Mukteswar Mothadaka - Academia.edu (original) (raw)

Papers by Mukteswar Mothadaka

Research paper thumbnail of Multidrug-resistant phenotypes among biofilm-producing staphylococcal isolates from farm-raised fish: a molecular scrutiny

Journal of Applied Microbiology

Aims To describe the molecular characteristics of methicillin-resistant Staphylococcus aureus (MR... more Aims To describe the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates from farm-raised fish. Methods and results Fish samples (n = 180) collected from aquaculture farms in three major districts of Kerala, yielded 45 methicillin-resistant staphylococci (MRS) (25%) isolates. All of the isolates were resistant to tested beta-lactams, and 19 (42.22%) were resistant to flouroquinolones. According to the resistance profile of each isolate, 33 of 45 (73.33%) are identified as multidrug-resistant (MDR) isolates, with an average multiple antibiotic resistance (MAR) index of 0.41 ± 0.09. Notably, virulence determinants such as classical enterotoxin (sea & seb), and SE-like toxin (seg & sei) genes co-existed with Antimicrobial Resistance Genes (ARGs) in isolates studied. Regardless of the isolates being strong biofilm producers, only 23 (51.1%) harbored icaA and icaD genes. The heterogeneity of MRSA (n = 17) clones were evident as the species belonged to...

Research paper thumbnail of Evolution, Characteristics, and Clonal Expansion of Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA): Global Perspectives

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of AMR Global Scourge: Literacy as an End-to-End Containment Measure

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Status of AMR in Food Sector: Implications for Food Safety and Food Security with Special Reference to Fisheries

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Economic Impact of Antimicrobial Resistance and Projected Future Trends

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Genome Characterization and Infectivity Potential of Vibriophage-ϕLV6 with Lytic Activity against Luminescent Vibrios of Penaeus vannamei Shrimp Aquaculture

Viruses

Shrimp aquaculture, especially during the hatchery phase, is prone to economic losses due to infe... more Shrimp aquaculture, especially during the hatchery phase, is prone to economic losses due to infections caused by luminescent vibrios. In the wake of antimicrobial resistance (AMR) in bacteria and the food safety requirements of farmed shrimp, aqua culturists are seeking alternatives to antibiotics for shrimp health management, and bacteriophages are fast emerging as natural and bacteria-specific antimicrobial agents. This study analyzed the whole genome of vibriophage-ϕLV6 that showed lytic activity against six luminescent vibrios isolated from the larval tanks of P. vannamei shrimp hatcheries. The Vibriophage-ϕLV6 genome was 79,862 bp long with 48% G+C content and 107 ORFs that coded for 31 predicted protein functions, 75 hypothetical proteins, and a tRNA. Pertinently, the vibriophage-ϕLV6 genome harbored neither AMR determinants nor virulence genes, indicating its suitability for phage therapy. There is a paucity of whole genome-based information on vibriophages that lyse lumines...

Research paper thumbnail of Antimicrobial Resistance in Fisheries

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Handbook on Antimicrobial Resistance

Handbook on Antimicrobial Resistance

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

Research paper thumbnail of Comparison of single and multi-host enrichment approach for harnessing lytic phages against antimicrobial-resistant E. coli: Repurposing the enrichment step

Biologia

Escherichia coli has been enlisted as a pathogen of antimicrobial resistance (AMR) importance pos... more Escherichia coli has been enlisted as a pathogen of antimicrobial resistance (AMR) importance posing a threat to human health. In the wake of the widespread AMR, lytic bacteriophages remain a promising alternative to antibiotics for controlling the multidrug-resistant (MDR) pathogens. However, the major hindrance for phage therapy is the lack of a rapid procedure to harness broad host range phages. Hitherto in vogue, lytic phage isolation methods are based on conventional single host enrichment (M1). Limitation to the available methods includes a higher number of steps, additional instrumentation, cost and time involved in the screening of samples and more recovery of narrow host range phages.To improve the conventional method of isolation, a multiple host enrichment approach (modified method; M2) is developed and validated with a classical approach using 24 MDR extended-spectrum β-lactamase producing (ESBL) E. coli and universal coliphage host E. coli NCIM 2089. A total of 58 phages were isolated using both the methods (27 phages from M1 and 31 phages from M2) and were categorized, based on the DNA restriction digestion pattern, to 25 groups with a maximum host range of 17 in host range analysis. Even though there is no significant difference (P > 0.01) in recovering number of phages between M1 and M2 methods, excepting in one occasion where MFB13 host yielded 3 more morphologically distinct phages in M2 (p ≤ 0.05), the M2 approach was better in terms of reduction in time (4.72%) and cost (23.5%) and same instrumentation requirement. This emphasizes that the proposed method has the potential to yield broad host range lytic phages against localized strain repository of AMR E. coli which can be leading to its application in food, food contact surfaces as well as phage therapy.

