Hot plate method: A painful stimulus to induce anxiety in Wistar rats

Background: Pain is a common stimulus that induces anxiety in both Animals and human beings. Aim and Objective: We have undertaken this study to evaluate the induction of anxiety in Wistar rats using hot plate method. Materials and Methods: 24 Wistar rats of either gender were used. Elevated plus maze (EPM) and light and dark arena (LDA) were used to evaluate the anxiety and hot plate analgesiometer was used to induce anxiety. After baseline reading from EPM and LDA, the Wistar rats were exposed to the hot plate and then evaluated for the induction of the anxiety behavior. Results: After exposing to the hot plate, the ratio of time spent in the open arms to the time spent on the closed arms was decreased from 0.027 to 0.010 and also the ratio of time spent on the light chamber to the time spent on the dark chamber was decreased from 0.093 to 0.012. Hot plate method has shown statistical significant induction of anxiety as evaluated by EPM and also LDA. Conclusion: Hot plate method is a good intervention to induce anxiety in Wistar rats. Instead of injecting drugs that causes anxiety to explore the anxiolytic effects of the drugs the hot plate analgesiometer method is a good alternative.

Antinociceptive effect of methanolic extract of Murraya koenigii leaves in swiss albino mice

Background: The objective of the study was to evaluate anti-nociceptive effect of methanolic extract of Murraya koenigii leaves on thermal and mechanical pain in swiss albino mice.Methods: Thirty adult male swiss albino mice weighing 25-30 grams were selected and allocated in to five groups. Each group consists of six animals. The control group received vehicle (10 ml/kg), standard group received morphine (10 mg/kg) and test groups received dried methanolic extract of Murraya koenigii leaves (100 mg/kg, 200 mg/kg, 400 mg/kg per oral respectively) 1 hour before placing the animal over the hot plate at temperature of 55?C . A cut off period of 10 sec was observed to avoid damage of the paw. The response in the form of withdrawal of paws or licking of the paws. The delay in the reaction time denotes analgesic activity. The latency was recorded before and after 15, 30, 60, 120 minutes administration of drug. After washout period of 1 month the same group of animals were utilized to evaluate the analgesic effect by tail clip method for better comparison.Results: All the doses of Murraya koenigii leaves significantly delayed reaction time in hot plate method and tail clip method. The results were comparable to that produced by standard drug morphine.Conclusions: Murraya koenigii leaves has analgesic activity which was comparable to morphine.

Screening and identification of fibrinolytic enzyme-producing microbes in fermentation process of Sojae Semen Praeparatum / 中草药

Objective: To screen and identify the dominant strains which produce fibrinolytic enzyme during the processing of Sojae Semen Praeparatum (SSP, Dandouchi in Chinese). Methods: SSP was prepared according to the Chinese Pharmacopoeia (2020 edition), and samples were taken at different time points during the fermenting process of SSP.The casein plate method and fibrin plate method were used to screen the fibrinolytic enzyme-producing microorganisms in samples at different time points. The fibrinolytic enzyme-producing microorganisms were inoculated in the designated liquid medium to obtain single strain fermentation broth, and fibrin plate method was used to measure the fibrinolytic activity of the fermentation broth. The DNA sequences of fibrinolytic enzyme-producing bacteria and fungi were amplified using 16S rDNA and 18S rDNA universal primer by PCR respectively.The amplified products were sequenced, and the sequencing results were identified through NCBI homology comparison. Molecular biological identification was done by phylogenetic tree constructed by MEGA 4.1 software. Results: Three types of fibrinolytic enzyme-producing bacteria were screened out and identified in this study. They were Bacillus subtilis, Stenotrophomonas maltophilia and Micrococcus, respectively. The result of fibrin plate method showed that the fermentation broth of S. maltophilia had the highest fibrinolytic activity, reaching 527.49 IU/mL. Conclusion: There are fibrinolytic enzyme-producing dominant microorganisms existing in the fermenting process of SSP and the thrombolytic effect of SSP is worthy of further study. This study lays the foundation for revealing the formation mechanism of fibrinolytic enzyme in the fermentation process of SSP.

