Group G streptococcal bacteremia. The clinical experience at Boston University Medical Center and a critical review of the literature

Twenty-six patients with bacteremia caused by group G streptococci were seen during a 29-month period. Our findings suggest that the epidemiology of these infections has not changed appreciably during the last 15 years. The disease occurs most commonly as an acute community-acquired infection in older persons with underlying conditions predisposing to skin breakdown. Patients with these bacteremias fall into three categories: those with associated cutaneous infection only; those with serious focal infection; and those with probable infection. Underlying neoplastic conditions were relatively uncommon (25%) in our series compared with others (65%). In contrast to recent reports emphasizing this complication, endocarditis was uncommon in our patients. A prompt response to therapy with beta-lactam antibiotics occurred in most of our patients.     

Bacteremia in narcotic addicts at the Detroit Medical Center. II. Infectious endocarditis: a prospective comparative study

For one year all narcotic addicts admitted to the Detroit Medical Center with infectious endocarditis (74 cases) were compared with a control group of bacteremic addicts who had other infections (106 cases). Endocarditis was caused by Staphylococcus aureus (60.8% of cases), streptococci (16.2%), Pseudomonas aeruginosa (13.5%), mixed bacteria (8.1%), and Corynebacterium JK (1.4%). S. aureus endocarditis most frequently involved the tricuspid valve; streptococci infected left-sided valves significantly more often than other organisms (P = .001). Biventricular and multiple-valve infections were commonest in patients with pseudomonas endocarditis (P = .05). Two-dimensional echocardiography, when combined with an abnormal chest roentgenogram, was highly predictive of endocarditis. Bacteremia in the absence of endocarditis was associated with primary skin and soft tissue infection, mycotic aneurysm at the site of narcotic injection, septic arthritis, septic thrombophlebitis, pneumonia, osteomyelitis, mediastinal abscess, and unclassified infection. Polymicrobial bacteremia in the nonendocarditis group was associated with markedly increased morbidity. Mild hyponatremia occurred in 41% of all patients and was also associated with significantly increased morbidity. Analysis of the two groups disclosed similarities and differences with implications for the pathophysiology and treatment of addicts with bacteremic infection.     

Group C streptococcal bacteremia: analysis of 88 cases

Eighty-eight cases of group C streptococcal bacteremia were reviewed retrospectively. Most patients had underlying diseases (72.7%), predominantly cardiovascular disease (20.5%) or malignancy (20.5%). The infection originated most often from the upper respiratory tract (20.5%), the gastrointestinal tract (18.2%), or the skin (17.1%). Prior exposure to animals or animal products was reported in 23.9% of cases. The most common clinical manifestations of group C streptococcal bacteremia were endocarditis (27.3%), primary bacteremia (22.7%), and meningitis (10.2%). Of streptococcal isolates, 61.4% were not speciated, 19.3% were Streptococcus equisimilis, 17.1% were Streptococcus zooepidemicus, and two (2.3%) were Streptococcus equi. The isolates were sensitive to most antibiotics, and most patients were treated with beta-lactam agents. Mortality was high (25.0%), especially among older patients and patients with endocarditis, meningitis, and disseminated infection. Group C streptococcal bacteremia does not differ from bloodstream infection caused by other beta-hemolytic streptococci with regard to clinical presentation, treatment, or outcome.     

Mycobacterium fortuitum bacteremia in patients with cancer and long-term venous catheters

Primary bacteremia due to Mycobacterium fortuitum is an uncommon occurrence. Four cases of M. fortuitum bacteremia in patients with cancer, one of whom was neutropenic, are presented. None of the patients had evidence of disseminated disease or endocarditis, and there was no mortality directly associated with this infection. Two patients had polymicrobial sepsis with skin commensal organisms. The infection was related to the use of long-term central venous catheters or recent instrumentation in all patients. M. fortuitum should be added to the growing list of organisms causing catheter-related infections.     

Infections due to group C streptococci in man.

