Cat scratch disease: a bacterial infection.

Histopathologic examination of lymph nodes from 39 patients with clinical and pathological criteria for cat scratch disease revealed delicate pleomorphic Gram-negative bacilli in 34 of the 39 nodes. They were within the walls of capillaries in or near areas of follicular hyperplasia and within microabscesses. They were best seen with the Warthin-Starry silver impregnation stain. Organisms in lymph node sections exposed to convalescent serum from three patients and to immunoperoxidase stained equally well with all three samples. The organisms did not react with hyperimmune sera to Legionella pneumophila nor to several species of Rickettsia. These bacilli appear to be the causative agents of cat scratch disease.

Life-threatening cat-scratch disease in an immunocompromised host.

We describe a renal allograft recipient with cat-scratch disease in whom refractory hypotension, severe metabolic acidosis, pulmonary infiltrates, and encephalopathy developed. The patient first presented with a history of cat bites and scratches, fever, headache, and arthralgias. Four weeks later, the clinical presentation of septic shock suddenly developed in the patient. Cat-scratch disease was documented clinically and by finding delicate pleomorphic bacilli in Warthin-Starry silver stains of biopsy specimens taken from the primary inoculation site and regional lymph node. The administration of intravenous sulfamethoxazole and trimethoprim, erythromycin lactobionate, and tobramycin sulfate therapy correlated with recovery. Although cat-scratch disease is usually a benign, self-limited illness, this article illustrates its systemic nature, its potential for devastating complications in the immunocompromised host, and its possible response to vigorous antibiotic therapy.

The effects of electron and chemical ionization modes on the MS profiling of whole bacteria.

Free fatty acid profiling of whole bacteria [Francisella tularensis, Brucella melitensis, Yersinia pestis, Bacillus anthracis (vegetative and sporulated), and Bacillus cereus] was carried out with direct probe mass spectrometry under 70-eV electron ionization (EI) and isobutane chemical ionization in both the positive (CI+) and negative modes (CI-). Electron ionization produced spectra that contained molecular ions and fragment ions from various free fatty acids. Spectra acquired with isobutane chemical ionization in the positive mode yielded molecular ions of free fatty acids as well as ions from other bacterial compounds not observed under EI conditions. Spectra obtained with negative chemical ionization did not contain as much taxonomic information as EI or CI+; however, some taxonomically significant compounds such as dipicolinic acid and poly(3-hydroxybutyrate) did produce negative ions. All ionization modes yielded spectra that could separate the bacteria by Gram-type when observed with principle components analysis (PCA). Chemical ionization in the positive ion mode produced the greatest amount of differentiation between the four genera of bacteria when the spectra where examined by PCA.

Investigation of cell culture media infected with viruses by pyrolysis mass spectrometry: implications for bioaerosol detection.

Mass spectrometry coupled with a pyrolysis inlet system was used to investigate media from cell cultures infected with viruses. Cell culture media is an intricate mixture of numerous chemical constituents and cells that collectively produce complicated mass spectra. Cholesterol and free fatty acids were identified and attributed to lipid sources in the media (blood serum supplement and plasma membranes of host cells). These lipid moieties could be utilized as signature markers for rapidly detecting the cell culture media. Viruses are intracellular parasites and are dependent upon host cells in order to exist. Therefore, it is highly probable that significant quantities of media needed to grow and maintain viable host cells would be present if a viral agent were disseminated as an aerosol into the environment. Cholesterol was also detected from a purified virus sample, further substantiating its use as a target compound for detection. Implications of this research for detection of viral bioaerosols, using a field-portable pyrolysis mass spectrometer, is described.

Tubo-ovarian abscess caused by Streptococcus pneumoniae.

