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R Facklam

Publications and source records attributed to R Facklam.

32 records · Page 2Linked to original sources
PubMed1995

Evaluation of three disk tests for identification of enterococci, leuconostocs, and pediococci.

Simple rapid tests for presumptive identification of catalase-negative non-beta-hemolytic cocci (i.e., enterococci, leuconostocs, and pediococci) have not previously been available. Seven hundred thirty-four strains of aerobic and facultatively anaerobic, catalase-negative, non-beta-hemolytic gram-positive cocci were tested for susceptibility to vancomycin (Vans) by a screening procedure and production of leucine aminopeptidase (LAPase) and pyrrolidonylarylamidase (PYRase) in disk tests. Three unique patterns of activity in response to the three disks (30 micrograms of vancomycin, PYRase, and LAPase) can be used to presumptively identify the vancomycin-resistant (Vanr) enterococci (Vanr and PYRase and LAPase positive), leuconostocs (Vanr and PYRase and LAPase negative), and pediococci (Vanr, PYRase negative, and LAPase positive). The results indicate that, together with Gram stain characteristics and the catalase test, the vancomycin, LAPase, and PYRase disk tests can be used to presumptively identify Vanr strains of enterococci as well as Leuconostoc and Pediococcus strains from human infections.

Aminopeptidases↗
PubMed1992

Molecular epidemiology of group B streptococcal infections: use of restriction endonuclease analysis of chromosomal DNA and DNA restriction fragment length polymorphisms of ribosomal RNA genes (ribotyping).

Epidemiologic investigation of group B streptococcal (GBS) infections has been limited by the lack of a discriminatory typing system. Therefore, the use of restriction endonuclease analysis of chromosomal DNA (REAC) and DNA restriction fragment length polymorphisms of rRNA genes (ribotyping) to subtype molecularly GBS isolates associated with human invasive disease was investigated. Chromosomal DNA of selected GBS isolates was initially digested with 24 different restriction enzymes. HhaI gave the best discrimination of hybridization banding patterns (ribotypes) and was used with all study isolates. Ribotyping and REAC differentiated among isolates of the same and different serotypes. Nine ribotype patterns were noted among the 76 isolates studied, including 4 among serotype Ia/c and 4 additional ribotypes among serotype III isolates. Epidemiologically related isolates (e.g., mother-infant or twin-twin pairs) had identical REAC and ribotype patterns. Epidemiologically unrelated isolates with the same ribotype usually had different REAC patterns, suggesting that REAC may be a more sensitive technique for strain differentiation. REAC and ribotyping were reproducible and proved to be successful molecular epidemiologic methods for subtyping GBS.

Adult↗
PubMed1992

Analysis of multiply antimicrobial-resistant isolates of Streptococcus pneumoniae from the United States.

Streptococcus pneumoniae isolates resistant to penicillin, chloramphenicol, tetracycline and sulfamethoxazole-trimethroprim are being recovered with increasing frequency in the United States. We analyzed the penicillin-binding proteins (PBPs), multilocus enzyme electrophoresis (MLEE) genotypes, and ribotypes of 22 multiresistant serotype 23F isolates of S. pneumoniae from the United States and 1 isolate each from Spain and South Africa. Also included were seven multiresistant isolates of other serotypes, three penicillin-resistant but chloramphenicol-susceptible serotype 23F isolates, and two penicillin-susceptible isolates (one penicillin-susceptible isolate was serotype 23F). Fifteen of the 22 multiresistant isolates from the United States and the isolates from Spain and South Africa had identical PBP patterns, MLEE profiles, and ribotypes. Six of the remaining seven multiresistant isolates were related by PBP pattern, but demonstrated slightly different MLEE and/or ribotype profiles, possibly because of acquisition of additional resistance markers (four of the six isolates were also resistant to erythromycin). The remaining multiresistant serotype 23F isolate had a unique PBP pattern and ribotype and was only distantly related to the other pneumococcal isolates by MLEE analysis. The PBP patterns, MLEE profiles, and ribotypes of the multiresistant serotype 23F isolates were easily distinguished from those of six multiresistant isolates of other serotypes; three other penicillin-resistant, chloramphenicol-susceptible, serotype 23F isolates; and two penicillin-susceptible isolates. One exception was a multiresistant serotype 19A isolate that was highly related to the clonal group by PBP pattern and MLEE analysis and that had a ribotype similar to those of the other erythromycin-resistant serotype 23F isolates. MLEE analysis and ribotyping were more discriminating than were the PBP patterns in discerning strain differences. These data strongly suggest that a multiresistant clone of S. pneumoniae serotype 23F that is related to multiresistant isolates from Spain and South Africa has become disseminated in the United States. Clinicians should be alerted to the spread of these multiresistant strains in the United States.