Although a common cause of infection in animals, group C streptococci are rarely noted to be pathogenic in man. A total of 150,000 blood cultures obtained at the Mayo Clinic from 1968 to 1977 revealed group C streptococci in only eight patients. Acute bacterial endocarditis, meningitis, pheumonia, cellulitis and bacteremia due to group C streptococci are described in a host who had undergone immunosuppression (immunosuppressed host), and the relatively few cases previously reported are reviewed. Although severe, these infections may respond favorably to penicillin therapy. Endocarditis caused by group D streptococci is acute and destructive, and associated with early cardiac decompensation. The manifestations of cellulitis and pneumonia are similar to those when group A streptococci are causative organisms. Meningitis due to group C streptococci is acute and severe, and responds slowly to antimicrobial therapy. Colonization also occurs.     

Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia due to a linezolid "tolerant" strain

Persistent Staphylococcus aureus bacteremia is most frequently related to S. aureus acute bacterial endocarditis, myocardial abscess, extracardiac abscess, or a device-associated infection. Patients with continuous high-grade bacteremia who do not have acute bacterial endocarditis, an abscess, or a device-related infection should be considered to have antimicrobial "tolerance" as a possible cause. Antimicrobial "tolerance" is defined as a wide discrepancy between the minimal inhibitory concentration and the minimal bactericidal concentration of an isolate. Tolerance was first described in S. aureus and has since been described with streptococci and enterococci. Despite apparent in vitro susceptibility, infections caused by "tolerant" strains are not cured by appropriate antimicrobial therapy. The lack of bactericidal activity of the antibiotic becomes apparent when minimal bactericidal concentrations are determined for "tolerant" strains, and there is a great discrepancy between the minimal inhibitory concentration being used. Antibiotic tolerance to S. aureus has been described with a variety of antibiotics. To the best of our knowledge, this is the first case of continuous, high-grade methicillin-resistant S. aureus bacteremia due to a linezolid-tolerant strain.     

Targeted bacteremia surveillance throughout a year--comparison of community-acquired and hospital-acquired infection

To keep an eye on severe nosocomial infection and to evaluate the clinical difference of blood-stream infection between community-acquired and hospital-acquired infection, a survey of blood culture was performed in National Tokyo Medical Center from the period between November 2000 and October 2001. There were 252 episodes detected in 219 patients (80 community-acquired episodes in 80 patients and 172 hospital-acquired episodes in 139 patients). The three most common foci of infection/pathogens were as follows: in the community-acquired cases; urinary tract, pneumonia, infective endocarditis/Escherichia coli, viridant group of streptococci, Streptococcus pneumoniae, and in the hospital-acquired cases; intra-venous catheter, urinary tract, neutropenia-related bacteremia/Staphylococcus aureus, coagulase negative Staphylococcus, Enterococcus. Fifteen patients with community-acquired bacteremia and 37 patients with hospital-acquired bacteremia had been died within a month of the episode; the mortality was not significantly different between the both. The average of peak serum concentrations of C-reactive protein during the episodes of community-acquired bacteremia was higher than that of hospital-acquired bacteremia. These findings probably show that life threatening bloodstream infections seemed to be more common in the community. The rate of nosocomial bacteremia was approximately 1%, and no outbreak was observed during the period. Targeted bacteremia surveillance is maybe useful and efficient method to detect severe hospital-acquired infections.     

Group C beta-hemolytic streptococcal infections in children: nine pediatric cases and review

Streptococci of Lancefield group C colonize healthy individuals but infrequently cause invasive disease. Eight pediatric cases of infection due to group C streptococci were identified in a retrospective survey of a recent 6-year period at a children's hospital. An additional case of group C meningitis diagnosed in 1975 was included. These nine cases and 22 pediatric cases from the literature are presented to illustrate important points with respect to clinical presentations and complications and to show that these organisms can cause serious, sometimes fatal infection: pneumonitis, sinusitis, septicemia, endocarditis, osteomyelitis, and meningitis. Group C streptococci are described in terms of their biochemical properties, the infections they cause in animals, and their tendency to produce disease in humans. With increasingly frequent serologic grouping of non-group A beta-hemolytic streptococci, recognition of the role of specific non-group A streptococci is likely to increase. The antimicrobial agent of choice for infections due to group C streptococci is penicillin G. The minimum inhibitory and minimum bactericidal concentrations for the organism should be determined since penicillin tolerance may occur and may be responsible for the slow response to penicillin therapy in some cases.     

