Capnocytophaga infection involving a portal-systemic vascular shunt

Capnocytophaga sp., a microaerophilic gram-negative isolate of the human oral cavity, has previously been reported to cause sinusitis, empyema, wound infections, conjunctivitis, subphrenic abscess, osteomyelitis, bacteremia, cervical abscess, and endocarditis. We report the unusual case of infection with this organism at the anastamotic site of a splenorenal portosystemic vascular shunt. In this case, the pathogenesis is presumed to be bacteremia related to mucosal trauma from endoscopic injection sclerotherapy or bacteremia secondary to dental infection. The characteristics and antibiotic sensitivities of Capnocytophaga are reviewed.     

Capnocytophaga species: increased resistance of clinical isolates to serum bactericidal action

Capnocytophaga, a newly recognized genus of capnophilic gram-negative bacilli, is part of the normal oral flora. The capacity of Capnocytophaga to cause sepsis and local infections in both immunocompromised and nonimmunocompromised hosts has been documented. Given the recognition that serum resistance may contribute to the virulence of some gram-negative bacteria, we attempted to define the serum sensitivity of clinical isolates of Capnocytophaga from blood and other sites of infection. Whereas nine of nine isolates from human subgingival plaque showed greater than 95% loss of viability under standardized assay conditions, nonoral isolates exhibited variable serum sensitivity. Six of six isolates from blood showed considerable serum resistance (mean survival, 59.7% +/- 38.3%; range, 14.4%-113.3%). Comparison of the electrophoretic mobilities of lipopolysaccharides (LPSs) from sensitive and resistant strains revealed reduced LPS heterogeneity and lower apparent molecular weight among serum-resistant strains. Thus, serum resistance, possibly influenced by LPS structure, may be an important factor contributing to the pathogenic potential of Capnocytophaga spp.     

Capnocytophaga bacteremia in a patient with Hodgkin's disease following bone marrow transplantation: case report and review.

Capnocytophaga is a gram-negative, capnophilic, facultatively anaerobic bacillus that normally inhabits the oral cavity. We report the case of a patient who developed capnocytophaga bacteremia following autologous bone marrow transplantation for Hodgkin's disease, and we review other reported cases of capnocytophaga bacteremia in immunocompromised patients. In our case infection followed pretransplantation conditioning and was associated with severe oral mucositis and neutropenia. Antibiotic therapy resulted in clinical resolution of infection. Capnocytophaga bacteremia should be included in the differential diagnosis of febrile neutropenia in immunocompromised patients (e.g., those undergoing bone marrow transplantation) especially in the presence of mucositis and gingival bleeding.     

Clinical and prognostic categorization of extraintestinal nontyphoidal Salmonella infections in infants and children.

The study included 172 patients, aged 0-15 years, for whom at least 1 nonfecal, nonurinary specimen was culture-positive for nontyphoidal Salmonella. Ninety-five percent had positive blood cultures. Immunocompromising diseases were found in 19% of 74 infants and 77% of 98 children. Associations between the study factors and outcomes, as localized infection or death, were assessed by logistic regression analysis. Thirty-three patients had localized infections. An adjusted risk factor for development of localized infections was an age of <12 months (P=.003). There were 17 deaths. The case-fatality rates were 43% and 10% for immunocompromised and 5% and 0% for nonimmunocompromised infants and children, respectively. Adjusted risk factors for death were age of <12 months (P=.006), inappropriate antimicrobial therapy (P=.014), meningitis or culture-proven pneumonia due to nontyphoidal Salmonella (P=.004), and immunocompromised status (P<.001). The clinical courses and prognoses for infants and children with extraintestinal infection due to nontyphoidal Salmonella can be categorized into 4 groups according to the characteristics of age (infants vs. children) and host status (immunocompromised vs. nonimmunocompromised).     

