scholarly journals Modified coagglutination procedure for the serological grouping of streptococci

1979 ◽  
Vol 9 (3) ◽  
pp. 329-332
Author(s):  
J R Carlson ◽  
L R McCarthy

Cowan I staphylococci coated with antisera to streptococcal groups A, B, C, D, F, and G were used as coagglutination reagents in a modified coagglutination procedure (MCAP). Streptococcal group antigens were extracted with a Streptomyces albus-lysozyme enzyme mixture for 30 min at 55 degrees C and centrifuged, and the supernatant was tested by slide coagglutination. Positive coagglutination reactions occurred within 30 s. The cell pellets from overnight broth cultures and colonies taken directly from sheep blood agar plates were tested and compared with the results of the Lancefield capillary precipitin method. Of the 102 strains of broth-grown cells tested, 100 were grouped by the MCAP and the Lancefield capillary precipitin method. The remaining two isolates were serologically identified only by the MCAP. Of the original 102 strains, 97 were tested by MCAP after extraction of five well-isolated colonies from a sheep blood agar plate. When this latter method was used, 95.9% of the strains were correctly identified. Nonspecific reactions were observed only while testing the MCAP with the direct plate assay. These cross-reactions were remedied promptly by either absorption or dilution of the antisera involved. The MCAP was found to be a rapid and reliable technique for the serological grouping of streptococci.

1978 ◽  
Vol 7 (5) ◽  
pp. 426-427
Author(s):  
R E Schmid ◽  
J A Washington ◽  
J P Anhalt

Previous studies have suggested that the yield of Streptococcus pneumoniae from respiratory secretions can be increased by using a 5% sheep blood agar plate supplemented with 5 microgram of gentamicin (GBA) per ml. We report our experience with 245 lower respiratory specimens in which this method was compared with 5% sheep blood agar (SBA) alone. Of 35 specimens with growth of S. pneumoniae on either plate, 21 were detected exclusively on SBA, whereas only 3 were detected on GBA alone (P less than 0.01). By subculturing representative alpha-hemolytic colonies from the final 169 specimens, the yield of S. pneumoniae was increased by 27% compared with the number of identifications that could be made directly from the primary culture. Minimal inhibitory concentrations of gentamicin for the last 25 isolates were greater than or equal to 8 microgram/ml. Our results do not substantiate the previous observations that S. pneumoniae from respiratory secretions gives an increased yield in cultures on GBA.


1979 ◽  
Vol 9 (1) ◽  
pp. 144-146 ◽  
Author(s):  
T Kurzynski ◽  
C Meise ◽  
R Daggs ◽  
A Helstad

The primary plate bacitracin differentiation disk susceptibility test identified 85% of group A streptococci from throat cultures on SXT-BA(CO2) plates within 24 h, as compared to only 26% on a conventional sheep blood agar plate.


2018 ◽  
Vol 23 (4) ◽  
pp. 311-314 ◽  
Author(s):  
Vi Ean Tan ◽  
Alan T. Evangelista ◽  
Dominick M. Carella ◽  
Daniel Marino ◽  
Wayne S. Moore ◽  
...  

OBJECTIVES There is a lack of standardization and supporting data regarding the duration preassembled and preprimed extracorporeal membrane oxygenation (ECMO) circuits are expected to be sterile. Therefore, the purpose of this study was to prospectively evaluate whether preassembled and preprimed ECMO circuits could maintain sterility for a period up to 65 days. DESIGN Four ECMO circuits (2 neonatal/pediatric¼” and 2 adolescent/adult ⅜ ”) were assembled and primed under sterile conditions and maintained at room temperature. Culture samples were obtained from each circuit and plated within 1 hour. Culture samples were obtained on day 0 when assembled and primed then every 5 days up to day 65. Samples were plated on several different media including the following: blood agar plate: trypticase soy agar with 5% sheep blood, MacConkey agar, and thioglycollate broth then incubated at 35°C for 3 days. RESULTS All cultures obtained from the priming solution from of the¼” and ⅜ ” ECMO circuits produced no microbial or fungal growth for the 65-day study period. CONCLUSION These pilot data suggest preprimed ECMO circuits may maintain sterility for a period up to 65 days. Additional studies evaluating a larger number of ECMO circuits are needed to confirm these findings.


PEDIATRICS ◽  
1996 ◽  
Vol 97 (2) ◽  
pp. 288-288
Author(s):  
S. DUBOSE RAVENEL ◽  
GREGORY CARL ELLIS ◽  
WILLIAM N. MICHAL

Roddey et al have reported an important study on the sensitivity and specificity of the Strep A OIA test compared with two culture techniques—5% sheep blood agar and Todd-Hewitt broth—in an office practice setting. They found the sensitivity and specificity of OIA as compared with sheep blood culture to be 91.4% and 95.6%, and compared with the broth method, 90.4% and 94.1%, respectively. They conclude that the OIA method is preferable for the majority of their patients, but recommend a throat culture be performed in cases with a negative OIA test.