Enterococcal bacteremia: clinical features, the risk of endocarditis, and management

The enterococci, members of the group D streptococci and the predominant aerobic streptococci of the gastrointestinal and female genital tracts, have long been recognized as significant pathogens in infective endocarditis. Over the past 2 decades, enterococci have become increasingly important nosocomial pathogens, related to their intrinsic resistance to many antibiotics, especially the cephalosporins, and the greatly increased use of antimicrobial therapy in hospitals. Recent reports have documented an alarming increase in the frequency of high-level resistance to aminoglyclosides, and strains resistant to ampicillin by production of a beta-lactamase and to vancomycin have now been encountered. We have reviewed the clinical features and course of 153 cases of enterococcal bacteremia occurring in a university hospital over the 14-year period, 1970 to 1983, 1) to understand better the importance of enterococci as human pathogens, 2) to identify the clinical features of enterococcal bacteremia, 3) to isolate those findings that help to identify associated endocarditis, and 4) to develop guidelines for more effective antimicrobial therapy of bacteremic enterococcal infections. The annual incidence of enterococcal bacteremia in our center rose three-fold over the period reviewed. In 65 cases (42%), bacteremia was polymicrobial, caused by Enterococcus and at least 1 other microorganism, usually an aerobic gram-negative bacillus. Most bacteremias were nosocomial and derived from infections of the urinary tract (29 cases), intravenous catheters (24 cases), intra-abdominal infections or surgical wounds (46 cases), burn wounds (25 cases), or cholangitis (21 cases); only 1 case originated from a pneumonia. Endocarditis was identified in association with 12 of 35 community-acquired bacteremias, but only 1 of 118 bacteremias acquired in the hospital (P less than .001). Endocarditis was also significantly associated with pre-existent valvular heart disease and cryptogenic bacteremia, and was negatively associated with polymicrobial enterococcal bacteremia (no endocarditis in 65 cases, P less than .001). Isolated enterococcal bacteremia produced an indolent infection rarely associated with shock (3 of 64 cases evaluated, all cases due to valve destruction by endocarditis); conversely, with polymicrobial enterococcal bacteremia, primarily with gram-negative bacilli, shock or disseminated intravascular coagulation developed in 50% of cases (P less than .001).(ABSTRACT TRUNCATED AT 400 WORDS)     

Listeriosis in patients infected with human immunodeficiency virus

Although resistance to Listeria monocytogenes infection requires intact T cell-mediated immunity, only 20 patients with human immunodeficiency virus (HIV) infection and listeriosis (including one patient described herein) have been reported to date. Listeriosis developed before AIDS in five cases. Syndromes included meningitis in nine cases, bacteremia in nine, brain abscess in one, and endocarditis in one. Eighteen patients were treated with ampicillin, penicillin, or amoxicillin with or without aminoglycosides. Clinical and microbiologic responses were obtained in one patient with bacteremia treated with vancomycin and in one patient with meningitis treated with trimethoprim-sulfamethoxazole. Three of the nine patients with meningitis died, as did the patient with brain abscess. All nine patients with bacteremia and the patient with endocarditis survived. No case of relapse was documented. L. monocytogenes, although uncommon, should be considered in the differential diagnosis of febrile illness, meningitis, and brain abscess in patients with HIV infection.     

Invasive Haemophilus influenzae disease in adults

In a five-year period, 29 cases of bacteremia and/or meningitis in adults caused by Haemophilus influenzae were seen in our large community hospital. There were 17 cases of bacteremic pneumonia and 12 cases of serious extrapulmonary infections. The extrapulmonary infections included cases of endocarditis, meningitis, cholecystitis, epiglottitis, tubo-ovarian abscess, and cellulitis. In contrast with the pediatric experience, H influenzae type B was the causative pathogen in only 45% of patients and only one isolate was ampicillin resistant.     

