Antimicrobial resistance in Streptococcus pneumoniae: implications for patients with community-acquired pneumonia.

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. During the past decade, the prevalence of penicillin resistance in S pneumoniae has increased dramatically, with resistance rates approaching 45% in some areas of the United States. Streptococcus pneumoniae has also acquired resistance to other commonly used antimicrobials, including cephalosporins, macrolides, and trimethoprim-sulfamethoxazole. While vancomycin and the newer quinolones are currently highly active against most strains of S pneumoniae, reduced susceptibilities to these agents have been identified in some strains. Prior use of antimicrobial agents is the major risk factor for colonization and infection with antibiotic-resistant strains. beta-Lactam antibiotics remain the treatment of choice for infections caused by susceptible S pneumoniae. The optimum therapy for penicillin-resistant strains remains unclear. Appropriate empirical therapy for patients with community-acquired pneumonia depends in part on the community-specific resistance patterns of S pneumoniae to various antibiotics. In this article, we provide an overview of the development of S pneumoniae resistance to commonly used antibiotics and discuss the implications of the development of resistance on treatment decisions.

Acquired immunodeficiency syndrome-related visceral leishmaniasis presenting in a pleural effusion.

Visceral leishmaniasis is increasingly reported in immunocompromised patients, including patients with AIDS. We report a case of visceral leishmaniasis in an AIDS patient who presented with pulmonary symptoms and bilateral pleural effusions. Histologic evaluation of pleural fluid and bone marrow revealed histiocytes with intracellular Leishmania amastigotes. Visceral leishmaniasis should be considered in AIDS patients with a significant travel history who present with unexplained pulmonary symptoms.

Donor-to-recipient transmission of bacteria as an unusual cause of mediastinitis in a heart transplant recipient.

We present a 54-year-old male heart transplant recipient who developed mediastinitis caused by Klebsiella oxytoca and Veillonella species. Culture of the donor's bronchus also grew K. oxytoca and a Veillonella species. Pulsed-field gel electrophoresis revealed that the K. oxytoca isolates had identical banding patterns. This case illustrates transmission of pathogenic bacteria via a contaminated organ.

Colonization and infection with antibiotic-resistant bacteria in a long-term care facility.

OBJECTIVE: To assess colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA), high-level gentamicin-resistant enterococci (R-ENT) and gentamicin and/or ceftriaxone-resistant Gram-negative bacilli (R-GNB) and the factors that are associated with colonization and infection with these organisms. DESIGN: Monthly surveillance for colonization and infection over a period of 2 years. In the second year, an intervention to decrease MRSA colonization by the use of mupirocin ointment was carried out. SETTING: Long-term care facility attached to an acute care Veterans Affairs Medical Center. PATIENTS: A total of 551 patients in the facility were followed for a period of 2 years. MEASUREMENTS: Colonization and infection rates with MRSA, R-ENT, and R-GNB. Analysis of risk factors associated with colonization and infection with these three groups of organisms. MAIN RESULTS: In the first year, colonization rates were highest for MRSA (22.7 +/- 1% patients colonized each month) and R-ENT (20.2 +/- 1%) and lower for R-GNB (12.6 +/- 1%). After introduction of decolonization of nares and wounds with mupirocin, the rate of MRSA colonization fell significantly to 11.5 +/- 1.8%, but rates remained unchanged for R-ENT and R-GNB. Risk factors for MRSA colonization included the presence of wounds and decubitus ulcers. For R-ENT, the presence of wounds, renal failure, intermittent urethral catheterization, low serum albumin, and poor functional level were significant. For R-GNB, intermittent urethral catheterization, chronic renal disease, inflammatory bowel disease, presence of wounds, and prior pneumonia were significantly associated with colonization. Overall, of infections caused by known organisms, 49.6% were due to MRSA, R-ENT, or R-GNB, and 50.4% were due to susceptible organisms. Infections were more commonly due to R-GNB (21.1% of all infections) than to R-ENT (8.3%) or MRSA (4.6%). The most common infections were urinary tract infections (42.9% of all infections) and skin and soft tissue infections (31.9% of all infections). Risk factors for MRSA infections were diabetes mellitus and peripheral vascular disease, for R-GNB infections were intermittent urethral catheterization and indwelling urethral catheters, and no one factor was associated with R-ENT infection. CONCLUSIONS: In our long-term care facility, colonization with resistant MRSA and R-ENT was more common than R-GNB, but infections were more often due to R-GNB than R-ENT and MRSA. Several host factors, which potentially could be modified in order to prevent infections, emerged as important in colonization and infection with these antibiotic-resistant organisms.

