Comparison of throat culture methods for the recovery of group A streptococci in a pediatric office setting.

OBJECTIVE: To compare a single-plate method for the recovery of group A streptococci with other methods that have recently been reported as being significantly more sensitive. DESIGN: Throat swabs were allowed to dry for 2 to 6 hours before inoculating 5% sheep blood agar plates. Stabs were made into the agar, bacitracin disks were placed on the primary plates, and the cultures were incubated aerobically. Using duplicate throat swabs, the recovery rates of the above method were compared with the following ones: a carbon dioxide-enhanced incubation atmosphere, an anaerobic atmosphere with a selective blood agar medium, and a Todd-Hewitt broth medium. SETTING: A five-pediatrician office. PATIENTS: A total of 301 pediatric patients with pharyngitis were evaluated using all comparative methods. In addition, duplicate swabs from 590 pediatric patients were compared with each other using the same single-plate method. RESULTS: There were no significant differences between any of the methods. The sensitivity of the single-plate method compared with selective plates incubated anaerobically was 96%. CONCLUSIONS: In a pediatric office setting, a single-plate method using aerobic incubation was adequately sensitive for the recovery of group A beta-hemolytic streptococci. Transport medium, selective medium, carbon dioxide enhancement, and anaerobic incubation did not significantly improve recovery. The present federal regulations that restrict the use of nonselective media and bacitracin disks on primary plates should be reevaluated.

Comparison of an optical immunoassay technique with two culture methods for the detection of group A streptococci in a pediatric office.

For detecting group A beta-hemolytic streptococci in an office setting, an optical immunoassay method was compared with two culture methods. The sensitivity and specificity of OIA as compared with 5% sheep blood agar cultures were 91.4% and 95.6%, and as compared with a Todd-Hewitt broth method were 90.4% and 94.1%, respectively.

Furosemide-associated fever.

We describe a 5-month-old infant who had fever of unknown origin leading to an exhaustive evaluation during a 7-week period. Fever caused by the use of furosemide was proved; the fever resolved after discontinuation of this medication and recurred after its reintroduction.

Comparison of immediate and delayed culture methods for isolation of group A streptococci.

Recovery rates of Group A beta-hemolytic streptococci in throat cultures from 300 children were studied using three different methods. The swabs were streaked onto plates immediately, streaked from the same dry swabs held at room temperature for 3 to 6 hours and streaked from swabs held in transport media at room temperature for 3 to 6 hours. The cultures were processed in a pediatric office and interpreted by a microbiologist. The recovery rates were similar for the three methods, but the cultures were easier to interpret when the swabs had been allowed to dry before streaking as a result of a decrease in the normal flora on these plates. In a separate study the recovery of Group A beta-hemolytic streptococci from 187 swabs was identical whether the swabs were streaked at 3 to 6 hours or at 18 to 24 hours.

Acute suppurative thyroiditis caused by Eikenella corrodens.

Eikenella corrodens is a slow-growing facultative anaerobe present in the normal oral flora. Two children have been described with acute suppurative thyroiditis with E corrodens as the major pathogen. Staphylococci are the most frequently identified pathogens in acute suppurative thyroiditis. Penicillin or ampicillin are the drugs of choice for infections caused by E corrodens. Anatomic defects should be searched for in children with acute suppurative thyroiditis.

Comparison of a latex agglutination test and four culture methods for identification of group A streptococci in a pediatric office laboratory.

A latex agglutination test and four culture methods for the detection of group A hemolytic streptococci were compared in a pediatric office laboratory. The anaerobic (GasPak) and Detekta-Kit methods produced the highest recovery rates, but aerobic incubation of 5% blood agar plates gave very acceptable results (sensitivity 92%, or 98% if the 1+ positive cultures were eliminated; specificity 100%), and had fewer disadvantages. Delaying inoculation of plates for 2 to 6 hours resulted in significantly greater numbers of strongly positive (3+ and 4+) cultures. The group A selective sheep blood agar media as used in this study offered no advantage. The Culturette test had a sensitivity of 72% and specificity of 98%, compared with the GasPak method, and 77% and 97%, respectively, compared with standard aerobic cultures. Thus it appears too insensitive to be used alone, but might complement culture methods in selected patients.

