Cases in Medical Microbiology and Infectious Diseases. Melissa B. Miller

aureus Catalase-positive, Gram-positive cocci in clusters Hospitalized patients Pneumonia, pneumonia superinfections Stenotrophomonas maltophilia Glucose-nonfermenting, Gram-negative bacillus Hospitalized patients Ventilator-associated pneumonia Streptococcus pneumoniae Catalase-negative, Gram-positive diplococcus Children, adults Otitis media, sinusitis, conjunctivitis, pneumonia Fungi Aspergillus spp. Acute-angle-branching, septate hyphae in tissue; molds Children and adults with chronic lung disease, adults with cavitary lung lesions, neutropenic individuals Allergic bronchopulmonary aspergillosis, aspergilloma (fungus ball), invasive pneumonia Blastomyces dermatitidis Broad-based budding yeast; dimorphic Adults Pneumonia Coccidioides posadasii/immitis Spherules in tissue; mold with arthroconidia at 30°C Children and adults, especially in desert southwest of United States and northern Mexico Flu-like illness with pneumonia; can disseminate Cryptococcus neoformans Encapsulated, round yeast Adults with defects in cell-mediated immunity, especially with AIDS Pneumonia, often asymptomatic, preceding meningitis Histoplasma capsulatum Very small, intracellular yeast; dimorphic Adults, primarily with AIDS, especially in Missouri and Ohio River Valleys and Caribbean Pneumonia, mediastinal fibrosis Pneumocystis jirovecii Clusters of 4- to 6-μm cysts in tissue and secretions Immunocompromised individuals, especially with AIDS Pneumonia Rhizopus spp., Mucor spp. Ribbon-like, nonseptate hyphae in tissue; rapidly growing molds Diabetics, neutropenic individuals Rhinocerebral zygomycosis, invasive pneumonia Parasites Ascaris lumbricoides Larvae Children, adults Usually asymptomatic, incidental finding Echinococcus granulosus Tapeworm (cestode) Exposure to dogs in areas with sheep Cyst in lung growing over the course of years; rupture from liver may lead to pleural space Entamoeba histolytica Ameba Children and adults with amebic liver abscess Empyema, hepatobronchial fistula, lung abscess Hookworm (Necator americanus, Ancylostoma duodenale) Larvae Children, adults Usually asymptomatic, incidental finding Paragonimus westermani Fluke (trematode) Children and adults in endemic areas Hemoptysis, chronic bronchitis, bronchiectasis Schistosoma spp. Fluke (trematode); granulomas form around eggs Children and adults in endemic areas Pulmonary hypertension due to trapping of eggs in pulmonary capillaries Strongyloides stercoralis Rhabditiform larvae Immunocompromised individuals Wheezing, cough, pneumonia Viruses Adenovirus Enveloped, dsDNA^c Children, adults Pharyngitis, bronchiolitis, pneumonia, conjunctivitis (“pink eye”) Coronaviruses (229E, HKU1, NL63, OC43) Enveloped, ssRNA^d Children, adults Common cold; pneumonia in immunocompromised individuals Coronaviruses, novel (SARS-CoV,^e MERS-CoV^f) Enveloped, ssRNA Primarily adults Acute respiratory distress syndrome Cytomegalovirus Enveloped, dsDNA Immunocompromised individuals Pneumonia Enteroviruses Nonenveloped, ssRNA Children Common cold, hand-foot-and-mouth disease, herpangina, pharyngitis, bronchiolitis, pneumonia Hantaviruses Enveloped, ssRNA Children, adults Acute respiratory distress syndrome, pneumonia Herpes simplex virus Enveloped, dsDNA Immunocompromised individuals Pneumonia Influenza viruses Enveloped, ssRNA Children and adults, particularly elderly Influenza, pneumonia Metapneumovirus Enveloped, ssRNA Infants, young children, adults, immunocompromised individuals