Colonization and transmission of high-level gentamicin-resistant enterococci in a long-term care facility.

OBJECTIVES: To assess the prevalence of high-level gentamicin-resistant enterococcus (HGRE) colonization, transmission patterns, and spectrum of illness among residents of a long-term care facility. DESIGN: Monthly surveillance for HGRE colonization of wounds, rectum, and perineum over a 1-year period. SETTING: A Veterans Affairs long-term care facility attached to an acute-care facility. PATIENTS: All 341 patients in the facility during the observation period. RESULTS: Over the 1-year period, 120 patients (35.2%) were colonized with HGRE at least once, with an overall monthly colonization rate of 20 +/- 1.5%. HGRE were isolated from rectum (12.8%), wounds (11.7%), and perineum (9.3%). Patients with the poorest functional status had the highest rate of colonization (P < 0.0005). HGRE-colonized patients were more likely to be colonized with methicillin-resistant Staphylococcus aureus (51% versus 25%; P < 0.0005). Seventy-four patients (21.7%) were colonized at admission or at the start of the study. Another 46 patients (13.5%) acquired HGRE during the study, including 36 who acquired HGRE while in the long-term care facility and 10 who were positive when transferred back from the acute-care hospital. Based on plasmid profiles, only two patients appeared to have isolates similar to those of current or previous roommates. Carriage of HGRE was transient in most cases. Only 20 patients were colonized for 4 or more months, and those patients usually carried different strains intermittently. Infections were infrequent, occurring in only 4.1% of total patients. CONCLUSIONS: In our long-term care facility, HGRE were endemic, and new acquisition of HGRE occurred frequently. However, only two patients had evidence of acquisition from a roommate, suggesting that cross-infection from a roommate was not a major route of spread of HGRE.

Postexposure chemoprophylaxis for occupational exposure to HIV in the dental office.

Occupational exposure to HIV continues to be a concern for health care workers. Preventing exposure through the use of universal precautions is the primary means of protection. New Public Health Service interagency work group recommendations for postexposure chemoprophylaxis provide information to help manage occupational exposure to HIV.

Efficacy of ampicillin versus trimethoprim-sulfamethoxazole in a mouse model of lethal enterococcal peritonitis.

Lethal enterococcal peritonitis in mice was used to compare trimethoprim-sulfamethoxazole (TMP-SMX) therapy with ampicillin therapy. Peritoneal fluid showed a 10(3)-CFU decrease in enterococci with ampicillin compared with TMP-SMX. Mortality of the untreated mice was 100%, compared with 40% for ampicillin and 95% for TMP-SMX, despite adequately measured levels in serum and peritoneal fluid.

Disseminated Scedosporium apiospermum infection in a previously healthy woman with HELLP syndrome.

A previously healthy 33-year-old female died of disseminated infection with Scedosporium apiospermum in association with Hemolysis, Elevated Liver enzymes, and Low Platelets (HELLP) syndrome following the delivery of twins. Her postpartum course was complicated by multisystem organ failure managed with extracorporeal membrane oxygenation (ECMO). She also developed bowel and left lower extremity ischemia requiring surgical resection. Blood cultures yielded S. apiospermum, and histologic findings revealed in vivo adventitious sporulation, an unusual occurrence with this pathogen. Autopsy showed extensive fungal infection of brain, lungs, thyroid, heart, and kidneys.

Cefotetan-induced immune hemolytic anemia.

Immune hemolytic anemia due to a drug-adsorption mechanism has been described primarily in patients receiving penicillins and first-generation cephalosporins. We describe a patient who developed anemia while receiving intravenous cefotetan. Cefotetan-dependent antibodies were detected in the patient's serum and in an eluate prepared from his red blood cells. The eluate also reacted weakly with red blood cells in the absence of cefotetan, suggesting the concomitant formation of warm-reactive autoantibodies. These observations, in conjunction with clinical and laboratory evidence of extravascular hemolysis, are consistent with drug-induced hemolytic anemia, possibly involving both drug-adsorption and autoantibody formation mechanisms. This case emphasizes the need for increased awareness of hemolytic reactions to all cephalosporins.

