Low pulse oximeter-measured hemoglobin oxygen saturations with hemoglobin Cheverly.

Unexpectedly low hemoglobin oxygen saturation as determined by pulse-oximeter analysis was observed in a patient who underwent an elective surgical procedure. Specific hemoglobin derivatives such as carboxyhemoglobin, methemoglobin, and reduced hemoglobin that have been described to lower pulse-oximetry determination of oxygenation were not detected. Absorbance spectra revealed the patient's hemoglobin to be different than that obtained from two normal volunteers. High-pressure liquid chromatographic analysis of the hemoglobin showed an unknown band that comprised 15% of the patient's hemoglobin. DNA sequence analysis showed a point mutation in the second nucleotide of the 45th codon of the beta-globin chain. This mutation encodes for an abnormal beta-chain (beta-45 Phe-->Ser) that has been described as hemoglobin Cheverly. Hemoglobin Cheverly is an unstable hemoglobin that has a similar mutation as the beta-42 Phe-->Ser mutation seen in hemoglobin Hammersmith. Hemoglobin Hammersmith and another unstable hemoglobin, hemoglobin Köln, have previously been described to have unexpectedly low pulse-oximeter-determined oxyhemoglobin levels. That we find hemoglobin Cheverly to result in a similar phenomenon suggests that pulse-oximeter monitoring of oxygenation status may not be appropriate for the unstable hemoglobins. Low pulse-oximeter oxygenation determinations for these hemoglobins do not appear to predict clinical hypoxemia.

Core and comprehensive health care services: 4. Economic issues.

This article reviews the economic dimensions of the CMA's decision-making framework on core and comprehensive services. The framework was developed in a policy context characterized by three government objectives: reduction, reallocation and reassignment of health care resources. One economic-evaluation tool for the determination of core services is cost-effectiveness analysis. Some of the critical demand-side and supply-side considerations include the perceived value of medical services, the availability of private insurance and the supply of health care providers. The article concludes that shifting services to the private sector should not be viewed as a panacea for reducing the costs and improving the economic efficiency of the health care system, or for increasing patient access to, or the cost-effectiveness of high-quality care.

Tetanus immunity in emergency department patients.

Demographic data and blood samples were collected from 278 patients seen at two District of Columbia emergency departments, and tetanus antitoxin assays by hemagglutination were performed at the Centers for Disease Control. Twenty-seven patients (10%) had antibody levels below the 0.01 U/mL considered protective. Four demographic characteristics were different in the patients with inadequate immunity (in decreasing order of significance): advanced age, fewer years of education, female sex, and non-US origin. Fourteen of the inadequately immunized patients were over 70 years of age. Of the 84 patients who reported their immunization histories, five reported no complete series of tetanus shots but had adequate antibody levels, while three reported a complete series but had inadequate levels. Twenty-two patients with inadequate immunity were not offered immunization in the emergency department because they did not have wounds. Patient recall of immunization history is not a reliable guide to tetanus immunization in the emergency department, but patients in certain demographic groups, such as older women, are more likely to have inadequate immunity.

Comparison of serologic screening tests for brucellosis.

The slide agglutination test (SAT), microagglutination test (MAT), and card agglutination test (CAT) were compared with each other, using the tube agglutination test (TAT) as the standard method, by two reference laboratories to determine effectiveness as screening tests for human brucellosis. TAT titers of 1,253 sera tested in both laboratories were compared. In one laboratory, 1,270 sera were tested by the TAT and SAT, while the other laboratory tested 1,261 sera by both methods. Of these sera, 1,155 were tested in one laboratory by the CAT and 187 sera were tested by the MAT. Compared with that of the TAT (greater than or equal to 160 positive), the sensitivities were 97 to 100% (SAT), 90% (CAT), and 88% (MAT). The specificities were 88 to 89% (SAT), 98% (CAT), and 88% (MAT). For populations with a low prevalence of disease, increased specificity offers higher predictive value, so the CAT and MAT are preferable for screening purposes and the choice between tests depends on the number and frequency of tests performed. All sera reactive in the CAT and MAT should be retested with the TAT.

Commercial latex agglutination tests for detection of Haemophilus influenzae type b and Streptococcus pneumoniae antigens in patients with bacteremic pneumonia.

