us to recognize atypical as well as typical strains within species.
Abstract: The speciation of 262 strains of group D streptococci isolated from human sources is described. One hundred forty-two isolates from blood cultures were included; 96 of these were submitted as isolates from clinical cases of subacute bacterial endocarditis. The results show that 98 Streptococcus faecalis, 29 S. faecalis var. zymogenes, 44 S. faecalis var. liquefaciens, 27 S. faecium, 13 S. durans, 44 S. bovis, and 7 unspeciated S. bovis-like group D isolates were identified. No S. faecium var. casseliflavus, S. equinus, or S. avium (group Q streptococci) were identified among the human isolates. The speciation procedures and techniques are detailed. The procedures and limitations of the tests used are discussed. Ninety-eight percent of the 262 strains were speciated by a spectrum of tests that allowed us to recognize atypical as well as typical strains within species.
335 citations
TL;DR: The results strongly suggest that the inhibition of the synthesis of the mycolic acids is closely associated with the primary mechanism of action of isoniazid on the tubercle bacilli.
Abstract: When an actively growing culture of the H37Ra strain of Mycobacterium tuberculosis was exposed to isoniazid at a concentration of 0.5 μg/ml, the cells began to lose their ability to synthesize mycolic acids immediately. After 60 min, the cells had completely lost this ability. The synthesis of the three mycolate components—α-mycolate, methoxymycolate, and β-mycolate—was inhibited. The viability of the isoniazid-treated cells was unaffected up to about 60 min of exposure, after which time there was a gradual decline in the viability to about 18% after 180 min. Correspondingly, growth of the drug-treated cells slowed down and stopped after 24 hr. The inhibition of the synthesis of mycolic acids was reversible if the drug was removed before the loss of viability set in. Incubation of the viable cells in the absence of the drug for 24 hr restored the mycolate synthesis. These results strongly suggest that the inhibition of the synthesis of the mycolic acids is closely associated with the primary mechanism of action of isoniazid on the tubercle bacilli. The sequence of events which leads to the loss of viability of cells exposed to isoniazid is described.
287 citations
TL;DR: The API system for identification of Enterobacteriaceae was evaluated with 366 cultures and overall accuracy of identification was 96.4%; of the 13 cultures misidentified, 7 were atypical strains.
Abstract: The API system for identification of Enterobacteriaceae was evaluated with 366 cultures. Overall accuracy of identification was 96.4%; of the 13 cultures misidentified, 7 were atypical strains.
236 citations
TL;DR: These studies have given some indication that bacillary dysentery may be controlled by an oral live vaccine, and field trials designed to quantitate induced immunity are planned for the near future.
Abstract: Two attenuated strains of Shigella flexneri 2a, a Shigella-E. coli hybrid, and a streptomycin-dependent mutant, were safely given to adult male volunteers. When vaccinated individuals ingested virulent S. flexneri 2a, clinical disease and fecal excretion of virulent organisms occurred with less frequency than in unvaccinated volunteers. The level of immunity resembled that seen after recovery from active infection. These studies have given some indication that bacillary dysentery may be controlled by an oral live vaccine, and field trials designed to quantitate induced immunity are planned for the near future.
192 citations
TL;DR: This chapter summarizes all significant matters concerning Taenia saginata taeniasis and cysticercosis—that is, nomenclature, host relationships, structure and biology, clinical and therapeutic features, epidemiology and epizootiology, and prevention of infection.
Abstract: Publisher Summary This chapter summarizes all significant matters concerning Taenia saginata (T. saginata) taeniasis and cysticercosis—that is, nomenclature, host relationships, structure and biology, clinical and therapeutic features, epidemiology and epizootiology, and prevention of infection. It considers some taxonomic problems and the hosts of T. saginata. The structure and biology of the adult worm, egg, onchosphere, and cysticercus is discussed. The clinical aspects of taeniasis are dealt in terms of symptomatology, clinical pathology, diagnosis, and treatment. Yomesan is the drug of choice for T. saginata infection in Man at present, and some suggestions are made for treatment with this and other drugs. The chapter discusses epidemiology, epizootiological, and losses due to taeniasis and cysticercosis. Losses are difficult to estimate, because infection is rarely fatal, but some figures are available for European, African, and American areas. Meat inspection is dealt with as a means of prevention, likewise serological diagnosis and the immunization of cattle. Sanitation is a matter discussed, its improvement, expensive but connected with higher standards of living.