Research paper thumbnail of Gene sequencing analysis of tailed phages identified diverse (Kayfunavirus and Berlinvirus) coliphages in aquatic niche against AMR Escherichia coli

Research paper thumbnail of Multi-drug resistance, integron and transposon-mediated gene transfer in heterotrophic bacteria from Penaeus vannamei and its culture environment

Environmental Science and Pollution Research

Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food pr... more Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food production avenues including aquaculture. One hundred and sixty out of 2304 bacterial isolates from shrimp farm samples (n = 192) of Andhra Pradesh, India, were MDR. Based on biochemical identification and 16S rRNA sequencing, they were grouped into 35 bacterial species with the predominance of Vibrio parahaemolyticus (12.5%). The MDR isolates showed highest resistance toward oxytetracycline (89%) with more than 0.2 MAR (multiple antibiotic resistance), demonstrates a high-risk source. The most prevalent antibiotic-resistance gene (ARG) and mobile genetic element (MGE) detected were tetA (47.5%) and int1 (46.2%), respectively. In conjugation experiments, overall transfer frequency was found to be in the range of 1.1 × 10−9 to 1.8 × 10−3 with the transconjugants harbouring ARGs and MGEs. This study exposed the wide distribution of MDR bacteria in shrimp and its environment, which can further aggravate the already raised concerns of antibiotic residues in the absence of proper mitigation measures.

Research paper thumbnail of Iron-Enriched Fish Powder Improved Haemoglobin Levels in Adolescent Girls of West Jaintia Hills District of Meghalaya, India

Biological Trace Element Research

This study was carried out to assess the efficacy of sodium iron EDTA (NaFeEDTA) salt-enriched fi... more This study was carried out to assess the efficacy of sodium iron EDTA (NaFeEDTA) salt-enriched fish powder in addressing iron deficiency in adolescent anaemic girls. This was a 60-day randomised double-blinded, controlled intervention trial involving 123 girls age ranging from 10 to 19 years in three villages of West Jaintia Hills District of State of Meghalaya in India using soup made out of sodium iron EDTA (NaFeEDTA)-enriched fish powder (250 mg/100 g). The influence of the iron-enriched powder on blood haemoglobin levels and serum iron was determined. The research also analysed the food consumed by the study subjects during the study period and it was found that there were no significant differences between the iron-enriched and control groups. The results indicated that the girls predominantly consumed cereals with little fruits, vegetables and meat. On an average, 100 ml of soup prepared out of 10 g of fish powder per day was consumed that theoretically provided about 25 mg of iron each day. Following intervention, all the participants in the group that consumed soup made out of NaFeEDTA-enriched fish powder had significantly higher haemoglobin levels and serum iron and a lower prevalence of anaemia than the control group. The effects of NaFeEDTA salt-enriched fish powder were statistically significant and it can be inferred that NaFeEDTA-enriched fish powder was highly effective in controlling iron deficiency and reducing the prevalence of iron-deficiency anaemia among the adolescent girls.

Research paper thumbnail of A revisited two-step microtiter plate assay: Optimization of in vitro multiplicity of infection (MOI) for Coliphage and Vibriophage

Journal of Virological Methods, 2021

A 2-step microtiter plate assay was developed to simultaneously check wide values of MOIs of bact... more A 2-step microtiter plate assay was developed to simultaneously check wide values of MOIs of bacteriophages, ranging between MOI-0.0001 and MOI-10000 in the first step and optimize the most suitable MOI (lowest quantity of phage) for inhibiting the growth of the target bacteria in the second step. The results of the first step revealed that the effective MOI of coliphage-ɸ5 for controlling the growth of antimicrobial resistant (AMR) E. coli was between 4.36 and 43.6 for E.coli-EC-3; between 38.2 and 382 for E.coli-EC-7 and between 81.5 and 815 for E.coli-EC-11. The optimum MOI of coliphage-ɸ5 determined in the second step was 17.44, 191 and 326 for controlling the growth of E.coli-EC-3; E.coli-EC-7 and E.coli-EC-11, respectively. The effective MOI of vibriophage-ɸLV6 for controlling luminescent Vibrio harveyi in the first step was found to be between 18.3 and 183 and the optimum MOI as determined in the second step was 79. The sequential 2-step microtiter plate method yielded faster optimization of MOI and was economical compared to the conventional flask method. The measurement of OD values at 550 nm and 600 nm showed similar trend and replicate data from 5-wells and 3-wells yielded identical pattern indicating that the measuring absorbance data in 3-replicate wells at either OD550 or OD600 is sufficient to generate quantifiable phage lysis data. The 2-step microtiter plate assay finds application in phage therapy in human health care, agriculture and animal agriculture for determining the optimum MOIs for selected bacteriophages.