A 46-year-old black woman underwent exploratory surgery for evaluation of a tender mass in her abdomen. During the exploratory surgery bilateral tubo-ovarian abscesses ruptured. Specimens from both tubes and from the wall of the abscesses contained bacteria seen on the Brown-Hopps tissue gram stain. The bacteria were gram-positive, lancet-shaped diplococci characteristic of Streptococcus pneumoniae. Immunoperoxidase stains confirmed the identification of the organism as S pneumoniae.

Endocarditis caused by Rochalimaea henselae.

A case of community-acquired, culture-negative, infective endocarditis was diagnosed in a 57-year-old construction worker. Small, pleomorphic gram-negative rods were seen in Brown-Hopps tissue gram stains and Warthin-Starry silver stains. The organism was identified as Rochalimaea henselae by polymerase chain reaction amplification and sequencing of the 16S rDNA gene sequence. This is the first report of infective endocarditis caused by R henselae.

Pasteurella multocida pneumonia in a man with AIDS and nontraumatic feline exposure.

A case of acute pneumonia due to Pasteurella multocida ssp multocida occurred in a young man with AIDS and chronic sinusitis. The pneumonia was diagnosed by bronchoscopy and responded to treatment with aztreonam. Epidemiologic investigation revealed the case was temporally related to nontraumatic exposure to cat secretions that the patient presumably had acquired via an aerosol. The cat's oral cavity was cultured and an isolate of P multocida ssp multocida with identical biochemical reactions, DNA restriction patterns, and nearly identical fatty acid profile to that of the patient's isolate was obtained suggesting they were identical strains and therefore epidemiologically linked. A control strain with identical biochemical reactions and antibiotic sensitivities exhibited different patterns. To our knowledge, this is the first such reported infection in a patient infected with human immunodeficiency virus.

Whipple's disease presenting as chronic wastage and abdominal lymphadenopathy.

We describe a 24-year-old man who presented with chronic wastage and massive abdominal lymphadenopathy which strongly resembled a malignant neoplasm. Biopsy of mesenteric lymph nodes with ancillary studies led to the correct diagnosis of Whipple's disease. These symptoms began 2 months after the patient returned from military service in the Persian Gulf.

Susceptibility of Bordetella pertussis to five quinolone antimicrobic drugs.

Five quinolone antimicrobic agents were tested to determine the mean inhibitory concentration (MIC) of each of 17 clinical strains of Bordetella pertussis by the agar dilution method. Ciprofloxacin demonstrated the best in vitro activity with an MIC90 of 0.06 microgram/ml. Norfloxacin, ofloxacin and enoxacin were also highly active with MIC90s of 0.25, 0.25, and 0.5, respectively. Cinoxacin was only moderately active (MIC90 4.0 microgram/ml).

Bacteriologic and histologic features in mice after intranasal inoculation of Brucella melitensis.

OBJECTIVE: To characterize effects of intranasal inoculation of virulent Brucella melitensis strain 16M in mice. ANIMALS: Female Balb/c mice, 6 to 8 weeks old. PROCEDURE: Studies were designed to elucidate gross morphologic lesions, bacterial burden in target organs, and histologic changes in tissues following experimental intranasal inoculation of mice with B melitensis 16M, which could be used to characterize a model for testing vaccine efficacy. RESULTS: Measurable splenomegaly was evident at 3 and 7 weeks after inoculation. A demonstrable increase in splenic colony-forming units (CFU) from infected mice increased over time with increasing dose when comparing inocula of 10(3), 10(4), and 10(5) CFU. Recovery of brucellae from the lungs was possible early in infection with 10(1), 10(3), and 10(5) CFU, but only the group inoculated with 10(5) CFU consistently yielded quantifiable bacteria. At a dose of 10 CFU, few organisms were located in the spleen. Bacteria were recovered up to 140 days after inoculation in mice given 10(3) CFU. At an inoculum of 10(5) CFU, bacterial counts were highest early in infection. Histologic examination of tissues revealed an increase in white pulp and marginal zone in the spleen and lymphohistiocytic hepatitis. CONCLUSION AND CLINICAL RELEVANCE: Changes in the spleen and liver increased with increases in dose and with increased time following intranasal inoculation with B melitensis 16M. Surprisingly, histologic changes were not observed in the lungs of inoculated mice.

