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The article focuses on aspiration pneumonia among older adults. It states that aspiration pneumonia is commonly acquired by individuals admitted to acute care from continuing care facilities. It mentions that caring for patients with aspiration pneumonia involves monitoring for timely clinical response to therapy and for possible complications. Procedures for diagnosis and risk factor assessment are discussed, as well as clinical considerations, prevention, and treatment.

We used light microscopy and scanning and transmission electron microscopy to study the structure of Candida parapsilosis vegetations on five surgically removed porcine bioprosthetic valves. Scanning electron microscopy revealed a "mossy" amorphous surface. In some areas, C. parapsilosis cells could be seen below the surface layer. In areas in which the vegetation had cracked, myriads of healthy C. parapsilosis cells were seen to be loosely adherent to one another. These cells were covered with a flocculent or fibrillar matrix. A compact intercellular matrix was evident by transmission electron microscopy. Hyphal elements were seen invading valvular tissue. The loose matrix that bound large clumps of C. parapsilosis cells explains why large emboli are frequent complications of Candida endocarditis.

We immunized 31 renal transplant patients and 6 control subjects with a pneumococcal vaccine containing 14 capsular polysaccharides. Antibody levels to Streptococcus pneumoniae types 3 and 6A were measured by a radioimmunoassay, and opsonic activity to S. pneumoniae types 3 and 6B was determined by using a luminol-enhanced chemiluminescence phagocytic assay on serum samples obtained before and 1 month after immunization. There was a 10.2-fold and a 2.9-fold increase in antibody to S. pneumoniae type 3 (P less than 0.005) and type 6A (P less than 0.01), respectively, but only a 1.3-fold (P greater than 0.05) and 1.1-fold (P greater than 0.05) increase in opsonic activity. For S. pneumoniae type 3, changes in opsonic activity correlated well with antibody concentration (P less than 0.05). However, for S. pneumoniae type 6, these two tests correlated poorly (P greater than 0.05). This poor correlation suggests that concentrations of antibody to type 6A polysaccharide which are achieved after immunization may not be opsonically active in vitro against S. pneumoniae type 6B.

The mode of growth of the bacteria adherent to the surfaces of various components of cardiac pacemakers infected with coagulase-negative staphylococci was examined by scanning and transmission electron microscopy. Within developing adherent microcolonies, coccoid cells could be clearly seen to be enveloped by an amorphous material that condensed radically upon dehydration for electron microscopy, producing an amorphous residue in scanning electron micrographs and a fibrous anionic ruthenium red-staining residue in transmission electron micrographs. The differences in morphologies of the condensed residues may reflect differences in exopolysaccharides elaborated by the microorganisms and the degree to which materials of host origin are incorporated. The coccoid cells of coagulase-negative staphylococci were less clearly seen in thick, mature, adherent biofilms on heavily colonized surfaces because the condensed residue of their exopolysaccharide glycocalyces covered, and sometimes occluded, the bacteria cells. These coagulase-negative staphylococcal strains appeared to produce more exopolysaccharide material than did the strains infecting various intravascular catheters.

We characterized the aerobic and anaerobic urethral flora of five healthy females by performing urethral and midstream urine cultures once weekly for 8 weeks. Aerobic cultures were performed monthly for an additional 3 months. Lactobacillus spp. were isolated from 52 of 57 samples, Staphylococcus epidermidis from 42 of 57, Corynebacterium spp. from 26 of 57, and alpha-hemolytic streptococci from 14 of 57. Two subjects had E. coli serogroup O6 and group B streptococci isolated on five occasions, respectively. Anaerobes were isolated from 32 of 35 urethral urines (91%). Bacteroides melaninogenicus accounted for 46% of these isolates. The anaerobic urethral flora varied slightly from week to week, and a similar anaerobic flora was isolated from the introitus, fourchette, and cutaneous perineum. In addition, anaerobes were isolated from 16 of 18 healthy females who had a urethral urine sample cultured once only, and B. melaninogenicus was the most frequent isolate. Of the 21 B. melaninogenicus isolates identified to subspecies, 14 were subsp. intermedius.

The activity of moxalactam, cefoxitin, cephalothin, cefamandole, chloramphenicol, clindamycin, metronidazole, and ticarcillin was determined against 344 isolates of anaerobic bacteria. The activity of penicillin G was determined as well for 234 isolates not of the Bacteroides fragilis group. Moxalactam was more active than cephalothin and cefamandole and slightly less active than cefoxitin. Metronidazole was the most active antimicrobial agent against the B. fragilis group, whereas chloramphenicol was most active overall. Clostridium species were the most resistant group of organisms tested. Relatively high concentrations of penicillin were required to inhibit the C. perfringens strains: 80% at 0.5 U/ml and 100% at 16 U/ml. Our study demonstrates the need for periodic anaerobe susceptibility testing in order to better guide empiric antibiotic therapy.