Evaluation of opioid sparing effect of dexmedetomidine and pregabalin using acute pain model in male wistar rats

Background: Adjuvant analgesics are added to pain management regimen to reduce opioid consumption and minimise their side effect. Newer ones like dexmedetomidine and pregabalin have not been thoroughly researched. Objectives of the study to study the opioid sparing effect of dexmedetomidine and pregabalin using tail flick and hot plate method in male wistar rats.Methods: Forty two rats were grouped into seven groups with six in each group. Analgesic activity was tested using tail flick, where in the reaction time to flick its tail on a heated surface was noted. In the hot plate method, the reaction time to withdraw or lick the paws when placed on heated surface was noted.Results: The reaction time to flick its tail was prolonged with dexmedetomidine and pregabalin when combined with opioids even in sub therapeutic doses.Conclusion: Adjuncts like dexmedetomidine and pregabalin can be very useful in mutimodal pain management and also to reduce the opioid consumption.

A study to evaluate the analgesic activity of Origanum vulgare in mice using hot plate method

Background: The International Association for Study of pain, has defined pain as actual or potential tissue damage or described in terms of such damage. But the burden of unwanted side effects with current regimens are high. To explore the potential of Ayurveda drugs, this study is done by using Origanum vulgare.Methods: In vivo model used-Hot plate method. Origanum vulgare (84 mg/kg p.o) was administered in mice. The analgesic activity was studied by recording the reaction time after administration of the drug at frequent intervals up to 3 hrs. The results were analysed by ANOVA and Tukey’s test. P value <0.05 was considered as significant. Pentazocine showed statistically prolongation in the reaction time after 30 min as compared to Origanum vulgare.Results: In hot plate method, pentazocine showed statistically significant increase in the reaction time after 30 min of administration as compared to control group. However, Origanum vulgare in a dose of 84 mg/kg showed significantly increase in the reaction time after 30 min of administration as compared to control group. On comparing pentazocine and Origanum vulgare, pentazocine showed highly significant increase in the reaction time after 30 min as compared to Origanum vulgare at 84 mg/kg dose.Conclusions: From the present study, it was concluded that extract of Origanum vulgare exerted analgesic activity in both the models. However, it was less potent than pentazocine. Thus, Origanum vulgare can be used in mild to moderate painful conditions.

Diversity of fungi on surface of Pheretima / 中国中药杂志

Traditional Chinese medicines( TCMs) are easily contaminated by fungi during planting,harvesting,processing,transportation and storage. The 2015 version of Chinese Pharmacopoeia stipulates the detection of aflatoxin in Dilong. After reviewing the literature,it has been found that there are no domestic and foreign scholars who have studied the surface fungi of Dilong. Pheretima,known as Dilong in China,is a commonly used TCMs in animal. In this experiment,8 batches of Dilong were collected from retail pharmacies in Beijing. The fungi on the surface of Dilong were cultured by traditional plate method and the single strain was obtained by the top purification method. The fungal colony morphology,microstructure characteristics and DNA barcode were used to isolate and identify the fungi. At the same time,based on Illumina Hi Seq 2500 high-throughput sequencing platform,the diversity of fungi on the surface of Dilong was analyzed. The results showed that 287 strains of 9 species of fungi were isolated and identified by plate method. Combined with 3 kinds of identification method,eight of nine fungi could be identified,respectively,Aspergillus niger,Penicillium,Alternaria nees,A. flavus,and Penicillium oxalicum,Humicola sp.,Talaromyces purpurogenus and A. insuetus,1 kind of fungi was not identified yet. Among them,Penicillium and Aspergillus were the dominant genus. The results of high-throughput sequencing belonged to 2 boundaries,6 gates,19 classes,44 orders,98 families,127 genus and 121 species in different classification levels. Wallemia,Aspergillus and Cordyceps were the dominant genus,and the relative abundances are 63. 33%,15. 28%,and 10. 28%,respectively. Through the diversity study on the surface fungi of Dilong in Beijing retail pharmacies,it can provide a reference for its safe storage and clinical use.