Autoradiography↗
PubMed1991

Epidemiologic studies of group 9 pneumococci in terms of protein type and 9N versus 9V capsular type.

The variability among Streptococcus pneumoniae isolates of capsular group 9 was analyzed with a panel of six monoclonal antibodies to pneumococcal proteins. These antibodies differentiated the 104 group 9 isolates into 18 protein types and a group (PO) not typable with the antibody panel was used. Capsular type was determined for 87 isolates: 70% were capsular type 9V, 28% 9N, and 2% 9A. In terms of protein type, the 9V isolates were four times as diverse as the 9N isolates. Significant associations were observed between the protein type, geographic origin, and year of isolation. Statistically significant associations were also observed between different manifestations of pneumococcal disease and protein type of the capsular type 9V isolates. Thus, even within capsular types, pneumococci can be highly diverse; pneumococcal protein types may be useful in epidemiologic studies to distinguish related strains in the environment.

Adolescent↗
PubMed1989

Identification of gram-positive coccal and coccobacillary vancomycin-resistant bacteria.

A total of 84 of 150 vancomycin-resistant (defined as no inhibition of bacterial growth around a 30-micrograms vancomycin disk placed on 5% sheep blood-Trypticase soy agar [BBL Microbiology Systems, Cockeysville, Md.]) bacteria were definitively identified by determining the phenotypic criteria. The identity of representatives was also confirmed by DNA-DNA hybridizations. The following strains were identified: 1 Enterococcus faecium, 18 Leuconostoc mesenteroides, 15 Leuconostoc citreum, 9 Leuconostoc pseudomesenteroides, 2 Leuconostoc lactis, 20 Pediococcus acidilactici, 5 Pediococcus pentosaceus, and 14 Lactobacillus confusus. The remaining vancomycin-resistant strains were identified as probable Leuconostoc (6 strains), probable Pediococcus (1 strain), and probable lactobacilli (28 strains). A total of 32 strains of gram-positive coccobacillary bacteria remained unidentified. Tests used for the phenotypic identification of strains to the genus level included a Gram stain of bacteria grown in thioglycolate broth, gas production in Lactobacillus Mann, Rogosa, and Sharpe broth, hydrolysis of pyrrolidonyl-beta-naphthylamide, bile-esculin reaction, demonstration of streptococcal group D antigen, and growth at 10 and 45 degrees C and in 6.5% NaCl broth. Strains were identified to the species level by hydrolysis of esculin, reactions in litmus milk, slime production on 5% sucrose agar, acidification of maltose, melibiose, and raffinose broths, deamination of arginine, and growth at 42 degrees C and in 6.5% NaCl broth.

Catalase↗
PubMed1988

Microbiological and clinical significance of a new property of defective lysis in clinical strains of pneumococci.

A pneumococcal isolate that caused relapsing meningitis in a patient infected with human immunodeficiency virus (HIV) was found to display an unusual response to penicillin--rapid death but a striking lack of cellular lysis. This lytic defect was also detected in all four pneumococcal isolates from three additional HIV-infected patients and in more than half of the clinical isolates from patients with bacteremia. In a rabbit model of meningitis, the lysis-defective strain remained cryptic, with a delay of 5 h in the onset of leukocytosis in cerebrospinal fluid. A marked burst of leukocytosis was associated with ampicillin-induced lysis of a lysis-sensitive strain but not of a lysis-defective strain. Pneumococcal clinical isolates have different lytic responses to penicillin; defective lysis may adversely affect the course of meningitis, an observation suggesting that autolysins play a role in modulating infectious diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Comparison of physiologic tests used to identify non-beta-hemolytic aerococci, enterococci, and streptococci.

