Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28 degreesC with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg-1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.
In this study, a Lactic acid bacteria (LAB) strain was isolated on MRS medium from gastro-intestinal tissues of Broadhead catfish (Clarias macrocephalus). Out of 50 isolates, 25 isolates were found to be positive on lactose utilisation test and were identified to be gram positive cocci. Using disc diffusion methods, one out of 22 isolates, i.e., a strain A5 demonstrated inhibitions against three indicator organisms; Bacillus cereus, Staphylococcus aureus and Salmonella thyphimurium. Partial 16S rDNA sequencing identified isolate A5 as a member of Lactococcus lactis, with 100% DNA homology. Cell free supernatant fluid from Lactococcus lactis A5 showed inhibitory activities against both gram positive pathogens (Bacillus cereus and Staphylococcus aureus) and gram negative pathogens (Salmonella thyphimurium). Chloroform precipitated bacteriocin retained antagonistic activities in the presence of catalase and lysozyme; and was completely inactivated by Proteinase K treatment. The bacteriocin has a molecular weight of 3.4 kDa, based on SDS-PAGE analysis and the extract was heat stable at 37°C and 65°C, for 15 minutes. The antibacterial activity was suppressed with the addition of EDTA but was significantly increased with the addition of SDS, Triton X-100, Tween 20 and Tween 80. This bacteriocin belongs to class 1 bacteriocin, which was shown to have a nisin-like properties. This strain can be used as potential probiotics in animal or aquaculture feeding; and the bacteriocin it produces will be useful in food preservative.
This study aimed to detect the presence of enterococci in the root canals of untreated and treated teeth with periapical disease and to compare this to their presence in the saliva and in the immediate surgical environment during root canal treatment. Using an aseptic technique, 33 samples were obtained from 27 untreated and 6 previously treated teeth associated with apical periodontitis. Reduced Transport Fluid (RTF) was used as transport medium. Saliva samples and areas in the surgical environment were also sampled. These were performed prior to chemo-mechanical debrjdement and obturation for every case. The saliva was diluted to 10- J and was plated on Bile Aesculin Azide (BEA) agar whereas the rest of the samples were plated on Bile Aesculin (BE) agar. These plates were then incubated aerobically at 37°C for 48 hours. All the colony types that blackened the agar were sub-cultured to obtain pure isolates and tested on 6.5% sodium chloride (NaCI). Growth on this medium was Gram stained for further confirmation of cell morphology. Gram positive cocci isolated from previous positive test were identified as enterococci. Enterococci were recovered from untreated cases only; from 2 teeth (in 2 patients) prior to chemo-mechanical debridement, from 3 teeth (in 3 patients) prior to obturation and I from saliva sample. A 'total of 5 samples from 5 different patients were positive for enteroco•cci. Sampling in the immediate surgical environment revealed a low occurence in the range of3.0% (1/33) to 15_2% (5/33). In conclusion, the occurence of enterococci in patients and the immediate surgical environment was low number.
Intrauterine infection has emerged to be the main and frequent cause of premature delivery and foetal demise. Microorganisms gain entry into the amniotic cavity via ascending route, haematogenous dissemination, retrograde seeding from peritoneal cavity and accidental introduction during invasive procedures. This is a case of foetal loss in utero from a twin pregnancy due to intrauterine sepsis diagnosed through placenta examination. Both maternal and foetal evidences of inflammatory response were demonstrated in the placenta on histology. Microscopically, there were acute chorioamnionitis and villitis as well as abundant gram positive cocci in the foetal blood within placental villous capillaries. The presence of intravascular bacterial organism provides evidence for a conclusive diagnosis of intrauterine sepsis, particularly where the placenta or foetal blood microbiological cultures results are not available or equivocal. More attention should therefore be given when sampling, as pathological evidences of underlying foetal compromise or death could be provided by well-represented placental tissue samples.
In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1), and four other known metabolites, aplysidiol (2), cupalaurenol (3), 1-methyl-2,3,5-tribromoindole (4), and chamigrane epoxide (5), were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae.