Bacteremia due to Fusobacterium species

Twenty-six patients were identified as having bacteremia with Fusobacterium species over a five-year period at Boston City Hospital. They represented 0.9 percent of bacteremic patients and were equally divided as to sex. Bacteremia with Fusobacterium occurred primarily in young adults and in patients over 60 years of age and was not observed in children. In 16 patients (62 percent), Fusobacterium was the only blood culture isolate. The most common primary foci of infection were the female genital tract, the upper respiratory tract, the oral cavity, and the lower respiratory tract. Five patients had primary foci of infection that were initially occult. Three of these patients were found to have unappreciated oral and pharyngeal lesions, and one had a liver abscess; no primary infection was established in the remaining patient. Shock related to bacteremia developed in six patients (23 percent), four of whom had Fusobacterium species as the only blood culture isolate. Death occurred in three patients (12 percent), all of whom were over 60 years old. Metastatic infection occurred in only one patient in whom hematogenous osteomyelitis developed. Postpartum fusobacterial bacteremia was uniformly benign. Evaluation of bacteremia with Fusobacterium species in nonpostpartum patients, without an overt focus of infection, should be directed to a search for occult abscess, especially of the upper respiratory tract and oral cavity.     

Rhodococcus equi infections in immunocompetent hosts: case report and review.

Rhodococcus equi is an unusual cause of infection in humans. Infection in immunocompetent patients is extremely rare-only 19 cases in immunocompetent hosts have been reported. Localized infections represent nearly 50% of reported cases. Pulmonary infections account for only 42% of infections in immunocompetent hosts, compared with 84% of infections in immunocompromised hosts. The mortality rate among immunocompetent patients is approximately 11%, compared with rates of 50%-55% among human immunodeficiency virus (HIV)-infected patients and 20%-25% among non-HIV-infected immunocompromised patients. Treatment of infections in immunocompetent hosts depends on the site of infection. Serious infections need to be treated with combinations of parenteral antibiotics, followed by combinations of oral antibiotics. Surgical treatment is necessary for certain types of local infections. We report a pulmonary infection due to R. equi in an immunocompetent patient, and we review all reported cases of R. equi infection in immunocompetent hosts.     

Pulmonary cryptococcosis in nonimmunocompromised patients

BACKGROUND: Cryptococcus neoformans can cause serious systemic infections requiring systemic antifungal therapy in immunocompromised hosts. However, isolated pulmonary cryptococcosis in nonimmunocompromised hosts has been reported to resolve spontaneously without treatment. STUDY OBJECTIVE:s: To determine the role of antifungal therapy in the management of isolated pulmonary cryptococcosis in nonimmunocompromised hosts. DESIGN: Retrospective study. SETTING: Tertiary care, referral medical center PATIENTS: Thirty-six nonimmunocompromised subjects with isolated pulmonary cryptococcosis who received diagnoses at the Mayo Clinic (Rochester, MN) from 1976 to 2001. INTERVENTIONS: None. Measurements and results: Of 42 nonimmunocompromised subjects with cryptococcal infections, 36 (86%) had isolated pulmonary cryptococcosis. The mean (+/- SD) age of these 36 patients was 61 +/- 15 years (range, 14 to 88 years), and the groups included 17 men (47%) and 19 women (53%). Twenty-four patients (67%) were symptomatic, and 12 patients (33%) were asymptomatic. The most common presenting symptoms were cough, dyspnea, and fever. Cultures of sputum and bronchial washings most commonly yielded the diagnosis. Cerebrospinal fluid examination was performed in 11 patients (31%) and was negative in all of them. Follow-up information was available on 25 patients (69%) with a median duration of 19 months (range, 1 to 330 months). Twenty-three of these patients (92%) had resolution of their disease (no treatment, 8 patients; surgical resection only, 6 patients; and antifungal therapy, 9 patients). The condition of the two remaining patients had improved. There was no documented treatment failure, relapse, dissemination, or death in any of these 25 patients. CONCLUSIONS: Our findings suggest that an initial period of observation without the administration of antifungal therapy is a reasonable option for nonimmunocompromised subjects with pulmonary cryptococcosis in the absence of systemic symptoms or evidence of dissemination, as well as after surgical resection for focal cryptococcal pneumonia.     

