Infections caused by Pseudomonas maltophilia. Expanding clinical spectrum.

Pseudomonas maltophilia (Xanthomonas maltophilia) is a frequently isolated commensal that is gaining increasing recognition as an opportunistic pathogen in debilitated hosts. We report three unusual infections due to P maltophilia that illustrate the ability of the organism to cause life-threatening illness. We describe a case of postoperative meningitis, a case of recurrent bacteremia complicated by ecthyma gangrenosum, and a case of native valve endocarditis in a drug addict. Because of frequent isolation from noninfected sites, the pathogenic potential of P maltophilia may be overlooked. The notable resistance of this organism is commonly used beta-lactam and aminoglycoside antibiotics may complicate therapy.

Routine culturing for Legionella in the hospital environment may be a good idea: a three-hospital prospective study.

The source for nosocomial Legionnaires' disease is the water distribution system. However, the implications for legionella contamination in a hospital without known Legionnaires' disease is unclear. Therefore, culturing for Legionella pneumophila in the environment has not been routinely recommended. The authors conducted a prospective pneumonia study in three hospitals, none of which was known to have a major problem with endemic legionellosis. The water system of Hospital 1 was colonized with L. pneumophila, serogroup 1; Hospital 2 was colonized by L. pneumophila, serogroup 5 (which is rarely associated with disease); Hospital 3 was essentially free of L. pneumophila. Sputum culture on selective legionella media, direct fluorescent antibody testing, and serology were performed for all nosocomial pneumonias regardless of clinical impression. At the end of the study the incidence of nosocomial legionnaires' disease was found to be 9%, 0%, and 0% in Hospitals 1, 2, and found to be 9%, 0%, and 0% in Hospitals 1, 2, and 3, respectively. In Hospital 1, monoclonal antibody subtyping confirmed that the patient isolates were identical to the environmental isolates. The authors conclude that environmental culturing, despite the absence of known Legionnaires' disease, is useful. Positive cultures from the hospital water supply would mandate the introduction of legionella testing into the laboratory and stimulate physicians to consider Legionnaires' disease when encountering nosocomial pneumonias.

Cefoperazone-induced coagulopathy.

A number of recent articles have reviewed the problem of hypoprothrombinemia and bleeding associated with antibiotic therapy. We report three cases in which bleeding is believed to be related to a prolonged prothrombin time secondary to cefoperazone therapy. Reports of coagulopathies such as these are increasing in number and call attention to the need to monitor the prothrombin time during cefoperazone therapy.

Myelopathy after herpes zoster.

A 73-year-old woman with a remote history of carcinoma of the ovary had herpes zoster involving several lumbosacral dermatomes. There subsequently developed a progressive myelopathy with normal myelographic findings and CSF pleocytosis. Vidarabine (15 mg/kg/day) was given for ten days. No further progression occurred. The syndrome of progressive myelopathy following herpes zoster is rare; direct viral invasion of the cord with subsequent necrosis appears to be the pathogenic mechanism. Antiviral therapy may have halted progression, but it did not lead to recovery of function.

Nosocomial Legionnaires' disease uncovered in a prospective pneumonia study.

Most hospitals have yet to record a case of nosocomial legionnaires' disease; the importance of isolation of Legionella pneumophila in the water system of such an institution is unclear. We undertook a prospective pneumonia study in tandem at a veterans hospital where legionnaires' disease was known to be endemic and a community teaching hospital where legionnaires' disease had never been documented. Legionella serological tests were performed on all patients with pneumonia; selective culture media and direct fluorescent antibody testing for Legionella were made readily available. Simultaneous environmental surveys for Legionella were performed. At the community hospital, we discovered that 64% of sites in the water distribution system yielded L pneumophila and that 14.3% of nosocomial pneumonias were legionnaires' disease. The epidemiologic implications of these findings are discussed. Options concerning case detection and eradication measures in the face of hospital water contamination with L pneumophila are presented.

Ciguatera fish poisoning in Miami.

Ciguatoxic fish constitute a continuing foodborne disease problem in Miami. Information from 129 cases of ciguatera fish poisoning reported to the Dade County (Miami) department of Public Health during 1974 to 1976 was used for epidemiologic study of the syndrome. The case definition required that both gastrointestinal and paresthetic neurological symptoms be experienced within 36 hours after eating fish. Grouper and snapper were the fish most frequently implicated. Neither methods of storage nor means of preparation seemed to affect fish toxicity. A predominantly late spring and summer seasonality was noted. The true annual incidence of this syndrome in Miami may be ten times the number reported to the health department, suggesting an average annual incidence of at least five cases per 10,000 resident population. Recent advances in ciguatoxin research may lead to much needed assays for toxin detection.

