Tapas Kumar Sar

Chronic arsenicosis in cattle with special reference to its metabolism in arsenic endemic village of Nadia district West Bengal India

Thirty Milch cattle were selected randomly from a village of Nadia district of West Bengal, India containing high arsenic in water and soil samples. Milk, feces and hair samples were collected to analyze arsenic status in animals. Water and straw samples were also estimated for arsenic. Milk products prepared from milk of cattle rearing in arsenic prone village were also collected to quantify total arsenic and speciation of arsenic in milk and feces samples were also carried out. It was observed that high amount of arsenic was present in milk, feces, hair of cattle and water and straw samples in arsenic prone village. Milk product also contained significant amount of arsenic than that of milk product of control village. Speciation study revealed arsenite fraction was mainly eliminated through milk, whereas organoarsenic species were mainly excreted through feces.

Quantitative imaging of arsenic and its species in goat following long term oral exposure

Severity of arsenic toxicity was reported to vary depending on its species. The present study reflects the status of different species of arsenic in goat following long-term exposure of arsenic leading to hepatic damage. The experiment was conducted with six black Bengal goats, which were administered with sodium arsenite orally at a dose rate of 2 mgkg(-1) daily for 84 days. Faeces, urine, hair and blood samples were collected from those animals at 14 days interval. Excretion of total arsenic was reduced from 56 days onwards through both faeces and urine indicating higher accumulation of arsenic in body. The speciation study revealed that urinary arsenic was mainly of organic type, whereas hair accumulated almost equal proportion of arsenite, arsenate and organo arsenicals. Goats excreted high proportion of organo arsenicals through faeces possibly due to hepatobiliary secretion of organo arsenic into the gut. Significantly elevated serum alanine aminotransferase and aspartate aminotransferase activities (p<0.05) along with histopathological changes in liver indicated hepatotoxicity. The arsenite fraction increased and organic proportion decreased in urine as the time progressed, which indicates that arsenite gets methylated in liver of goat. The study thus alluded that the toxicity of arsenic would aggravate if the animals were exposed for long time as the hepatotoxicity progressed resulting in decreased methylation and formation of organo arsenicals and decreased excretions through urine.

Virulence Repertoire, Characterization, and Antibiotic Resistance Pattern Analysis of Escherichia coli Isolated from Backyard Layers and Their Environment in India

SUMMARY This study was undertaken to observe the prevalence, serogroup, avian pathogenic Escherichia coli (APEC)-associated virulence gene, randomly amplified polymorphic DNA (RAPD) pattern, and antibiotic resistance genes of E. coli in backyard layers and their environment in India. From the 360 samples of healthy layers and their environment, 272 (75.5%) E. coli were isolated. The majority (28.67%) of them were untypeable. Among the studied virulence genes (papC, tsh, iucC, astA), 52 (14.32%) isolates were found to possess astA, including the isolates from the drinking water of the birds (4/272, 1.47%). These strains belonged to 18 different serogroups. Most of the isolates were typeable by RAPD and they produced different patterns. Phenotypic resistance of the isolates was most frequently observed to erythromycin (95.83%), chloramphenicol (87.52%), and cotrimoxazole (78.26%). None of the isolates was found to possess extended-spectrum beta-lactamases (blaTEM, blaSHV, blaCTX-M) or quinolone resistance (qnrA) genes by PCR. The present study was the first attempt in India to assess APEC distribution in backyard poultry production. RESUMEN Repertorio de virulencia, caracterización y análisis de los patrones de resistencia a los antibióticos de Escherichia coli aisladas de gallinas de postura de traspatio y de su medio ambiente en la India. Este estudio se realizó para determinar la prevalencia, el serogrupo, los genes asociados a virulencia de Escherichia coli patógena para las aves (APEC), los patrones de ADN polimórfico amplificado aleatoriamente (RAPD), y los genes de resistencia a los antibióticos de E. coli en gallinas de traspatio y su ambiente en la India. De las 360 muestras de gallinas sanas y de su ambiente, se aislaron 272 cepas de E. coli (75.5%). La mayoría (28.67%) de ellas no fueron tipificables. Entre los genes de virulencia estudiados (papC, tsh, iucC, astA), se encontró que 52 aislamientos (14.32%) poseían el gene astA, incluyendo los aislamientos de agua de bebida de las aves (4/272, 1.47%). Estas cepas pertenecían a 18 serogrupos diferentes. La mayoría de los aislamientos fueron tipificables mediante RAPD y produjeron diferentes patrones. La resistencia fenotípica de los aislamientos se observó con mayor frecuencia contra eritromicina (95.83%), cloranfenicol (87.52%), y contra cotrimoxazol (78.26%). Se encontró mediante PCR que ninguno de los aislamientos poseía genes de un espectro extendido de beta-lactamasas (blaTEM, blaSHV, blaCTX-M), o resistencia contra quinolonas (qnrA). El presente estudio es el primer intento en la India para evaluar la distribución de E. coli patógena para la producción de aves de traspatio.

