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Abstract Background M. catarrhalis is a gram-negative, gamma-proteobacterium and an opportunistic human pathogen associated with otitis media (OM) and exacerbations of chronic obstructive pulmonary disease (COPD). With direct and indirect costs for treating these conditions annually exceeding $33 billion in the United States alone, and nearly ubiquitous resistance to beta-lactam antibiotics among M. catarrhalis clinical isolates, a greater understanding of this pathogen's genome and its variability among isolates is needed. Results The genomic sequences of ten geographically and phenotypically diverse clinical isolates of M. catarrhalis were determined and analyzed together with two publicly available genomes. These twelve genomes were subjected to detailed comparative and predictive analyses aimed at characterizing the supragenome and understanding the metabolic and pathogenic potential of this species. A total of 2383 gene clusters were identified, of which 1755 are core with the remaining 628 clusters unevenly distributed among the twelve isolates. These findings are consistent with the distributed genome hypothesis (DGH), which posits that the species genome possesses a far greater number of genes than any single isolate. Multiple and pair-wise whole genome alignments highlight limited chromosomal re-arrangement. Conclusions M. catarrhalis gene content and chromosomal organization data, although supportive of the DGH, show modest overall genic diversity. These findings are in stark contrast with the reported heterogeneity of the species as a whole, as wells as to other bacterial pathogens mediating OM and COPD, providing important insight into M. catarrhalis pathogenesis that will aid in the development of novel therapeutic regimens.

Abstract Background Despite vaccination since the 1950s, pertussis has persisted and resurged. It remains a major cause of infant death worldwide and is the most prevalent vaccine-preventable disease in developed countries. The resurgence of pertussis has been associated with the expansion of Bordetella pertussis strains with a novel allele for the pertussis toxin (Ptx) promoter, ptxP3, which have replaced resident ptxP1 strains. Compared to ptxP1 strains, ptxP3 produce more Ptx resulting in increased virulence and immune suppression. To elucidate how B. pertussis has adapted to vaccination, we compared genome sequences of two ptxP3 strains with four strains isolated before and after the introduction vaccination. Results The distribution of SNPs in regions involved in transcription and translation suggested that changes in gene regulation play an important role in adaptation. No evidence was found for acquisition of novel genes. Modern strains differed significantly from prevaccination strains, both phylogenetically and with respect to particular alleles. The ptxP3 strains were found to have diverged recently from modern ptxP1 strains. Differences between ptxP3 and modern ptxP1 strains included SNPs in a number of pathogenicity-associated genes. Further, both gene inactivation and reactivation was observed in ptxP3 strains relative to modern ptxP1 strains. Conclusions Our work suggests that B. pertussis adapted by successive accumulation of SNPs and by gene (in)activation. In particular changes in gene regulation may have played a role in adaptation.

Risk factors for cytomegalovirus and severe bacterial infections were studied prospectively by univariate, multivariate and time-dependent Cox model analysis in 79 consecutive liver transplant patients treated with selective bowel decontamination. Cytomegalovirus infection occurred in 39 patients (49%) and was symptomatic in 22 patients. Twenty-six patients (33%) developed at least one of 43 documented severe bacterial infections. In a multivariate analysis of risk factors for all cytomegalovirus infections, the cytomegalovirus seronegative recipient-cytomegalovirus seropositive donor group was the highest risk group (P < 0.001). Using the same analysis for risk factors for symptomatic cytomegalovirus infections, a prolonged prothrombin time (P < 0.005), a diagnosis of acute fulminant hepatitis as the underlying liver disease (P < 0.01) and a cytomegalovirus seronegative patient receiving a liver from a seropositive donor (P < 0.001) were significant. The treatment with OKT3 therapy (P < 0.008) and hepatic artery thrombosis (P < 0.02) were found to be significant risk factors in a time-dependent univariate analysis but were not independent risk factors when multivariate analysis was utilized. Significant risk factors for major bacterial infections (P < 0.03) using univariate analysis included a prolonged anesthesia, anhepatic and surgical times, as well as the transfusion of large amounts of fresh frozen plasma or autologous blood. In a multivariate analysis, only the transfusion of large amounts of fresh frozen plasma (P < 0.04) was a significant independent risk factor. Cytomegalovirus infection was a risk factor for the development of severe bacterial infections (P < 0.03) in a multivariate time-dependent analysis.

