Difference in Cryptococcus neoformans cellular and capsule size in sequential pulmonary and meningeal infection: a postmortem study.

Cryptococcus neoformans is an encapsulated yeast that primarily causes a life-threatening meningoencephalitis in immunosuppressed individuals especially those with HIV/AIDS. Its main virulence factor is its polysaccharide capsule which interferes with complement-mediated phagocytosis. C. neoformans infections ensue following inhalation of small desiccated less encapsulated propagules leading to pulmonary pneumonia or colonization of the host's respiratory tract. Numerous murine experimental studies have shown major discrepancies in cryptococcal cell and capsule enlargement between the lung and brain. In this report, we describe a nonmurine experimental model of the striking variability between cryptococcal cell and capsule size diameters in histology sections of postmortem lung and brain in a fatal cryptococcal infection in a heart transplant recipient.

Disseminated histoplasmosis presenting as AIDS cholangiopathy.

Histoplasma capsulatum is a common opportunistic pathogen that often causes disseminated infection among AIDS patients from endemic areas. Virtually any organ system can be affected, but biliary involvement has not been described. We report the first case of AIDS cholangiopathy associated with H. capsulatum.

Bacillus cereus, a volatile human pathogen.

Bacillus cereus is a Gram-positive aerobic or facultatively anaerobic, motile, spore-forming, rod-shaped bacterium that is widely distributed environmentally. While B. cereus is associated mainly with food poisoning, it is being increasingly reported to be a cause of serious and potentially fatal non-gastrointestinal-tract infections. The pathogenicity of B. cereus, whether intestinal or nonintestinal, is intimately associated with the production of tissue-destructive exoenzymes. Among these secreted toxins are four hemolysins, three distinct phospholipases, an emesis-inducing toxin, and proteases. The major hurdle in evaluating B. cereus when isolated from a clinical specimen is overcoming its stigma as an insignificant contaminant. Outside its notoriety in association with food poisoning and severe eye infections, this bacterium has been incriminated in a multitude of other clinical conditions such as anthrax-like progressive pneumonia, fulminant sepsis, and devastating central nervous system infections, particularly in immunosuppressed individuals, intravenous drug abusers, and neonates. Its role in nosocomial acquired bacteremia and wound infections in postsurgical patients has also been well defined, especially when intravascular devices such as catheters are inserted. Primary cutaneous infections mimicking clostridial gas gangrene induced subsequent to trauma have also been well documented. B. cereus produces a potent beta-lactamase conferring marked resistance to beta-lactam antibiotics. Antimicrobials noted to be effective in the empirical management of a B. cereus infection while awaiting antimicrobial susceptibility results for the isolate include ciprofloxacin and vancomycin.

Susceptibility testing of clinical isolates of pseudomonas aeruginosa to levofloxacin, moxifloxacin, and gatifloxacin as a guide to treating pseudomonas ocular infections.

PURPOSE: Pseudomonas aeruginosa ocular infections most frequently originate from an environmental source; successful treatment with various ocular antibiotics is well established. However, emergence of resistant clones to available antibiotics poses a real threat to successful treatment. The purpose of this study was to evaluate the antibiotic susceptibilities of 100 random clinical isolates of P. aeruginosa to levofloxacin, moxifloxacin, and gatifloxacin, potential agents for the treatment of ocular infections caused by this microorganism. METHODS: One hundred consecutive strains of P. aeruginosa were isolated from clinical specimens submitted to the clinical microbiology hospital laboratory. Duplicate isolates were not included. The minimum inhibitory concentrations (MICs) of these isolates were determined by using Etests, performed according to the manufacturer's instructions. American Type Culture Collection (ATCC) strains of Escherichia coli, P. aeruginosa, and Staphylococcus aureus served as reference controls. RESULTS: Although most isolates were susceptible to levofloxacin, moxifloxacin, and gatifloxacin and the MICs were not significantly different, significant numbers were resistant. The standardized controls rendered expected MICs. The susceptibility of the isolates varied with regard to source, and resistant strains showed increased resistance. CONCLUSIONS: Based on the data, the treatment of ocular infections caused by P. aeruginosa with levofloxacin, moxifloxacin, and gatifloxacin still has a high likelihood of success. However, six of the isolates collected were resistant to all three of the fluoroquinolones tested. Based on the data, clinicians must be aware that clinical resistance can occur even with the newer fluoroquinolones.

O1 and non-O1 Vibrio cholerae bacteremia produced by hemolytic strains.

Vibrio cholerae are Gram-negative bacteria capable of producing serious infections. They are differentiated into O1 and non-O1 serogroups, depending on their ability to agglutinate with specific antiserum. In contrast to non-O1 V. cholerae, which are more prone to invading the bloodstream, V. cholerae O1 is rarely the cause of bacteremia. We describe 2 cases of O and non-O1 V. cholerae bacteremia in patients with hepatitis C virus cirrhosis. We postulate that the hemolytic properties of the isolates contributed to their virulence in immunocompromised hosts.