A study on the use of male animal models for developing a live vaccine for brucellosis.

To study the safety of Brucella melitensis WR201, a live vaccine candidate, we compared the course of infection of this strain with that of virulent 16M in male BALB/c mice. At various times after oral immunization with strains WR201 or 16M, lungs, liver, spleen, testis, epididymis, inguinal and cervical lymph nodes were removed. Tissues were divided for microbiologic culture and histopathological examination. WR201 infection in male BALB/c mice had lower intensity and shorter duration than infection caused by virulent 16M. Pathological examination of testis and epididymis revealed no inflammation following strain WR201 immunization. In contrast, animals given virulent 16M strain had substantial inflammation in infected tissues. These data confirm the marked attenuation of WR201 relative to 16M. In addition, these studies suggest that male mice may be useful to assess the safety of live, attenuated Brucella vaccine candidates.

Macrophage and lymphocyte contributions in resistance of Candida albicans infections.

Model in vivo and in vitro experimental systems have been used to study the efficacy of specific and nonspecific immunization against Candida albicans infection induced in mice. Experiments were designed to compare the extent of resistance in specificity immunized, endotoxin treated and saline treated animals. In vitro phagocytic and postphagocytic killing (cytopepsis) of macrophages or lymphocyte-macrophage combinations from such animals were determined. In the in vitro experiments the macrophage systems destroyed the yeast cells more rapidly than did the lymphocyte-macrophage combinations. Since equivalent numbers of yeast cells were phagocytized, the differences observed were a function of cytopepsis of the organisms.

An outbreak of antibiotic-resistant Salmonella enteritidis in Liberia, West Africa.

Between October 1980 and August 1982, 100 patients in the pediatric population at Curran Lutheran Hospital, Zorzor, Liberia were identified as having multiple drug-resistant Salmonella enteritidis serotype enteritidis. The illness usually presented as an enteric fever but also as meningitis, gastroenteritis, empyema, subcutaneous abscesses, chronic otitis media, or a combination of these conditions. Predisposing factors were young age and debilitation from malnutrition or measles. The mortality of infected patients was 27.8%. The organism was originally misidentified as a Citrobacter species because of a delayed reaction on lysine decarboxylase medium. Incubation of the medium for five days resulted in a positive reaction that identified the organism as a Salmonella species. The isolates were resistant to multiple antibiotics. Genes mediating resistance were located on a 120-megadalton conjugative plasmid. A cryptic nonconjugative 40-megadalton plasmid was also present in several isolates.

In situ methylation of nucleic acids using pyrolysis/mass spectrometry.

Curie-point pyrolysis/triple quadrupole mass spectrometry (Py/MS/MS) has been used with tetramethylammonium hydroxide (TMAH) to conduct in situ methylation of nucleic acid bases. Nitrogen bases in free nucleotides, oligonucleotides, calf thymus DNA and whole bacterial cells reacted in situ during pyrolysis with TMAH to form the methylated bases. Derivatization increased the volatility of the nitrogen bases and the mass of the diagnostic base peaks, thereby removing them from the positions of lower-mass background peaks. The degree of methylation as a function of TMAH concentration for the oligonucleotide, calf thymus DNA, and the whole bacteria samples was determined and found to correlate with the nature of DNA. The methylated bases were identified by their positive-ion electron ionization fragmentation patterns and confirmed with tandem mass spectrometry. The detection of the methylated bases by Py/MS/MS facilitates the goal of identifying the nucleic acids in a complex mixture (i.e. whole bacterial cells) without extraction and prior derivatization.

Demonstration of Chlamydia trachomatis in inguinal lymphadenitis of lymphogranuloma venereum: a light microscopy, electron microscopy and polymerase chain reaction study.