In this study we evaluated the association between cytomegalovirus infection alone or in relation to human leukocyte antigen matching and the development of vanishing bile duct syndrome, a form of chronic hepatic allograft rejection. A total of 81 consecutive liver transplant recipients were studied. Cytomegalovirus infection developed in 46 recipients (57%), and vanishing bile duct syndrome occurred in 9 recipients (11%). Cytomegalovirus infection developed in only five of the nine patients with vanishing bile duct syndrome. Univariate analysis of pretransplant recipient/donor cytomegalovirus serological tests and human leukocyte antigen typing showed they were not significant risk factors for the development of vanishing bile duct syndrome. Time-dependent analysis of cytomegalovirus infection after transplantation as a risk factor for vanishing bile duct syndrome, in a multivariate analysis with human leukocyte antigen match, showed no statistical significance. In our study, no association was found between cytomegalovirus infection alone or in relation to class I or II human leukocyte antigen match and the subsequent development of vanishing bile duct syndrome.

Immunostaining techniques that use a monoclonal antibody against an early cytomegalovirus antigen or a polyclonal antibody, in situ DNA hybridization and inoculation of cell cultures for the detection of cytomegalovirus from liver biopsy specimens were studied in 20 liver transplant patients with cytomegalovirus hepatitis, as defined by histological criteria. A total of 108 liver biopsy specimens from 20 patients with a diagnosis of cytomegalovirus hepatitis (obtained per protocol at 7, 21, 90, and 180 days or whenever liver dysfunction occurred), which had previously been examined histologically and in cell culture, were again studied by recutting the liver tissue for histological examination, DNA hybridization and immunostaining with monoclonal or polyclonal antibodies to cytomegalovirus. In 5 of 20 patients, the diagnosis of cytomegalovirus hepatitis could have been made earlier (mean = 9.6 days) by immunostaining with a monoclonal antibody. Of 47 biopsy specimens with cytomegalovirus inclusion bodies, the sensitivity and specificity of the diagnostic procedures were immunostaining with monoclonal antibody (84% and 90%) and polyclonal antibody (72% and 97%), in situ DNA hybridization (72% and 100%) and cell culture detection (52% and 95%), respectively. Immunostaining with a monoclonal antibody against an early CMV antigen frequently detected cytomegalovirus infection in the liver allograft earlier than identification of typical histological inclusion bodies. DNA in situ hybridization was less sensitive than other techniques but highly specific; cytomegalovirus cell culture lacked sensitivity compared with the other procedures.

Chemotaxis of polymorphonuclear leukocytes and mononuclear leukocytes was studied in six patients who had persistent cutaneous anergy. Four had previous infections (three fungal and one caused by Mycobacterium kansasii), one had sarcoidosis, and one had late-onset immunoglobulin deficiency. Our data indicate that some patients with persistent cutaneous anergy have a combined defect of leukocyte function. Lymphocytes incubated in vitro with mitogen failed to elaborate active lymphocyte-derived chemotactic factor when compared with controls. Polymorphonuclear leukocytes and mononuclear leukocytes responded poorly to normal chematactic factors compared with controls. The abnormal mononuclear leukocyte chemotaxis may play a role in the persistent cutaneous anergy of these patients.

The main antifungal agents used for deep-seated mycotic infections are the broad-spectrum antifungal drug amphotericin B, the narrow-spectrum agent flucytosine, and the newer broad-spectrum agents ketoconazole, miconazole, and itraconazole. Amphotericin B remains the cornerstone of antifungal therapy. For the treatment of cryptococcal meningitis, the current recommendation is for the combined use of amphotericin B and flucytosine. Published clinical experience with the newer agents is limited. Not all patients from whom fungal agents have been isolated require treatment; the extent of the fungal infection should be determined, when possible, for evaluation of the need for treatment.

Twenty patients with fever of unknown origin were found to have idiopathic granulomatosis of the liver, lymph nodes, spleen, or bone marrow. At the time of initial examination, these patients had persistent or recurrent fever and pronounced constitutional symptoms but few physical findings. The most common laboratory abnormalities were increased erythrocyte sedimentation rate in 18, abnormal results of liver function tests in 12, anemia in 11, and hypergammaglobulinemia in 10. Of the 20 patients, 14 required corticosteroids at the beginning of the illness for control of symptoms, especially fever. After 5 to 10 years of follow-up, an alternative diagnosis had been established in 5 of the 20 patients. Of the remaining 15 patients with fever and idiopathic granulomatosis, 6 are still receiving corticosteroids. Corticosteroid treatment did not result in progression or dissemination of an unrecognized infection. No clinical or laboratory abnormality helped to predict the need for long-term corticosteroid treatment.