Disseminated tuberculosis presenting with finger swelling in a patient with tuberculous osteomyelitis: a case report.

BACKGROUND: Extrapulmonary manifestations of tuberculosis have become increasingly important in the era of HIV/AIDS. CASE PRESENTATION: We describe a case of tuberculosis (TB) dactylitis in a patient with AIDS who originated from the Ivory Coast. The diagnosis was established by direct visualization of acid-fast bacilli on joint fluid and bone biopsy of the proximal phalanx. Imaging of the chest revealed multiple bilateral nodules. Confirmation of the diagnosis was made by isolation of Mycobacterium tuberculosis from sputum and bone cultures. CONCLUSION: Tuberculosis should be considered in patients with unusual soft tissue or skeletal lesions, especially when an immunosuppressive condition is present. Ziehl-Neelsen staining and culture of tissue obtained via surgical biopsy offer the most direct approach to diagnosis.

Mycobacterium chelonae keratitis: elucidation of diagnosis through evaluation of smears of fluid from patient's contact lens care system.

PURPOSE: To describe the microbiologic diagnosis of putative Mycobacterium chelonae keratitis in a soft contact lens wearer by initial evaluation of Gram- and Kinyoun (acid fast)-stained smears of fluid from patient's contact lens care system. METHODS: Corneal ulcer of suspected Acanthamoeba etiology developed in a 28-year-old soft contact lens wearer. After corneal scrapings were negative, microbiologic consultation led to evaluation of stained smears and culture of fluid from patient's contact lens care system. RESULTS: Gram stain of smears showed a polymicrobic flora distinguished by numerous gram-positive, beaded, tightly banded, "diphtheroid-like" bacilli strongly suggestive of a rapidly growing mycobacterial species. Kinyoun-stained smears revealed innumerable acid-fast bacilli singly and in tightly woven bundles (cords), which culturally proved to be M. chelonae. Treatment with ciprofloxacin and amikacin resolved the ulcer. CONCLUSION: Diagnosis of M. chelonae keratitis in contact lens wearers is often delayed or even overlooked. Additionally, in the absence of overt corneal injury, eg, trauma or surgery, a source for the infecting mycobacterial species in the setting of contact lens wear has not been identified. If searched for, however, as in the present case, the patient's contact lens care system may serve as the reservoir for the microorganism. Staining for acid-fast bacilli is further recommended when smears of contact lens care solution of a patient with a corneal ulcer shows the presence of gram-positive "diphtheroid-like" organisms.

Cutaneous adiaspiromycosis: a distinct dermatologic entity associated with Chrysosporium species.

Primary cutaneous infection with Chrysosporium, a saprophytic fungus commonly found in soil, is believed to be very rare, with only two previously reported cases. We present a case of localized cutaneous Chrysosporium in an immunocompromised heart transplant patient. Considering that the histology of the skin in this case is superimposable on that seen in pulmonary Chrysosporium known as adiaspiromycosis, we regard the cutaneous variant in the absence of pulmonary disease as a distinct dermatologic entity. The low frequency of reports of primary cutaneous Chrysosporium infection suggests either underreporting of this diagnosis in the literature, or misidentification of this fungus as another more common mycotic species sharing morphologic similarities. By amplifying our understanding of Chrysosporium infection in the skin, this disorder will be easier to identify and treat.

Fusospirochetosis causing necrotic oral ulcers in patients with HIV infection.

Under certain permissive circumstances, normally occurring fusiform bacteria and Borrelia spirochetes can result in a symbiotic overgrowth that leads to necrotic oral ulcers (stomatitis), gingivitis, and periodontitis. These lesions are collectively known as oral fusospirochetosis and may be under-appreciated in patients with HIV infection and AIDS. Fusospirochetal oral ulcers in patients with HIV are often large, necrotic, and malodorous; they respond completely to penicillin. We report 3 patients with HIV infection and fusospirochetal ulcerative stomatitis and review the clinical presentation, microbiologic diagnosis, potential pathogenesis, and treatment of these lesions.

Ineffectiveness of handwashing with lotion soap to remove nosocomial bacterial pathogens persisting on fingertips: a major link in their intrahospital spread.

The effectiveness of five 30-second handwashes with a non-antiseptic lotion soap to remove nosocomial pathogens (10(8) CFU) applied to fingertips was studied. CFU for all species dropped rapidly after the first handwash; persistence (10 to 15 CFU) was maintained thereafter. Wiping hands with an antiseptic (70% isopropyl or 10% povidone-iodine) sponge removed persisters.

Giant blastoconidia of Candida albicans. A case report and review of the literature.

We describe a patient with extranodal non-Hodgkin lymphoma who developed systemic candidiasis after treatment with a cyclophosphamide-based chemotherapy regimen. Histologically, the fungal organisms demonstrated markedly enlarged blastoconidia with a variety of morphologic forms, mimicking other mycotic organisms, such as Cryptococcus neoformans, Blastomyces dermatitidis, and Paracoccidioides brasiliensis. The in vivo occurrence of such giant forms is rare, and when observed histologically may result in an erroneous diagnosis or a diagnosis of multiple mycotic organisms.

