ENHANCED METHOD FOR AMPLIFYING ANTIMICROBIAL ACTIVITY OF LACTOPEROXIDASE SYSTEM IN MILK AND DERIVED PRODUCTS BY CARROT EXTRACT AND BETA CAROTENE

OSCN–  has  been  known  and  well  documented  as  natural  antimicrobial  agent    generated  from the  lactoperoxidase  system (LPOS)  but  the  antimicrobial  activity  exerted  from  this  system  is  too  low  for  certain  food  such  as  milk  and  derived products (up to 1.2 log CFU/ml) resulting in the restriction on industrial  development  of  LPOS.  Our  previous  study  concluded  that  involvement  of  carrot  extract and beta carotene in LPOS significantly boosted the antimicrobial activity  (up  to  6  log  CFU/ml)  against  S.  enteritidis.  This  finding  should  be  continued  to  the  application  on  food.  Since  we  found  that  LPOS  generates  low  antimicrobial  activity  on  milk  and  derived  product,  our  research  will  be  conducted  on  the  application  of  LPOS  plus  carrot  extract  and  beta  carotene  on  milk  and  derived  product.  Because  the  high  antimicrobial  activity  is  needed  for  industrial  purposes,  this  research  may  open  the  way  for  industrial  development  of  natural  antimicrobial agent from LPOS.  This research will be conducted in three steps of experiment: (1) ensuring  the  incredible  antimicrobial  activity  of  LPOS  plus  carrot  extract  and  beta  carotene  against  three  poisonous  tropical bacteria:  C. jejuni,  S. enteritidis,  and E.  coli,  (2)  utilization  of  LPOS  plus  carrot  extract  and  beta  carotene  in  milk:  full  cream and skimmed milk, and (3) utilization of LPOS plus carrot extract and beta  carotene  in  milk  derived  product:  yogurt  and  tropical  fruity  milk.  The  purification  of  LPO  from  bovine  milk,  the  complimentary  data  analysis  for  generation  of  LPOS  antimicrobial  activity  by  the  addition  of  carrot  extract  and  beta  carotene  will  be  conducted  in  Japan  and  for  the  application  in  tropical  poisonous  bacteria,  milk,  and  milk  derived  product  will  be  conducted  in  Indonesia.  The  outcomes  of  this  research  from  three  step  of  research  are  three  international  publications  at  international‐scopus‐indexed‐journals  :  International Journal of  Dairy Science and  one  of  patent:  “enhanced  method  for  improvement of LPOS antimicrobial activity by involvement of carrot extract and  beta carotene in milk and derived product”.     Keywords:  Lactoperoxidase,  antimicrobial  activity,  carrot  extract,  beta  carotene,  milk, derived products

Antimicrobial and Antioxidant Activity of Endophyte Bacteria Associated with Curcuma Longa Rhizome

Most cases of bacterial resistance towards antibiotics, encourage various efforts to gain new sources of antibiotics. Endophyte bacteria is a microorganism has important role as the producer of bioactive compounds. Endophyte bacteria from Curcuma longa with antimicrobial and antioxidant activities have not been studied yet. Curcuma longa has been utilized as the main ingredients of traditional herbal medicines (jamu). The objective of this research was to investigate the antimicrobial and antioxidant activity of endophyte bacteria associated with Curcuma longa rhizome. Based on morphological characteristics of bacterial colonies, eight endophyte bacteria was isolated from Curcuma longa rhizome. Screening of endophyte isolate has antimicrobial activity was done using agar well diffusion method. The culture supernatant of each endophyte isolate was dropped on agar well against pathogenic bacteria Salmonella enterica ser. Typhi, Staphylococcus aureus and yeast Candida albicans. Three endophyte isolates K3, K2 and M1b showed antimicrobial activity against pathogenic bacteria and yeast. Isolate K3 showed strong antimicrobial activity against C. albicans and S. aureus, however, isolate K2 and isolate M1b showed antimicrobial activity against Salmonella enterica ser. Typhi and S. aureus, respectively. Those endophyte bacteria also had antioxidant activity shown by scavenging ability toward DPPH radical with consecutive percentage of isolate K3 (72.3 %), K2 (51.3 %) and M1b (64.6 %). Isolate K3 showed the highest antimicrobial and antioxidant activity. Based on biochemical characteristics using Microbact 24E kit, isolate K3 was identified as Paenibacilus alvei and isolate K2 as Enterobacter agglomerans