Comparative study of analgesic effect of Moringa oleifera leaf extracts with aspirin on experimental animals

Background: Moringa oleifera is highly valued with a wide range of medicinal uses. It is abundantly available in tropical and sub-tropical countries. It has been used as an analgesic and anti-inflammatory in Indian folk medicine since centuries. The mechanism of action of analgesic effect is by the phytochemical components of its leaves which contain alkaloids, glycosides, phenols, saponins and tannin.Methods: This experiment is carried out in mice by using the thermal method of analgesiometer, that is Eddy’s Hot Plate method. Thermostatically controlled electrically heated plate is used in this method. Ethanolic and aqueous extracts of Moringa oleifera leaf extracts are compared with aspirin.Results: When the analgesic properties of the standard drug aspirin were compared to the analgesic properties of ethanolic and aqueous extracts of Moringa oleifera, the ethanolic extract showed a comparable analgesic effect with aspirin at 90min. Among these two extracts, the ethanolic extract showed a higher response than aqueous extract.Conclusions: When the analgesic properties of the standard drug aspirin were compared to the analgesic properties of ethanolic and aqueous extracts of Moringa oleifera, the ethanolic extract showed a comparable analgesic effect with aspirin at 90min. Among these two extracts, the ethanolic extract showed a higher response than aqueous extract.

Study of biofilm formation and its correlation with highly drug resistant uropathogens in catheter-associated urinary tract infection

Aims and objectives: 1. To put culture and sensitivity of urine samples from catheterised patients withsymptomatic and asymptomatic bacteriuria. 2. To detect the biofilm formation by tube adherence and tissueculture plate method. 3. To compare the antibiotic sensitivity between biofilm and non-biofilm formingorganisms. Materials and Methods: The study was conducted in the Department of Microbiology of YenepoyaMedical College and Hospital, Mangalore, India. A total of 100 bacterial isolates obtained from urine samples ofcatheterised patients were included in the study. The processing of the samples (culture and sensitivity) weredone according to standard microbiological techniques. The biofilm formation was done by tube adherence andtissue culture plate method. Results: Out of 100 uropathogens isolated, 96(96%) were Gram negative bacilli.Four isolates were Gram positive cocci. Amongst the Gram negative bacilli, E.coli were 69%, Klebsiellapneumoniae 19%, Acinetobacter species 5% and Pseudomonas aeruginosa 3%. All gram positive cocci wereEnterococci (4%). In the tube adherence method, the number of isolates showing biofilm formation was 51%and non-biofilm producers was 49%. By tissue culture plate method, the number of isolates showing biofilmformation was 63% and non-biofilm producers was 37%.The predominant organism showing biofilm formationwere K.pneumoniae(89%) followed by Acinetobacter spp. (40%).There was significant correlation betweenbiofilm formation and multi-drug resistance. Conclusion: Significant correlation between biofilm productionand multi-drug resistance was observed in our study. The study will help the clinician to take a call on nonresponding uropathogens and decide on better therapeutic options amongst those available in CAUTIs.

