False-positive detection of Group B Streptococcus (GBS) in chromogenic media due to presence of Enterococcus faecalis in High Vaginal Swabs

Background Group B Streptococcus (GBS) is a gram-positive bacterium and its vaginal colonization is associated with preterm births and neonatal sepsis. Thus, routine screening of GBS in prenatal care before the onset of labour is recommended. Recently chromogenic media have been develop and are found to be useful in rapid and sensitive screening for GBS in vaginal swabs. In the present study we evaluated the performance of chromogenic media for the detection of GBS in vaginal swabs of pregnant Indian women near term. Methodology In this study 201 vaginal swab samples were collected from pregnant women. Swabs were inoculated in chromogenic media (carrot broth).The positive and negative cultures were inoculated on Blood agar and Crome agar plates. The colonies were subjected to 16S rRNA sequencing and gene-specific PCR for confirmation. CAMP and BEA were used for biochemical confirmation. PCR was done on genomic DNA isolated from uncultured vaginal swabs. Result 20/201(9.9%) vaginal swab samples were positive in the carrot broth. 17/20 (85%) and 19/20 (95%) of these samples yielded colonies on Blood agar and Crome agar respectively. Of the 181 carrot broth negative samples 1(0.5%) and 38 (20.9%) yielded colonies on Blood agar and crome agar plates respectively. However 16s rRNA sequencing revealed that none of the 20 carrot broth positive cultures were that of GBS and had sequence similarities to the Enterococcus faecalis. This was also confirmed by using gene specific PCR and BEA positivity. Furthermore, Enterococcus faecalis was detected by PCR in DNA isolated from 57 uncultured vaginal swabs samples, GBS could be detected by PCR only in 4 samples. Conclusion Carrot Broth-based culture can lead to false-positive detection due to the presence of Enterococcus faecalis. Keywords: Streptococcus agalactiae, Infection, PCR, pregnant women, Carrot Broth, Blood agar, Crome agar, Preterm birth, Sepsis

Microbial Analysis of Contact Lenses

Introduction: Contact lenses are small, thin lenses which are worn directly on the surface of the eyes. They can be worn aesthetically or to correct vision. Contact lens related eye infections can lead to serious complications such as blindness, and are associated with several risk factors such as sleeping with lenses, exposure to water, not adhering to replacement schedules, and reusing disinfecting solutions, among others. The severity of the infection may vary with the degree of pathogenicity of the microorganism. Hygiene and handling of contact lenses play a very important role. The main aim of this study is to assess the microbial analysis of contact lenses. Materials and Methods: A total of 15 lenses were collected in 2 ml sterile saline solution individually and manually agitated for five minutes. The lens was then removed using a sterile toothpick from the container. The sterile container was stored at 4°C till it was processed. 50 microliter of the sample was transferred using a pipette and inoculated on nutrient agar, blood agar and sabouraud dextrose agar. The microorganism (fungus or bacteria) were identified by standard protocol. Results and Discussion: Bacillus, Staphylococcus aureus and CONS [Coagulase Negative Staphylococci] were found in blood agar. No fungal growth was found among the samples. More importance could be given to contact lenses handling and hygiene to avoid eye related bacterial and fungal infections. Conclusion: In the present study, the total CFU (Colony Forming Unit) was found to be confluent in all the participants who wore contact lenses for 4 months compared to those who have worn contact lenses from 15 and 28 days. Only bacterial growth was seen in the culture plate. There was no fungal growth seen from the samples collected.

Dentistry and Intensive Care Unit: A Brief Report

Objective The aim of this study is to verify whether removable dentures of patients admitted to an intensive care unit (ICU) are niches of microorganisms that can cause pathologies (Staphylococcus aureus, Candida spp., and enterobacteria). Materials and Methods Fifteen patients who were denture wearers (removable partial denture and complete denture) were included in this study. Patients must wear their dentures daily, and these dentures must have acrylic parts. Microbial biofilm was collected from the acrylic part of one denture of each patient. Then, the biofilm was seeded on different culture media: Sabouraud agar, blood agar, MacConkey agar, and mannitol salt agar. In this study, biochemical evaluations of microorganisms were performed. Statistical analysis The percentage of dentures with the microorganism identified by each culture medium was calculated. Results In total, 100% of the dentures were positive for Staphylococcus spp. (blood agar) and Candida spp. (Sabouraud agar); 33.3% of the dentures were positive for S. aureus (Mannitol salt agar); and 13.3% of the dentures were positive for Shigella spp. (MacConkey agar). Conclusion Removable dentures of patients (removable partial dentures and complete dentures) admitted to an ICU are niches of microorganisms that can cause pathologies.

CAMP test v1

Group B Streptococcus agalactiae has CAMP factor which allow it to hemolized zones when it is grown on blood agar plates near to Staphylococcus aureus ATCC 25293 colonies, this effect is brought about by Staphylococcus aureus sphingomyelinase.

