Biofilms

Aims: Nowadays, Staphylococcus aureus, especially methicillin resistant Staphylococcus aureus (MRSA), emerged as a major pathogenic agent of nosocomial infection and sepsis worldwide. Infections caused by these bacteria are often difficult to treat because of the development of antibiotic resistance. Biofilm formation is an important factor in the pathogenicity of staphylococcal infections and one of the reason of antibiotic treatment failure. In this study, the relationship between biofilm formation properties, the presence of mecA, icaA/D genes and antimicrobial resistance pattern were investigated in 10 methicillin sensitive Staphylococcus aureus (MSSA) and 10 MRSA clinical isolates. Methodology and results: Staphylococcal strains were identified by conventional microbiological methods, while determination of methicillin susceptibility was distinguished by the presence of mecA gene. To investigate biofilm production, congo red agar and microtiter plate test were performed. PCR was done to detect the presence of icaA/D genes, which responsible for biofilm production. Antibiotic sensitivity was carried out by agar diffusion method. The majority of MRSA isolates (90%) were not able to form biofilm, only one isolate (10%) showed capability of weak biofilm producer. Meanwhile, fully established biofilms were formed by all of MSSA isolates (100%). In addition, all MRSA and almost MSSA isolates (90%) harboured both icaA/D genes in their chromosomes. Antibiotic resistance profile of MRSA was more dominant than MSSA isolates. Conclusion, significance, and impact of study: Biofilm production of staphylococci showed difference regulation with regard to methicillin susceptibility. Antibiotic resistance profile was more dominant in MRSA, however biofilm production was found mostly in MSSA isolates.
Biofilms

Aims: Biofilm is an assemblage of microorganisms enclosed in a matrix of extracellular materials, such as, extracellular polysaccharide (EPS), and relates to bacterial virulence, pathogenesis, and environmental survival. Bacteria inside biofilm are more resistant to conventional antibiotics and the host immune system. Non-biocidal antibiofilm compounds have been developed to address this problem. Specifically, actinomycetes have known to produce many metabolite compounds that have useful application in medicine and biotechnology. The study aimed to characterize bioactive compounds from actinomycetes crude extract that have capability as a multispecies antibiofilm agent. Methodology and results: In this study, none of the isolates had shown any antimicrobial activity. Based on the antibiofilm assay, most of the isolates have the capability to inhibit and to destroy biofilm formation of pathogenic bacteria at a 5% and 10% dosage. The crude extracts showing the highest activity for antibiofilm inhibition were extracted from Streptomyces sp. The characterization of the bioactive compounds showed that different components of a particular isolate responsible for its antibiofilm activity against pathogenic bacteria. The SW19 isolate had a nucleic acid, KP12 isolate had a combination of the three component (polysaccharide, protein, and nucleic acid), and CW17 isolate had a combination of polysaccharide and nucleic acid as the active compound for antibiofilm activity. Conclusion, significance and impact study: Thus, the bioactive crude extracts from actinomycetes has high potential to be used in treating biofilm-related infection and further research is needed to purify the bioactive compound from the crude extract which has antibiofilm activity against Gram-positive and Gram-negative pathogens.
Biofilms

Introduction: The formation of bacterial biofilms by opportunistic microorganisms on the surfaces of the implants is the leading etiopathogenetic factor of peri-implant mucositis and peri-implantitis. The purpose of this research was to study the adhesive and biofilm-forming properties of clinical strains of K. kristinae isolated from patients with peri-implant mucositis. Methods: 18 clinical strains of K. kristinae isolated from the patients were the object of the study. The adhesion of the microorganisms was determined by using formalized human red blood cells of the blood group O (1) Rh+ by the G. Brilis technique. The study of biofilm-forming properties of clinical isolates of K. kristinae was performed by using the spectrophotometric technique by G.D. Christensen (MtP microtiter plate test). Results: The representatives of genus Kocuria were isolated in 70% of patients. Total proportion of clinical isolates of Kocuria spp. among all isolated microorganisms reached 18.3%. The representatives of the species K. kristinae showed a high adhesion to red blood cells and high ability to form biofilms. The r-Pearson coefficient (+0.87) between adhesion and the ability to form biofilms by K. kristinae strains pointed out a direct correlation. Conclusions: Obviously, Kocuria spp. take part in peri-implant mucositis development. It is proved by their presence on the mucous membrane of peri-implant area of patients with complications after dental implant placement. The representatives of the species K. kristinae showed a high adhesion and high biofilmformation.
Biofilms