Between March 1985 and June 1987, the first 100 liver transplantations at the Mayo Clinic were performed in 83 patients (primarily adults). The most frequent diagnoses were chronic active hepatitis (in 24 patients), primary sclerosing cholangitis (in 22), and primary biliary cirrhosis (in 20). The median operating time was 406 minutes, and the median usage of erythrocytes was 13.2 units. A venovenous bypass was used in all patients older than 10 years of age. Hepatic artery thrombosis occurred in 10% of the 100 transplants. A choledochocholedochostomy was done in 58 patients and a choledochojejunostomy in 25 patients. Revision of the biliary anastomosis was necessary in 9 of the 83 patients (11%). Rejection, diagnosed by clinical and histologic criteria, occurred in 50 patients (60%) and was treated with a corticosteroid bolus, followed by OKT3 (monoclonal antibody) treatment if necessary. Selective bowel decontamination helped prevent infections; only 16 bacteremias occurred, 1 of which was caused by a gram-negative organism. Fungal infections were rare. Cytomegalovirus infection occurred in 47 patients (57%). Of the 83 patients, 16 required retransplantation, in 11 of whom graft rejection had occurred. One- and 2-year patient survival was 83% and 70%, respectively. Although problems still remain, liver transplantation is a reasonable option for patients with end-stage liver disease.

Only a few agents with antiviral activity are available for routine clinical use. Amantadine hydrochloride is effective in the prophylaxis of influenza A. In addition, accumulated evidence shows that amantadine has some therapeutic effect when used early in the course of an influenza A infection. Idoxuridine and adenine arabinoside have found application as topical agents in the treatment of herpes simplex keratitis. Adenine arabinoside has also been approved for the treatment of disseminated infections due to herpes zoster and herpes simplex. Acyclovir sodium has been approved as a topical agent in the treatment of limited mucocutaneous herpes simplex viral infections in immunosuppressed patients and of initial episodes of genital herpes simplex infections in patients with normal immunity. Ribavirin, an experimental agent with a wide spectrum of activity in vitro, has not fulfilled expectations in clinical trials. Because of the eradication of smallpox, methisazone has become obsolete as a prophylactic agent in smallpox.

Frequently, the presence of endocarditis is disguised. The emphasis of this description of the clinical manifestations of endocarditis is on the various modes of presentation, rather than on individual symptoms and signs. Endocarditis can manifest with cardiac, pulmonary, ophthalmic, central nervous system, renal, orthopedic, phthisic, and peripheral vascular disorders. The following clinical data are most useful in helping to establish a diagnosis of endocarditis: a history of fever, anorexia, weight loss, and back pain; a search for petechiae; splenomegaly; and daily examination, especially cardiac auscultation and funduscopic examination, of those patients in whom incomplete evidence exists at admission. The most helpful laboratory tests include those revealing anemia, increased erythrocyte sedimentation rate, abnormalities in the urine compatible with nephritis, or embolization. In patients who have not received antimicrobial therapy just before the diagnostic workup, one set of three blood cultures is sufficient to isolate the offending microorganism in about 95% of cases.

Cryptococcus neoformans was isolated from 65 patients: 11 had meningitis, 11 had disseminated cryptococcosis without meningitis, and 43 had C neoformans isolated from the respiratory tract. Predisposing conditions and the diagnostic value of cultures from various sites and of the latex agglutination test on cerebrospinal fluid and serum are analyzed for patients with extrapulmonary disease. Nine patients had pleural effusions; the effusion was cultured in six and yielded C neoformans in four. None of 11 deaths among 43 patients with respiratory tract isolates could be attributed to cryptococosis. The 32 survivors were nor treated with antifungal agents. Twenty-six of 43 patients with respiratory isolates had various bronchopulmonary disorders, with chronic obstructive pulmonary diseases and asthma the most common (28 percent). Seven of 28 patients (25 percent) with roentgenographically detected lung lesions had carcinoma of the lung. Roentgenographic evidence of a lung lesion and C neoformans grown from the respiratory tract warrant a further search for carcinoma of the lung.

Patients with group G streptococcal bactermia represented 10.8% of those with beta-hemolytic streptococcal bacteremia and 0.3% of all those with bacteremia between 1970 and 1980 at Mayo Clinic-affiliated hospitals. The most frequent portal of entry was the skin, usually in cases with preexisting edema due to previous surgical removal, irradiation, or tumor infiltration of lymph nodes, or to chronic venous insufficiency. The majority of these patients had underlying hematologic malignancies or solid tumors. Clinical response to therapy with beta-lactam antibiotics was rapid.