Primary cutaneous Nocardia otitidiscaviarum infection: case report and review.

Organisms of the genus Nocardia cause a variety of illnesses in humans and other mammals. Nocardiae normally enter the body via the respiratory tract, but they may also be directly inoculated into the skin, causing primary cutaneous disease. Nocardia otitidiscaviarum is one of the less commonly isolated species of Nocardia, but it can produce localized or disseminated infection. We report a case of primary cutaneous N. otitidiscaviarum infection and review the clinical and microbiological features of other reported cases. Cutaneous N. otitidiscaviarum infection usually occurs in the setting of trauma, most often in otherwise healthy hosts. The manifestations of N. otitidiscaviarum skin infection range from cellulitis and abscess formation to the development of mycetomas. Cutaneous infection by N. otitidiscaviarum can mimic disease caused by more common pyogenic organisms, often leading to delay in diagnosis and treatment. Appropriate antibiotic therapy, usually with a sulfa drug-containing regimen, is generally successful.

Nosocomial infections in adult patients undergoing extracorporeal membrane oxygenation.

The use of extracorporeal membrane oxygenation (ECMO) for adult patients has increased in recent years. A retrospective cohort study of adult patients undergoing ECMO was performed between 19 February 1985 and 10 October 1995 to evaluate nosocomial infections. Seventy-one evaluable patients underwent ECMO for a total of 799 days. Forty-six infections were identified in 32 (45%) of 71 patients. There were 15 bloodstream infections, 13 lower respiratory infections, 11 urinary tract infections, and 7 miscellaneous infections. The rates of bloodstream infection (18.8 cases per 1,000 ECMO days) and urinary tract infection (13.8 cases per 1,000 ECMO days) were significantly higher than those reported through the Centers for Disease Control and Prevention / National Nosocomial Infection Surveillance System (P < .0001 and P < .001, respectively). The rate of bloodstream infection increased with the duration of ECMO cannulation. This study highlights the increased risk for nosocomial infections in this patient population. Infection may not be apparent, and increased physician awareness of infection risk is imperative.

Achromobacter xylosoxidans bacteremia: report of four cases and review of the literature.

Seventy-seven cases of bacteremia due to Achromobacter xylosoxidans were reviewed, and susceptibility studies were performed on 11 clinical isolates of A. xylosoxidans. Nosocomial bacteremia was noted in 54 of 77 patients (70%), and 28 (36%) had infection associated with an outbreak or acquired from a discrete point source. The most common underlying illnesses were malignancies (30%) and cardiac disease (21%); immunosuppression affected 27%. The most common clinical syndromes were primary and catheter-associated bacteremia (19% each) and pneumonia (16%). The case-fatality rate was 30%; only 3% of patients with primary or catheter-associated bacteremia died, but 65% of patients with meningitis, endocarditis, and pneumonia died. The case-fatality rate in neonates was 80%. Susceptibility studies showed that all strains were resistant to aminoglycosides, most were resistant to quinolones, and all were susceptible to broad-spectrum penicillins, imipenem, ceftazidime, and trimethoprim-sulfamethoxazole. Two-disk approximation and time-kill studies showed synergy or additive effects for the combination of gentamicin and piperacillin against most strains.

Mycoplasma felis septic arthritis in a patient with hypogammaglobulinemia.

We describe the first documented case of Mycoplasma felis infection in a woman who had common variable immunodeficiency and who presented with septic arthritis of the left hip and right knee. M. felis was isolated from both joints. She had been exposed to cats before the diagnosis of M. felis septic arthritis was made. Both of the patient's joints were surgically debrided, and she was treated with doxycycline for several months. In spite of initial improvement, destruction of her hip was noted. Subsequently, she underwent hip arthroplasty; histopathological examination of the bone at the time of surgery showed chronic osteomyelitis, and doxycycline therapy was continued.