Gardnerella vaginalis Bacteremia in Male Patients: A Case Series and Review of the Literature.

Gardnerella vaginalis colonization and invasive disease of the genitourinary tract in women has been well described. In men, this organism uncommonly causes infection, and bacteremia is rare. We describe 2 cases of G vaginalis bacteremia in men and present a review of the literature. Our 2 patients each had underlying comorbid conditions that predispose to serious bacterial infection. One presented with symptoms of urinary tract infection, the other presented with sepsis. Urine, cultured under usual aerobic conditions, was negative in both cases, but blood cultures after prolonged incubation yielded G vaginalis. Treatment with antibiotics was successful in both cases. Our review of the medical literature revealed 12 previously reported cases of G vaginalis bacteremia in men. Almost all infections in men have originated in the genitourinary tract. Three patients had no reported history of or evidence for disease of the urinary tract, one each with endocarditis, empyema, and odontogenic abscess. Isolation and identification of G vaginalis is often delayed. Selection and duration of treatment have ranged widely in previously reported cases, likely due to the absence of reports on antibiotic susceptibility of G vaginalis and a lack of guidance regarding effective treatment.

The remarkable history of pneumococcal vaccination: an ongoing challenge.

Although it varies with age and geographical distribution, the global burden of infection with Streptococcus pneumoniae (pneumococcus) remains considerable. The elderly, and younger adults with comorbid conditions, are at particularly high risk of pneumococcal infection, and this risk will increase as the population ages. Vaccination should be the backbone of our current strategies to deal with this infection.Main body: This manuscript reviews the history of the development of pneumococcal vaccines, and the impact of different vaccines and vaccination strategies over the past 111 years. It documents the early years of vaccine development in the gold mines of South Africa, when vaccination with killed pneumococci was shown to be effective, even before the recognition that different pneumococci were antigenically distinct. The development of type-specific vaccines, still with whole killed pneumococci, showed a high degree of efficacy. The identification of the importance of the pneumococcal capsule heralded the era of vaccination with capsular polysaccharides, although with the advent of penicillin, interest in pneumococcal vaccine development waned. The efforts of Austrian and his colleagues, who documented that despite penicillin therapy, patients still died from pneumococcal infection in the first 96 h, ultimately led to the licensing first of a 14-valent pneumococcal polysaccharide in 1977 followed by the 23-valent pneumococcal polysaccharide in 1983. The principal problem with these, as with other polysaccharide vaccines, was that that they failed to immunize infants and toddlers, who were at highest risk for pneumococcal disease. This was overcome by chemical linking or conjugation of the polysaccharide molecules to an immunogenic carrier protein. Thus began the era of pneumococcal conjugate vaccine (PCV), starting with PCV7, progressing to PCV10 and PCV13, and, most recently, PCV15 and PCV20. However, these vaccines remain serotype specific, posing the challenge of new serotypes replacing vaccine types. Current research addresses serotype-independent vaccines which, so far, has been a challenging and elusive endeavor.Conclusion: While there has been enormous progress in the development of pneumococcal vaccines during the past century, attempts to develop a vaccine that will retain its efficacy for most pneumococcal serotypes are ongoing.

The Microbial Etiology of Community-Acquired Pneumonia in Adults: from Classical Bacteriology to Host Transcriptional Signatures.

All modern advances notwithstanding, pneumonia remains a common infection with substantial morbidity and mortality. Understanding of the etiology of pneumonia continues to evolve as new techniques enable identification of already known organisms and as new organisms emerge. We now review the etiology of pneumonia (at present often called "community-acquired pneumonia") beginning with classic bacteriologic techniques, which identified Streptococcus pneumoniae as the overwhelmingly common cause, to more modern bacteriologic studies, which emphasize Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Enterobacteriaceae, Pseudomonas, and normal respiratory flora. Urine antigen detection is useful in identifying Legionella and pneumococcus. The low yield of bacteria in recent studies is due to the failure to obtain valid sputum samples before antibiotics are administered. The use of high-quality sputum specimens enables identification of recognized ("typical") bacterial pathogens as well as a role for commensal bacteria ("normal respiratory flora"). Nucleic acid amplification technology for viruses has revolutionized diagnosis, showing the importance of viral pneumonia leading to hospitalization with or without coinfecting bacterial organisms. Quantitative PCR study of sputum is in its early stages of application, but regular detection of high counts of bacterial DNA from organisms that are not seen on Gram stain or grown in quantitative culture presents a therapeutic dilemma. This finding may reflect the host microbiome of the respiratory tract, in which case treatment may not need to be given for them. Finally, host transcriptional signatures might enable clinicians to distinguish between viral and bacterial pneumonia, an important practical consideration.

Clinical prediction of bacteremia and early antibiotics therapy in patients with solid tumors.

