Screening Lactic Acid Bacteria for Antimicrobial Compound Production

Lactic Acid Bacteria was known as potential probiotic used in food industries and dairy products and probable to produce antimicrobial compound that inhibit variety of microorganisms. The objectives of the research are to determine the optimum condition and glucose utilization in relation to antimicrobial compound production. Two species of Lactic Acid Bacteria namely Lactococcus and Lactobacillus were used as probiotic. The Lactic Acid Bacteria were fermentated in different medium, initial substrate pH and incubation temperature for the production of antimicrobial compound. The test organisms such as E.coli and Salmonella were selected as test organisms. Amongst the two species of Lactic Acid Bacteria, Lactococcus produced the highest amount of antimicrobial compound than Lactobacillus

DAYA ANTI MIKROBA EKSTRAK PROPOLIS TERHADAP KOLONI Staphylococcus aureus SECARA IN VITRO

Staphylococcus aureus is a positive gram coccus bacterial and prime invasive human pathogen. Propolis is known to have the antimicrobial ability to positive and negative gram bacterial. It is suspected to have the ability to cause antimicrobial effect due to the active substances it contains; flavonoid, phenolic acid and terpenoid which work by damaging cytoplasm membrane. The objective of this research is to prove the antimicrobial effects of propolis extract to Staphylococcus aureus, using True Experiment Post Test Only Control Group Design. The method used in this research was tube dilution with 6 propolis extract concentrations of: 12.5%, 6.25%, 3.125%, 1.56%, 0.78%, 0.39% and 2 controls (material and germ control). The data was analyzed by variant analysis (ANOVA). The result of MBC (Minimal Bactericidal Concentration) was on the concentration of 12.5%. The result of ANOVA test showed that was significant difference among treatments (p = 0.000). In short, propolis extract had anti­microbe effect to Staphylococcus aureus growth

EFEK ANTIMIKROBA EKSTRAK BATANG KAYU MANIS (Cinnamomun burmanni) TERHADAP Salmonella typhi

Salmonella typhi is enteropatogenik organism that cause typhoid fever which stiil can be epidemologic problem in the world. The first drug of choice for Salmonella typhi is chloramphenikol. From some research of the role resistant for antibiotics to Salmonella typhi, it has been resistant toward chloramphenikol, ampicillin and cotrimoxasol. Indonesia have a lot of tradisional medicines one of them is cinnamomun burmanni. Cinnamomun burmanni is supposed to have antimicrobial effect because it is contains atsiri oil as active substance, flavonoid and tannin, they work by damage to cytoplasma membrane. This research to proof the antimicrobial effect of cinnamomun burmanni extract to growth of Salmonella typhi with using Post Test Only Control Group Design. Method being used is tube dilution test with 8 cinnamomun burmanni extract concentrations: 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, 1.56%, 0.78% and 2 controls (material control and germ control). Analysis of data using one way ANOVA. MBC (Minimal Bactericidal Concentration) of Cinnamomun burmanni extract from the experiment is on 6.25% concentration. One way ANOVA test shows significant difference between cinnamomun burmanni extract concentration (p = 0.000). Cinnamomun burmanni extract have antimicrobial effect to growth of Salmonella typhi

The antimicrobial activity of oil-in-water microemulsions is predicted by their position within the microemulsion stability zone

It has been shown previously that thermodynamically stable oil-in-water microemulsions have significant antimicrobial activity against planktonic cells and biofilm cells over short periods of exposure. It was the aim of this study to identify whether the position of the microemulsion within the microemulsion stability zone of the pseudo-ternary phase structure predicts the efficiency of the antimicrobial action of the microemulsion. Microemulsions were formulated at different points within the microemulsion stability zone. Experiments were performed to observe the kinetics of killing of these microemulsions against selected test microorganisms (Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538 and Aspergillus niger ATCC 16404). The results indicated that the antimicrobial activity of the microemulsion is dependant upon its position within the zone of stability and is greater nearer the centre of that zone. The results indicate that significant antimicrobial activity can be observed at all points within the zone of microemulsion stability, but that maximal activity is to be found at the centre of that area

Identification, Genotyping and Antimicrobial Susceptibility Testing of Brucella spp. Isolated from Livestock in Egypt

Brucellosis is a highly contagious zoonosis worldwide with economic and public health impacts. The aim of the present study was to identify Brucella (B.) spp. isolated from animal populations located in different districts of Egypt and to determine their antimicrobial resistance. In total, 34-suspected Brucella isolates were recovered from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats from nine districts in Egypt. The isolates were identified by microbiological methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Differentiation and genotyping were confirmed using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis (AMOS) and Bruce-ladder PCR. Antimicrobial susceptibility testing against clinically used antimicrobial agents (chloramphenicol, ciprofloxacin, erythromycin, gentamicin, imipenem, rifampicin, streptomycin, and tetracycline) was performed using E-Test. The antimicrobial resistance-associated genes and mutations in Brucella isolates were confirmed using molecular tools. In total, 29 Brucella isolates (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were identified and typed. The resistance of B. melitensis to ciprofloxacin, erythromycin, imipenem, rifampicin, and streptomycin were 76.2%, 19.0%, 76.2%, 66.7%, and 4.8%, respectively. Whereas, 25.0%, 87.5%, 25.0%, and 37.5% of B. abortus were resistant to ciprofloxacin, erythromycin, imipenem, and rifampicin, respectively. Mutations in the rpoB gene associated with rifampicin resistance were identified in all phenotypically resistant isolates. Mutations in gyrA and gyrB genes associated with ciprofloxacin resistance were identified in four phenotypically resistant isolates of B. melitensis. This is the first study highlighting the antimicrobial resistance in Brucella isolated from different animal species in Egypt. Mutations detected in genes associated with antimicrobial resistance unravel the molecular mechanisms of resistance in Brucella isolates from Egypt. The mutations in the rpoB gene in phenotypically resistant B. abortus isolates in this study were reported for the first time in Egypt

Antimicrobial properties of garlic oil against human enteric bacteria: evaluation of methodologies and comparisons with garlic oil sulfides and garlic powder.