Pseudomonas aeruginosa bacteremia associated with hematologic disorders [I]. Predisposing factors and clinical manifestations

We experienced 57 episodes of Pseudomonas aeruginosa bacteremia in 55 patients with hematologic disorders in a 16-year period. Ninety-five percent of the patients had hematologic malignancies such as acute leukemia. All but one patient received cytotoxic or immunosuppressive therapy at or prior to the onset of bacteremia. Seventy-seven percent of the episodes occurred during profound granulocytopenia of below 100/mm3. All the patients acquired their infection in the hospital, and 96% had received antibiotic therapy during the preceding two weeks. Periodontal, anorectal, lower respiratory tract, and urogenital infections were the sources of bacteremia in about three-quarters of the episodes. Periodontal infection tended to progress to cellulitis of the face or the floor of the mouth, often resulting in bacteremia of the unimicrobial type, while anorectal infection predisposed to abscess formation, frequently leading to bacteremia of the polymicrobial type. Cellulitis at onset was seen in 35% of the episodes. Most sites of infection did not become apparent until one to three days after the onset of fever, probably because of depressed inflammatory response associated with severe granulocytopenia. The majority of patients complained of gastrointestinal symptoms such as nausea and vomiting, abdominal pain, diarrhea, and abdominal fullness at the onset of bacteremia. Major complications included bacteremic shock (63%), impaired consciousness (25%), ecthyma gangrenosum or hemorrhagic gangrenous cellulitis (18%), and jaundice (12%). Furthermore, there were one case each of endocarditis and disseminated intravascular coagulation. It was thus suggested that the clinical picture of P. aeruginosa bacteremia complicating hematologic disorders is influenced by the predisposing conditions associated with the underlying diseases and their treatment.     

Primary cytomegalovirus infection and gastric ulcers in normal host

Summary A 42-year-old woman presented with epigastric pain and vomiting. Upper gastrointestinal endoscopy revealed three gastric ulcers. Histologic examination of biopsies from the ulcers showed cytomegalovirus inclusion bodies. The appearance of IgM antibodies to cytomegalovirus indicated a recent and primary infection. Stored serum from her last pregnancy 17 months previously contained no cytomegalovirus antibodies. A thorough evaluation of her immune system revealed no abnormality. We are aware of only two other cases where seroconversion was documented in normal hosts. Cytomegalovirus infections in the gastrointestinal tract of normal hosts are very unusual but a common cause of morbidity in immunocompromised hosts. We believe that cytomegalovirus may have a role in the pathogenesis of gastrointestinal lesions in nonimmunocompromised patients.     

Sternotomy infections with Mycoplasma hominis

Mycoplasma hominis caused sternal wound infections with mediastinitis in three patients. One infection occurred in a nonimmunocompromised man after coronary artery bypass grafting. The wound did not heal after repeated debridement, closed irrigation of the mediastinum with povidone-iodine solution, and antimycoplasmal chemotherapy; muscle flap grafting was eventually required. Two infections occurred in recipients of heart-lung transplants after the isolation of mycoplasma from bronchial secretions. Although no Mycoplasma species were isolated after specific antimycoplasmal therapy was begun, the wounds still did not heal. Both patients died of other complications. Infection of wounds after sternotomy is another of an increasing number of infections caused by M. hominis in the normal and immunocompromised host. Familiarity with the morphologic characteristics of M. hominis on bacteriologic culture media may increase the recognition of this pathogen in atypical clinical settings.     

Bacterial infections in adult patients with the acquired immune deficiency syndrome (AIDS) and AIDS-related complex

Sixty-four episodes of bacterial infection were identified over a 44-month period in 16 of 28 patients with the acquired immune deficiency syndrome (AIDS) and 14 of 31 patients with AIDS-related complex. Nineteen of the 30 infected patients were parenteral drug abusers, 10 were from Caribbean Islands and had no identified risk factor, and one was a homosexual male. Fourteen patients had 21 episodes of community-acquired pneumonia: Streptococcus pneumoniae (10), Haemophilus influenzae (three), other Haemophilus species (three), group B beta-hemolytic streptococci (one), Staphylococcus aureus (one), Branhamella catarrhalis (one), Legionella pneumophila (one), and Mycoplasma pneumoniae (one). Seven patients had eight episodes of nosocomial pneumonia caused by gram-negative bacilli. Twenty-five episodes of community-acquired bacteremia and nine episodes of nosocomial bacteremia were associated with specific sites of infection. Other infections included meningitis (two), urinary tract infection (one), and abscesses involving subcutaneous and deep tissues (12). Sixteen patients had recurrent infections; 11 of these had or eventually had AIDS. Community-acquired bacterial infections in patients with AIDS or AIDS-related complex are common and may be recurrent but have low fatality rates. In comparison, nosocomial bacterial infections occur primarily in patients with AIDS and have high fatality rates.     