171 citations
TL;DR: A restricted, hospital-centred outbreak of Lassa fever involving 28 persons occurred early in 1970 in Jos, Nigeria, and every patient, save the index, could be traced to some prior known human source of infection.
Abstract: A restricted, hospital-centred outbreak of Lassa fever involving 28 persons occurred early in 1970 in Jos, Nigeria 24 patients were in hospital Every patient, save the index, could be traced to some prior known human source of infection Complement-fixing antibody to Lassa virus was detected in the sera of only 4 of 172 family and hospital contacts bled These 4 persons had all been ill Animal studies have so far failed to reveal a non-human host
150 citations
TL;DR: Experimlental Neisseria gonorrhoeae infections were established in five species of small laboratory animals after subcutaneolusly implanted chambers were inioculated with gonococci.
Abstract: Experimlental Neisseria gonorrhoeae infections were established in five species of small laboratory animals (rabbits, guinea pigs, hamsters, mice, and rats) after subcutaneolusly implanted chambers were inioculated with gonococci. The chamber fluid was easily available for study or culture. A systemic immune response was indicated by hemnagglutination assay.
120 citations
TL;DR: The strain showed a marked decrease in resistance to inactivation by acetic acid, glutaraldehyde, chlorine dioxide, and a quaternary ammonium compound when compared with naturally occurring cells grown in mist therapy unit water.
Abstract: A strain of Pseudomonas aeruginosa was isolated in pure culture from the reservoir of a hospital mist therapy unit by an extinction-dilution technique; its natural distilled water environment was used as a growth and maintenance medium. After a single subculture on Trypticase soy agar, the strain showed a marked decrease in resistance to inactivation by acetic acid, glutaraldehyde, chlorine dioxide, and a quaternary ammonium compound when compared with naturally occurring cells grown in mist therapy unit water. The following factors were observed to affect the relative resistances of naturally occurring and subcultured cells of the P. aeruginosa strain: (i) temperature at which the cultures were incubated prior to exposure to disinfectants, (ii) growth phase of the cultures at the time of exposure to disinfectants, (iii) nature of the suspending menstruum for disinfectants, and (iv) exposure to fluorescent light during incubation of inocula prior to testing. The applied significance of these findings may alter the present concepts of disinfectant testing as well as routine control procedures in the hospital environment.
101 citations
TL;DR: The ID test was found to be 100% specific in an evaluation of its effectiveness with 65 sera from individuals with other systemic mycotic infections, bacterial or neoplastic diseases, and from apparently normal humans.
Abstract: The diagnostic value of an immunodiffusion (ID) test with standardized precipitinogens derived from five Aspergillus species was determined with sera from 60 proven and 12 suspected cases of aspergillosis. The data demonstrated that the greatest number of aspergillosis cases were detected by the concurrent use of A. fumigatus and A. niger precipitinogens. With these precipitinogens, the ID test permitted the serodiagnosis of aspergillosis in 82% of the 60 proven cases and in 83% of the 12 suspected cases. The presence of one or more precipitins was indicative of aspergilloma, of allergic bronchopulmonary aspergillosis, or of invasive aspergillosis. Precipitins were detected in 93% of the sera from patients with aspergilloma, in 50% of the sera from patients with allergic bronchopulmonary aspergillosis, and in 88% of the sera from patients with invasive aspergillosis. Although the presence of one or two precipitin bands could indicate any form of aspergillosis, the presence of three or four was strong evidence of either aspergilloma or invasive aspergillosis. The ID test was found to be 100% specific in an evaluation of its effectiveness with 65 sera from individuals with other systemic mycotic infections, bacterial or neoplastic diseases, and from apparently normal humans. In diagnosed cases of aspergillosis, the examination of serial serum specimens provided information about the clinical course of the disease. A reduction in the number of precipitin bands and significant titer changes were noted as the patients responded to therapy.
101 citations
TL;DR: Amputation of the inoculated feet within 18 days after inoculation was a life-saving procedure, indicating that the virus stays at or near the site of introduction for most of the long incubation period, to the incubation periods seen in man.