Isolation, molecular characterization and antibiotic resistance of Shiga Toxin–Producing Escherichia coli (STEC) from buffalo in India

In total, 363 Escherichia coli were isolated from 165 faecal samples of healthy buffaloes in West Bengal, India. Twenty‐four of these isolates (6·61%) were found to carry at least one gene characteristic for Shiga toxin–producing Escherichia coli (STEC). These STEC strains belonged to 13 different O‐serogroups. The stx1 gene was present in 23 (95·8%) of total STEC isolates, whereas 20 (83·3%) STEC isolates carried the gene stx2. Twelve strains of E. coli (50% of total STEC isolates) possessed enterohaemolysin (ehxA) gene in combination with others. Fourteen (58·33%) isolates found to possess saa gene. However, no E. coli was detected harbouring gene for intimin protein (eaeA). Of 23 stx1‐positive isolates, seven (30·43%) were positive for genes of the stx1C subtype. Of the 20 isolates with the stx2 gene, 25% (5/20) possessed stx2C and 10% (2/20) possessed stx2d gene. The phylogenetic analysis after RAPD of STEC strains revealed six major clusters. The isolated STEC strains were resistant most frequently to erythromycin (95·83%), cephalothin (62·5%), amikacin (54·17%), kanamycin (45·83%) and gentamicin (41·67%) group of antibiotics. No ESBL‐producing (blaCTXM, blaTEM, blaSHV) or quinolone resistance gene (qnrA) was detected in the STEC isolates.

Approaches to characterize extended spectrum beta-lactamase/beta-lactamase producing Escherichia coli in healthy organized vis-a-vis backyard farmed pigs in India

The study was undertaken to investigate the occurrence and to characterize the ESBL/beta-lactamase producing-Escherichia coli in healthy pigs of organized and backyard farms in West Bengal, India. Total 200 rectal swabs were collected randomly from healthy pigs maintained in four organized farms and 10 backyard farms (n=100 each) and 76 isolates were identified as E. coli from organized (48/100, 48%) and backyard pigs (28/100, 28%). Twelve E. coli isolates (6%) in the present study were detected to possess any of the ESBL/beta-lactamase genes studied. ESBL/beta-lactamase producers were isolated with significantly more frequency from backyard pigs than the organized farm pigs (p=0.026). Six of ESBL/beta-lactamase producing isolates were phenotypically confirmed as CTX-M producers and ten of them were confirmed as TEM/SHV producers. PCR and sequencing of the amplified product from representative isolates revealed the presence of blaCTX-M-9, blaSHV-12 and blaTEM-1. No unique combination of the studied beta lactamase genes for organized and backyard farm pig isolates was noted. The ESBL isolates belonged to O13, O55, O133, O153, O157, O158, O166, rough and OUT serogroups. The association of heat labile toxin (elt) (p<0.0005) with organized farm isolates and heat stable toxin (estA) (p=0.0143) with backyard piggery sector was significantly higher. The ESBL/beta-lactamase producers from organized farm (Ak/Ex) and indigenous pigs (Ak/Ex/Te; Ak/CoT/G) showed a characteristic phenotypical antibiotic resistance pattern. Two pairs of isolates from organized and backyard farm pigs showed clonal relationship indicating a possible transmission between the farms which were situated adjacently. Thus the present study revealed backyard farm pigs as major source of ESBL/beta-lactamase producing-E. coli associated with STa and characteristic antibiotic resistance pattern in India.