The common features in our two patients were late onset of infections that are known to complicate both T-cell and B-cell deficiencies, decreased numbers of circulating B-cells with low serum immunoglobulin levels, and normal numbers of circulating T-cells, which were, however, defective in the response to delayed hypersensitivity skin test antigens and to mitogens in vitro. The composite of clinical and immunologic aberrations is consistent with the presence of an immune deficiency involving the B-cell system quantitatively and the T-cell system qualitatively.

Fifty patients with late-onset idiopathic immunoglobulin deficiency were studied and the frequency of various clinical associations and complications was observed. Men and women were equally affected, although the age at onset in men peaked in the third decade whereas it was more uniformly distributed in women. Sinobronchopulmonary infections were common and were caused by Haemophilus influenzae. Diplococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus: bronchiectasis occurred in 28 per cent. Thirty patients (60 per cent) had diarrhea, which was often associated with steatorrhea, giardiasis, achlorhydria, abnormal Schilling tests and morphologic abnormalities on small bowel biopsy specimens, including nodular lymphoid hyperplasia; three patients had pernicious anemia. In the 20 patients without diarrhea these abnormalities were not observed except for giardiasis in one patient and achlorhydria in two patients. Cholelithiasis occurred in both groups in about a third of the patients tested. A high degree of susceptibility to neoplasia was noted. Thyroid abnormalities, including primary hypothyroidism and Graves' disease, were observed in six patients. Additional occasional findings were vitiligo, keratoconjunctivitis sicca and arthritis. Splenomegaly occurred in 14 (28 per cent) patients. The percentage of B lymphocytes in the blood was determined in 10 patients; it was normal or slightly decreased in eight patients and low in two patients.

The main antifungal agents used for deep-seated mycotic infections are the broad-spectrum antifungal drug amphotericin B, the narrow-spectrum agent flucytosine, and the newer broad-spectrum agents miconazole and ketoconazole. Amphotericin B remains the cornerstone of antifungal therapy. For the treatment of cryptococcal meningitis, the current recommendation is for the combined use of amphotericin B and flucytosine. 2-Hydroxystilbamidine is used only in indolent cases of blastomycosis; however, this condition is usually treated with amphotericin B. Clinical experience with the newer agents is limited. Not all patients from whom fungal agents have been isolated require treatment; the extent of the fungal infection should be determined, when possible, for evaluation of the need for treatment.

Fifty-five patients with late-onset idiopathic immunoglobulin deficiency were studied and upper or lower respiratory tract infections were encountered in about 90%. Cylindrical bronchiectasis was shown in all of the 21 patients in whom bronchograms were done. A thymoma was found in four patients. Three patients had diffuse interstitial pulmonary disease--two with proved and one with presumed lymphocytic interstitial pneumonitis. Five patients had no evidence of pulmonary disease, including two patients with long-standing late-onset immunoglobulin deficiency who had essentially no serum immunoglobulins. This small subgroup of patients with immunoglobulin dificiency without severe pulmonary infections cannot be explained in the context of current understanding of immunoglobulin deficiency. Thirty-two patients were followed up for long enough for the response to treatment to be assessed.

Vancomycin is a narrow-spectrum bactericidal antibiotic used primarily for treatment of serious staphylococcal infections. It is the alternative therapy of choice when the penicillins and cephalosporins cannot be used. Vancomycin is also used in (1) methicillin-resistant Staphylococcus aureus infections; (2) streptococcal endocarditis in conjunction with an aminoglycoside in patients intolerant of penicillin or ampicillin; (3) infections, including those involving prosthetic devices, caused by gram-positive organisms with multiple antibiotic resistance; (4) antibiotic-induced enterocolitis caused by Clostridium difficile; and (5) prophylaxis for endocarditis in patients who are at risk and cannot tolerate a penicillin, cephalosporin, or erythromycin. The major toxic effect associated with the use of vancomycin is ototoxicity, which may develop when serum levels exceed 30 micrograms/ml.

Treatment with flucytosine of 20 patients with fungal infections gave favorable results in four patients with crytococcal infections, two of four patients with disseminated candidiasis, eight of ten patients with urinary tract infections due to Candida albicans and Torulopsis glabrata, and tow of three patients with miscellaneous infections due to Calbicans. Two patients with crytococcal meningitis and altered host resistance and one patient with an aorto femoral graft infection due to C albicans were treated with flucytosine and smphotericin B. The infection was eradicated in one of the patients with meningitis, and cultures from an infected arterial graft became negative. Adverse side effects of flucytosine included mild leukopenia and thrombocytopenia, a transient increase in alkaline phosphatase and glutamic oxaloacetic transaminase, and nausea and diarrhea.