Abstract: to the incubation periods seen in man. Amputation of the inoculated feet within 18 days after inoculation was a life-saving procedure, indicating that the virus stays at or near the site of introduction for most of the long incubation period. Equine antiserum to rabies administered 24 hr after inoculation of virus failed to reduce mortality but resulted in singularly prolonged incubation periods. A significant reduction in mortality was noted in only two groups, one given equine antiserum to rabies and daily doses of duck-embryo vaccine (23% vs. 51% in the controls), and the other given one dose of a highly potent tissue-culture vaccine (3% vs. 51%). In rabies studies over the years, attempts have been made to establish animal models that simulate the incubation periods in man in order to study the pathogenesis of the disease and to evaluate treatment. Most experiments were done with some type of fixed virus or "street" virus isolate, with relatively short periods of incubation between inoculation of virus and onset of disease [1-6], and were often terminated within a few months after initiation. In the majority of the experiments, no protection was found with any kind of postexposure treatment. Incubation periods in man are rarely as short as those observed in experimental animals; the median for 22 persons who died of rabies in the United States between 1946 and 1965
96 citations
TL;DR: Screening enrichments of surface water specimens by means of a polyvalent fluorescent antibody reagent for the salmonellae yielded approximately 60% more positive specimens than was obtained by cultural procedures.
Abstract: Screening enrichments of surface water specimens by means of a polyvalent fluorescent antibody reagent for the salmonellae yielded approximately 60% more positive specimens than was obtained by cultural procedures It is not known what fraction of the excess of fluorescent antibody-positive over culturally positive specimens represents staining of non-salmonellae or non-arizonae as opposed to the staining of non-cultivatable organisms of these two genera Cotton gauze and rayon-polypropylene fiber swabs were equally sensitive for collecting salmonellae from the streams examined Tetrathionate enrichment incubated at 415 C appeared to be superior to selenite-cystine for isolation of salmonellae from surface waters Twenty-eight serotypes of Salmonella and two serotypes of Arizona were identified in the 121 positive specimens In water rated moderately polluted, 65% of all specimens tested were positive; in minimally polluted waters, 38% were positive; and in unpolluted streams, 44% were positive
TL;DR: The age at radiographic appearance of postnatal ossification centers of 1,942 American Negro children proved to be advanced over the age at appearance in the same hand centers in 3,046 boys and girls of European ancestry, by approximately 0.5 standard deviations.
TL;DR: Four attenuated strains of Shigella flexneri 2a have been tested for stability and safety as vaccines in man, and one strain was virulent for man in doses of 108 cells, while a mutant strain reverted to virulence when 1010 cells were administered orally.
Abstract: Four attenuated strains of Shigella flexneri 2a have been tested for stability and safety as vaccines in man. One strain, a Shigella-Escherichia coli hybrid, was virulent for man in doses of 108 cells, while a mutant strain reverted to virulence when 1010 cells were administered orally. Two vaccine strains, a Shigella mutantE. coli hybrid and a streptomycin-dependent mutant, were safely given to adult males in doses of 5-10 X 1010 cells. Pretreatment with sodium bicarbonate was essential for the assurance of intestinal transit of viable vaccine organisms, and less than one-third of those vaccinated developed rises in humoral antibody. Streptomycin-independent revertants could be recovered only rarely in vivo when the streptomicin-dependent mutant was used, and one revertant found was avirulent. These studies have outlined the important biologic requirements of potential live oral shigella vaccines. Strains must not penetrate the intestinal mucosa and must be stable without reverting to virulence at levels of dosage used.
TL;DR: The cellular fatty acid composition of 10 reference strains representing eight species of Pseudomonas was determined by gas-liquid chromatography by detecting a variety of acids, including branched and straight-chained acids, cyclopropane, and hydroxy acids.
Abstract: The cellular fatty acid composition of 10 reference strains representing eight species of Pseudomonas was determined by gas-liquid chromatography A variety of acids were detected in these organisms, including branched and straight-chained acids, cyclopropane, and hydroxy acids Comparison of the presence and relative amounts of these acids among strains was useful for distinguishing various Pseudomonas species
TL;DR: N-nitrosodimethylamine, a potent carcinogen, was produced along with other amines by P. mirabilis in all urines tested (both in vivo and in vitro) and in cooked-meat medium and the significance of these findings was evaluated.