Optimization of extraction technology from compound Huanghuai based on coagulation activity and central composite design-response surface methodology / 中国中药杂志

To establish a method for the determination of coagulation activity in vitro by using fibrinogen plate method. The extraction route of compound Huanghuai was optimized by selecting thrombin as the reference substance. The comprehensive score of extract yield and the extraction transfer rate of baicalin and rutin was set as the dependent variable, with alcohol concentration, solvent volume and extraction time as the influence factors in central composite design for quadratic fitting, and the extraction process of compound Huanghuai was optimized by using response surface methodology. The results of thrombin concentration and precipitation zone area showed a good linear relationship in 0.4-16 U•mL⁻¹, r=0.997 5. The average recovery rate was 103.8% and the RSD was 4.7 %. The circle of precipitation area of compound Huanghuai combined extract was 38.81 mm², which was bigger than that of fractionated extract. The activity on the daily amount of compound Huanghuai extract was 84.28 U; and the optimum extraction technology was as follows: alcohol concentration 40%, extracted 3 times, the liquid-solid ratio 6∶1, and extraction time 2 h. The predicted value of comprehensive score was 94.26 and the measured value was 88.34, respectively, with a relative deviation of 6.28%. The coagulation activity of the intermediate obtained by optimal extraction process was better. So the method established in this paper was simple, fast and accurate for determination of coagulation activity of compound Huanhuai, which can be also used for the screening of follow-up process and quality control.

Re-evaluation for quality standard of Compound Lumbrical Capsule based on enzyme activity / 中草药

Objective: The quality standard of Compound Lumbrical Capsule (CLC) was re-evaluated using blood and anti-coagulation intensity as indexes. Methods: Fibrin plate method was used to determine the strength of promoting blood circulation and anti-coagulation for CLC by selecting urokinase and thrombin as reference substances. Results: The results of urokinase concentration and transparent circle area showed a good linear relationship in 200-1 000 U/mL, r = 0.999; The results of thrombin concentration and precipitation circle area showed a good linear relationship in 8-40 U/mL, r = 0.997. The blood anti-coagulant activity of compound earthworm capsule of temporary regulations were not less than 12 840 U/g and 113 822 U/g. Conclusion: The method is rapid, simple, and accurate for determining the activity of promoting blood circulation and anticoagulation for compound lumbrical capsule, thus it can be used for the quality control of CLC.

Study on Analgesic and Anti-inflammatory Effect of Mandelic Acid / 中国药师

Objective: To observe the analgesic and anti-inflammatory effect of mandelic acid. Methods: Fifty Kunming mice were randomly divided into 5 groups:the blank control group (0. 1 ml/10 g), mandelic acid high (300 mg·kg-1), medium (200 mg ·kg-1 ) and low (140 mg·kg-1 ) dose groups, and the positive control ( aspirin) group, ig, qd. The analgesic effect of mandelic acid was observed by writhing test and hot plate method in mice. The ear swelling model caused by dimethyl benzene in mice was a-dopted to observe the analgesic effect. Results:Mandelic acid in each dose group could make the number of writhing in mice signifi-cantly reduced and pain threshold extended, and when compared with the blank control group, the difference was statistically significant (P<0. 01). The writhing times of mice mandelic acid high dose group was fewer than that of the positive control group, and there was no statistically significant between the groups (P>0. 05). In low and medium dose group, the writhing times of mice were more than those of the positive control group, and there was a significant difference between the low dose group and the positive control group( P<0. 05). The pain threshold of the mice in each mandelic acid dose group was higher than that of the positive control group, the pain threshold increased significantly in the high dose group before and after the administration, and the difference was statistically signifi-cant when compared with the positive control group (P<0. 05). The effect of mandelic acid on the ear swelling of mice was not signifi-cant, and when compared with the blank control group, the difference was not significant (P>0. 05). Conclusion:Mandelic acid has significant analgesic effect, while anti-inflammatory effect is not obvious.