Twelve liver and 5 kidney transplant recipients with severe cytomegalovirus infection were treated with Ganciclovir (7.5 mg/kg/day, intravenously). Ten were evaluable (compatible clinical picture, organ involvement shown histopathologically or by culture, viremia, and absence of concomitant infection). All 17 patients were studied for adverse drug side effects. A total of 9 evaluable patients survived the infection; 1 died during treatment due to infection or drug toxicity. A death 19 days after completion of treatment was due to unrelated causes. Patients became afebrile after 2-9 days (mean, 5.3 days) of treatment. Liver function improved, pulmonary infiltrates cleared, and hypoxemia reversed during therapy. Viremia ceased during therapy in 9 patients; asymptomatic viruria persisted or recurred in 6 of 7 patients studied. No relapses occurred during follow-up (7-17 months; mean, 13 months). Transient neutropenia and thrombocytopenia occurred in 3 and 1 patients, respectively. Ganciclovir appears promising for treatment of severe CMV infection in patients with kidney or liver transplants.

The main emphasis in this paper is on the broad-spectrum antifungal agent amphotericin B and the narrow-spectrum agent flucytosine. Amphotericin B remains the cornerstone of antifungal therapy. For the treatment of cryptococcal meningitis, the current recommendation is for the combined use of amphotericin B and flucytosine. 2-Hydrostilbamidine is used only in indolent cases of blastomycosis; this condition is usually treated with amphotericin B. A number of newer agents and combinations of drugs also warrant mention, but clinical experience is limited and these agents or combinations have not been approved for clinical use. Not all patients from whom fungal agents are isolated require treatment and the extent of the fungal infection should be determined when possible for evaluation of the need for treatment.

We report three patients (followed up for 13, 9, and 12 years) who had multiple episodes of disseminated histoplasmosis. Clinically, all three patients had high yields of positive cultures and all developed corticoadrenal insufficiency; all survived the recurrent relapses. One patient had unilateral progressive panophthalmitis, with ocular cultures positive for Histoplasma capsulatum. These relapses occurred despite conventional treatment with large doses of amphotericin B. Prolonged remissions were associated with using small doses of this drug. One patient had a long-term remission while taking ketoconazole daily for more than four years. These patients did not have conditions associated with immunosuppression. Lymphocyte proliferation to mitogens and, in one patient, to histoplasmin, was markedly reduced at the time of relapse and when tested preceding a relapse. All three patients showed a reversal to normal lymphocyte proliferation at the time of the longest last remission.

Idiopathic late-onset immunoglobulin deficiency in a young man was associated with achlorhydria and a severe intestinal malabsorption syndrome that did not respond to conventional therapy. Combined therapy with high doses of prednisone and tetracycline hydrochloride resulted in weight gain, cessation of diarrhea, improved absorption of water, fat, and vitamin B12, and production of gastric acid after stimulation with histamine. Serum immunoglobulin levels, however, did not increase.

The antimicrobial therapy of musculoskeletal infections does not differ in basic principles from the therapy of any infection. However, the chronic nature of certain of these infections and the need for long-term treatment make essential the proper selection and monitoring of the antimicrobial agents. This can be done only by obtaining proper specimens for microbiologic identification and, in many cases, by in vitro susceptibility tests of the infecting organisms. Thus, the least toxic, effective antimicrobial agent can be selected and administered without inadequate therapy or toxic side effects.

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.

A study was undertaken to determine whether a process audit of outpatient medical care would correlate significantly with the outcomes of care and thus prove to be a valid method for assessing the quality of medical care in the outpatient setting. Acute bacterial cystitis in women was selected as the model for study. A series of 42 cases was reviewed by retrospective analysis of patient records supplemented by follow-up interviews and collection of a follow-up urine culture from each patient to document the outcome of treatment. No positive association was demonstrated between the processes for satisfactory care selected by the expert criteria committee and the observed outcomes. Reasons for this failure in the present study and for deficiencies of the process audit method in general are discussed.

Only a few agents with antiviral activity are available for regular clinical use. Amantadine hydrochloride is effective in the prophylaxis of influenza A2. Idoxuridine and adenine arabinoside have found application as topical agents in the treatment of herpes simplex keratitis. Adenine arabinoside is also under investigation in the treatment of disseminated infections due to herpes zoster and herpes simplex. Ribavirin, an agent with a wide spectrum of activity in vitro, has not fulfilled expectations in clinical trials. Because of the near eradication of smallpox, methisazone has become less important as a prophylactic agent in smallpox.