The validity of commercial latex agglutination kits for detection of Haemophilus influenzae type b and Streptococcus pneumoniae antigens in serum and urine specimens was studied. We tested serum and urine specimens from 44 patients with bacteremic pneumonia (23 S. pneumoniae, 13 H. influenzae type b, 11 other) with commercial latex agglutination kits (Directigen, Bactigen) for S. pneumoniae and H. influenzae type b antigens. All specimen samples were randomized and read blindly by two readers. Interreader reproducibility was 100%. The sensitivity and specificity of both kits for H. influenzae type b antigens in serum and urine were greater than 90%. None of the 24 urine samples from S. pneumoniae bacteremic patients were positive by either kit, although 6 ng of type 3 polysaccharide could be detected in spiked urine. Sensitivity for S. pneumoniae antigens in serum was 27% for Directigen and 38% for Bactigen. Specificity for S. pneumoniae antigens in serum was 95% for Directigen and 74% for Bactigen. The results suggest that the kits are useful in diagnosing H. influenzae type b pneumonia. However, the commercially available S. pneumoniae reagents tested appear to have limited utility for diagnosing S. pneumoniae pneumonia because both kits lack sensitivity and Bactigen lacks specificity, as well.

Production and characterization of monoclonal antibodies to toxic shock syndrome toxin 1 and use of a monoclonal antibody in a rapid, one-step enzyme-linked immunosorbent assay for detection of picogram quantities of toxic shock syndrome toxin 1.

Twenty-six hybridoma cell lines that produced monoclonal antibodies to toxic shock syndrome toxin 1 (TSST-1) were generated by immunizing mice with a highly purified preparation of TSST-1 and fusing their splenic lymphocytes with SP2/0-Ag-14 cells. One monoclonal antibody of the immunoglobulin G1 isotype, designated as PEC-1 10-2SCH, was selected for extensive study. The specificity of this antibody was determined by testing spent culture fluid filtrates of TSST-1- and non-TSST-1-producing strains of Staphylococcus aureus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and enzyme-linked immunoelectrotransfer blot techniques. Monoclonal antibody PEC-1-10-2SCH was specific for TSST-1-producing strains of S. aureus, reacting with TSST-1 and two other proteins which appear to be unique to S. aureus strains that produce TSST-1. Monoclonal antibody PEC-1-10-2SCH was used in conjunction with polyclonal rabbit antibodies to TSST-1 in a rapid, one-step, sensitive, specific, and quantitative enzyme-linked immunosorbent assay. This assay was shown to be more sensitive, faster, and simpler to perform than previously described isoelectric focusing, immunodiffusion, and solid-phase radioimmunoassays for TSST-1. Monoclonal antibody PEC-1-10-2SCH was not reactive with Staphylococcus protein A under the conditions of the test.

Four serologic tests for syphilis: results with comparison of selected groups of sera.

The specificity of the fluorescent treponemal antibody-absorbed (FTA-Abs) test was assessed for 17 sera from syphilitic patients that were nonreactive in the Treponema pallidum immobilization (TPI) test but reactive in the FTA-Abs test. Thirty-three other sera from syphilitic patients and 19 sera from nonsyphilitic individuals were also examined by fluorescent treponemal and microhemagglutination Treponema pallidum (MHA-TP) tests and by the enzyme-linked immunosorbent assay (ELISA). Specific absorptions of sera with calf thymus DNA or Treponema pallidum biotype Reiter (Reiter treponemes) were performed. In quantitative immunofluorescence assays (IFA) with antihuman IgG and IgM conjugates, results were similar to those for reactive sera from a control group. Results of both the MHA-TP and ELISA tests supported the specificity of the FTA-Abs test; reactivity in the latter was not removed by specific absorption either with calf thymus DNA or with Reiter treponemes. This evaluation suggests a format for serodiagnosis in cases in which test results are discrepant.

Comparison of guinea pig and protozoan models for determining virulence of Legionella species.

Legionella pneumophila organisms are able to infect and multiply within the ciliated protozoan Tetrahymena pyriformis. This ability may be associated with virulence, because an attenuated strain of L. pneumophila fails to multiply within this protozoan, whereas a virulent strain increases 10,000-fold in number when coincubated with T. pyriformis. Seventeen strains (11 species) of legionellae were evaluated for virulence by intraperitoneal injection of guinea pigs and inoculation of protozoan cultures. Analysis of the data indicates that there are four categories of legionellae with respect to virulence as follows: organisms that infect and kill guinea pigs and multiply in T. pyriformis; organisms that infect but do not kill guinea pigs and multiply in T. pyriformis; organisms that do not infect guinea pigs but are lethal at high concentrations and multiply in T. pyriformis; and organisms that neither infect nor kill guinea pigs and fail to multiply in T. pyriformis. Evidence suggests that these distinctions are based on two virulence factors: intracellular multiplication in a host and toxic activity.

Strain characterization and grouping of Campylobacter jejuni and Campylobacter coli by interaction with lectins.