A prospective multicenter study of Staphylococcus aureus bacteremia: incidence of endocarditis, risk factors for mortality, and clinical impact of methicillin resistance

Our objectives were to determine the incidence of endocarditis in patients whose Staphylococcus aureus bacteremia was community-acquired, related to hemodialysis, or hospital-acquired; to assess clinical factors that would reliably distinguished between S. aureus bacteremia and S. aureus endocarditis; to assess the emergence of methicillin-resistant S. aureus (MRSA) as a cause of endocarditis; and to examine risk factors for mortality in patients with S. aureus endocarditis.We conducted a prospective observational study in 6 university teaching hospitals; we evaluated 505 consecutive patients with Staphylococcus aureus bacteremia. Thirteen percent of patients with S. aureus bacteremia were found to have endocarditis, including 21% with community-acquired S. aureus bacteremia, 5% with hospital-acquired bacteremia, and 12% on hemodialysis. Infection was due to MRSA in 31%.Factors predictive of endocarditis included underlying valvular heart disease, history of prior endocarditis, intravenous drug use, community acquisition of bacteremia, and an unrecognized source. Twelve patients with bacteremia had a prosthetic valve; 17% developed endocarditis. Unexpectedly, nonwhite race proved to be an independent risk factor for endocarditis by both univariate and multivariate analyses. Persistent bacteremia (positive blood cultures at day 3 of appropriate therapy) was identified as an independent risk factor for both endocarditis and mortality, a unique observation not reported in other prospective studies of S. aureus bacteremia.Patients with endocarditis due to MRSA were significantly more likely to have complicating renal insufficiency and to experience persistent bacteremia than those with endocarditis due to MSSA. The 30-day mortality was 31% among patients with endocarditis compared to 21% in patients who had bacteremia without endocarditis (p = 0.055). Risk factors for death due to endocarditis included severity of illness at onset of bacteremia (as measured by Apache III and Pitt bacteremia score), MRSA infection, and presence of atrioventricular block on electrocardiogram.Patients with S. aureus bacteremia who have community acquisition of infection, underlying valvular heart disease, intravenous drug use, unknown portal of entry, history of prior endocarditis, and possibly, nonwhite race should undergo echocardiography to screen for the presence of endocarditis. We recommend that blood cultures be repeated 3 days following initiation of antistaphylococcal antibiotic therapy in all patients with S. aureus bacteremia. Positive blood cultures at 3 days may prove to be a useful marker in promoting more aggressive management, including more potent antibiotic therapy and surgical resection of the valve in endocarditis cases. MRSA as the infecting organism should be added to the list of risk factors for consideration of valvular resection in cases of endocarditis.     

Streptococcal meningitis in adult patients: current epidemiology and clinical spectrum.

Streptococci other than Streptococcus pneumoniae are a rare cause of bacterial meningitis in adults. We report 29 cases of streptococcal meningitis (1977-1997). The patients comprised 19 men and 10 women, with a mean age +/- standard deviation of 47 +/- 18 years. Nine cases were secondary to neurosurgical procedures, seven to brain abscess, five to cerebrospinal fluid pericranial fistula, and three to endocarditis. Causative microorganisms included the following: viridans group streptococci, 20 cases; anaerobic streptococci, 3; Streptococcus agalactiae, 3; Streptococcus bovis, 2; and Streptococcus pyogenes, 1. Four Streptococcus mitis strains showed decreased susceptibility to penicillin (MIC, 0.5-2 microg/mL). Five patients (17%) died. The infection is increasing in the hospital setting. Streptococci resistant to penicillin should be considered in the empirical treatment of nosocomial meningitis. In cases of community-acquired infection, anaerobic streptococci or streptococci of the Streptococcus milleri group should alert the clinician to the presence of an undiagnosed brain abscess, whereas oral streptococci of the viridans group suggest the diagnosis of bacterial endocarditis.     

Extra-abdominal infections due to Gemella species.