Meconium enhances the growth of perinatal bacterial pathogens.

OBJECTIVE: To demonstrate the effects of meconium on growth of bacterial pathogens, which are common causes of intra-amniotic infection and neonatal sepsis. METHODS: Meconium collected from 9 healthy neonates was suspended as a 20% solution using sterile saline. In experiment 1, separate test tubes of meconium solution and sterile saline (the control) were individually inoculated with 10(6) colony-forming units of a single species of the following test pathogens: Escherichia coli, Enterococcus faecalis, Group B Streptococcus, Staphylococcus aureus, Pseudomonas aeruginosa, and Listeria monocytogenes. After incubation at 37 degree C for 24 hours, 1 L each of the bacterial-meconium and bacterial-saline solutions was inoculated onto 5% sheep blood agar. After 24 hours of incubation, the number of developing colonies was counted. In experiment 2, equal volumes of meconium and saline solutions were inoculated with 10(5) colony-forming units of either E. coli or Group B Streptococcus. At intervals of 6, 9, and 24 hours post-incubation, 1 L each of the bacterial-meconium and bacterial-saline solutions was inoculated onto 5% sheep blood agar plates, and colonies were counted after overnight incubation. RESULTS: In the first experiment, 24 hours of incubation resulted in bacterial amplification in the meconium solution from an initial inoculum of 10(6) colony-forming units/mL to 10(9) colony-forming units/mL. In contrast, the same inoculation of saline solution (control) showed no increase in colony counts over the same time interval. For E. coli and Group B Streptococcus in experiment 2, growth enhancement in meconium was seen as early as 6 hours, as colony counts of a test species increased from 105 colony-forming units/mL to 10(9)-10(10) colony-forming units/mL. CONCLUSION: Enhanced growth of perinatal pathogens in meconium was constantly observed, and can occur as early as 6 hours after bacterial interaction of meconium.

Production by Bacillus pumilus (MSH) of an antifungal compound that is active against Mucoraceae and Aspergillus species: preliminary report.

A compound produced by Bacillus pumilus (MSH) that inhibits Mucoraceae and Aspergillus species is described. Fungicidal activity was demonstrated by lawn-spotting and by diffusion through 0.45 microm Millipore membranes placed on 5 % sheep-blood agar, nutrient agar, trypticase soy agar and Mueller-Hinton agar, followed by spore inoculation of the bacterium-free underlying agar surface. With either technique, zones of fungal inhibition correlated with the zone of haemolysis produced by B. pumilus (MSH). The active compound inhibited Mucor and Aspergillus spore germination and aborted elongating hyphae, presumably by inducing a cell-wall lesion. Antifungal activity was stable in agar for a minimum of 8 days, resistant to Pronase degradation, and partially inactivated by chloroform exposure and at pH 5.6. Its molecular mass was determined by diffusion through dialysis membrane to be 500-3000 Da. Attempts at further isolation of the compound have proven unsuccessful to date.

Evaluation of dedicated stethoscopes as a potential source of nosocomial pathogens.

OBJECTIVE: To determine whether the ear tips of dedicated stethoscopes (DS) that are used on patients prescribed contact precautions for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium, or multiple antibiotic-resistant Acinetobacter baumannii become contaminated with these micro-organisms. DESIGN: Culture of DS ear tips. SETTING: A 524-bed tertiary care university hospital. METHODS: DS ear tips were inoculated directly onto bacteriologic media and incubated for 48 to 72 hours. Growth of more than 10 colonies from the 2 ear tips collectively was indicative of contamination. RESULTS: Ear tips of 78 DS from 69 patients were cultured. Ear tips from 17% (13/78) of the DS were contaminated with potentially pathogenic bacteria: 2 with S aureus (1 MRSA), 1 with E faecalis, 7 with Acinetobacter species, 2 with Pseudomonas species, 1 with Escherichia coli, and 1 with Moraxella. None of the stethoscope ear tips was contaminated with the same pathogen for which the patient was prescribed contact precautions (95% CI, 0-3.8%). CONCLUSION: Although the ear tips of DS from patients who were prescribed contact precautions for MRSA, vancomycin-resistant E faecium, or multiple antibiotic-resistant A baumannii were not contaminated with the indicated nosocomial pathogen, 94% of the evaluable ear tips were contaminated, including with MRSA (1.3%) and Acinetobacter (11%). Regular disinfection of ear tips of DS between users should be considered.

Unsuspected Toxoplasma gondii empyema in a bone marrow transplant recipient.

Toxoplasma gondii is an opportunistic parasite that can cause severe disease in immunosuppressed individuals. We report a case of unsuspected T. gondii empyema in a bone marrow transplant recipient that was diagnosed by the visualization of numerous intracellular and extracellular tachyzoites in Giemsa- and Gram-stained smears. The patient was treated with pyrimethamine, sulfadiazine, clindamycin, and atovaquone, and she survived 110 days after diagnosis, despite having a large parasite burden.