Strains of Campylobacter jejuni and Campylobacter coli were characterized and grouped by their distinct reaction patterns with lectins. Heating of the Campylobacter cultures to 100 degrees C and holding for 30 to 60 min greatly enhanced their reactivity with lectins and permitted the grouping of all but 3 of 155 cultures tested in this study without interference of autoagglutination and other nonspecific activities. The lectin reaction patterns of the heated cultures were stable and reproducible. They were strain specific and independent of the heat-stable antigenic types. The lectin-reactive sites of C. jejuni and C. coli may be useful as additional markers for strain characterization. Based on these observations, a simple slide agglutination procedure is described for differentiating strains of C. jejuni and C. coli by their interaction with a selected group of commercially available lectins.

Isolation of protozoa from water associated with a legionellosis outbreak and demonstration of intracellular multiplication of Legionella pneumophila.

At the site of a legionellosis outbreak, amoebae and two ciliates, Tetrahymena sp. and Cyclidium sp., were isolated from cooling-tower water containing Legionella pneumophila. The Tetrahymena sp. and the amoebae repeatedly showed the ability to support intracellular multiplication of L. pneumophila. Both were isolated from cooling towers specifically implicated as the source for the spread of legionellosis. These protozoa may be reservoirs supporting the survival and multiplication of virulent legionellae in cooling-tower water.

Isolation of Listeria monocytogenes from raw milk.

During a recent outbreak of listeriosis, we examined 121 raw milk samples and 14 milk socks (filters). Listeria monocytogenes was recovered from 15 (12%) of 121 milk specimens and 2 (14%) of 14 milk socks. The optimal processing method consisted of cold enriching diluted milk for 1 month with culture to selective broth, followed by plating.

Induction of autoimmune diseases with adjuvants: separation of delayed hypersensitivity and antibody formation from diseases in experimental thyroiditis and aspermatogenesis with Legionella adjuvant.

The induction of autoimmune diseases in animals was studied with Legionella and mycobacteria as adjuvants, emulsified in oil with antigen extracts of thyroid, testis, spinal cord, and peripheral nerve. Both adjuvants were equally effective in inducing delayed hypersensitivity and humoral antibody to the tissue antigens. The Legionella adjuvant, however, induced little or no thyroiditis and aspermatogenesis, whereas the mycobacterial adjuvant induced thyroiditis and aspermatogenesis. Both adjuvants caused allergic encephalomyelitis and peripheral neuritis. The results indicated that delayed hypersensitivity by itself may not be sufficient to cause thyroiditis and aspermatogenesis. Legionella adjuvant apparently lacked the ability to induce certain immune factor(s) which caused the disease in experimental thyroiditis and aspermatogenesis. The differential properties of Legionella adjuvant and mycobacterial adjuvant in inducing immunity to autoantigens could provide a useful means to study the pathogenic and immunoregulatory mechanisms of some experimental autoimmune diseases.

Plasmid characterization of Salmonella typhimurium transmitted from animals to humans.

The transmission of pathogenic bacteria from animals to humans is widely studied because of its public health importance. In this study, we show the transmission of Salmonella typhimurium from cattle which had received no growth-promoting antibiotics to humans who had direct contact with the ill animals. On one cattle farm, the veterinarian attending the sick animals became ill, and two other individuals living on the farm later developed salmonellosis. The strains isolated from both humans and animals at one farm were identical as to antibiotic susceptibility and phage type, and they were specifically traced by the presence of a common 24-megadalton plasmid. Restriction enzyme digests of this plasmid from both human and animal strains were identical. At another farm, tetracycline-resistant S. typhimurium strains possessing a different profile (eight plasmids) were isolated from both animals and humans. The tetracycline-resistant clone was also isolated from animals at a third farm, but with animals and humans having no known contact with those of the other two farms.

Water-related nosocomial pneumonia caused by Legionella pneumophila serogroups 1 and 10.

Between August 1978 and November 1983, 21 cases of pneumonia caused by Legionella pneumophila occurred in the Leiden University Hospital, mainly among immunocompromised patients. A new serogroup of L. pneumophila, designated serogroup 10 (prototype strain Leiden 1), was isolated from bronchial secretions of four patients, and five patients had serological evidence of infection with this organism. Nine patients had a culture-confirmed infection with L. pneumophila serogroup 1. L. pneumophila serogroups 1 and 10 were also isolated from the hot potable water supply in the building to which 19 of the 21 patients had been admitted. The isolates of L. pneumophila serogroup 1 from patients and the hot potable water were identical in studies with monoclonal antibodies and had the same plasmid profiles. These findings provide further evidence that in our hospital potable water contaminated with L. pneumophila is a source of infection, mainly in immunocompromised patients.

