Estimation of antibacterial activity of purified bioactive compounds separately and in combination with Chloramphenicol against Shiga toxin producing and Enterotoxigenic Escherichia coli

The study was carried out in order to investigate potential antibacterial efficacy of p-Coumaroyl-glucoside + p-Coumaroylquinic acid, Ferulic acid and Steroidal sapogenin individually as well as in combination with Chloramphenicol against Shiga toxin producing and standard Enterotoxigenic E. coli strain. Estimation of antibacterial effect was carried out by well-diffusion method. Strongest inhibitory result was observed from p-Coumaroyl-glucoside + p-Coumaroylquinic acid with zone of inhibition of  23.3 ±0.6 mm for Shiga toxin producing E. coli  and 24.0 ± 1.1mm for standard Enterotoxigenic E. coli strain. The zone of inhibition recognized from Ferulic acid was of 14.6± 2.4 mm and 12.0±0.0 mm respectively for Shiga toxin producing and Enterotoxigenic E. coli strain. From Steroidal sapogenin the recognized inhibitory zone diameter found in the two strains were of 16.6±0.6 mm and 12.0±1.1 mm. Combined administration of the bioactive compounds and Chloramphenicol strongest interaction was recognized with -Coumaroyl-glucoside + p-Coumaroylquinic acid and Steroidal sapogenin whereas neither synergism nor antagonism was recognized on combined administration of Ferulic acid and Chloramphenicol determined on the basis of enhancement of inhibitory zone diameter

Comparative investigation of antibacterial activity of cold and hot extracts of Acacia arabica against E. coli

Both cold and hot fruit extracts of Acacia arabica were prepared in methanol, acetone, chloroform and water and their antibacterial activity was detected against five different diarrheagenic E. coli strains by broth microdilution method. MIC of cold methanolic fruit extract was found to be 0.6 mg/ml whereas MIC of hot methanolic fruit extract was observed to be 0.12-0.15 mg/ml. MIC of cold and hot acetone extract was observed to be ranged from 1.23-3.3 mg/ml and 0.4 -1.25 mg/ml whereas MIC of cold and hot chloroform fruit extract was found to be same of 0.3 mg/ml. No antibacterial activity was observed from aqueous extract. Results revealed that hot acetone and methanolic extract were more effective over cold extracts

Validation of antibacterial activity of Saponin against diarreagenic E.coli isolated from leaves and bark of Acacia arabica

The leaf and bark extract of Acacia arabica constitute large amount of saponin (sapogenin aglycon) along with other polyphenolic compounds. The isolated sapogenin aglycon was tested against E.coli O22 associated with diarrheal infections in domesticated animals along with E.coli MTCC 723 strain. Both well-diffusion and broth micro dilution technique was used to detect antibacterial activity. Synergistic interaction was observed on combined administration of saponin with Chloramphenicol to inhibit tested organism

LC/ TOF/ ESI/ MS based detection of bioactive compounds present in leaf and bark extract of Acacia arabica

An HPLC / MS/MS was employed to investigate bioactive principles present in methanolic leaf and bark extracts of Acacia arabica . The compounds commonly present in leaf and bark extracts were Oleic acid (C18H34O2), Myristic acid (C14H28O2), Palmitic acid (C16H32O2), Ferulic acid (C10H10O4), p-Coumaroyl-glucoside (C15H19O7),  p -Coumaroylquinic acid (C16H18O8), Quercetine 3-O- (4’-O-acetyl)-rhamnopyranoside (C28H30O16) and Steroidal sapogenin. The other compounds observed in leaf extract were Caffeic acid phenethyl ester (CAPE) (C17H16O4), Epi catecine-3-gallate (C22H18O10) and Methyl 3,4,5 tri hydroxyl benzoate (C8H8O5). One compound seperately identified from bark extract was 3, 4, 5-trihydroxybenzoate (C7H6O5)

Identification of Escherichia coli from potable water sources of Durg-Bhilai, Chhattisgarh (India), using 16S rRNA gene sequence Analysis

Potable water sources mainly municipal water and ground water (from tube wells) were studied for the presence of multidrug resistant pathogenic Escherichia coli. A total of 11 isolates were obtained, eight from municipal water and three from tube well water. Antibiotic resistance analysis (ARA) showed that only two strains named EcPH2 and EcPul2 isolated from municipal tap waters were multidrug resistant (MDR). The strains were characterized using 16S ribosomal RNA gene sequencing. Phylogenetic analysis and similarity search showed isolate EcPH2 had 98% similarity and EcPul2 had 94% similarity to E. coli. The 16S rRNA sequences were submitted to Genbank with accession no. KC254645, KC254646 for isolate EcPH2 and isolate EcPul2 respectively

Studies on antibiotic resistance profiles of thermotolerant Escherichia coli and multiple antibiotic resistance index of different water sources