OBJECTIVES: To understand the role of Gemella species as a pathogen causing extra-abdominal infections in the Hospital General Universitario Gregorio Mara?ón. MATERIALS AND METHODS: Between 1994 and 1998, one or more isolates of Gemella sp. were found in 128 patients. The 113 patients with isolates from nonsignificant specimens or representing intra-abdominal infections were excluded. The clinical records of the remaining 15 patients were reviewed as well as the more recent literature. RESULTS: Mean age of patients was 41 years. The underlying conditions most frequently noted were intravenous drug users (n=6; 3 positive for human immunodeficiency virus), alcoholism (n=2), cardiovascular disease (n=2), chronic lung disease (n=2), diabetes (n=1), kidney transplant (n=1). The extra-abdominal infections were skin and soft tissue abscess (n=5), empyema (n=4), brain abscess (n=2), primary bacteremia (n=1), lung abscess (n=1), septic thrombophlebitis (n=1), complicated urinary tract infection (n=1). The infection was monomicrobial in six and polymicrobial in nine cases. Surgical drainage and betalactam antibiotics were used. The outcome was favorable in almost all cases. CONCLUSIONS: Gemella sp. should be included as a cause of localized soft-tissue abscesses, empyema, and bloodstream infection. No case of infective endocarditis was found. Although it is susceptible to several antibiotics, Gemella sp. requires a careful microbiologic diagnosis and a subtle clinical interpretation.     

Infections due to Lancefield group G streptococci

The group G streptococcus has surfaced in the past 10 to 15 years as an important opportunistic and nosocomial pathogen. Although more precise organism recognition accounts for a portion of these cases, there can be little doubt that the group G streptococcus has become a more prevalent pathogen. Commercial kits, utilizing staphylococcal coagglutination or latex agglutination, are now available, affording all clinical laboratories the opportunity to identify this organism easily. Published reviews encompassing the experiences of a single institution or even several institutions affiliated with a single medical center, particularly as they were influenced by referral patterns, did not reflect the broad scope of infections that we discovered by extending our survey into the community, beyond the medical center complex and its immediate affiliated hospitals. Although malignancy is the single most obvious background factor, alcoholism and diabetes are also important host determinants of infection. Skin and soft-tissue infections (and surface sources of infection) are equally important among patients with or without the element of malignancy. Polymicrobial infection, including polymicrobial bacteremia, is an important feature, with S. aureus infections accounting for most of these cases, relating to the skin and soft tissue sources of infections so commonly seen. We saw a panorama of problems including endocarditis, septic arthritis, pleuropulmonary infections, bone and joint infections, puerperal sepsis and neonatal infection, peritonitis and ophthalmitis; we also saw a significant number of patients with bacteremia and no apparent primary source of infection. Response to antibiotic therapy was dictated by the nature of the underlying diseases, and individuals without a background of malignant disease did well, particularly those with skin and soft-tissue infections. While the literature suggests that patients with endocarditis and septic arthritis due to this organism respond poorly to antibiotic therapy, implying that such failures relate to in vitro antibiotic phenomena, we preferred to examine the problem from the viewpoint of the host(s) involved. Subacute endocarditis and acute endocarditis due to the group G streptococcus may be clinically separable, and thus require separate therapeutic approaches. In patients with septic arthritis, prosthetic devices, prior joint disease and immunosuppressive diseases and therapy often adversely influence the response to antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)     

Extra-intestinal manifestations of salmonella infections

While salmonellosis is often considered to affect primarily the gastrointestinal tract, infection at other sites may occur, producing characteristic clinical syndromes. We reviewed cases from our institutions and the literature on focal manifestations of salmonella infections. In the past, most extra-intestinal salmonella infections were caused by S. choleraesuis; however, we found S. typhimurium to be the predominant serotype. The mortality rate for patients in our series was considerably lower than the rate described for focal infections in other reviews. This may in part be due to lower proportion of infections due to S. choleraesuis, improved microbiologic and diagnostic techniques, increased use of ampicillin, and improved surgical techniques. Salmonella endocarditis usually occurs in patients with preexisting heart disease. Unlike other salmonella infections, S. choleraesuis is the most frequent serotype. Salmonella endocarditis is often very destructive, with a fatality rate of 70%. Nonvalvular (mural) endocarditis occurs in one-fourth of patients and survival has not been reported. While antibiotic therapy should be tried initially, if response is not prompt the clinician should look for an associated site of infection (intra- or extra-cardiac abscess), which will often require surgery. Salmonella pericarditis often presents with cardiac or pulmonary symptoms, but typical signs of pericardial disease (pulsus paradoxus, friction rub) or characteristic electrocardiographic changes (low voltage, elevated ST segments) are uncommon. Early diagnosis, before infection involves other areas of the heart, is crucial for survival. In addition to antibiotic therapy, pericardiocentesis or pericardiectomy is required. Salmonella may infect the peripheral or visceral arteries, but the abdominal aorta is the most frequent site of vascular infection. Most patients are men over age 50 with preexisting atherosclerosis of the aorta who do not have a previous history of gastroenteritis. About one-fourth of patients have associated lumbar osteomyelitis. No patients have been reported to survive with medical therapy alone. Specific guidelines for surgical removal of infected aneurysms have been proposed and these (in addition to increased use of ampicillin) may be responsible for higher survival rates in recent years. Due to the high incidence of relapses, postoperative blood cultures should be done routinely. Arterial infection should be considered in any elderly patient with salmonella bacteremia especially with prolonged fever or bacteremia after an "adequate course" of antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)     