Abstract: Reproducible procedures suitable for routine analysis of small quantities of body fluids and culture media were developed by use of gas-liquid chromatography, heptafluorobutyric-anhydride derivatives, and electron-capture detectors. Proteus mirabilis was isolated from two clinical cases of bacteriuria, and the alkalineextractable products elaborated by this organism in vivo were compared with those produced in vitro. N-nitrosodimethylamine, a potent carcinogen, was produced along with other amines by P. mirabilis in all urines tested (both in vivo and in vitro) and in cooked-meat medium. This compound was not produced in vitro by a strain of Escherichia coli tested on the same substrates. The significance of these findings was evaluated, with emphasis on the carcinogenic activity and toxicity of N-nitrosodimethylamine and on the use of gas-liquid chromatography as a tool for the diagnosis of urinary-tract disease.
TL;DR: The demonstration of particles compatible with alveolar deposition supports the hypothesis that cryptococcosis may originate as a pulmonary infection.
Abstract: Although the portal of entry of Cryptococcus neoformans is believed to be the lungs, viable airborne particles of C neoformans small enough to reach the alveoli have not been observed previously in nature. Airborne particles from pigeon excreta were sampled with an Andersen sampler and a venturi scrubber. When sampled in a 6.2-liter laboratory air chamber and in a church belfry, approximately 0.01960.3396 of viable, airborne C neoformans existed in particles with diameters between 1 [i and 5.5 jx. The demonstration of particles compatible with alveolar deposition supports the hypothesis that cryptococcosis may originate as a pulmonary infection.
TL;DR: At least four distinct nonspecific protein R antigens were found in streptococci of groups A, B, and C by immunodiffusion in agar gel with anti-R sera.
Abstract: At least four distinct nonspecific protein R antigens were found in streptococci of groups A, B, and C by immunodiffusion in agar gel with anti-R sera.
TL;DR: The outbreaks reported in this paper constitute the first confirmed foodborne epidemics due to V. parahaemolyticus in the United States.
Abstract: Vibrio parahaemolyticus was the etiological agent in three food-related epidemics of gastroenteritis in Maryland, during August 1971. These outbreaks involved crab food products. Fifteen isolates of V. parahaemolyticus were made which included 11 from patients and 4 from foods. Serotype 04:K11 was the cause of the outbreaks. It was recovered from patients in each outbreak and gave a positive Kanagawa reaction, an indication of enteropathogenicity. Other patient isolates included types 03:K30, 03:K33, and an untypable isolate, all of which were Kanagawa negative. Food isolates included serotypes 03:K30, 02:K28, and two untypable isolates, all of which were Kanagawa negative. The outbreaks reported in this paper constitute the first confirmed foodborne epidemics due to V. parahaemolyticus in the United States. Methods for the isolation and identification of V. parahaemolyticus are presented, including a procedure for the simple conversion of conventional laboratory media into suitable culture media for this halophilic organism.
TL;DR: A human coronavirus, strain OC 43, was propagated in suckling mouse brain and purified 5000-fold with, a 90% yield, and the association of a host cell antigen with the virion was confirmed by standard HI and CF tests.
TL;DR: Long-term dialysis for patients undergoing long-term hemodialysis may have adversely affected enzyme activity or function, and loss of pyridoxine by dialysis may be the most likely cause of low aspartate amino-transferase activities reported by Wolf et al.