Infections due to Lancefield group C streptococci

Our experience with group C streptococcal infection over the past 15 years demonstrates an important and emerging role for this hemolytic organism as an opportunistic and nosocomial pathogen. Significant risk factors in this predominantly male population included chronic cardiopulmonary disease, diabetes, malignancy, and alcoholism. Bacteremia occurred in 74% of cases seen in our series. Nosocomial acquisition of infection was observed in 26%, and infection was frequently polymicrobial in nature with gram-negative enteric bacilli isolated most commonly along with group C streptococci. We observed a broad spectrum of infections including puerperal sepsis, pleuropulmonary infections, skin and soft-tissue infection, central nervous system infection, endocarditis, urinary tract infection, and pharyngeal infections. Several cases of bacteremia of unknown source were observed in neutropenic patients with underlying leukemia. New syndromes of infection due to group C streptococci observed in our series included intra-abdominal abscess, epidural abscess, and dialysis-associated infection. Response to therapy and outcome was related to the underlying disease. While the literature suggests that patients with group C endocarditis respond better to synergistic penicillin-aminoglycoside regimens, patient numbers are too small to draw definite conclusions. The clinical significance of antibiotic tolerant group C streptococci remains uncertain. In patients with serious group C infections including endocarditis, meningitis, septic arthritis, or bacteremia in neutropenic hosts, we advocate the initial use of cell-wall-acting agents in combination with an aminoglycoside.     

Persistent fever after recovery from granulocytopenia in acute leukemia

We reviewed the hospital admissions of 168 patients with acute leukemia to determine the incidence of persistent fever following recovery from chemotherapy-induced granulocytopenia. This phenomenon was observed during 26 (15.5%) hospital admissions. The microbiologically and/or clinically documented causes identified in 23 instances included viral infection (two patients), perirectal abscess (two patients), Hickman catheter-related bacteremia (two patients), intraabdominal infection (four patients), and nine fungal infections (five resolving pneumonia, one disseminated candidiasis, three focal hepatic and/or splenic mycosis). One patient had both cholecystitis and a pneumonia of uncertain origin and three patients had drug reactions. Although overall the source of fever was usually readily apparent, focal hepatic and/or splenic mycosis produced protracted fevers that were difficult to diagnose. Visceral fungal infection should be a leading diagnostic consideration in patients with leukemia who remain persistently febrile following recovery from chemotherapy-induced granulocytopenia.     

Invasive non-typhoidal salmonellosis in immunocompetent infants and children.

OBJECTIVE: To investigate the extraintestinal manifestations of non-typhoidal Salmonellae (NTS) infection in immunocompetent infants and children. METHOD: The study took place at the University General Hospital at Heraklion, Crete. Over a 10-year period from 1993-2002 we studied 1087 patients, of whom 443 were children less than 14 years old, with a culture-proven diagnosis of NTS infection. Stool and blood cultures were routinely obtained in patients presenting with fever and diarrhea. The cases of invasive infection in otherwise well children, including bacteremia and/or extraintestinal focal infections were further analyzed. RESULTS: Invasive cases were less common in children than adults (4.06% vs. 8.7%; relative risk 0.467; 95% confidence intervals (CI) 0.279-0.784; p=0.0033). Furthermore, invasive cases were much less common in the otherwise well than in immunocompromised children (3.5% vs. 21.4%; relative risk 0.163; 95% CI 0.053-0.500; p=0.0008). The 15 otherwise well children with invasive NTS infection were aged from 3 weeks to 7.5 years, and nine were aged less than 12 months. Among them, 11 presented with bacteremia, and four with focal extraintestinal infections (rectal abscess, deep neck abscess, urinary tract infection, elbow arthritis). Salmonella enterica subsp. enterica serovars Enteritidis and Virchow were the most common invasive serotypes. All invasive strains were susceptible to beta-lactams including ampicillin, and to cotrimoxazole. All patients made a complete recovery with intravenous antibiotics and did not present with relapses or major infections during long-term follow-up. CONCLUSION: Invasive non-typhoidal salmonellosis in immunocompetent children is less frequent than in both immunocompromised children and in adulthood. However, invasive cases may well occur in otherwise healthy children, especially during infancy. In these patients, prompt appropriate treatment leads to favorable outcomes.     

