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A newly recognized protozoan human parasite, Cyclospora has been incriminated as the cause of prolonged diarrhea. Five patients had episodes of diarrhea accompanied by nausea, weight loss, and/or low-grade fever for 10-45 days. Multiple fecal samples fixed in sodium acetate-acetic acid-formalin contained spherical organisms measuring 8-10 microns in diameter; a modified concentration technique was used to detect them. The sediment was examined by direct microscopy and autofluorescence, and the identification was confirmed by acid-fast stain. All patients had visited either Mexico or Thailand. The presence of Cyclospora organisms in these patients shows that these can be etiologic agents of traveler's diarrhea in both immunocompetent and immunocompromised hosts. Fecal specimens from patients with unexplained diarrhea should be routinely examined for their presence.

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Serologic tests for Lyme borreliosis and for syphilis were performed on 75 patients seen in a 1-week period at the Bascom Palmer Eye Institute in Miami. The incident of syphilis was 8% and of Lyme borreliosis 3% in this study in a nonendemic area. The most common cause for a high titer serologic response for Lyme borreliosis in this group was a prior Treponema pallidum infection. The importance of getting VDRL, FTA-ABS, Lyme IFA, and Lyme ELISA tests in all suspected cases was emphasized.

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The CO2, O2, and pH levels of commercially available blood culture bottles with tryptic soy broth medium from five different manufacturers were compared. Ranges of 1.3 to 6.9% for CO2, 1.1 to 6.0% for O2, and pH 6.94 to 7.26 were found. Different venting procedures revealed that blood culture bottles from which the rubber diaphragm was removed equilibrated the most rapidly (24 h) to the atmosphere (10, 5, and 2.5% CO2) they were incubated in. In contrast, blood culture bottles vented with cotton-plugged needles required 48 h to achieve similar CO2 levels in the medium. The ability of these venting procedures to support bacterial growth was confirmed by measuring the growth of a CO2-dependent Escherichia coli isolate in such vented bottles; blood culture bottles that showed rapid atmospheric (5 and 10% CO2) equilibration had the fastest growth curves. Our results suggest that the differences in the recovery of certain microorganism from blood culture bottles may be due in part to the large variability seen in CO2 and O2 concentrations and the use of various venting procedures.

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Susceptibility testing of 96 clinical group IVe isolates to 19 antimicrobial agents by agar dilution revealed that, at drug levels achievable in serum, the isolates were susceptible only to aminoglycosides, cephalosporins, and colistin, whereas at drug concentrations attainable in urine, they were susceptible to erythromycin, tetracycline, and nitrofurantoin as well.

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A sensitive, specific, and rapid enzyme-linked immunosorbent assay has been developed for the detection of immunoglobulin G to Staphylococcus aureus teichoic acid in human sera. Detection of S. aureus teichoic acid antibody is at least 800 times more sensitive than a double diffusion in gel assay, and positive titers of 1:25,600 and greater were observed with this assay. Results with the enzyme-linked immunosorbent assay can be obtained within 3.5 h by using antigen-coated cuvettes. Quantitation of S. aureus teichoic acid antibody by this enzyme-linked immunosorbent assay may be useful in the initial as well as the follow-up diagnosis of serious S. aureus infections.

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Actinomycosis of the common bile duct can masquerade as cholecystitis. This is the first report of a case. The bacteriologic and pathologic characteristics are described. This opportunistic saprophytic organism took advantage of 15 years of prednisone therapy for rheumatoid arthritis. The actinomycosis was successfully treated with tetracycline-deoxycycline for 6 weeks.

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A new species of bacteria that is an etiologic agent of human pneumonia has been isolated and characterized. Clinical symptoms of infection with this organism are not readily distinguishable from those caused by Legionella pneumophila infection. The organism was isolated from respiratory tract specimens from four patients. Two cases of infection apparently originated in California and one in Georgia, and a fourth was of unknown geographic origin. The name Legionella longbeachae species nova is proposed for this organism. The type strain of L. longbeachae is Long Beach 4 (= American Type Culture Collection 33462).

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A total of 153 clinical isolates and 10 reference strains were employed in an investigation of CO2-dependent streptococci. Their selection was based on a lactic acid homofermentative end product. This group of organisms grew best in 5 to 10% CO2, and several species, including Streptococcus mutans, S. intermedius, Streptococcus MG, S. anginosus, and S. constellatus, required increased CO2 for primary recovery. A basal medium of thioglycolate with 0.1% Tween 80 and phenol red was prepared and used with selected carbohydrates. This media provided luxuriant growth. Serological testing failed to give any definitive correlation with species identification. A shortened differentiation scheme, combined from previous studies, was proposed.

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A kanamycin-esculin bile medium was useful for selective isolation and presumptive identification (24 h) of the Bacteroides fragilis group.

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In a case of septicemia and endarteritis the causative agent was initially misidentified. The Salmonella had atypical biochemical properties and was resistant to numerous antibiotics. Therapy with gentamicin and cephalothin failed to eliminate the organism. Identification of the organism as a lactose-fermenting Salmonella serotype typhimurium var. copenhagen was confirmed. The possible dissemination of the isolate from Brazil was analyzed by serologic studies of family members and friends.