Abstract: Wolf et al. (1) found little or no serum aspartate aminotransferase (EC 2.6.1.1) activity in the sera of 11 of 19 patients undergoing long-term hemodialysis. The authors concluded that low aminotrans-ferase (transaminase) activities seen in these patients may have been due to loss of the enzyme and (or) to pynidoxine depletion during long-term dialysis. We recently examined the sera of 54 long-term hemodialysis (HD) patients for aspartate aminotransferase and alanine aminotransferase (EC 2.6.1.2) activities, and found most of the pa-tients' activities to be within the normal range of 3 to 15 U. In our study we used both manual colonimetric and manual uv-kinetic methodologies (Sigma)1 and analyzed pre-and post-dialysis serum samples collected from patients who had been on maintenance dialysis for at least six months. Hemodialysis was regularly performed with parallel-flow Western Gear or Drake-Willock units for an 8-h period three times a week. All patients in our study received 5 mg of pyridoxine per day (\" Theragran-M \" or its equivalent) as a dietary supplement. Our study group of 54 HD patients demonstrated mean pre-dialysis aspar-tate and alanine aminotransferase activities of 9 U and 5 U, respectively, with standard deviations of 4 U and 3 U, respectively. These activities were not significantly different from post-dialysis serum aminotransferase activities, suggesting that the dialysis itself had no immediate deleterious effect on either of the two enzymes. We did note, however, that three of our patients had aspartate aminotransferase activities of less than 3 U, while seven patients (including two of the above three) had alanine amino-transferase activities of less than 3 U, indicating long-term dialysis for these patients may have adversely affected enzyme activity or function. The discrepancies in aminotransferase activities reported by Wolf et al. and those found in our study might be explained by differences in methodology (2), by the small sample size selected by Wolf's group, or by differences in patient pynidoxine status. Depletion of ascorbic acid, pantothenic acid, folic acid, and biotin in plasma of patients undergoing chronic HD has been demonstrated (3,4). For this reason we believe that gradual 1 Use of firm or trade names is for identification purposes only and does not constitute endorsement by the U.S. Department of HEW. loss of pyridoxine by dialysis may be the most likely cause of low aspartate amino-transferase activities reported by Wolf et al. Loss of enzyme by dialysis, which they suggested as one possibility, is not …
TL;DR: Chimpanzee susceptibility to hepatitis B virus was inferred from a lack of demonstrable HBAb in serum by both HA and RIA techniques.
Abstract: THE effects of viral hepatitis in chimpanzees are similar to those in man1,2, and the disease can be transmitted from chimpanzees to humans3. Hepatitis B or Australia antigen (HBAg) has been reported in healthy chimpanzees4 and we have demonstrated antibody (HBAb) in 55% of these animals by radioimmunoassay. We have also shown the immunological identity between human and chimpanzee HBAg and HBAb5. Two susceptible chimpanzees (Xat and Yon) were inoculated intravenously with 1.0 ml. of a 1 : 10 dilution of human plasma containing HBAg and known to cause hepatitis B in humans. The animals were bled three times weekly and liver biopsies were obtained twice monthly in order to study immunological, biochemical, and histological responses. To determine HBAg, matrix gel diffusion (MGD)6, complement fixation (CF)7, radioimmunoassay (RIA)8 and passive haemagglutination (HA)9 techniques were used. To detect HBAg, the CF and MGD tests were used in addition to a “solid phase direct” radioimmunoassay system. Chimpanzee susceptibility to hepatitis B virus was inferred from a lack of demonstrable HBAb in serum by both HA and RIA techniques. Serum titre of HBAg in the diluted human plasma inoculum was 1 : 128 by the CF technique.
TL;DR: Results indicated a moderate though variable overall hypereactivity in SLE to the viral antigens tested, both by the complement‐fixation and hemagglutination‐inhibition methods.
Abstract: Antibody titers to a group of viral antigens have been determined in sera from patients with systemic lupus erythematosus (SLE), control groups with inflammatory diseases and normals. Mean titers in SLE sera for all viruses tested were significantly greater than in four control groups, but not greater than in active tuberculosis, both by the complement-fixation (CF) and hemagglutination-inhibition (HI) methods. By the CF method, only measles virus showed significantly higher titers in SLE than in all control groups; by the HI method, measles antibody titers were higher in SLE than in all groups but tuberculosis. There was no correlation between antibody titers and gammaglobulin levels. The results indicated a moderate though variable overall hypereactivity in SLE to the viral antigens tested.
TL;DR: During August, 1971, three separate outbreaks of foodborne disease occurred in Maryland and involved about 425 of an estimated 745 at risk and Vibrio parahaemolyticus was isolated from the crab and from stools of some ill persons in each outbreak.
Abstract: During August, 1971, three separate outbreaks of foodborne disease occurred in Maryland and involved about 425 (57%) of an estimated 745 at risk. Steamed crabs or crabmeat was the suspected vehicle of disease transmission in each outbreak. Vibrio parahaemolyticus was isolated from the crab and from stools of some ill persons in each outbreak. During August, 1971, three separate foodborne disease outbreaks occurred in Maryland, involving about 425 (57%) persons of an estimated 745 at risk. In each outbreak, steamed crabs or crabmeat was the suspected vehicle of disease transmission. From the crab and from the stools of some ill persons in each outbreak, Vibrio parahaemolyticus was isolated.