The initial treatment of suspected life-threatening bacterial infection should be sufficiently broad to cover the likely causative agents. Definitive therapy depends on microbial isolation, identification, and, when indicated, in vitro susceptibility tests. Parenteral therapy should be used, at least initially, and optimal doses are necessary. The dose is particularly important when aminoglycosides are administered; a concern for potential side effects with use of these agents had engendered a tendency to administer inadequate doses. The problems leading to recurrence or persistence of fever during antimicrobial therapy include failure to diagnose and drain abscesses, superinfection, drug fever, and clinical or microbiologic errors. Combinations of antibiotics are indicated in severe infections due to Pseudomonas aeruginosa, enterococcal group D streptococci, and Cryptococcus neoformans. Laboratory assistance for the selection of antimicrobial therapy can be valuable but is not always necessary because certain microorganisms--for example, Streptococcus pneumoniae and S. pyogenes--have stable, predictable susceptibilities. Cautious conservatism is advocated with regard to the use of new antimicrobial agents.

Twelve of 50 consecutive patients with idiopathic late-onset immunoglobulin deficiency had cholelithiasis. This represents a prevalence rate of 24%, which is significantly above the rate in a control group of 500 patients from this medical center matched 10:1 for age and sex (P less than 0.005). This finding adds a new gastrointestinal abnormality to those known to occur in idiopathic late-onset immunoglobulin deficiency.

In the initial therapy of life-threatening infections in which a bacterial cause is suspected, the emphasis should be on broad antibiotic coverage in contrast to definitive therapy, which is dependent on microbial isolation and, when indicated, in vitro susceptibility tests. In severe infections, antimicrobial agents should be given parenterally, at least initially. The need for optimal dosage is emphasized. This is particularly important when aminoglycosides are administered, for there is a tendency to use inadequate dosage because of concern for potential side effects with these agents. The problems leading to recurrence and persistence of fever during antimicrobial therapy include failure to diagnose and drain abscesses, superinfection, drug fever, and clinical or microbiologic errors. Combinations of antibiotics are indicated in severe infections in severe infections due to Pseudomonas aeruginosa, enterococcal group D streptococci, Klebsiella pneumoniae, and Cryptococcus neoformans. Laboratory aid for the selection of antimicrobial therapy can be of great value but need not always be done, because certain microorganisms have stable, predictable susceptibilities, for example, Streptococcus pneumoniae and Streptococcus pyogenes. Cautious conservatism is advocated with regard to the use of new antimicrobial agents.

Group F streptococci are part of the oropharyngeal, bowel, and perineal flora. Abscess formation by these organisms most commonly involves the cutaneous system: the next most common sites, in descending order, are the cervicofacial, dental, and intraabdominal areas. Among our population of patients with abscesses, serious infection rarely occurred in otherwise healthy individuals in the absence of trauma. Group F streptococci represented 2% of beta-hemolytic streptococcal isolates from all patients with bacteremia who were hospitalized at Mayo Clinic-affiliated hospitals from 1970 to 1980. In five of seven bacteremic patients, some manipulation, perforation, or underlying pathology associated with the gastrointestinal tract existed. Polymicrobial bacteremia was common. All isolates of group F streptococci were susceptible to less than or equal to 0.1 microgram of penicillin/ml.

Four adult patients had life-threatening soft-tissue infections of the neck. One had Hemophilus influenzae infection, one had Streptococcus pyogenes infection, and two had polymicrobial mixed aerobic and anaerobic infections. Three of the four patients died despite appropriate antimicrobial therapy and surgical intervention. These cases demonstrate the spectrum of serious soft-tissue infections of the neck in both the compromised and the uncompromised host. Soft-tissue infections of the neck may be necrotizing or nonnecrotizing. Cellulitis secondary to H. influenzae and beta-hemolytic streptococci is usually non-necrotizing, whereas necrotizing infections are caused most commonly by synergistic organisms. Potential complications include septic shock, disseminated intravascular coagulation, acute renal failure, adult respiratory distress syndrome, mediastinitis, and pericarditis. Early recognition with aggressive medical and surgical therapy is essential to reduce the mortality.