Nosocomial infection after lung surgery: incidence and risk factors

STUDY OBJECTIVES: To assess the incidence and risk factors for nosocomial infection after lung surgery. DESIGN: Prospective cohort study. SETTING: Service of thoracic surgery of an acute-care teaching hospital in Santander, Spain. PATIENTS: Between June 1, 1999, and January 31, 2001, all consecutive patients undergoing lung surgery were prospectively followed up for 1 month after discharge from the hospital to assess the development of nosocomial infection, the primary outcome of the study. INTERVENTIONS: During the hospitalization period, patients were visited on a daily basis. Postdischarge surveillance was based on visits to the surgeon. MEASUREMENTS AND RESULTS: We studied 295 patients (84% men; mean age, 60.9 years), 89% of whom underwent resection operations. Ninety episodes of nosocomial infection were diagnosed in 76 patients, including pneumonia (n = 10), lower respiratory tract infection (n = 47), wound infection (n = 16; one third were detected after hospital discharge), urinary tract infection (n = 9), and bacteremia (n = 8; three fourths were catheter-related bacteremia). Twenty patients had severe infections (pneumonia or empyema), with a mortality rate of 60%. COPD (adjusted odds ratio [OR], 2.70; 95% confidence interval [CI], 1.52 to 4.84), duration of surgery with an increased risk for each additional minute (Mantel-Haenzel chi(2) test for trend, p = 0.037), and ICU admission (OR, 3.69; 95% CI, 1.94 to 7.06) were independent risk factors for nosocomial infection. The use of an epidural catheter was a protective factor (OR, 0.45; 95% CI, 0.22 to 0.95). There were no differences according to the use of amoxicillin/clavulanate or cefotaxime for surgical prophylaxis. CONCLUSIONS: Nosocomial infections are common after lung surgery. One third of wound infections were detected after hospital discharge. The profile of a high-risk patient includes COPD as underlying disease, prolonged operative time, and postoperative ICU admission.     

Early infections in adult patients undergoing unrelated donor cord blood transplantation

Early transplant-related mortality after cord blood transplantation from unrelated donors (UD-CBT) is close to 50%, mainly due to infectious complications. We have studied the incidence and characteristics of early infections (before day 100) in a series of 27 adult patients (median age 30 years, range 16-46) undergoing UD-CBT at a single institution. All 27 patients experienced at least one infectious episode and 18 (66%) suffered a severe infection. Bacteremia occurred in 55% of patients (13 with Gram-positive and 11 with Gram-negative microorganisms). Eleven of 19 CMV-seropositive patients (58%) developed CMV antigenemia and one patient had CMV disease. Fungal infections were documented in three patients (11%), comprising invasive fungal infections in two cases and a localized esophagitis in one. Ten patients (37%) died before day 100 after transplantation. Infection was considered the primary cause of death in four patients (sepsis by Acinetobacter spp. bacteremia in three cases) and contributed to death in another four. The most striking findings in this series were the high incidence of, and mortality due to multiresistant Acinetobacter spp. and the low incidence of and lack of mortality due to CMV disease. This report confirms that infection is a major complication in adults undergoing UD-CBT.     

Culture-negative Capnocytophaga canimorsus meningitis diagnosed by 16s ribosomal RNA polymerase chain reaction in an immunocompetent veterinarian and a review of the literature

Capnocytophaga canimorsus is a fastidious, capnophilic and facultative anaerobic Gram-negative rod found commonly in the oral flora of dogs that may cause zoonotic infections such as cellulitis and eye infections. In immunocompromised patients, it may cause fulminant sepsis. Meningitis due to C. canimorsus is, however, a rare manifestation. This is the first reported case of C. canimorsus meningitis in Australia in an immunocompetent veterinarian diagnosed by 16s ribosomal RNA polymerase chain reaction.     