The antimicrobial effects of aqueous garlic extracts are well established but those of garlic oil (GO) are little known. Methodologies for estimating the antimicrobial activity of GO were assessed and GO, GO sulfide constituents, and garlic powder (GP) were compared in tests against human enteric bacteria. Test methodologies were identified as capable of producing underestimates of GO activity. Antimicrobial activity was greater in media lacking tryptone or cysteine, suggesting that, as for allicin, GO effects may involve sulfhydryl reactivity. All bacteria tested, which included both gram-negative and -positive bacteria and pathogenic forms, were susceptible to garlic materials. On a weight-of-product basis, 24 h MICs for GO (0.02 to 5.5 mg/ml, 62 enteric isolates) and dimethyl trisulfide (0.02 to 0.31 mg/ml, 6 enteric isolates) were lower than those for a mixture of diallyl sulfides (0.63 to 25 mg/ml, 6 enteric isolates) and for GP, which also exhibited a smaller MIC range (6.25 to 12.5 mg/ml, 29 enteric isolates). Viability time studies of GO and GP against Enterobacter aerogenes showed time- and dose-dependent effects. Based upon its thiosulfinate content, GP was more active than GO against most bacteria, although some properties of GO are identified as offering greater therapeutic potential. Further exploration of the potential of GP and GO in enteric disease control appears warranted

The continued value of disk diffusion for assessing antimicrobial susceptibility in clinical laboratories: Report from the Clinical and Laboratory Standards Institute Methods Development and Standardization Working Group

Expedited pathways to antimicrobial agent approval by the U.S. Food and Drug Administration (FDA) have led to increased delays between drug approval and the availability of FDA-cleared antimicrobial susceptibility testing (AST) devices.</jats:p

Determination of antimicrobial susceptibilities on infected urines without isolation

A method is described for the quick determination of the susceptibilities of various unidentified bacteria contained in an aqueous physiological fluid sample, particularly urine, to one or more antibiotics. A bacterial adenosine triphosphate (ATP) assay is carried out after the elimination of non-bacterial ATP to determine whether an infection exists. If an infection does exist, a portion of the sample is further processed, including subjecting parts of the portion to one or more antibiotics. Growth of the bacteria in the parts are determined, again by an ATP assay, to determine whether the unidentified bacteria in the sample are susceptible to the antibiotic or antibiotics under test

Impacts of indoor surface finishes on bacterial viability.

Microbes in indoor environments are constantly being exposed to antimicrobial surface finishes. Many are rendered non-viable after spending extended periods of time under low-moisture, low-nutrient surface conditions, regardless of whether those surfaces have been amended with antimicrobial chemicals. However, some microorganisms remain viable even after prolonged exposure to these hostile conditions. Work with specific model pathogens makes it difficult to draw general conclusions about how chemical and physical properties of surfaces affect microbes. Here, we explore the survival of a synthetic community of non-model microorganisms isolated from built environments following exposure to three chemically and physically distinct surface finishes. Our findings demonstrated the differences in bacterial survival associated with three chemically and physically distinct materials. Alkaline clay surfaces select for an alkaliphilic bacterium, Kocuria rosea, whereas acidic mold-resistant paint favors Bacillus timonensis, a Gram-negative spore-forming bacterium that also survives on antimicrobial surfaces after 24 hours of exposure. Additionally, antibiotic-resistant Pantoea allii did not exhibit prolonged retention on antimicrobial surfaces. Our controlled microcosm experiment integrates measurement of indoor chemistry and microbiology to elucidate the complex biochemical interactions that influence the indoor microbiome

Ingestion of Milk Containing Very Low Concentration of Antimicrobials: Longitudinal Effect on Fecal Microbiota Composition in Preweaned Calves.

Although antimicrobial drugs are central to combat disease in modern medicine, the use of these drugs can have undesired consequences for human and animal health. One consequence is the post-therapy excretion of pharmacological agents, such as the elimination of drug residues at very low concentrations in the milk of lactating mammals. Limited information is currently available on the impact from the exposure of the gut microbiota to drug residues using in vivo natural models. The objective of our study was to address this knowledge gap and evaluate the effect on the fecal microbiota composition from feeding preweaned dairy calves raw milk with residual concentrations of ampicillin, ceftiofur, penicillin, and oxytetracycline from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 μg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth, prior to the first feeding in the trial (pre-treatment), until 6 weeks of age. Sequencing of the microbial 16S rRNA genes was conducted using the Illumina MiSeq, which provides a high resolution of the microbiota down to the genus level. Discriminant analysis showed that, except for pre-treatment samples, calves fed milk with drug residues and calves fed milk without drug residues easily discriminated at the genus level on their weekly microbial profile. However, analysis comparing the abundance of taxon between NR and DR showed significant differences only at the genus levels, and not at the phylum, class, order or family levels. These results suggest that although drug residues can result in clear discriminate gut microbial communities, they do not result in disruption of taxonomic levels above the genus