Heat-labile enterotoxigenic Escherichia coli induced diarrhea aboard a Miami-based cruise ship.

Beginning in late December, 1975, almost one-third of the passengers on two successive cruises of a Miami-based cruise ship noted the onset of diarrheal illness while on board. A single serotype of Escherichia coli that produced heat-labile enterotoxin without producing heat-stable enterotoxin was recovered from the stool of most ill passengers cultured. Epidemiological investigation could not specifically define the mode of spread. The clinical picture presented was similar to the illness caused by enterotoxigenic E. coli that produce only heat-stable enterotoxin or that produce heat-stable and heat-labile enterotoxins.

Hyperpyrexia due to air-conditioning failure in a nursing home.

During the period August 9--13, 1976, 21 of 89 residents of a nursing home in southeastern Florida had sudden onset of fever--temperature greater than 38.1 degrees C (100.6 degrees F) with no accompanying symptoms. Five residents, whose temperatures ranged from 39.4 degrees C (103 degrees F) to 41.3 degrees C (106.4 degrees F), died. No viral or bacterial pathogens were isolated. None of the nursing home's 123 employees and volunteers had similar illness. The air-conditioning system was shut down for repairs from August 9 through August 12, a time when recorded peak temperatures outdoors ranged from 30.6 degrees C (87 degrees F) to 32.2 degrees C (90 degrees F). The only recorded temperature inside the nursing home for that period was 31.7 degrees C (89 degrees F). Laboratory and epidemiologic data were consistent with the theory that the illness was due to hyperpyrexia, secondary to environmental conditions, rather than to an infectious agent. The episode was considered analogous to the nonspecific increased mortality of elderly and chronically ill persons during an urban heat wave. The episode points up the need for prompt recognition and intervention when there is the potential for heat stress in elderly and chronically ill patients. Buildings housing such patients must be designed so that alternative ventilation can be provided when the central air-conditioning system fails.

Therapy of neutropenic rats infected with Pseudomonas aeruginosa.

Rats made profoundly neutropenic with cyclophosphamide were injected with 100 or 1,000 50% lethal doses of a strain of Pseudomonas aeruginosa suspended in mucin. Rats were treated for 24, 48, or 72 hr with thrice daily intramuscular administration of carbenicillin (400 mg/kg), gentamicin (10 mg/kg), both of these agents at the same doses, or saline. One hour after injection of antibiotics, the mean bactericidal titers in serum were 1:4.7, 1:21., and 1:8.6 for rats receiving carbenicillin, gentamicin, and a combination of the two agents, respectively. Combination chemotherapy produced a greater reduction in mortality rate than did either agent alone for both inoculum sizes and for all three durations of therapy. Gentamicin was at least as effective as carbenicillin regardless of inoculum size or duration of therapy. Fourfold or greater increases in minimal inhibitory concentrations of P. aeruginosa were seen in 54% of postmortem blood culture isolates from animals treated with carbenicillin, in 15% from rats treated with gentamicin, and in none from animals receiving both agents.

Cinoxacin: in vitro antibacterial studies of a new synthetic organic acid.

Cinoxacin (compound 64716) is a synthetic organic acid with antibacterial activity against most aerobic gram-negative bacilli. Minimal inhibitory concentrations of cinoxacin (agar-dilution method) were determined for 419 strains. Escherichia coli was the most susceptible group of organisms. The majority of Klebsiella sp., Enterobacter sp., Proteus sp., and Serratia marcescens were inhibited by 8 mug of cinoxacin per ml. Pseudomonas aeruginosa and all gram-positive isolates tested were resistant to 64 mug or less of cinoxacin per ml. Zones of inhibition using a 30-mug disk correlated well with agar-dilution minimal inhibitory concentrations (r = -0.9). Cinoxacin was bactericidal when tested with inocula of 5 x 10(6) organisms per ml. Resistance to cinoxacin was readily developed in all three strains tested by serial passage on drug-containing agar. The in vitro properties of this agent were similar to those of nalidixic acid.