Salmonella arizonae bacteremia as the presenting manifestation of human immunodeficiency virus infection following rattlesnake meat ingestion

Recurrent nontyphoid salmonella septicemia is one of the opportunistic infections characteristic of AIDS. The increased incidence of severe salmonellosis in immunocompromised patients is due, in part, to defective cellular immunity. The literature contains reports of nine cases of extraintestinal Salmonella arizonae infections in patients ingesting rattlesnake capsules, all of whom had known underlying medical illnesses. We describe a previously healthy Hispanic man who developed S. arizonae bacteremia as his initial manifestation of infection with the human immunodeficiency virus (HIV). The patient ultimately stated that he had consumed rattlesnake meat for medicinal purposes--a relatively common practice among Hispanics. S. arizonae was cultured from the powder of all capsules remaining in his possession. To our knowledge, this represents the first reported case of S. arizonae bacteremia as the presenting manifestation of HIV infection following the ingestion of capsules containing rattlesnake meat.     

Polymicrobial bacteremia: clinical and microbiologic patterns

Between 1971 and 1987, 97 patients with polymicrobial bacteremia (PMB) were seen by a consulting infectious disease service. Seventy-four had severe underlying illnesses, and infection was hospital acquired in 80. PMB resulted from intraabdominal, urinary tract, or soft tissue infection in 45 patients, but a wide range of sources were implicated in the rest. Eleven patients had more than one source for the bacteremia, and, despite intensive diagnostic efforts, 24 had no identifiable source for at least one blood isolate. Bacteremia due to gram-negative bacilli most commonly occurred in intraabdominal, urinary tract, and wound infections; Escherichia coli and Klebsiella species were most frequently isolated. Streptococcus faecalis and Staphylococcus aureus were the predominant gram-positive isolates. Certain bacterial combinations seemed to provide a clue for predicting the source of PMB: for example, S. aureus together with gram-negative facultative rods usually arose from a skin or soft tissue source, whereas S. faecalis together with a gram-negative bacillus could often be traced to an intraabdominal infection. No unique clinical features appeared to predict the occurrence of bacteremia due to multiple rather than to a single organism. The mortality in patients was 21%, lower than has previously been described in PMB but similar to that reported for bacteremia due to a single organism.     

Pasteurella multocida infections. Report of 34 cases and review of the literature

Pasteurella multocida, a small, gram-negative coccobacillus , is part of the normal oral flora of many animals, including the dog and cat. P. multocida is the etiologic agent in a variety of infectious disease syndromes. We have reported 34 cases of infection caused by P. multocida and have reviewed the English literature. P. multocida infections may be divided into three broad groups: 1. Infections resulting from animal bites and scratches : The most common infections caused by P. multocida are local wound infections following animal bites or scratches . Cats are the source of infection in 60 to 80% of cases and dogs in the great majority of the remainder. Local infections are characterized by the rapid appearance of erythema, warmth, tenderness, and frequently purulent drainage. The most common local complications are abscess formation and tenosynovitis. Serious local complications include septic arthritis proximal to bites or scratches , osteomyelitis resulting from direct inoculation or extension of cellulitis, and the combination of septic arthritis and osteomyelitis, most commonly involving a finger or hand after a cat bite. 2. Isolation of P. multocida from the respiratory tract: The isolation of P. multocida from the respiratory tract must be interpreted differently than its isolation from other systemic sites. Most commonly P. multocida found in the respiratory tract is a commensal organism in patients with underlying pulmonary disease, but serious respiratory tract infections including pneumonia, empyema, and lung abscesses may develop. Most patients with respiratory tract colonization or infection have a history of animal exposure. 3. Other systemic infections: P. multocida is recognized as a pathogen in a variety of systemic infections including bacteremia, meningitis, brain abscess, spontaneous bacterial peritonitis, and intra-abdominal abscess. P. multocida often acts as an opportunistic pathogen with a predilection for causing bacteremia in patients with liver dysfunction, septic arthritis in damaged joints, meningitis in the very young or elderly, and pulmonary colonization or invasion in patients with underlying respiratory tract abnormalities.(ABSTRACT TRUNCATED AT 400 WORDS)