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

Antimicrobial Activity of N-hexane Extracts of Red Frangipani (Plumeria Rocea)

Antimicrobial assay of n-hexane plant extracts against Escherichia coli and Staphylococcus aureus had been done. Extraction with n-Hexane of the flowers yielded 2,08% of extract, while leaves and stems yielded 3,21% and 2,19% of n-hexane extracts, respectively. The extracts showed different activity against both bioindicators. The leaves extracts showed the strongest activity indicated by wider diameters of inhibition zone, 19,7 mm against E. coli and 13,3 mm against S. aureus at 10% of the extracts' concentration. At the same concentration (10%), the steam and flower extracts showed less inhibitory activities with 11,3 mm and 8,3 mm against E. coli, and 12,0 mm and 11,0 mm against S. aureus. At the lowest concentration of the extracts, the leaves extracts showed the strongest activity against E. coli (14,3 mm) while the steam extracts showed highest inhibitory activity against S. aureus ( 7,7 mm). Based on antimicrobial assay, it was suggested that the leaves extracts demonstrated strongest activity than other extracts. It was assumed that leaves extracts contained more secondary metabolite than flowers and steams, and the leaves have phenol compounds which are not present in other extracts

Development and application of an antibiotic spectrum index for benchmarking antibiotic selection patterns across hospitals

Standard metrics for antimicrobial use consider volume but not spectrum of antimicrobial prescribing. We developed an antibiotic spectrum index (ASI) to classify commonly used antibiotics based on activity against important pathogens. The application of this index to hospital antibiotic use reveals how this tool enhances current antimicrobial stewardship metrics.Infect Control Hosp Epidemiol 2017;38:993–997</jats:p