Gram-negative bacterial and fungal infections are a major cause of morbidity and mortality following liver transplantation. We therefore used selective bowel decontamination (SBD) to eliminate the endogenous source of gram-negative aerobic bacteria and Candida pathogens in an attempt to reduce the high incidence of infection related to these organisms. Thirty consecutive patients undergoing liver transplantation were treated with SBD starting 3 days prior to donor search and continuing for 21 days postliver transplantation. Selective bowel decontamination consisted of administering nonabsorbable antibiotics (Polymixin E, gentamicin, Nystatin) and a low bacterial diet. Surveillance cultures of the throat and rectum were obtained to monitor efficacy of selective bowel decontamination. In addition, in the posttransplant period, tracheal, wound, blood, and bile cultures were obtained to screen for gram-negative bacterial and Candida colonization and infection. Our baseline surveillance culture revealed that 29/30 (97%) of recipients were colonized with gram-negative aerobic bacteria and 16/30 (53%) with Candida. Three days after selective bowel decontamination was started, 26/30 (87%) were free of gram-negative bacteria, and 100% were free of Candida colonization of the gastrointestinal tract. There was a similar reduction in the oropharyngeal gram-negative aerobic bacteria and Candida colonization. In the first 30 days following liver transplantation, gram-negative infections were not diagnosed in any of our patients. Following discontinuation of SBD, recolonization of the gastrointestinal tract with gram-negative aerobic bacteria and Candida occurred within 5 days in 26/28 (90%) and 11/28 (35%), respectively. Our study suggests that prophylactive administration of nonabsorbable antibiotics will markedly reduce gram-negative aerobic bacterial and Candida colonization and appears to reduce the high incidence of infection related to these organisms in the early posttransplant period.

Group C streptococci are generally considered to be a rare cause of infection in man. Infections due to these microorganisms, however, are common in several animal species. To our knowledge, the literature contains only two previous cases of meningitis in man which were due to group C streptococci. In one of these cases meningitis developed as a complication of endocarditis due to group C streptococci. Our recent clinical experience with a patient with severe acute meningitis caused by group C streptococci is reported and the pertinent literature is reviewed. The illness manifested itself as a severe form of acute meningitis, with slow but statisfactory response to therapy with penicillin.

Sixty-six patients who had undergone 78 liver transplantations, with no detectable cytomegalovirus (CMV) infection before transplantation, were studied to assess the value of CMV serology compared with the rapid detection of the virus in shell vial cell cultures or histology for the diagnosis of (1) the first evidence of infection, (2) symptomatic disease, and (3) asymptomatic infection. Of 28 evaluable patients, shell vial cell culture assay and histologic findings provided the first evidence of CMV infection earlier in 22 (79%) or at the same time as the serologic response in 5 (18%). Serologic results yielded the first indication of CMV infection in only 1 of these 28 patients (3%). Of 17 evaluable transplantations in 15 patients in whom symptomatic invasive disease developed, shell vial culture or histology provided a laboratory diagnosis of CMV infection earlier or at the same time as serologic responses in 16 (94%). Similarly, shell vial culture or histology provided evidence of CMV infection in 10 of 11 patients (91%) who had asymptomatic CMV infection and remained asymptomatic. Urine surveillance cultures yielded the first evidence of CMV infection in 14 of 19 patients who initially had an asymptomatic infection, of which 6 became symptomatic. Culturing of the blood with use of the rapid shell vial technique showed that viremia preceded CMV organ involvement in 7 of 10 patients. We recommend culture by the shell vial assay as the most rapid and sensitive method of determining CMV infection in liver transplant patients.

Amantadine is well established as the preferred antiviral agent for the prophylaxis of influenza A and may also be beneficial therapeutically when used early in the course of the disease. Idoxuridine is applicable only in the treatment of herpetic keratitis. Currently, acyclovir is the most effective agent for the treatment of herpes simplex and varicella-zoster virus infections. Ribavirin has recently been released for use in aerosol form for severe respiratory syncytial virus infections that occur in infants and young children. Vidarabine, which previously was the drug of choice in the treatment of severe herpetic infections, has now been replaced by the more effective acyclovir. Ganciclovir, an experimental agent, has shown promise against cytomegalovirus infections in patients who have undergone kidney or liver transplantation, but its effects are only temporary in patients who have undergone bone marrow transplantation and patients with acquired immunodeficiency syndrome (AIDS) who have cytomegalovirus infections.

Use of antimicrobial agents must be tailored to the individual patient, site of infection, and etiologic organism. The choice of drug should be based on efficacy, safety, low toxicity, and acceptable cost. Empiric therapy should be broad enough to cover the pathogens that are suspected of causing the infection, based on the site of infection and the type of host. Definitive therapy may differ from initial therapy and should be started as soon as specific laboratory and clinical data are available. Cautious conservatism is advocated with regard to the use of new antimicrobial agents. The effects of the agents on the microbial ecology and hospital environment should be considered. Judicious use is necessary to prevent antimicrobial pollution.