Our objectives in this study were to elucidate various aspects of the epidemiology of Staphylococcus saprophyticus. This organism was isolated from the midstream urine specimens of 7.5% of 145 college women with frequency and urgency of urination and dysuria, but from only 0.07% of 14,835 urine specimens from adult inpatients at the Victoria General Hospital. It was found to be part of the urethral flora of only 2% of healthy women. Other staphylococci which formed part of the urethral flora of 100 healthy women included S. epidermidis (59 women), S. hominis (15 women), S. haemolyticus (13 women), S. warneri (9 women), and S. aureus (6 women). Finally, we determined that resistance to the 5-micrograms novobiocin disk has a 93% positive predictive accuracy as a presumptive test for S. saprophyticus.

We characterized the aerobic and anaerobic urethral flora of healthy females in three physiological age groups (premenarcheal, reproductive, and postmenopausal) and of females with urinary tract infections. The mean number of species per sample was 6.5, 7.7, and 10.3 for each of the physiological age groups, respectively, and 6.5 for the urinary tract infection group. Marked quantitative changes were seen with age and disease. Aerobes accounted for 65.6 and 73.8% of the flora of the premenarcheal and reproductive age groups, respectively, whereas anaerobes were dominant in the postmenopausal age group, accounting for 65.5% of the flora. Aerobic gram-negative rods were not isolated from any of the premenarcheal or reproductive-age subjects. Of the 10 postmenopausal subjects, 5 carried aerobic gram-negative rods, but these organisms accounted for only 1% of the flora. In contrast, they constituted 95% of the urethral flora of the urinary tract infection group. Bacteroides melaninogeneicus was commonly isolated and was the dominant isolate in the postmenopausal age group. Bacteroides fragilis was recovered from 7 of the 10 postmenopausal subjects, but these organisms constituted only 3% of the total flora. The factors responsible for the changes in urethral flora with age remain to be determined.

The level of lactic acid in cerebrospinal fluid has been suggested as a useful diagnostic parameter to differentiate between bacterial and viral meningitis, especially in patients partially treated before admission to hospital. A concentration of greater than or equal to 35 mg/dl, determined by either gas-liquid chromatography or an enzymatic method, has been considered in several studies to provide definite evidence of meningitis of bacterial origin, whereas a lower level indicates no bacterial involvement. Over the past 18 months, we have analyzed by the enzymatic method the lactate level in 493 spinal fluids submitted from 434 adult patients with various conditions involving the central nervous system. Fifty fluids had a lactate level of greater than 35 mg/dl, of which 19 were cases of infective meningitis of varying etiology. The 435 specimens with lactate levels within the range considered normal included three cases of infective meningitis, of which two were cryptococcal and one was bacterial. In this adult study, the lactate level in the cerebrospinal fluid did not provide unequivocal evidence of bacterial infection and did not provide assistance to any greater degree than the standard parameters of leukocyte count, protein, and glucose contents in the differential diagnosis of bacterial meningitis from that of any other etiology.

The in vitro activity of penicillin, cefoxitin, moxalactam, ticarcillin, clindamycin, chloramphenicol, and metronidazole against 590 anaerobic isolates collected from five Canadian hospitals during 1984 was determined by an agar dilution technique. Cefoxitin, clindamycin, chloramphenicol, and metronidazole were very active against most of the isolates. No major regional differences in the susceptibility patterns were observed.

A collection of 120 oxacillin-susceptible and 120 oxacillin-resistant coagulase-negative staphylococci (CNS) from six tertiary care hospital laboratories were tested by agar disk diffusion, three microdilution broth systems (Sensititre, Dynatech, and Alpkem), and the Vitek AutoMicrobic system for comparison with reference agar dilution results. The antimicrobial agents tested were oxacillin, cefazolin, cefotaxime, cefuroxime, cefamandole, fusidic acid, rifampin, and vancomycin. Incubation was at 30 or 35 degrees C for 24, 48, and 72 h. The broth media were supplemented with 2% NaCl for some antimicrobial agents, and the agar dilution method was used with and without the addition of 4% NaCl. The CNS were identified to species by the method of Kloos and Schleifer. The results showed a lack of concordance between two hospitals with respect to oxacillin susceptibility testing by agar dilution with no NaCl supplement. The reasons are not clear but may be related to variations in media. The 4% NaCl supplement or extended incubation to 48 h eliminated this difference. The cefazolin and cefotaxime susceptibility results in the agar disk diffusion test were unreliable if accepted at face value. Cefamandole testing correlated well with the reference method regardless of the method used, and salt supplementation is not recommended. Most of the oxacillin-resistant CNS were resistant to the other beta-lactam drugs except cefamandole. Of 22 CNS resistant to cefamandole, 21 were S. haemolyticus.

Direct examination of material from two cases of persistent (2 and 60 years) osteomyelitis by morphological and culture techniques showed that the pathogens comprised several bacterial species whose cells grew predominantly in discrete exopolysaccharide-enclosed microcolonies made up of a single bacterial morphotype. Bacterial microcolonies were seen between tissue elements in infected connective tissue, and the microcolonies adherent to bone surfaces coalesced to form extensive biofilms that occluded the surfaces of dead bone in sequestrae. Decalcification techniques were required to examine the interior of infected bone, but recognizable remnants were associated with very large amounts of fibrous, ruthenium red-stained material. All bacterial growth in these persistent infections occurred within an intercellular matrix, and some elements of this matrix, which was fibrous in transmission electron microscopy and amorphous in scanning electron microscopy, were associated with the surfaces of bacterial cells in a manner that suggested their production by these organisms. All of the implications of this microcolony mode of bacterial growth in osteomyelitis, and in other chronic bacterial diseases, have yet to be determined.