Twenty-one reference strains and 88 clinical isolates of Aerococcus, Enterococcus, and Streptococcus species were tested for reactions in the Rapid Strep (RS) and modified conventional tests. We conclude that some but not all of the tests in the RS system could be used to substitute for conventional tests. RS tests for hydrolysis of arginine, esculin, L-pyrrolidonyl-naphthylamide, production of acetyl methyl carbinol (Voges-Proskauer), and fermentation of arabinose, lactose, mannitol, raffinose, and sorbitol were satisfactory substitutes for conventional tests. However, the RS tests for hydrolysis of hippurate and starch and fermentation of inulin were not satisfactory substitutes for conventional tests. We also conclude that, of the five test tube Voges-Proskauer tests, the Coblentz modification is the most discriminatory.

Bacteriological Techniques↗
PubMed1985

Comparative evaluation of the API 20S and AutoMicrobic gram-positive identification systems for non-beta-hemolytic streptococci and aerococci.

The API 20S system (Analytab Products, Plainview, N.Y.) and the AutoMicrobic Gram-Positive Identification system (GPI; Vitek Systems, Hazelwood, Mo.) were evaluated for their capacity to identify the non-beta-hemolytic streptococci and aerococci to the species level. The 20S system identified 86% (six of seven strains) of nonhemolytic group B streptococci, whereas 100% of the same group B streptococcal strains were correctly identified by the GPI system. With both systems 99% (134 of 135 strains) of four species of group D enterococcus strains and 92% (24 of 26 strains) of the Aerococcus spp. strains were identified. The 20S system identified 84% (41 of 49 strains) of three species of group D non-enterococcus strains. The GPI system identified 96% of the same group D non-enterococcus strains. The 20S system identified 84% (190 of 226 strains) of 10 species of viridans streptococci; however, supplemental conventional tests were required to identify 49% (110 of the 226 strains) of the viridans strains to the species level. The GPI system identified 79% of the same viridans streptococci without the need for supplemental tests. Both systems identified 84% (161 of 192 strains) of the seven most commonly occurring viridans Streptococcus spp. The 20S system identified 82% (75 of 92 strains) and the GPI system identified 84% (54 of 64 strains) of Streptococcus pneumoniae.

Bacteriological Techniques↗
PubMed1978

Serological identification of group A streptococci from throat scrapings before culture.

The use of a microtechnique (modified nitrous acid extraction) to test samples from 150 school children and from patients with acute follicular tonsillitis has indicated that group A streptococci in the throat can be identified from tonsillar scrapings in 30 min. The results are comparable to the grouping results obtained by standard throat culture techniques and the Lancefield procedure for grouping. No cross-reaction with other bacteria or cellular material occurs. Study has also shown that the nitrous acid extraction yields three- to fourfold more polysaccharides than the Lancefield hot-HCl of Fuller formamide techniques. The use of the microtechnique leads to another 20-fold concentration of the antigen. Immune salting-out effect could be obtained with 1.00 M sodium acetate. Such molarity is too low to cause nonspecific slating out. It leads to a strong ampliciation of the precipitin reaction.

Child↗
PubMedDate not supplied

emm typing and validation of provisional M types for group A streptococci.

This report discusses the following issues related to typing of group A streptococci (GAS): The development and use of the 5' emm variable region sequencing (emm typing) in relation to the existing serologic typing system; the designation of emm types in relation to M types; a system for validation of new emm types; criteria for validation of provisional M types to new M-types; a list of reference type cultures for each of the M-type or emm-type strains of GAS; the results of the first culture exchange program for a quality control testing system among the national and World Health Organization collaborating centers for streptococci; and dissemination of new approaches to typing of GAS to the international streptococcal community.

Antigens, Bacterial↗
PubMedDate not supplied

Foodborne streptococcal pharyngitis after a party.

Following a private party in Río Piedras, PR, 23 (56 percent) of those who attended developed an illness characterized by pharyngitis, myalgia, fatigue, headache, and fever. Consumption of carrucho (conch) salad was significantly associated with illness (P = 0.013, Fisher's exact test). Group A beta-hemolytic streptococci (M nontypable T12, serum opacity factor positive) were isolated both from throat cultures in 11 of 47 persons who attended the party and from the implicated food. The original source of contamination of the conch salad was not identified. Because complications may still occur from such infections and only a small percentage of persons with sore throats seek medical attention and ultimately receive treatment for their illnesses, it is important to recognize these outbreaks.

Disease Outbreaks↗