OBJECTIVE: To investigate the relationship between the systemic inflammatory response syndrome (SIRS), early antibiotic use, and bacteremia in solid-tumor patients. DESIGN, SETTING, AND PARTICIPANTS: We conducted a retrospective observational study of adults with solid tumors admitted to a tertiary-care hospital through the emergency department over a 2-year period. Patients with neutropenic fever, organ transplant, trauma, or cardiopulmonary arrest were excluded. METHODS: Rates of SIRS, bacteremia, and early antibiotics (initiation within 8 hours of presentation) were compared using the χ2 and Student t tests. Binomial regression and receiver operator curves were analyzed to assess predictors of bacteremia and early antibiotics. RESULTS: Early antibiotics were administered in 507 (37%) of 1,344 SIRS-positive cases and 492 (22%) of 2,236 SIRS-negative cases (P < .0001). Of SIRS-positive cases, 70% had blood cultures drawn within 48 hours and 19% were positive; among SIRS negative cases, 35% had cultures and 13% were positive (19% vs 13%; P = .003). Bacteremic cases were more often SIRS positive than nonbacteremic cases (60% vs 50%; P =.003), but they received early antibiotics at similar rates (50% vs 49%, P = .72). Three SIRS components predicted early antibiotics: temperature (OR, 1.7; 95% CI, 1.31-2.29; P = .0001), tachycardia (OR, 1.4; 95% CI, 1.10-1.69; P < .0001), and white blood-cell count (OR, 1.8; 95% CI, 1.56-2.14; P < .0001). Only temperature (OR, 1.6; 95% CI, 1.09-2.41; P = .01) and tachycardia (OR, 1.5; 95% CI, 1.09-2.06; P = .01) predicted bacteremia. SIRS criteria as a composite were poorly predictive of bacteremia (AUC, 0.57). CONCLUSIONS: SIRS criteria are frequently used to determine the need for early antibiotics, but they are poor predictors of bacteremia in solid-tumor patients. More reliable models are needed to guide judicious use of antibiotics in this population.

Contributions of Animal Studies to the Understanding of Infectious Diseases.

Experiments in animals have played an integral role in furthering basic understanding of the pathophysiology, host immune response, diagnosis, and treatment of infectious diseases. However, competing demands of modern-day clinical training and increasingly stringent requirements to perform animal research have reduced the exposure of infectious disease physicians to animal studies. For practitioners of infectious diseases and, especially, for contemporary trainees in infectious diseases, it is important to appreciate this historical body of work and its impact on current clinical practice. In this article, we provide an overview of some major contributions of animal studies to the field of infectious diseases. Areas covered include transmission of infection, elucidation of innate and adaptive host immune responses, testing of antimicrobials, pathogenesis and treatment of endocarditis, osteomyelitis, intra-abdominal and urinary tract infection, treatment of infection associated with a foreign body or in the presence of neutropenia, and toxin-mediated disease.

Candida species in community-acquired pneumonia in patients with chronic aspiration.

BACKGROUND: When Candida species is found in a sputum culture, clinicians generally dismiss it as a contaminant. We sought to identify cases of community-acquired pneumonia (CAP) in which Candida might play a contributory etiologic role. METHODS: In a convenience sample of patients hospitalized for CAP, we screened for "high-quality sputum" by Gram stain (> 20 WBC/epithelial cell) and performed quantitative sputum cultures. Criteria for a potential etiologic role for Candida included the observation of large numbers of yeast forms on Gram stain, intracellular organisms and > 106 CFU/ml Candida in sputum. We gathered clinical information on cases that met these criteria for possible Candida infection. RESULTS: Sputum from 6 of 154 consecutive CAP patients had large numbers of extra- and intracellular yeast forms on Gram stain, with > 106 CFU/ml Candida albicans, glabrata, or tropicalis on quantitative culture. In all 6 patients, the clinical diagnoses at admission included chronic aspiration. Greater than 105 CFU/ml of a recognized bacterial pathogen (Streptococcus pneumoniae, Staphylococcus aureus, or Pseudomonas) or > 106 CFU/ml of other 'normal respiratory flora' (Lactobacillus species) were present together with Candida spp. in every case. Blood cultures yielded Candida in 2 cases, and 1,3-beta-D glucan was > 500 ng/mL in 3 of 3 cases in which it was assayed. Since all patients were treated with anti-bacterial and anti-fungal drugs, no inference about etiology can be derived from therapeutic response. CONCLUSIONS: Candida spp. together with a recognized bacterial pathogen or normal respiratory flora may contribute to the cause of CAP in patients who chronically aspirate.

Erratum to: Clinical Features and Outcomes of Community-Acquired Pneumonia Caused by Haemophilus influenzae.

[This corrects the article DOI: 10.1093/ofid/ofaa622.].

Clinical Features and Outcomes of Community-Acquired Pneumonia Caused by Haemophilus Influenza.

BACKGROUND: Long regarded as the second most common cause of community-acquired pneumonia (CAP), Haemophilus influenzae has recently been identified with almost equal frequency as pneumococcus in patients hospitalized for CAP. The literature lacks a detailed description of the presentation, clinical features, laboratory and radiologic findings, and outcomes in Haemophilus pneumonia. METHODS: During 2 prospective studies of patients hospitalized for CAP, we identified 33 patients with Haemophilus pneumonia. In order to provide context, we compared clinical findings in these patients with findings in 36 patients with pneumococcal pneumonia identified during the same period. We included and analyzed separately data from patients with viral coinfection. Patients with coinfection by other bacteria were excluded. RESULTS: Haemophilus pneumonia occurred in older adults who had underlying chronic lung disease, cardiac conditions, and alcohol use disorder, the same population at risk for pneumococcal pneumonia. However, in contrast to pneumococcal pneumonia, patients with Haemophilus pneumonia had less severe infection as shown by absence of septic shock on admission, less confusion, fewer cases of leukopenia or extreme leukocytosis, and no deaths at 30 days. Viral coinfection greatly increased the severity of Haemophilus, but not pneumococcal pneumonia. CONCLUSIONS: We present the first thorough description of Haemophilus pneumonia, show that it is less severe than pneumococcal pneumonia, and document that viral coinfection greatly increases its severity. These distinctions are lost when the label CAP is liberally applied to all patients who come to the hospital from the community for pneumonia.