Study on the Method of Microbial Limit Test for Preparation Liquid of Iron Sucrose Injection before Filtration and Sterilization / 中国药房

OBJECTIVE:To establish a method of microbial limit test for liquid preparation of Iron sucrose injection before filtration and sterilization.METHODS:According to the microbial limit test in the 1005 and general rules 1006 of 2015 edition of Chinese Pharmacopoeia (vol.Ⅴ),plate method and membrane filtration method were used to measure total number of aerobic bacteria (Staphylococcus aureus,Pseudomonas aeruginosa,Bacillus subtilis,Candida albicans,Aspergillus niger) and total number of molds and yeasts (C.albicans,A.niger).The optimal test method was obtained by comparing the bacterial recoveries.RESULTS:By plate method,the recoveries of P aeruginosa and B.subtilis were 2％ and 5％.The test sample was diluted 10 times with pH 7.0 sodium chloride-peptone buffer solution,and the bacterial recoveries were in the range of 88％ to 96％;but he medium was dark in color.By membrane filtration method,without rinse solution,the bacterial recoveries in the range of 88％ to 95％.Add rinse solution,the bacterial recoveries were in the range of 91％ to 103％.After validated,the recoveries of menbrane filtration method with tlushing fluid ranged 50％-200 ％,which was in line with the requnements.CONCLUSIONS:The membrane filtration method established in this experiment has higher bacterial recovery rate than the plate method.The bacterial recoveries rate were higher after adding rinse solution,and no dark substance in the surface of filter membrane affect the accotmt.It can be used as the microbial limit test method for preparation liquid of Iron sucrose injection before filtration and sterilization.

Evaluation of Antinociceptive Activity of Methanol Extract from Cleome rutidosperma in Mice / 中草药·英文版

Objective Cleome rutidosperma (Capparidaceae), commonly known as “Fringed Spider Flower”, is a medicinal plant found in Southeast Asia. C. rutidosperma is used in folk medicine for diuretic, laxative, analgesic, anti-inflammatory, antipyretic, antimicrobial, anti-oxidant, hypoglycemic, and anthelmintic activities. We have evaluated the anti-nociceptive properties of methanol extract from C. rutidosperma (MECR) in vivo. Methods Thermal method (hot plate test and tail flick test) was induced to judge the anti-inflammatory effect and couple of chemical method also used (formalin induced licking test; writhing test carried by acetic acid) to evaluate analgesic effect. Both of these tests were made over animal models, like mice and rats. Two different doses (100 and 200 mg/kg) were used for each case of test, while morphine sulphate (5mg/kg, ip) was used as reference drug. Results MECR demonstrated the significantly anti-nociceptive activity in the analgesic and anti-inflammatory tests by reducing nociception in mice models (P < 0.001). In the hot-plate and tail-flick tests, MECR significantly elongated the time to response to the thermal stimuli (100 and 200 mg/kg with P < 0.05, 0.001). The remarkable increase in the latency was observed at 90 and 120 min. In acetic acid-induced writhing test and formalin induced licking test for anti-inflammatory activity, MECR at 100 and 200 mg/kg doses exhibited significant (P < 0.001) reduction of writhing and licking response. Conclusion The anti-inflammatory and analgesic effects of C. rutidosperma propose that this effect may be a result of both peripheral and central mechanisms. Further study is required to ensure the proper mechanism of action as well as the active ingredient.

Antimicrobial analysis of Triphala and comparison with its individual constituents.

Triphala, a well known ayurvedic formulation is used against number of ailments since ancient times. It consists of Emblica officinalis, Terminalia chebula and Terminalia bellerica in equal proportion. Triphala as a whole and its three individual constituents show specific antimicrobial activity against certain bacteria and fungi. Antimicrobial activity of aqueous extract of triphala and its constituents was studied against P.aeruginasa, E.coli , B.subtilis, K. pneumoniae and S.aureus by cup-plate method. Triphala was found strongly bactericidal against P. aeruginosa with 1.8 cm of inhibitory zone. This was on account of T. chebula which showed 1.2 cm of inhibitory zone against the same pathogen, followed by E. coli and other two Gram positive bacteria. T. bellerica however showed maximum inhibitory activity against B.subtilis by showing 2.2 cm of inhibitory zone. It was confirmed that antimicrobial activity against Gram negative bacteria is due to T. chebula and E. officinalis while antimicrobial activity against Gram positive bacteria is on account of T. bellerica. Antifungal activity of Triphala and its constituents was studied against two pathogenic fungi viz. Aspergillus niger and Candida albicans by the same method. Triphala was found more efficient against A. niger, this was on account of T. bellerica which showed nearly 2 cm zone of inhibition. T. bellerica and Triphala showed more than 2 cm inhibitory zone against C. albicans. Inhibitory zone of Emblica officinalis was observed to be of 1.5-2 cm against both the fungi, whereas T. chebula did not show inhibitory activity against C. albicans but showed nearly 1 cm of inhibitory zone against A. niger. This confirms that the antifungal activity of Triphala is primarily due to T. bellerica and E. offiicinalis.