The role of pili and capsule in the pathogenesis of neonatal infection with Escherichia coli K1.

The role of pili and capsule was studied in neonatal infection with Escherichia coli K1. E coli strains were selectively cultured into three phases: mannose-sensitive (MS) piliated, non-mannose-sensitive (NMS) piliated, and nonpiliated. A high percentage of neonatal rats fed each phase of K1 strains developed bacteremia; there was no bacteremia with non-K1 strains or an acapsular mutant of K1 strain C94 (C94K-). Oral cavity colonization was noted in nearly 100% of rats fed K1 strains, non-K1 strains, or C94K-, regardless of the phase of piliation at feeding. Only MS piliated bacteria were found on oral cavity culture, indicating a rapid shift of NMS piliated and nonpiliated bacteria to the MS piliated phase. Conversely, only nonpiliated bacteria were found on blood culture when neonatal rats were fed piliated bacteria. Colonization of ileal epithelium was not observed. Thus, in vivo phase variation may be important in colonization and bacteremia with E coli K1.

Mammaplasty-associated mycobacterial infection: a survey of plastic surgeons.

In a 3 1/2-year period, periprosthetic infections due to Mycobacterium fortuitum complex organisms complicated augmentation mammaplasty in at least 17 women. To determine the magnitude of the problem and to identify possible risk factors for infection, we conducted a questionnaire survey of 2062 members of the American Society of Plastic and Reconstructive Surgeons who had performed approximately 64,00 augmentation mammaplasties in 1978. Information about selected aspects of the procedures and practices in use with augmentation mammaplasty and about patients for whom augmentation mammaplasty had been performed was supplied by 67 percent of those surveyed. The estimated attack rate of wound infection after augmentation mammaplasty caused by all organisms was 0.64 percent. Only 5 cases of mycobacterial wound infection were documented after 39,455 augmentation procedures in 1978. Periprosthetic infection due to Mycobacterium fortuitum complex organisms appears, for the most part, to be a sporadic event that may occur after simple augmentation mammaplasty, subcutaneous mastectomy with augmentation, or reduction mammaplasty.

Infection due to organisms of the Mycobacterium fortuitum complex after augmentation mammaplasty: clinical and epidemiologic features.

Periprosthetic infections due to Mycobacterium fortuitum and Mycobacterium chelonei occurred in 17 women over a 3.5-year period after implantation of prostheses for breast augmentation. The median incubation period for 16 of the women was 28 days (range, one week to over two years) after surgery; etiologic diagnosis was usually delayed for weeks to months. Odorless and serosanguineous or purulent material was found when the implants were removed, and acid-fast bacilli were often present when smears were examined. Wound infections were chronic and refractory to therapy with various antimicrobial agents. Persistent or recurrent mycobacterial infections complicated attempts to implant new prostheses. Whereas M. fortuitum isolates were susceptible to amikacin, multiple strains of M. fortuitum were distinguished by conventional antituberculous and broth microdilution susceptibility tests. Several clusters of infections were temporally and geographically related; however, sporadic cases were also reported, and no evidence of a contaminated common product or other single source of infection was found.

Transmission of group B streptococci. Traced by use of multiple epidemiologic markers.