Pharmacokinetic interaction of intramammary ceftriaxone and oral polyherbal drug (Fibrosin®) in goats

Abstract Background: The aim of the present study was to determine pharmacokinetic interaction of ceftriaxone and polyherbal drug (Fibrosin®) in lactating goats following single dose intramammary administration of ceftriaxone with 1 h pre-single dose oral administration of Fibrosin®. Methods: Pharmacokinetic interaction of ceftriaxone and Fibrosin® was evaluated in lactating goats following single dose intramammary administration of ceftriaxone at 50 mg/kg with 1 h pre-single dose oral administration of Fibrosin® (1.9 g). Estimation of ceftriaxone and its metabolite, ceftizoxime, was determined by high performance liquid chromatography. Results: Fibrosin® treated goats showed a typical absorption-reabsorption phase of ceftriaxone in plasma following intramammary administration. Neither ceftriaxone nor ceftizoxime was detected in the plasma and urine of goats without Fibrosin® treatment, however, ceftriaxone persisted for 36 h and ceftizoxime was present from 48 h to 72 h in the plasma of Fibrosin® treated goats. Ceftizoxime was also available from 72 h to 360 h post-dosing in milk in the presence of Fibrosin® following intramammary administration of ceftriaxone suggesting the polyherbal drug played a major role in the penetration of ceftriaxone from milk to systemic circulation. Furthermore, the polyherbal drug increased the bioavailability of ceftizoxime in milk following the metabolism of ceftriaxone. Conclusions: Polyherbal drug (Fibrosin®) plays a major role in the penetration of ceftriaxone from milk to systemic circulation and may be responsible for increased bioavailability of its metabolite in the mammary gland resulting in higher concentration and longer persistence of the drug in milk.

Efficacy evaluation of Bauhinia variegata L. stem bark powder as adjunct therapy in chronic Staphylococcus aureus mastitis in goat

Objective: The objective was to study the effect of Bauhinia variegata L. stem bark powder as adjunct therapy in chronic Staphylococcus aureus mastitis in goat. Materials and Methods: Mastitis was induced by intracisternal inoculation of coagulase positive S. aureus (J638) at the concentration of 2000 colony forming units. Group I animals were treated with repeated dose of ceftriaxone at 20 mg/kg intravenously, and Group II animals were treated with once daily oral administration of B. variegata L. stem bark powder at 6 g/kg for 7 days followed by maintenance dose at 3 g/kg for next 7 days along with repeated dose of the antibiotic at 20 mg/kg intravenously at 4 days interval. Results: No significant improvement in the clinical condition of the udder was noticed in the group treated with repeated dose of ceftriaxone alone. However, in the group treated with B. variegata L. stem bark powder along with repeated dose of ceftriaxone, no S. aureus colony was seen at 96 h and onwards in milk samples with a marked decrease in somatic cell count and milk alkaline phosphatase activity and increased lactoperoxidase activity. Further, plasma and milk concentration of ceftriaxone/ceftizoxime was increased, which indicated antibacterial, bioenhancing and antiinflammatory properties of the bark powder. The Group II animals also exhibited marked reduction in polymorphonuclear cells and fibrous tissue indicating antifibrotic property of B. variegata L. Conclusion: B. variegata L. stem bark powder can be considered as an effective adjunct therapy to intravenous ceftriaxone in S. aureus chronic mastitis in goat.