Antimicrobial activity of carbon-based fillers

Diplomová práce se zabývá vlivem uhlíkatého plniva na životaschopnost a produkci extracelulárních látek vybrané bakterie Bacillus subtilis (CCM 1999) a kvasinky Yarrowia lipolytica (CCY 29-26-52). Antimikrobiální aktivita těchto částic, přítomných v kultivačním mediu, byla sledována pomocí následujících parametrů: růst daného mikroorganismu, produkce extracelulárních proteinů a v poslední řadě byla monitorována produkce extracelulárních polymerních substancí, které mají úzkou souvislost s tvorbou biofilmu. Suspenze materiálů (0,135 mg/mL) byly připraveny ve dvou rozdílných kultivačních mediích; tzn. živné medium s obsahem glukózy pro Bacillus subtilis a bazální medium s přídavkem Tweenu 80 pro Yarrowia lipolytica, a media byla inokulována příslušným typem mikroorganismu. Experimenty probíhaly po dobu 6 dnů při rychlosti třepání 160 rpm a teplotě 30 °C pro Bacillus subtilis a 28 °C pro Yarrowia lipolytica. Testovány byly celkem tři typy uhlíkatého nanomateriálu, získané z Katedry anorganické chemie, Vysoké školy chemicko-technologické v Praze. Tyto materiály specifikované jako materiál “A”, “B” a “C” se navzájem lišily velikostí částic a stupněm oxidace. Na základě skríningových studií byla vybrána koncentrace testovaného materiálu 0,135 mg/mL a rychlost třepání 160 rpm. Metodou měření optické hustoty vzorku při 600 nm byly sestaveny a porovnány růstové křivky obou mikroorganismů v přítomnosti testovaných nanočástic po dobu 5 dní. Tímto způsobem bylo zjištěno, že přítomnost nanočástic v mediu nemá velký vliv na růst zkoumaného mikroorganismu. Tato metoda, je však pouze orientační, protože se nevyhneme chybě díky přítomnosti mrtvých buněk. Dále byla testována produkce celkových a extracelulárních proteinů daným mikroorganismem v přítomnosti testovaných nanočástic. Nebyla však pozorována výrazná odchylka hodnot od hodnot kontrolního vzorku, který neobsahoval testovaný materiál. Na základě metod počítání kolonií (Bacillus subtilis) a buněk (Yarrowia lipolytica) byly určeny ztráty životaschopnosti mikroorganismu ve 3 časech (6, 48 a 144 hodin); v kratším časovém intervalu byl růst spíše podporován. Dále byla monitorována produkce extracelulárních polymerních substancí (EPS), tedy proteinů, redukujících substancí a polysacharidů. Tyto látky byly vylučovány daným mikroorganismem do prostředí v průběhu 24 hodin. Bacillus subtilis produkoval EPS ve větší míře než Yarrowia lipolytica. Předpokládáme, že produkce EPS by mohla souviset s tvorbou biofilmu, který chrání buňky před toxicitou nanočástic.The aim of this diploma thesis is focused on the impact of carbon-based fillers on viability and extracellular substances production by bacterium Bacillus subtilis (CCM 1999) and yeast Yarrowia lipolytica (CCY 29-26-52). Antimicrobial activity of these particles, present in cultivation nutrient medium was examined using following parameters: growth of mentioned microorganisms, production of extracellular proteins and finally extracellular polymeric substances production, which is strongly connected with biofilm formation. Nanomaterials suspension (0.135 mg/mL) was prepared in two different cultivation media i.e. nutrient medium supplemented with glucose for Bacillus subtilis and basal medium with the addition of 2% (vol.) Tween 80 for Yarrowia lipolytica and media were inoculated by appropriate type of microorganism. Experiments were performed for 6 days under shaking rate at 160 rpm and at temperature of 30 °C for Bacillus subtilis and 28 °C for Yarrowia lipolytica. Three types of carbon nanomaterials obtained from Department of Inorganic Chemistry, Institute of Chemical Technology, Prague were examined. These materials specified as material “A”, “B” and “C” are mutually different by the size of its particles and the degree of oxidation. Based on the screening studies the tested material concentration of 0.135 mg/mL and shaking rate of 160 rpm were chosen. According to the optical density measurement at 600 nm, the growth curves of both microorganisms in the presence of tested nanoparticles during 5 days period were compared. It was find out, that the presence of nanoparticles don’t have a significant influence on tested microorganisms growth, by this technique. However, this method is just wider point of view, due to mistakes caused by presence of dead cells. Further, production of total cells proteins and extracellular proteins by microorganisms in presence of tested nanoparticles was examined. There was not observed any significant deviation from control samples values, where the tested materials were absent. Based on colony counting method (used for Bacillus subtilis) and cells counting in Bürker counting chamber (used for Yarrowia lipolytica), loss of microorganism viability was determined in 3 cultivation periods (6, 48 and 144 hours); there was observed a support of growth of microorganisms rather in shorter incubation period. Thereafter the extracellular polymeric substances (EPS) production that means proteins, reducing substances and polysaccharides was monitored. These substances were secreted into the medium by mentioned microorganisms during 24 hours of incubation. Bacillus subtilis cells produce much more EPS than Yarrowia lipolytica cells. We suppose that the EPS production could be closely associated with production of biofilm, which protects cells against nanoparticles toxicity.

Evaluation of Antimicrobial Activity of Moringa Oleifera Leaf Extracts Against Pathogenic Bacteria Isolated From Urinary Tract Infected Patients

Antibiotic resistance has increased substantially in recent years and is posing an ever-increasing therapeutic problem. One of the methods to reduce the resistance to antibiotics is by using antibiotic resistance inhibitors from plants. The aim of this study is to evaluate the antibacterial properties of aqueous, petroleum ether and methanolic leaf extracts of Moringa oleifera plant against pathogenic bacteria isolated from urinary tract infected patients and five standard strains of American type culture collection. The antibacterial activity of Moringa oleifera leaf extracts was determined in vitro, using Cup plate method, and compared with sensitivity testing of some antibiotic agents using disc diffusion method. The results obtained showed that all concentration of methanolic extracts of Moringa oleifera had high inhibitory effects on S. aureus ATCC25923, K. pneumoniae ATCC35637 standard strains and the S. aureus, S. saprophyticus and E.coli isolated from UTI. The three concentration of water extract had inhibitory effects only on Proteus vulgaris NCTC8196 strain. The petroleum ether extracts showed no inhibitory activity on any organism. These results were compared with standard antibiotics Amikacin, Ciprofloxacin, and Norfloxacin which showed moderate sensitivity against S. aureus and Amikacin was completely resistant to K. pneumoniae isolated from UTI. These results provide valuable information that Moringa oleifera hold great promise as highly effective antibacterial agents