During a three-week period, septicemia caused by group B Streptococcus, serotype III, developed in four infants born at a community hospital. The first infant had early-onset disease; late-onset disease that appeared, from epidemiologic data, to be nosocomial developed in the other three infants. Bacteriophage typing and antimicrobial susceptibility testing confirmed the relatedness of the isolates. A prospective study designed to differentiate between vertical and nosocomial transmission of group B Streptococcus showed that of 82 infants, 21 (26%) were culture-positive during their hospitalization, and nine of these infants (43%) had been culture-negative at birth. Although serotype III strains were recovered from four of nine infants with apparently nosocomial acquisition, none of the isolates displayed an antibiogram or bacteriophage type similar to that of the isolates involved in the recent cluster. Bacteriophage typing and antimicrobial susceptibility testing in addition to the use of serotyping may be helpful in epidemiologic studies of group B Streptococcus.

Gentamicin treatment associated with later nosocomial gentamicin-resistant Serratia marcescens infections.

During a hospital epidemic of infections with gentamicin-resistant Serratia marcescens (GRS), we studied the relation between receiving antibiotics and acquiring GRS. In a five-month period, 22 patients acquired GRS, whereas 18 patients acquired gentamicin-sensitive Serratia (GSS). When compared with patients with nosocomial GSS infection, patients with nosocomial GRS had been in the hospital (p = 0.04) and the intensive care unit (p = 0.003) longer before infection and more had received gentamicin (p = 0.001) or ampicillin (p = 0.02) before infection. To control for the influence of underlying disease, we matched all 12 ICU patients with GRS infection and 12 patients without GRS infection for underlying illness and duration of intensive care. Use of any antibiotic (p = 0.04), or a combination of gentamicin plus ampicillin or cephalosporin (p = 0.047) was more common among patients with GRS infection. The hospital had not significantly increased the use of aminoglycosides from the previous year. We conclude that for the individual patient antimicrobial therapy, especially with gentamicin or ampicillin, creates a risk for later infection by GRS that is independent of the severity of the underlying illness.

Fulminant neonatal meningococcemia.

Neisseria meningitidis is a rare cause of infection in infants younger than 2 months of age, presumably because of transplacental passage of protective maternal antibodies. In most reported cases of meningococcal disease in neonates, a relatively mild clinical course has been observed. A 25-day-old infant survived acute, severe meningococcemia due to group B N meningitidis. This organism should be considered when neonates have signs of septicemia, especially in the presence of cutaneous petechiae and purpura.

Legionnaires' disease in Kingport, Tennessee.

In August and September 1977 a discrete cluster of 27 serologically or pathologically confirmed cases of Legionnaires' disease, plus six highly presumptive cases were identified in the area of Kingsport, Tennessee. Three patients died. Most patients manifested severe pneumonia and fever; no mild or asymptomatic disease forms were recognized despite intensive case-finding efforts. Illness was epidemiologically associated with residing, visiting, or working in one geographic area of Kingsport, residence there being the factor most strongly associated. Although the attack rate for area residents was 0.64%, the randomly determined prevalence of serologic reactors was 5.2%, which is not significantly different from that in a nonimplicated control neighborhood. The epidemic did not correlate temporally with any identified environmental or demographic event. No source of the bacterium was found either by a detailed case-control study of area associations or by bacterial isolation from sentinel guinea pigs or environmental specimens. There was no evidence of person-to-person spread.

Sporadic community-acquired Legionnaires' disease in the United States. A case-control study.

One hundred patients with sporadic, community-acquired, serologically confirmed Legionnaires' disease were matched with control subjects known by the patients (acquaintance controls) and control subjects chosen from among patients with negative serodiagnostic tests for Legionnaires' disease (clinical controls). Each clinical control subject was also matched with an acquaintance control of his own. Legionnaires' disease patients had smoked more cigarettes, consumed more alcohol, and were more likely to have resided near excavation sites than acquaintance or clinical control subjects. Parallel differences between clinical controls and their acquaintances were not seen. Legionnaires' disease patients had traveled away from home for more time during the 2 weeks before onset of illness than had their acquaintances. The difference was of greater magnitude than that between clinical control subjects and their acquaintances. Legionnaires' disease patients were more likely to have resided near construction sites than clinical controls, and there were more construction workers among patients than among clinical control subjects.