Análise da microbiota de fissuras de dentes molares e pré-molares hígidos de humanos (Estudo quantitativo)

To analyze the groups of microrganisms present on fissures of caries free molars of 5 patients after 24h with no oral hygiene, it was collected the material deposited on its fissures after using erithrosin 0,25% as a disclosing agent. The material was cultivated in blood agar, for analysys of viable microrganisms, and in Veillonella agar, SL agar, TSA and McCarthy meidium, for the study respectevelly of Veillonella, Lactobacillus, iodophilic polysaccharides microrganisms and fusobacterium. The results of the viable microrganisms showed 58% of Gram positive coccus, 32% of Gram negative coccus, 10% of Gram positive rods. It was not found Gram negative rods.

Antibacterial Effect of Gold Nanoparticles Coated Dental Floss against Cariogenic Bacteria

Background: Carious lesions can occur on the proximal surfaces of the posterior teeth. Streptococcus mutans and Streptococcus sobrinus, are the main acidogenic bacteria that are commonly associated to dental caries. Interproximal cleaning is an important form of oral self-care habits, considering such areas of the dentition are easily affected by caries. Accordingly, dental floss has been used as an additional tool to enhance the quality of the cleaning process. It is reasonable that dental flossing should reduce interproximal caries risk because it is capable of removing parts of the interproximal plaque. The aim of this study was to evaluate the antibacterial activity of gold nanoparticle (AuNPs), when coated on unwaxed dental floss.Methods: Streptococcus mutans and Streptococcus sobrinus were cultured in Brain Heart Infusion (BHI) agar. Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the AuNPs with subcultures so obtained. Then, the bacteria were grown and spread on blood agar on which identical lengths (20mm) of unwaxed dental floss coated with gold nanoparticles (AuNPs) at concentration of 0.05, 0.1, and 0.5 mg/mL were placed. Control included untreated unwaxed dental floss and unwaxed dental floss with 0.2% Chlorhexidine (CHX). Five randomized sites of the inhibition zones were measured in millimeters in each concentration per floss. Means ± S.D. of the inhibition zones were calculated.Results: The MIC and MBC of AuNPs against S. sobrinus and S. mutans were 0.5 μg/mL and 1.0 μg/mL, respectively. The results indicated that gold nanoparticles (AuNPs) coated unwaxed dental floss, placed on blood agar with S. mutans and S. sobrinus demonstrated significant inhibition of bacterial growth. Gold nanoparticles (AuNPs) coated unwaxed dental floss at 0.05, 0.1, 0.5 mg/mL resulted in zones of inhibition ranging from 2.93 ± 0.30 mm to 4.71 ± 0.32 mm for S. sobrinus and 2.95 ± 1.73 mm to 5.18 ± 0.61 mm for S. mutans, respectively.Conclusion: Invitro study demonstrated that the AuNPs-coated unwaxed dental floss had antibacterial activities against cariogenic bacteria.

Self Prepared Herbal Mouthwash Used As Pre-procedural Rinse in Reducing Dental Aerosol: A Substitute to Chemical Mouthrinse: A Clinico-Microbiological Study

Aim:To evaluate and compare the efficacy of pre-procedural mouth rinses in reducing microbial content of aerosol product during ultrasonic-scaling procedures by viable bacterial count.Materials And Methods:5 patients were assigned in each group: A- Neem, B -CHX, C-Triphala, D - Control Group.In Group A, B, C -Patient were asked to rinse their mouth with 10 ml mouthwash for 30 seconds before SRP, of which A and C are self- prepared herbal mouthwashes i.e Triphala and Neem. Aerosol will be collected, cultured and incubated on blood agar plates at specified sites from operator. CFU will be counted and result will be assessed statistically. Conclusion: The study suggests that 10 ml of Neem Mouth rinse when used 10 minutes prior to ultrasonic scaling is more potent in reducing the aerosol contamination as compared to the Triphala mouth rinse and commercially available 0.2 % Chlorhexidine mouthrinse. Also the reduction in aerosol content was seen in Tray location when rinsed with CHX and aerosol reduction in Spitoon and Chest location while rinsing with Neem mouthrinse.

Estudo sobre a influência da escovação dental na microbiota da placa dental de crianças

Samples of dental plaque were collected from twenty-eigth children (7 to 12 years) after three periods of eight days under different conditions of oral hygiene: without toothbrushing, with normal toothbrushing and with instructed toothbrushing. After the weigth of the materlal was determined, decimal dilutions were made and spreads in: blood agar, Mitis-Salivarius agar, Mc-Carthy Snyder agar, Rogosa-lactate agar, Rogosa SL medium, Sabouraud agar and Tripticase Soy agar, for enumeration of, respectively, the most numerous cultivated organisms, Streptococus, Fusobacterium, Veilionella, Lactobacillus, Candida and organisms that store intrecellular polysaccharides of the amylopectin type. The obtained results didn’t present sifnificative diferences after the three periods os the experience.