Invasive streptococcal infections in the era before the acquired immune deficiency syndrome: a 10 years' compilation of patients with streptococcal bacteraemia in North Yorkshire

Significant streptococcal (non-pneumococcal, non-enterococcal) bacteraemia was detected in 100 patients in two Health Districts of North Yorkshire in the decade 1978-1988. Patients with these infections accounted for 11% of the total 902 patients in the districts in whom bacteraemia was diagnosed during the period. Infection was most often seen with beta-haemolytic streptococci (52 patients) comprising Lancefield group A (Streptococcus pyogenes) (20 patients), group B (13), group C (5), group G (9), haemolytic Streptococcus milleri and non-groupable streptococci (5). The wide variety of serious infections included cellulitis, abscess, septicaemia, pneumonia, septic arthritis, necrotising fasciitis, acute endocarditis and mycotic aneurysm. Of these 52 patients, 21 (40%) died. alpha-Haemolytic streptococcal bacteraemia was diagnosed in 38 patients of whom 24 (63%) suffered from endocarditis and three (8%) died. Three of ten patients with non-haemolytic or anaerobic streptococcal bacteraemia died also. Six of the 100 patients with streptococcal bacteraemia had concomitant acute virus infections. Of the total 56 patients with infective endocarditis diagnosed in the districts during the period, streptococci were responsible in 30 (54%) of them. The predisposing factors, clinical features and outcome of the infections are described and discussed.     

Clinical and bacterial features of infections caused by Streptococcus milleri.

The clinical and bacteriological features of 51 infections due to Streptococcus milleri observed in 43 patients over a 2-year period were reviewed. Clinical syndromes included bacteremia in 6 cases, endocarditis in 4 cases, cellulitis and subcutaneous abscesses in 8 cases, pleural empyema in 8 cases, brain abscesses in 5 cases, abdominal infections in 5 cases, and other miscellaneous infections in 15 cases. An underlying condition was associated with infection in 33/43 patients (77%). S. milleri was the only pathogen isolated in 19 patients (44%). All strains of S. milleri were susceptible to penicillin. Surgery was combined with antimicrobial therapy in 27 (63%) patients. Nine patients died during hospitalization, and death was directly related to S. milleri infection in 4 patients (9%). These results confirm that S. milleri frequently causes serious suppurative infections and that species identification is a clinically useful procedure.     

Group C streptococcal endocarditis presenting as clinical meningitis: Report of a case and review of the literature

Lancefield group C streptococci are known to be pathogenic in a number of animal species, but cause human disease much less commonly than do streptococci of scrogroups A or B. Reported cases of bacteremic infection, pneumonia or meningitis in humans have been very severe with a grave prognosis. The authors describe a patient who presented with classic clinical and laboratory evidence of bacterial meningitis which proved to be a complication of endocarditis caused by a group C streptococcus. This is the first reported case in which meningitis was the presenting manifestation of group C streptococcal endocarditis and is only the second case in which group C streptococcal meningitis and endocarditis have been associated in the same patient. A total of 13 cases of group C streptococcal meningitis have now been reported in the medical literature. Five of these patients died, and four others recovered only to be left with neurological sequelae. The current case confirms the seriousness of group C streptococcal infections in humans. Such infections are associated with a poor prognosis despite apparently adequate antimicrobial therapy.