Intravacuolar organisms in vacuolated macrophages were associated with areas of necrosis and suppuration in 12 patients with suppurative inguinal lymphadenitis. The intravacuolar organisms measured 0.2 to 2.0 micrometers in diameter, stained Gram negative with the Brown-Hopp's tissue Gram stain, faintly blue with hematoxylin and eosin stain, and black with the Warthin-Starry silver impregnation stain. The organisms lined vacuolar membranes and/or clumped in centers of vacuoles. Electron microscopy revealed elementary and reticulate bodies and intermediate forms characteristic of the genus Chlamydia. Cultures of three lymph nodes in McCoy cells grew Chlamydia trachomatis, lymphogranuloma venereum (LGV) serovars. Polymerase chain reaction using primers for chlamydial 16S ribosomal DNA confirmed the organisms as Chlamydia in lymph nodes from nine patients. Recognition of chlamydial organisms by light microscopy in tissue sections of lymph nodes allows a definitive diagnosis of lymphogranuloma venereum.

The effect of anticancer therapy on peripheral blood T and B lymphocyte counts and function.

Patients categorized according to tumor type were compared to a control non-tumor population. Comparison of relative T cell values among the groups showed no significant differences; however, when absolute numbers of T cells/mm3 were compared, all cancer patients, whether from treated or untreated groups, had significantly depressed T cell values. No significant differences were observed in the relative or absolute numbers of B cells. Comparison of the total lymphocyte response to PHA showed no significant differences among the various cancer groups; however, response in all cancer groups whether from treated or untreated patients, was depressed by comparison to the control group. Patients categorized according to the type of treatment received showed significant depression in the white blood count, lymphocyte count, relative and absolute T cell counts and the absolute B cell count in the postsurgery, postadjunctive therapy group. The pretherapy group also showed significant depression in the absolute number of T cells/mm3 when compared to the controls. Response to PHA correlated with the absolute T cells values.

Microorganism gram-type differentiation based on pyrolysis-mass spectrometry of bacterial Fatty Acid methyl ester extracts.

Curie-point pyrolysis (Py)-mass spectrometry has been used to differentiate 19 microorganisms by Gram type on the basis of the methyl esters of their fatty acid distribution. The mass spectra of gram-negative microorganisms were characterized by the presence of palmitoleic acid (C(inf16:1)) and oleic acid (C(inf18:1)), as well as a higher abundance of palmitic acid (C(inf16:0)) than pentadecanoic acid (C(inf15:0)). For gram-positive microorganisms, a signal of branched C(inf15:0) (isoC(inf15:0) and/or anteisoC(inf15:0)) more intense than that of palmitic acid was observed in the mass spectra. Principal components analysis of these mass spectral data segregated the microorganisms investigated in this study into three discrete clusters that correlated to their gram reactions and pathogenicities. Further tandem mass spectrometric analysis demonstrated that the nature of the C(inf15:0) fatty acid isomer (branched or normal) present in the mass spectrum of each microorganism was important for achieving the classification into three clusters.

Real-time PCR detection of Brucella abortus: a comparative study of SYBR green I, 5'-exonuclease, and hybridization probe assays.

Real-time PCR provides a means of detecting and quantifying DNA targets by monitoring PCR product accumulation during cycling as indicated by increased fluorescence. A number of different approaches can be used to generate the fluorescence signal. Three approaches-SYBR Green I (a double-stranded DNA intercalating dye), 5'-exonuclease (enzymatically released fluors), and hybridization probes (fluorescence resonance energy transfer)-were evaluated for use in a real-time PCR assay to detect Brucella abortus. The three assays utilized the same amplification primers to produce an identical amplicon. This amplicon spans a region of the B. abortus genome that includes portions of the alkB gene and the IS711 insertion element. All three assays were of comparable sensitivity, providing a linear assay over 7 orders of magnitude (from 7.5 ng down to 7.5 fg). However, the greatest specificity was achieved with the hybridization probe assay.