TL;DR: Together, the LA and ID tests provided a simple, rapid, and accurate means of detecting and monitoring infections by species of Candida.
Abstract: A newly developed latex agglutination (LA) test and a modified immunodiffusion (ID) test were evaluated. The antigen used was a homogenate of Candida albicans. A total of 167 antisera were employed in the evaluation. They included 36 sera from clinically well persons; 78 from patients with various clinical forms of candidiasis; 52 from patients with proven cases of aspergillosis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, nocardiosis, paracoccidioidomycosis, sporotrichosis, and tuberculosis; and one serum from a patient with toruloposis. Use of the LA test in conjunction with the ID test permitted the detection of more than 90% of 43 proven candidiasis cases. Of all the heterologous cases and normal human sera tested, LA reactions were noted with 3 of 10 cryptococcosis case specimens, 1 of 9 tuberculosis case specimens, and with the torulopsemia case serum. In contrast, the only heterologous serum reactive in the ID test was that from the patient with torulopsemia. Torulopsis glabrata and C. albicans antisera gave identical reactions in LA and ID tests with T. glabrata or C. albicans antigens. ID tests with selected antigens, however, permitted differentiation of rabbit and human T. glabrata antibody from that of C. albicans antibody. Six different precipitins were recognized with the C. albicans antigens. The occurrence of multiple precipitin lines and high LA titers was suggestive of severe candidiasis. The LA test, in contrast to the ID test, appeared to have prognostic value. Together, the LA and ID tests provided a simple, rapid, and accurate means of detecting and monitoring infections by species of Candida.
TL;DR: The olfactory mucosa is a potential portal of entry and exit for airborne rabies virus in bat caves in caves by staining with fluorescent antibody and by isolation of the virus from the nasal tissues.
Abstract: Rabies virus was demonstrated in the olfactory mucosa of naturally infected bats by staining with fluorescent antibody and by isolation of the virus from the nasal tissues. The olfactory mucosa is a potential portal of entry and exit for airborne rabies virus in bat caves.
TL;DR: Five patients with Guillain-Barre (G.B.) syndrome, aged from 18 months to 27 years, had very high levels of antibodies to Epstein-Barr (E.B.") virus, which strongly suggest an association of E.B. virus with G. B. syndrome even without the signs of I.M.M.) disease.
TL;DR: It is suggested that the relatively simple expedient of providing safe supplies of drinking-water, found so useful in controlling the spread of Classical of the disease, may prove ineffective against the El Tor biotype.
TL;DR: A total of 109 cultures of Pseudomonas putrefaciens isolated from clinical specimens were studied and showed inability to grow in plain nutrient broth, but grew well in broth supplemented with NaCl at a concentration of 7 to 10% and above.
Abstract: A total of 109 cultures of Pseudomonas putrefaciens isolated from clinical specimens were studied. The cultures were separated into two groups. The majority of the group 1 isolates, comprising 31 cultures, were characterized by (i) growth in plain nutrient broth, but no growth in broth supplemented with NaCl at concentrations of 7% and above, (ii) no growth on Salmonella-Shigella (SS) agar, and (iii) production of acid from the carbohydrates, sucrose, maltose, arabinose, and dextrin. Most group 2 isolates, comprising 78 cultures, were (i) unable to grow in plain nutrient broth, but grew well in broth supplemented with NaCl at a concentration of 7 to 10%, (ii) able to grow on SS agar, and (iii) unable to produce detectable amounts of acid from any of the carbohydrates tested except for variable results with glucose and fructose.
TL;DR: Both dialyzable and nondialyzable leukocyte extracts from infected donors transferred delayed hypersensitivity to recipient monkeys, and skin test conversion was associated with in vitro transformation of the recipients' lymphocytes.
Abstract: Delayed hypersensitivity in Macaca mulatta infected with either Schistosoma mansoni or mycobacteria was demonstrated by biopsies of skin test sites. Both dialyzable and nondialyzable leukocyte extracts from infected donors transferred delayed hypersensitivity to recipient monkeys. In two recipients, skin test conversion was associated with in vitro transformation of the recipients' lymphocytes.