Aims: Accurate diagnosis and proper treatments of osteomyelitis are often difficult and ineffective due to several reasons such as less sensitive sample collected and the formation of biofilm following prosthetic use. Thus, our goal of this study is to identify suitable sample for laboratory diagnosis and also microbial species that cause osteomyelitic infection and discriminate between biofilm and non-biofilm producing strains in patients at Hospital Tengku Ampuan Afzan, Kuantan. Methodology and results: Samples of bone, prosthetic material, tissue and swab were collected from patient with suspected osteomyelitis at the hospital. Bacteria were isolated from sample using methods such as homogenization, direct transfer, and sonication. Then, species identification was done by colony characterization, biochemical test and the API identification system. Once species identified, tissue culture plate method was performed to discriminate the biofilm-producing strain from the non-biofilm-producing strain. The total number of 57 samples were collected from 17 cases of suspected osteomyelitis with 34 samples were found positive bacterial growth. Prosthetic samples produced highest positive growth with 81.3%, following by bone samples with 66.7% while swab and tissue samples with 46.2% and 43.8% respectively. We found that 14 from total 16 pathogens identified were biofilm producing-strains. Conclusion, significance, and impact of study: Prosthetic and bone samples produced higher bacterial growth, in contrast to other type of samples. Sonication method improves bacterial detection. Biofilm producing-bacteria were also the most common isolated strains from osteomyelitic infection. These have underscored the need to revise current clinical and laboratory practice as proper identification biofilm bacteria may influences management an outcome.
Biofilms ; Osteomyelitis

Aims: Biofouling is a common biology phenomenon occuring on ship surface. This phenomenon has become serious threat in marine industries because of great economic loss. Tributyltin has been used to prevent biofouling, but it turned to cause the environmental problem. Therefore, the discovery of alternative environment-friendly compound is necessarily needed. Methodology and results: Five Actinobacteria isolates and fourteen marine bacteria isolates were tested against the biofilm formation of eight biofouling bacteria isolates that isolated from boat surface and the attachment of three biofouling diatoms (Amphora, Navicula, Nitzschia). Actinobacteria CW17 supernatant showed the broad spectrum activity against all fouling bacteria, whereas BC 11-5 supernatant was the only marine bacteria that capable to inhibit biofilm formation of V. neocaledonicus. Moreover, three representative diatoms attachment could be inhibited by the bioactive compounds produced by Actinobacteria and marine bacteria. CW01 supernatant showed broad spectrum and high activity against all three representative diatoms which is very promising. Molecular identification based on 16S rDNA gene sequence showed eight fouling bacteria isolates were biofilm-forming bacteria. Conclusions, significance and impact of study: This research showed aquatic Actinobacteria and coral-associated marine bacteria have the potential to prevent biofouling formation. Further studies are needed to purify and characterize these antibiofouling compounds for environmental application.
Biofouling ; Biofilms

No abstract available.
Biofilms* ; Enterococcus*

No abstract available.
Biofilms* ; Lymphocytes* ; Porphyromonas gingivalis

No abstract available.
Biofilms* ; Porphyromonas gingivalis

OBJECTIVETo investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR).

METHODSReduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM) formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3 degrees C, however, it could quickly rise to over 50% above 3degrees C. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.