CHARACTERIZATION OF BIOFILM FORMATION BY CANDIDATE PATHOGENS ISOLATED FROM STOOL SAMPLE OF STUNTING AND HEALTHY INFANTS

• Main Author: Haunan Priena, Ghaitsa
• Format: Final Project
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/83020
• Institution: Institut Teknologi Bandung

Stunting is a chronic malnutrition condition that leads to non-optimal physical and cognitive development. Malnutrition in children is a risk factor for infections that cause an imbalance in the gut microbiota or dysbiosis, characterized by an increase in pathogenic bacteria. One of the defense mechanisms that pathogenic bacteria have is by forming biofilms on the intestinal mucosa. Therefore, the objectives of this study were: (1) Comparing microbial abundance in stool samples from infants with stunting and healthy prevalence; (2) Determining the ability of candidate pathogenic bacteria that can cause stunting based on resistance to stresses that mimic gastric conditions (pH 3, 4, 5, and 7) and mimic intestinal conditions (pH 4, 5, and 7 + 0.3% w/v bile salt) through biofilm formation ability; (3) Determining the growth pattern of selected candidate pathogenic bacteria; (4) Determining the resistance of selected candidate pathogenic bacteria to antibiotics. The study was conducted using fecal samples from 4 infant subjects aged <12 months in Rancakalong, Sumedang Regency. Isolation and purification were performed using selective medium Staphylococcus Agar, Salmonella Shigella Agar, Eosin-methylene Blue Agar, and Thiosulfate-citrate-bile salts-sucrose Agar, incubation 48 hours, temperature 37oC without agitation. Selection of candidate pathogen isolates was carried out through the biofilm assay method by giving gastrointestinal pH stress (3,4,5, and 7) on Luria Bertani growth medium, 48 hours incubation, 37oC temperature without agitation. Isolates passed the test, were selected again through the biofilm assay method by applying gastrointestinal pH stress (4, 5, and 7) + 0.3% w/v bile salt on Luria Bertani growth medium, incubation 48 hours, temperature 37oC without agitation. The growth pattern of candidate pathogenic bacteria was measured through growth curves for 24 hours, incubation at room temperature 25oC without agitation with Luria Bertani medium. Antibiotic resistance testing was performed using the Liofilchem Gram Negative SensiTest. Based on the results of the study, the abundance of fastidious and non-fastidious bacteria was higher in stunted samples (2.0x109 CFU/g and 1.2x109 CFU/g) compared to healthy samples (9.0 x108 CFU/g and 5.7x108 CFU/g). Based on the isolation results, 27 isolates of pathogenic candidates were obtained, which were dominated by Gram-negative rods-shaped bacteria. Based on the results of biofilm formation selection on medium with pH stress (3, 4, 5, and 7), 7 isolates were obtained that had biofilm former ability (OD>ODcut = 0.24) at pH 3, isolates FS705, FS801, FS808, FS810, FN702, FN801, and FN803. Meanwhile, further selection on the growth medium of pH 5 + 0.3% w/v bile salt stress with an incubation time of 48 hours, obtained 5 isolates of pathogen candidates that have strong biofilm former ability (OD > ODcut = 0.74), isolates FS705, FS801, FS808, FN702, and FN801. Isolates FS705, FS801, FS808, and FN702 experienced log phase in the first 12 hours and stationary in the 12th to 24th hours, but isolate FN801 experienced log phase in 9 hours and stationary phase in the 9th to 24th hours. Isolates that formed the strongest biofilm among strong biofilm former isolates were isolate FS705 (OD = 1.01) and isolate FS801 (OD = 0.77), with isolate FS801 resistant to Fosfomycin antibiotic.