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Eleven patients were colonized or infected with diphtheroids identified as Corynebacterium xerosis. All the patients were compromised hosts by nature of their underlying disease and/or therapy. Two patients developed bacteremia following colonization of the respiratory tract with C. xerosis. Other patients were colonized at various sites, which included the respiratory tract, abdominal and thoracic wounds, amputated limb, and arterial-venous shunt. Distinctive features for the identification of C. xerosis include negative reactions for hemolysis, urease, and motility, and positive reactions for catalase, glucose, sucrose and nitrate reduction. Antimicrobial susceptibility tests were performed by the disk diffusion method. In many instances the organisms were resistant to the antimicrobial regimens received by the patients. This was most frequent for nafcillin, gentamicin, kanamycin, clindamycin, and chloramphenicol. On the other hand, the organisms were highly susceptible to penicillin, ampicillin, cephalothin and carbenicillin.

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Two unusual anaerobic vibrio-like organisms were recovered from blood cultures of two patients. One isolate was identified as Desulfovibrio desulfuricans. It appeared to be the cause of a 24-h episode of fever, chills, and profuse perspiration. This is apparently the first documented report of human infection due to this organism. The second isolate was a Succinivibrio species. It has rarely been described as a cause of bacteremia. The clinical significance of the organism remains unclear.

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Microscopic examination of almost 2,000 sputum specimens was performed over a 3 1/2-month period. The specimens were categorized into 6 groups based on numbers of leukocytes (PMN's) and squamous epithelial cells (SEC's) observed at low magnification (X 100). Bacteriologic evaluation of specimens consisted of identification and antimicrobial susceptibility tests of potential pathogens when growth was equal or predominant to the growth of oropharyngeal flora. Specimens containing greater than 25 PMN's and less than 25 SEC's had potential pathogens identified in 51% of the samples. Specimen containing greater than 25 SEC's and any number of PMN's showed a rate on only 19%. Specimens containing less than 25 PMN's and SEC's had a rate of 13%. Since initiating the screening program in which sputum specimens containing greater than 25 SEC's were unacceptable for culture, the per cent of acceptable specimens received by the laboratory nearly doubled.

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Simplified dichotomous schemata are described for the identification of anaerobic bacteria commonly encountered in clinical material. The procedures used are combinations of routine biochemical tests and techniques that are used to uniformly characterize these organisms. Over 200 anaerobic organisms were used in a three-stage evaluation in which data were compared with those obtained by conventional methods. When there was inconsistency between the biochemical tests described in the presumptive identification schemes and gas-liquid chromatography, additional biochemical tests or reference procedures were used to confirm identification. Strains from the American Type Culture Collection and the Center for Disease Control, as well as recent clinical isolates, were included in this evaluation. The results show the simplified procedures to be useful for the identification of anaerobic isolates from clinical material.

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Fluorescent antibody conjugates were prepared from five species of anaerobic cocci commonly isolated from human infections. When tested with homologous and heterologous cells these conjugates were found to be highly specific. There was no evidence of a common genus antigen. Peptococcus magnus conjugates detected a species-specific antigen; cross-reactions with Peptostreptococcus anaerobius were readily eliminated by absorption. The conjugates from Peptococcus asaccharolyticus, Peptococcus prevotii, Peptostreptococcus, anaerobius, and Peptostreptococcus intermedius displayed a high degree of strain specificity. Occasional cross-reactions were detected with homologous strains, suggesting the presence of common antigens, but no attempt was made to determine the number of different serotypes in these species.

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The production of extracellular deoxyribonuclease was examined with anaerobic organisms isolated from clinical specimens. Nuclease activity was extraordinarily common. All strains of Fusobacterium, including eight species, as well as Bacteroides fragilis and B. melaninogenicus, displayed enzyme activity. Whereas the gram-positive bacteria were generally less productive, all strains of Clostridium perfringens, Peptostreptococcus intermedius, and P. anaerobius specifically produced deoxyribonuclease. The test is taxonomically valuable, particularly in the characterization of gram-positive cocci, since a deoxyribonuclease-producing coccus indicates P. intermedius or P. anaerobius. Additionally, possession of the enzyme may prove to be a useful correlate of the potential pathogenicity of anaerobes.

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Anaerobic organisms were tested for phosphatase activity in different pH ranges. Several groups of organisms displayed characteristic patterns. Bacteroides fragilis, B. melaninogenicus, and B. ruminicola produced phosphatase with strongest activity at pH 8.6. Fusobacterium mortiferum was the only species of this genus to show strong hydrolysis. The enzyme was active in both acid and alkaline ranges. The activity of gram-positive organisms was variable, the most active groups being Clostridium perfringens, Peptostreptococcus intermedius, P. micros, and Peptococcus constellatus. The incorporation of phosphatase activity into the identification scheme of anaerobes seems feasible. There was a correlation of hydrolysis with several important pathogens.

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