The bactericidal activity of moxalactam, alone and in combination with gentamicin, was studied with macrobroth two-dimensional checkerboard and killing curve techniques against gentamicin-resistant and -susceptible strains of Pseudomonas aeruginosa. Moxalactam was bactericidal at concentrations equal to or at least two to four times its inhibitory concentrations. Synergy at clinically applicable concentrations of moxalactam and gentamicin occurred with 6 of 14 gentamicin-resistant strains and 4 of 4 gentamicin-susceptible strains by the checkerboard technique and with 7 of 14 gentamicin-resistant strains by the killing curve technique. Synergy between moxalactam and gentamicin against gentamicin-resistant strains of P. aeruginosa is unpredictable and strain- and method-dependent.

Moxalactam was administered (20 mg/kg intravenously every 8 hours) as single-drug empiric antimicrobial therapy to 63 patients with bacteremia who were neither neutropenic nor immunosuppressed. Six patients (10%) had microorganisms that were susceptible to moxalactam and resistant to all other antimicrobial agents tested; two patients (3%) had microorganisms that were resistant to moxalactam and other agents tested. Of these 63 patients, 47 (75%) were cured with moxalactam therapy. Nine patients (14%) had breakthrough bacteremia while receiving other antimicrobial therapy and were cured subsequently with moxalactam therapy alone. The two major risk factors for failure of moxalactam therapy were polymicrobial bacteremia and an extrahepatic intra-abdominal source of infection; these two conditions frequently coexisted. Six of nine patients with polymicrobial bacteremia died. Superinfection (one pseudomonal, five enterococcal) was responsible for 6 of the 16 treatment failures. Enterococcal superinfection occurred exclusively among patients who had received relatively prolonged therapy with moxalactam for extrahepatic intra-abdominal infection, especially intraabdominal abscess. These five patients died, and postmortem examination showed that enterococcal superinfection was the major cause of death in all. Mild, reversible adverse reactions associated with use of moxalactam occurred in 14 of the 63 patients (22%). None had clinically overt bleeding. The use of moxalactam alone seems to be safe and effective and a cost-effective alternative empiric antimicrobial therapy for most patients with bacteremia who are not immunosuppressed or neutropenic and who are not at high risk of having Pseudomonas or polymicrobial bacteremia.

Of 83 patients who underwent 100 orthotopic liver transplantations, 53 had a single transplant procedure and at least 6 months of follow-up. In this main study group of 53 patients, major infections developed in 28 (53%) (a mean of 1.8 major episodes per infected patient). Of 51 major infections, 27 were bacterial, 19 were viral, 3 were protozoan, and 2 were fungal. Of the 27 bacterial infections, 22 (81%) occurred in the first 2 months after transplantation. Of the 40 bacterial isolates in the 27 bacterial infections, gram-positive aerobic bacteria were isolated in 26 (65%), anaerobic bacteria in 8 (20%), and aerobic gram-negative bacteria in 6 (15%). Only 1 of 16 bacteremic episodes was due to a gram-negative aerobic bacterium. Cytomegalovirus (CMV) infection occurred in 30 of the 53 patients (57%) and was symptomatic and invasive in 18. CMV infection was diagnosed a mean of 26 days after transplantation. Infections due to Pneumocystis carinii occurred later (2 to 3 months after transplantation). Death from infection occurred in 4 of the 53 patients (8%). In the group of 16 patients with two or more liver transplantations, fungal infection occurred in 2 and CMV infection in 13. In all 16 patients who underwent more than one liver transplantation, a major infection developed. The observations made in the main study group were consistent with findings in 13 patients with one liver transplantation but less than 6 months of follow-up. Infection is a major complication after liver transplantation, generally occurring in the first 2 months. Our observations suggest that the use of selective bowel decontamination may be associated with a relatively lower incidence of gram-negative aerobic bacterial infections.

Vancomycin is a narrow-spectrum bactericidal antistaphylococcal antibiotic that was introduced in 1956 because of its efficacy against resistant penicillinase-producing staphylococci. It was effective for serious staphylococcal infections for which no satisfactory alternative to penicillin G was available at the time. When methicillin and the other semisynthetic penicillins and the cephalosporins were introduced, the role of vancomycin was relegated to the alternative therapy of choice when the penicillins and the cephalosporins could not be used. In the future, vancomycin may be used more frequently in (1) methicillin-resistant Staphylococcus aureus infections, (2) streptococcal endocarditis in conjunction with an aminoglycoside in patients intolerant to penicillin or ampicillin, (3) infections associated with prosthetic devices caused by organisms with multiple antibiotic resistance, and (4) antibiotic-induced enterocolitis associated with Clostridium difficile.