The rationale behind this study was that no clear data from Durg District is available on the antibiotic resistance profiles of E. coli, the most common pathogen of both humans and animals. Water being one of the most prevalent routes of transmission of E. coli, the present study aimed at isolation and characterization of the same from widely used water sources of Durg-Bhilai region. Thermotolerant E. coli (n=50) were isolated from municipal water, ground water, lake (Talpuri Talab), and river Shivnath. Multiple antibiotic resistance (MAR) indexing was performed using antibiotics viz. amoxicillin, chloramphenicol, co-trimoxazole, ceftriaxone, ciprofloxacin, cephotaxime, nalidixic acid, gentamycin and tetracycline. 85.4% of isolates showed resistance to 2 or more antibiotics. Resistance to three or more antibiotics (multidrug resistance) was shown by 24.4% of isolates. Plasmid bands ranging in size from 0.5 kb – 35 kb were present in 35 out of 50 isolates. Multiple plasmids were shown in 6 isolates. MAR index of isolates ranged from 0.11 to 0.55. 61% of isolates in this study had an index of 0.22, 14.63% had 0.44, 7.23% had 0.33 and 2.44% had 0.55. A high index of 0.79 was shown by River Shivnath followed by 0.2 by Talpuri Talab. The MAR index >0.2 is considered to originate from high risk source of contamination. High MAR indices of individual isolates and sampling sites in Durg-Bhilai region showed that water sources are contaminated with antibiotic resistant E. coli arising from high risk sources of contamination

Search for in vitro antibacterial efficacy of phytoconstituents of Acacia arabica leaf extracts against various serogroups of E. coli associated with diarrheal infections in ruminants

The investigation was carried out in order to detect antibacterial activity of crude methanolic, acetone, chloroform and aqueous leaf extracts of Acacia arabica against four different E. coli strains E. coli O22, O11, O89 and O61 associated with diarrheal infections in ruminants. MIC of methanolic extract was observed to be ranged from 0.09 to 0.17 mg/ml where as acetone leaf extract ranged from 0.5 to 5 mg/ml whereas chloroform and aqueous leaf extract showed no inhibitory results against any tested organism.&nbsp

Investigation and quantification of bioactive compounds from leaf extract of Acacia arabica as an effective antibacterial agent against E.coli associated with diarrheal infections

In this study antibacterial effect of bioactive compounds present in crude methanolic leaf extract of Acacia arabica was investigated against four different E.coli serogroups associated with diarrheal infections in animals. The serogroups were E.coli O22, O11, O89 and O61 along with one standard E.coli strain carrying LT and ST enterotoxins. Separation and identification of bioactive compounds was carried out by CC (Column chromatography), Preparative HPLC coupled with LC TOF ESI MS. Determination of antibacterial activity was carried out by well diffusion and broth microdilution method. The main compounds were identified including, methyl 3,4,5 tri hydroxyl benzoate (C8H8O5), p-coumaroyl glucoside (C15H19O7), p -coumaroyl quinic acid (C16H18O8), Ferulic acid (C10H10O4), isoferulic acid, epi catecine-3-gallate (C22H18O10), ascorbic acid , quercetine 3-O- (4’-O-acetyl)-rhamnopyranoside (C28H30O16), oleic acid (C18 H34O2), myristic acid (C14H28O2), Palmitic acid (C16H32O2) and steroidal sapogenin aglycons. The compound p-coumaroyl glucoside and p -coumaroyl quinic acid was obtained in combined form and largest antibacterial efficacy was observed in this combination. In addition, Ferulic acid and sapogenin aglycon was found to be having antibacterial potential

Isolation, biochemical and molecular characterization of strains of coliforms from the water sample collected from Shivnath river

Coliform bacteria include organisms like Escherichia coli, Enterobacter sp., Klebsiella sp. and Citrobacter sp.and are gram negative, facultative anaerobic, non-sporulating and lactose fermenting organisms. E. coli is used as the indicator organism for detection of faecal contamination of water. Conventional methods for the detection of Coliforms in water include microbial culture technique in lactose containing media, Biochemical characterization, study of cell morphology, colony morphology etc. These methods are time consuming with limited specificity. DNA based molecular techniques like 16S rRNA gene sequencing is highly specific. In this research work, the16S rRNA gene sequencing technique was used to characterize the two isolates from water samples of Shivnath River after the above said preliminary tests were conducted. The two strains of coliforms identified by this technique were Escherichia coli strain GA and Enterobacter cloacae strain AB6

Frequent Arousal from Hibernation Linked to Severity of Infection and Mortality in Bats with White-Nose Syndrome

White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive dataloggers were attached to the backs of 504 free-ranging little brown bats (Myotis lucifugus) in hibernacula located throughout the northeastern USA. Dataloggers were retrieved at the end of the hibernation season and complete profiles of skin temperature data were available from 83 bats, which were categorized as: (1) unaffected, (2) WNS-affected but alive at time of datalogger removal, or (3) WNS-affected but found dead at time of datalogger removal. Histological confirmation of WNS severity (as indexed by degree of fungal infection) as well as confirmation of presence/absence of DNA from Gd by PCR was determined for 26 animals. We demonstrated that WNS-affected bats aroused to euthermic body temperatures more frequently than unaffected bats, likely contributing to subsequent mortality. Within the subset of WNS-affected bats that were found dead at the time of datalogger removal, the number of arousal bouts since datalogger attachment significantly predicted date of death. Additionally, the severity of cutaneous Gd infection correlated with the number of arousal episodes from torpor during hibernation. Thus, increased frequency of arousal from torpor likely contributes to WNS-associated mortality, but the question of how Gd infection induces increased arousals remains unanswered