Intravenous and intraarterial catheters were examined microbiologically and morphologically. Bacteria or yeasts were recovered from 38 of the 63 catheters examined, and Staphylococcus epidermidis was present on 29 of the 38 colonized catheters. Examination of unused Teflon catheters ( Jelco ; Surgikos , Inc., Peterborough , Ontario, Canada) showed surface irregularities, and the examination of colonized intravascular catheters recovered from patients showed very extensive amorphous accretions on both their lumenal and external plastic surfaces. Detailed scanning electron microscope examination of the accretions on vascular catheters from which S. epidermidis had been isolated showed (ca. 0.8 micron) coccoid bacteria within confluent biofilms , in which they were enveloped by amorphous material. Transmission electron microscope examination of these same accretions revealed coccoid cells (ca. 0.8 micron) with a gram-positive cell wall structure living in fibrous matrix-enclosed microcolonies in spaces between squamous epithelial cells. Staphylococcus aureus biofilms were seen to contain coccoid cells (ca. 1 micron) in a very extensive amorphous matrix, and a Candida parapsilosis biofilm contained very large numbers of large coccoid cells (ca. 4.3 microns) in a fibrous matrix resembling fibrin. Cells of a Corynebacterium species appeared to form much less extensive matrix-enclosed microcolonies on the colonized plastic surface. These data indicate bacteria and yeasts colonize intravascular catheters by an adherent biofilm mode of growth on these plastic surfaces.

We examined Tenckhoff peritoneal catheters by scanning and transmission electron microscopy to study the morphology of bacterial adherence. Two catheters were removed from uninfected patients, three from patients with exit site infections, four from patients with peritonitis, and one from a patient with both exit site infection and peritonitis. Infecting organisms included three of Staphylococcus aureus and one each of Enterobacter sp., Staphylococcus epidermidis, Achromobacter xylosoxidans, Serratia sp., Klebsiella sp., and Candida albicans. Considerable morphological variation in adherence to the peritoneal dialysis apparatus occurred. No inflammatory cells were ever seen in association with infected cuffs, only two of the five patients with peritonitis had inflammatory cells associated with their catheters. In both instances, these cells tended to occur in clumps and demonstrated no flattening when in contact with the surface. Colonization of the catheter was uneven--bacteria tended to occur in clusters. Extensive matrix formation was evident in several instances, and condensation of this matrix onto the bacteria during the dehydration process rendered clumps of bacterial cells amorphous at times. Bacteria were adherent to the subcutaneous cuff in those patients with exit site infections. Gram-negative bacteria attached to individual dacron fibers of the cuff, often several layers deep. Gram-positive bacteria tended to adhere in clusters.

A nine-test system using multiple-inoculation agar plates for biotyping of Escherichia coli is described. Testing of 959 strains resulted in 78 biotypes. On repeated testing, 96% of 182 strains had identical biotypes or differed by only one test. This system provides satisfactory differentiation among strains and is reproducible. Precise standardization of inoculum size is not required. Multiple inoculation allows time and cost-efficient testing of large numbers of strains.

STUDY OBJECTIVE: To assess the clinical value of blood cultures (BCs) in the management of adult patients discharged from the emergency department (ED) with a diagnosis of community acquired pneumonia (CAP). METHODS: The courses of antibiotic regimens and outcomes of patients with positive BC results were examined to assess their influence on BCs. RESULTS: BCs were obtained from 289 outpatients. Six clinically significant organisms were identified (a yield of 2.1%). Outpatients with CAP who had blood cultures performed had a 0.69% (2 of 289) chance of having a change of treatment directed by the results of the culture. CONCLUSION: BCs have little utility in the ambulatory management of CAP.

Background. Large studies of invasive pneumococcal disease (IPD) are frequently lacking detailed clinical information. Methods. A population-based 15-year study of IPD in Northern Alberta. Results. 2435 patients with a mean age of 54.2 years formed the study group. Males outnumbered females and Aboriginal and homeless persons were overrepresented. High rates of smoking, excessive alcohol use, and illicit drug use were seen. Almost all (87%) had a major comorbidity and 15% had functional limitations prior to admission. Bacteremia, pneumonia, and meningitis were the most common major manifestations of IPD. Almost half of the patients had alteration of mental status at the time of admission and 22% required mechanical ventilation. Myocardial infarction, pulmonary embolism, and new onset stroke occurred in 1.7, 1.3, and 1.1% of the patients, respectively; of those who had echocardiograms, 35% had impaired ventricular function. The overall in-hospital mortality was 15.6%. Conclusions. IPD remains a serious infection in adults. In addition to immunization, preventative measures need to consider the sociodemographic features more carefully. A standard set of data need to be collected so that comparisons can be made from study to study. Future investigations should target cardiac function and pulmonary embolism prevention in this population.