Antibacterial Effect of Shenju Lotion in Vitro / 医药导报

Objective To study the antibacterial effect of Shenju lotion in vitro. Methods The diameter of inhibition zone was determined by paper-disc agar-diffusion method. Minimum inhibitory concentration ( MIC) and Minimum bactericidal concentration ( MBC ) was determined by culture medium dilution methodand agar medium plate method, respectively. Antibacterial effect was compared between Shenju lotion and city sale of the gynecological lotion. Results Inhibitory effects of Shenju lotion on 5 pathogenic strains were significantly better than that of city sale of the gynecological lotion at the same concentrations (P<0. 05). MIC of Shenju lotion on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candida albicans was 33. 75, 67. 5, 67. 5, 67. 5 and 33. 75 mg ·mL-1 , respectively. MBC of Shenju lotion on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candida albicans was 33. 75, 67. 5, 67. 5, 135 and 33. 75 mg ·mL-1 , respectively. Conclusion Shenju lotion has obvious bacteriostasis and sterilization effect.

Study of Phytochemical and Antimicrobial Potential of The Leaves of Nilgirianthus Ciliatus Linn.

The present study was carried out to identify the phytochemical constituents and to evaluate antibacterial and antifungal activity of Nilgirianthus ciliatus Linn using ethanol, chloroform, petroleum ether and aqueous extracts on selected four bacterial pathogens such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and two fungal strains Aspergillus niger and Candida albicans (Fungus-unicellular/ multicellular yeast). For the antimicrobial test, cup plate method was used and the zone of inhibition was measured in mm. The extracts showed significant antimicrobial activity and were compared with Amoxicillin and Ketoconazole. The chloroform extract showed the higher antibacterial activity with a zone of inhibition of 23mm against gram negative pathogens and minimum 15mm against Aspergillus niger from 150mcg/ml. Ethanolic and petroleum ether extracts showed similar activity with an inhibition zone of 12 and 11 mm against fungal strains Candida albicans and Aspergillus niger respectively from 150mcg/ml. The phytochemical analysis revealed the presence of alkaloids, carbohydrates, flavonoids, saponins; proteins and tannins. The powdered leaves were analyzed for various physicochemical constants also.

Evaluation of analgesic activity of Emblica officinalis in albino rats.

Background: Amla is one of the most often used herbs in indigenous medicine, whose all parts including fruit, seed, leaves, root, bark, and fl owers are used in various Ayurvedic/Unani medicines. However, studies to establish analgesic potential of amla were limited, so the purpose of the present study was to evaluate analgesic activity of amla, if it possesses any. Methods: Albino rats were divided randomly in three groups of six rats each. Group 1 (control) received distilled water orally, Group 2 (test) received Emblica offi cinalis extract in dose of 600 mg/kg orally and Group 3 (standard) received Pentazocine in dose 10 mg/kg intraperitoneally. Results: Emblica offi cinalis extract did not produced statistically signifi cant (p>0.05) analgesia when compared with the control group in hot plate latency, but produced a statistically signifi cant reduction in 6% NaCl induced abdominal writhing (p<0.05). Conclusions: Since the plant extract signifi cantly reduced the number of writhes in abdominal writhing model, but do not increase hot plate latency, the commercially available crude extract of Emblica offi cinalis exhibit analgesic activity involving peripheral mechanisms.