2019 ◽  
Vol 8 (1) ◽  
pp. 1-7
Author(s):  
Dora Dayu Rahma Turista ◽  
Eka Puspitasari

BAP media is a medium used to distinguish pathogenic bacteria based on their hemolytic power on red blood cells. Staphyllococcus aureus is a bacterium that is able to emolate red blood cells with 3 types of hemolysis, namely α, β, γ, and δ. Usually BAP media is made by adding 5-10% sheep blood. Making BAP media using sheep blood has become a problem for several laboratories today, including health education laboratories. This is because the health education laboratory does not yet have a sheep farm, so it has not been able to procure sheep blood. The use of human blood as a substitute for sheep blood in making BAP media may be a solution, but it is not yet known whether there are differences in the growth and hemolysis of S. aureus bacteria on BAP media in sheep's blood and human blood. This research is an experimental study with a completely randomized design (CRD) of 3 replications which aims to determine whether there are differences in growth and hemolysis of bacteria S. aureus in BAP media of sheep blood and human blood groups A, B, AB, and O. The results showed that S. aureus bacteria could grow and show hemolysis in BAP media in sheep blood and human blood in groups A, B, AB, and O. The results of subsequent studies analyzed ANOVA using the software spss for windows with a significant level of 0.05. From the results of research and data analysis it can be concluded that S. aureus bacteria can grow and show hemolysis in BAP media of sheep blood and human blood groups A, B, AB and O, but there are significant differences in the number of S. aureus bacteria colonies grown in BAP media of sheep's blood and human blood groups A, B, AB and O.


Author(s):  
Kankan Gao ◽  
Qiulian Deng ◽  
Lianfen Huang ◽  
Chien-Yi Chang ◽  
Huamin Zhong ◽  
...  

Maternal vaginal/rectal colonization of group B streptococcus (GBS) is a main risk for neonatal invasive infection. Efficient determination of GBS colonization in pregnant women is crucial. This study aimed to investigate the prevalence of GBS carriage and evaluate the diagnostic performance of six methodologies for GBS screening conducted in China, including blood agar plate, liquid chromogenic medium, and loop-mediated isothermal amplification (LAMP) without pre-enrichment, chromogenic agar plate with pre-enrichment, and GBS antigen detection without and with pre-enrichment in comparison with the standard reference method (Lim broth-enriched subculture with plating on 5% sheep blood agar). Vaginal/rectal swabs were collected from 1,281 pregnant women at 35–37 weeks of gestation. Of them, 309 were taken in triplicate, one for Lim broth-enriched subculture, one for blood agar plate, and the third for GBS antigen detection (Reagent W); 177 were acquired in duplicate, one for Lim broth-enriched subculture and the other for GBS antigen detection (Reagent H); 502 were obtained in duplicate, one for Lim broth-enriched subculture and the other for liquid chromogenic medium; 158 were collected in duplicate, one for Lim broth-enriched subculture and the other for LAMP; and 135 were inoculated in Lim broth-enriched for GBS antigen detection (Reagent W) and subculture with chromogenic agar plate and 5% blood agar plate. The overall prevalence of GBS carriage was 10.1% (130/1,281, 95% CI: 8.5–12.1%) according to the standard reference method. Compared with the standard reference method, the LAMP had excellent performance of sensitivity (100%, 95%CI: 83.4–100%), specificity (94%, 95%CI: 88.1–97.1%), and Yoden index (0.940); as well as the blood agar plate with sensitivity (81.5%, 95%CI: 61.3–93.0%), specificity (100%, 95%CI: 98.3–100.0%), and Yoden index (0.815). The other four methods were not sufficient to reach the threshold in terms of sensitivity or specificity compared to the standard reference method. Furthermore, for LAMP, results can be obtained within 0.5–1 h, while for blood agar plate, which needed 24–48 h, and further identification was required. Our data suggested that the performance of LAMP was highly comparable to the standard Lim broth-enriched subculture and LAMP is considered as an alternative for fast and accurate GBS screening.


2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Sangeeta Umesh Nayak ◽  
Anushka Kumari ◽  
Valliammai Rajendran ◽  
Vijendra Pal Singh ◽  
Ashwini Hegde ◽  
...  

Objective. The risk to dentists, assistants, and patients of infectious diseases through aerosols has long been recognized. The aim of this study was to evaluate and compare the efficacy of commercially available preprocedural mouth rinses containing 0.2% chlorhexidine (CHX) gluconate, Befresh™ herbal mouthwash, and water in reducing the levels of viable bacteria in aerosols. Materials & Methods. This was a single-center, double-masked, placebo-controlled, randomized, three-group parallel design study. 30 patients (10 patients in each group) were recruited in the study. Patient rinsed mouth with 10 ml of CHX, 10 ml Befresh™, or 10 ml water. All the patients underwent supragingival ultrasonic scaling for a minimum of 30 min. The aerosol collection was done using a blood agar plate. The blood agar plates were kept approximately 12 inches from the patient’s mouth. The microbial culture was analyzed. The colony-forming unit (CFU) counting in all three groups was assessed using one-way ANOVA test to compare among the groups (p value <0.001). The intergroup comparison was done using the post hoc Tukey test. Result. There was a marked reduction in the CFU in the CHX group in all three areas. This was followed by Befresh™ (Sagar Pharmaceuticals) mouthwash. There was no reduction in the CFU of the water group. Conclusion. This study proves that a regular preprocedural mouth rinse could significantly reduce the majority bacteria present in aerosols generated by the use of an ultrasonic unit, and Befresh™ mouth rinse was found to be equally effective in reducing the aerosol contamination to 0.2% CHX gluconate.


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