Toxicokinetics and recovery studies of dicamba dimethyl amine salt in goats following single oral administration

BACKGROUND Toxicokinetics and recovery studies of dicamba dimethyl amine salt (DDAS) were conducted to obtain more information about its toxicity and tissue retention in farm animals. RESULTS The minimum oral toxic dose level of DDAS was determined as 1400 mg kg(-1) body weight. In the toxicokinetic study, blood DDAS concentration of 55.6 +/- 0.59 microg mL(-1) (mean +/- standard error) was detected at 0.08 h, which peaked to 102.3 +/- 5.03 microg mL(-1) at 0.25 h, and declined to a minimum of 4.1 +/- 0.06 microg mL(-1) at 36 h. In recovery studies, DDAS concentration in urine began to increase significantly (P < 0.05) from 12 h, peaked at 24 h and declined from 48 h onwards. Maximum excretion through faeces was at 24 h and was complete by 144 h. The residual level in tissues decreased significantly (P < 0.05) on day 7 as compared to day 4. In histopathological studies, cellular alterations in lungs, liver, kidney, adrenal gland and spleen were found. CONCLUSION DDAS persists in the body for a shorter period and its major excretory route is through urine. DDAS has lower affinity to accumulate in tissues, and intensity of cellular alterations is not severe after single-dose oral administration.

Pig farm environment as a source of beta-lactamase or AmpC-producing Klebsiella pneumoniae and Escherichia coli

The present study was undertaken to detect the occurrence of beta-lactamase-/AmpC-producing Klebsiella and Escherichia coli in healthy pigs, feed, drinking water, and pen floor or surface soil. The study also intended to detect the clonal relationship between the environmental and porcine isolates to confirm the route of transmission. Rectal swabs and environmental samples were collected from apparently healthy pigs kept in organized or backyard farms in India. The pigs had no history of antibiotic intake. Production of phenotypical beta-lactamase, associated genes, and class I integron gene was detected in E. coli and Klebsiella isolates. The phylogenetic relationship among the isolates was established on the basis of Random amplification of polymorphic DNA banding pattern. Beta-lactamase-producing Klebsiella were isolated from healthy pigs (20.0%), pen floor swabs/surface soil swabs (14.0%), and drinking water (100%). Escherichia coli isolated from healthy pigs (14.4%), pen floor/surface soil (8.0%), and drinking water (33.3%) were detected as beta-lactamase producers. Majority of beta-lactamase-producing isolates possessed blaCTX-M-9. Further, 35 (81%) Klebsiella and all the E. coli isolates were detected as AmpC beta-lactamase ACBL producers and possessed blaAmpC. Sixteen beta-lactamase-producing Klebsiella (37.20%) and 13 E. coli (86.67%) possessed class I integron. Few resistant isolates from environmental sources (surface soil swab and drinking water) and the studied pigs were detected within the same cluster of the dendrogram representing their similarities. The study indicated about the possible role of contaminated environment as a source of beta-lactamase/AmpC-producing Klebsiella and E. coli in pigs.

Enhanced intestinal reabsorption due to reduced metabolism of ceftriaxone

The polyherbal drug (Fibrosin®) is often used as supportive therapy with intramuscular ceftriaxone injection for treatment of mastitis. A single dose of ceftriaxone at 50 mg kg−1 was administered intramuscularly in six healthy lactating goats and a single oral dose of Fibrosin® (1.9 gm) was given 1 hr prior to intramuscular ceftriaxone injection to study disposition of ceftriaxone. Plasma and urine samples were collected at predetermined time schedule and ceftriaxone/ceftizoxime was extracted and analyzed by HPLC. Ceftriaxone persisted for 3 hr in plasma of fibrosin treated healthy lactating goats. Mean t½ K (distribution half life) following absorption phase and t½ K′(elimination half life) following intestinal re-absorption phase were respectively, 0.091 ± 0.01 and 0.43 ± 0.03 hr with a re-absorption half life (t½Ka′) of 0.18 ± 0.003 hr.Ceftriaxone at a lower concentration (67.91 ± 9.42 μg ml−1) was recovered at 24 hr post dosing from urine. This is the first report of pharmacokinetic interaction of intramuscular ceftriaxone injection and the oral polyherbal drug (which was found to be a cytochrome P450 inhibitor).