Interaction of Campylobacter jejuni and Campylobacter coli with lectins and blood group antibodies.

Lectins and blood group antibodies were used to probe the surface structures of Campylobacter jejuni and Campylobacter coli. Of the 29 strains tested, there were distinct reaction patterns. The lectin-reactive and blood group antibody-reactive sites on the bacterial surface were distinguishable from the heat-stable (lipopolysaccharide) antigenic determinants. The interactions were strain specific. The reactive sites were stable with respect to culture media and passage and may be useful as additional markers for strain characterization.

Typing of heat-stable and heat-labile antigens of Campylobacter jejuni and Campylobacter coli by coagglutination.

A coagglutination system has been devised for typing heat-stable and heat-labile antigens of Campylobacter jejuni and C. coli. The use of protein A-positive Staphylococcus aureus cells carrying Campylobacter sp. serotype antibody and the treatment of Campylobacter sp. cells with DNase in the antigen suspension permitted rapid and specific coagglutination of rough (autoagglutinable) as well as smooth cultures. Cells of S. aureus were sensitized with Campylobacter sp. serotype antisera. Four to five types of sensitized S. aureus cells were pooled. A strain of Campylobacter sp. was first tested with the pools and then typed with the individual reagents of the reactive pool. After the described procedures, 68 serotype strains tested blindly as unknowns were correctly typed according to their heat-stable or heat-labile antigens. The two most commonly used typing schemes which are based separately on the heat-stable or the heat-labile antigens as assayed by passive hemagglutination and slide agglutination, respectively, can be utilized simultaneously in the coagglutination system for strain characterization. The coagglutination system is simple, yields results rapidly, conserves typing reagents, and offers the flexibility of formulating the pools of reagents according to the experimental design or the prevalence of serotypes in a geographic location. It should be a practical system for the typing of Campylobacter spp. in public health or clinical laboratories.

Acquired ability of Staphylococcus aureus to produce toxic shock-associated protein and resulting illness in a rabbit model.

Staphylococcus aureus from patients with toxic shock syndrome (TSS) produce TSS toxin 1. We transferred, by a bacteriophage, the ability to produce TSS toxin 1 from a TSS toxin 1-positive to a TSS toxin 1-negative strain of S. aureus. This recombinant strain produced TSS toxin 1 as confirmed by isoelectric focusing, immunodiffusion, radioimmunoassay, and autoradiography. The recombinant produced TSS-like illness in rabbits, and was significantly (P less than 0.001) more lethal than the recipient strain. Both strains produced fever and diarrhea, but, in addition, rabbits challenged with the recombinant also developed lowered blood pressure (P = 0.002), conjunctival hyperemia, erythroderma, and respiratory distress. Histopathological findings in rabbits challenged with the recombinant strain were remarkably similar to those described for humans with TSS, e.g., erythrophagocytosis, liver "triaditis," and vasodilatation. This study demonstrates that this protein may contribute to the pathogenesis of the TSS.

Legionella anisa: a new species of Legionella isolated from potable waters and a cooling tower.

Between March 1980 and June 1981, five strains of Legionella-like organisms were isolated from water. Four were recovered from potable water collected from hospitals in Chicago, Ill., and Los Angeles, Calif., during outbreaks of nosocomial legionellosis. The fifth strain was isolated from water collected from an industrial cooling tower in Jamestown, N.Y. The strains exhibited biochemical reactions typical of Legionella species and were gram-negative motile rods which grew on buffered charcoal-yeast extract agar but not on blood agar, required cysteine, and were catalase positive, urease negative, nitrate negative, hippurate negative, and nonfermentative. All strains were positive for oxidase and beta-lactamase and produced a brown, diffusible pigment. Of the five strains, four exhibited blue-white autofluorescence under long-wavelength UV light. The fatty-acid composition and ubiquinone content of these strains were consistent with those of other Legionella species. Direct fluorescent-antibody examination of the five strains with conjugates to previously described Legionella species demonstrated no cross-reactions except with the conjugates to L. longbeachae serogroup 2 and L. bozemanii serogroup 2. Four strains gave a 4+ reaction to the L. longbeachae serogroup 2 conjugate and the fifth strain gave a 1+ reaction. Each of the five strains gave a 4+ reaction with the conjugate to L. bozemanii serogroup 2. DNAs from the five strains were highly related (84 to 99%) and showed 5 to 57% relatedness to other Legionella species. These strains constitute a new species in the genus Legionella, and the name Legionella anisa sp. nov. is proposed. The type strain of L. anisa is WA-316-C3 (ATCC 35292).