Anti-inflammatory and analgesic effects of Polygonum orientale extract / 中草药

Objective: To investigate the anti-inflammatory and analgesic effects of Polygonum orientale extract. Methods: The acute inflammatory models such as xylene-induced ear edema and egg white-induced paw edema and the chronic inflammatory model granuloma induced by cotton pellet implantation were used in researching the inflammatory effects of water and alcohol extract from P. orientale (POWE and POAE) by ig administration. Meanwhile, the analgesic effects of POWE and POAE were observed by hot plate and acetic acid writhing test. Results: Compared with the model group, high- and low-dose (7.5 and 3.75 g/kg) POWE and POAE could significantly inhibit ear edema in mice (P < 0.01) and paw edema in rats (P < 0.05, 0.01). Also, POWE and POAE decreased the granuloma of rats (P < 0.01). Moreover, after treatment with high- and low-dose POWE and POAE, the pain threshold with hot plate method was significantly prolonged (P < 0.01) compared with the model group. The writhing number was reduced after administration (P < 0.01) compared to the model group. However, there were substantial variations between the POAE groups and the same dose of POWE in high and low concentration (P < 0.05, 0.01). Conclusion: P. orientale extract possesses the anti-inflammatory and analgesic effect, and POWE has better effect than POAE.

Assessment of biofilm formation in device-associated clinical bacterial isolates in a tertiary level hospital.

Background: Biofilm formation is a developmental process with intercellular signals that regulate growth. Biofilms contaminate catheters, ventilators, and medical implants; they act as a source of disease for humans, animals, and plants. Aim: In this study we have done quantitative assessment of biofilm formation in device-associated clinical bacterial isolates in response to various concentrations of glucose in tryptic soya broth and with different incubation time. Materials and Methods: The study was carried out on 100 positive bacteriological cultures of medical devices, which were inserted in hospitalized patients. The bacterial isolates were processed as per microtitre plate method with tryptic soya broth alone and with varying concentrations of glucose and were observed in response to time. Results: Majority of catheter cultures were positive. Out of the total 100 bacterial isolates tested, 88 of them were biofilm formers. Incubation period of 16-20 h was found to be optimum for biofilm development. Conclusions: Availability of nutrition in the form of glucose enhances the biofilm formation by bacteria. Biofilm formation depends on adherence of bacteria to various surfaces. Time and availability of glucose are important factors for assessment of biofilm progress.

Screening of Quercus infectoria gall extracts as anti-bacterial agents against dental pathogens.

Background and Objectives: A number of bacteria have now become antibiotic-resistant. This increases the importance of ayurvedic drugs. We report, here, the activity of different extracts (petroleum ether, chloroform, methanol and water) of Quercus infectoria galls against dental pathogens - Streptococcus mutans, Streptococcus salivarius, Staphylococcus aureus, Lactobacillus acidophilus (designated) and Streptococcus sanguis (isolated). Materials and Methods: The cup-plate method was used in anti-bacterial activity of the extracts at concentration of 200 mg/ml against dental pathogens. Minimum inhibitory concentration (MIC) values of most effective extracts against the most susceptible bacteria were determined using a two-fold serial micro dilution method. Results: Methanolic extract showed maximum anti-bacterial activity against all the bacteria. The most susceptible bacteria were S. sanguis followed by S. aureus, S. mutans, S. salivarius and L. acidophilus. The MIC values showed that methanolic extract was more effective than water extract. Conclusion: The plant has the potential to generate herbal metabolites. The crude extracts demonstrating anti-dental caries activity could result in the discovery of new chemical classes of antibiotics. These chemical classes of antibiotics could serve as selective agents for the maintenance of human health and provide bio-chemical tools for the study of infectious diseases.