Antibiotic residues that enter the soil through swine manure could disturb the number, community structure and functions of microbiota which could also degrade antibiotics in soil. Five different concentrations of doxycycline (DOX) incorporated into swine manure were added to soil to explore the effects of DOX on microbiota in soil and degradation itself. The results showed that the soil microbiome evolved an adaptation to the soil containing DOX by generating resistance genes. Moreover, some of the organisms within the soil microbiome played crucial roles in the degradation of DOX. The average degradation half-life of DOX in non-sterile groups was 13.85 ± 0.45 days, which was significantly shorter than the 29.26 ± 0.98 days in the group with sterilized soil (P < 0.01), indicating that the soil microbiome promoted DOX degradation. DOX addition affected the number of tetracycline resistance genes, depending on the type of gene and the DOX concentration. Among these genes, tetA, tetM, tetW, and tetX had significantly higher copy numbers when the concentration of DOX was higher. In contrast, a lower concentration of DOX had an inhibitory effect on tetG. At the same time, the microbial compositions were affected by the initial concentration of DOX and the different experimental periods. The soil chemical indicators also affected the microbial diversity changes, mainly because some microorganisms could survive in adversity and become dominant bacterial groups, such as the genera Vagococcus and Enterococcus (which were associated with electrical conductivity) and Caldicoprobacter spp. (which were positively correlated with pH). Our study mainly revealed soil microbiota and DOX degradation answered differently under variable concentrations of DOX mixed with swine manure in soil.
Lactic acid bacteria is well known for it uses as starter culture in various fermented food, and it functions as a good natural antimicrobial agent. Cincaluk, a Malaysian fermented shrimp product commonly found in traditional dishes is commonly enriched with LAB. Out of 50 colonies from a local cincaluk, 7 strains were successfully isolated and shown to be positive in lactose utilization and catalase tests. The majority of the isolates from cincaluk showed Gram-positive cocci morphology and belonged to the group Staphyloccoccus spp. By using agar disc diffusion method, the anti-bacterial properties of these isolates (namely isolate 1, 2, 3, 4, 5, 6, and 7) moderately inhibited the growth of several pathogenic strains, i.e., Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Bacillus subtilis which were used as indicator bacteria. Other than isolates 1, 2, 3 and 5; the 16S rRNA gene for isolate 6 and 7 were successfully amplified. The 16S rRNA gene fragment from isolate 7 was successfully cloned and sequenced. Based on rRNA sequences, both isolates 6 and 7 belonged to the group Staphylococcus piscifermentans, a rare strain previously reported to be specifically isolated exclusive from fish sources.
A 55-year-old healthy lady with history of regular contact lens (CL) use presented with 10 days history of
progressive left eye blurring of vision, redness and pain. There was good CL hygiene practiced with no history of
swimming, trauma or contact with domestic pets. Left eye vision was hand movement and right eye was 1/60,
pinhole 6/18. On the left eye, there was a central, oval-shaped corneal infiltrate with an overlying large epithelial
defect and stromal oedema, with significant anterior chamber cells and fibrin. B-mode ultrasound showed no vitritis.
Intensive topical benzylpenicillin 10000iu/ml and topical gentamycin 1.4% hourly, homatropine 2% three times
daily, oral doxycycline and oral ascorbic acid were started. The gram stain results showed gram positive cocci
growth. Her ulcer improved with the treatment and preservative-free dexamethasone 0.1% once daily was
commenced to reduce inflammation and scarring. Interestingly, culture was reported as Pasteurella maltocida, a
gram negative bacilli sensitive to penicillin, and so treatment was continued until the ulcer completely healed. She
had central corneal scarring with best corrected vision of 6/24 in the left eye but was not keen on further surgery to
improve her vision. Although it has not been previously reported, Pasteurella multocida can cause CL related
corneal ulcer with severe anterior chamber inflammation. This diagnosis should be considered even if there is trivial
contact or no history of exposure to domestic animals.