Research paper thumbnail of Predominance of genetically diverse ESBL Escherichia coli identified in resistance mapping of Vembanad Lake, the largest fresh-cum-brackishwater lake of India

Environmental Science and Pollution Research, 2021

Antimicrobial resistance (AMR) burden in Escherichia coli along the 90 km stretch of Vembanad Lak... more Antimicrobial resistance (AMR) burden in Escherichia coli along the 90 km stretch of Vembanad Lake, Kerala, India was assessed. Seventy-seven percent of water samples drawn from different stations of the Lake harbored E. coli. Antibiotic susceptibility test performed on 116 E. coli isolates revealed 81% were resistant to ≥ one antibiotic with 39 AMR profiles, 30% multidrug resistant, 32% extended spectrum  lactamase (ESBL) producers as per CLSI.The probability of isolating cefotaxime resistant E. coli was the highest 0.7 (P ≤ 0.05) in the Lake. Genetically diverse ESBL types blaTEM-116,blaCTX-M-152, blaCTX-M-27,blaCTX-M-55, blaCTX-M-205, and blaSHV-27 were identified. Molecular typing (ERIC PCR, MLST and PBRT) confirmed the diversity among E. coli between and within the stations. ST11439 and Single and Double Loci Variants of ST443, ST4533 were identified in Multi locus sequence typing (MLST) analysis. Inc plasmids (B/O, F, W, I1, FIIA, HI1, P-1, K/B and N) identified in the Lake evidences the transmission potential. Low multiple antibiotic resistance index (average < 0.2) indicating lower risk to the human population albeit, an emerging concern of ESBL resistance in the Lake. The occurrence of genetically variant ESBL E. coli in Vembanad Lake signals health hazards and necessitates pragmatizing strategic control measures.

Research paper thumbnail of Antimicrobial resistance in Vibrios of shrimp aquaculture: Incidence, identification schemes, drivers and mitigation measures

Aquaculture Research, 2021

Research paper thumbnail of Antibiotic resistance of culturable heterotrophic bacteria isolated from shrimp (Penaeus vannamei) aquaculture ponds

Marine Pollution Bulletin, 2021

Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage ... more Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage has become an issue of great concern due to the development of antimicrobial resistance in bacteria. A total of 2304 bacterial isolates from 192 samples (sediment, water, shrimp, and source water) from Andhra Pradesh, India were screened. Antibiotic resistance of bacterial isolates was highest for oxytetracycline (23.4%) followed by erythromycin (12.7%), co-trimoxazole (10%) ciprofloxacin (9.6%), and chloramphenicol (6%), of which 11.9% isolates were multi-drug resistant. Bacterial isolates from shrimp (26.7%), water (23.9%), and sediment (19.6%) samples exhibited more resistance (p ≤ 0.05) towards oxytetracycline. Higher antibacterial resistance was observed from samples of southern Andhra Pradesh (locations L6 and L7). Gram negative bacteria were more prevalent (64%) and showed significantly (p ≤ 0.01) higher resistance. This study indicated the wider distribution of antibiotic-resistant bacteria in shrimp aquaculture ponds with potential risk to humans and the environment.

Research paper thumbnail of Role of Natural Additives on Quality and Shelf Life Extension of Fish and Fishery Products

Natural Food Additives, 2021

Fish and fishery products have drawn greater attention due to their high nutritional value owing ... more Fish and fishery products have drawn greater attention due to their high nutritional value owing to the presence of cheap superior quality proteins, essential fatty acids, and macro and micronutrients. But higher water content, non- protein nitrogen, and post mortem pH (6–7) in fish favor rapid spoilage by autolysis or putrefaction, and can result in health risk as well as economic loss. Moreover, the quality of fish is affected by species, harvesting season, handling and method of processing. Thus, application of food additives become necessary to maintain the shelf life, nutritional content, texture and flavor of the raw material as well as processed products. Considerable research is being done on applications of natural additives after the emergence of the concept ‘Green consumerism’ which resulted in decreased consumer preference for using synthetic food additives. In this background, this chapter will review the natural additives used for quality maintenance and shelf life ext...

Research paper thumbnail of Prevalence of Vibrio mimicus in Fish, Fishery Products, and Environment of South West Coast of Kerala, India

Journal of AOAC INTERNATIONAL, 2021

Background Vibrio mimicus is a seafood-borne bacterium involved in incidences of human infections... more Background Vibrio mimicus is a seafood-borne bacterium involved in incidences of human infections following consumption of raw or undercooked seafood. Regular monitoring of seafood for V.mimicus is necessary for risk assessment and to establish mitigation measures. Method During the period 2017–2020, a total of 250 samples comprising finfish, shellfish, water, ice, and sediment samples were collected from fish markets, fish landing centers, and fish farms in the Ernakulum district on the Southwest coast of Kerala, India. V. mimicus was isolated using enrichment in alkaline peptone water for 18 h followed by plating on thiosulfate citrate bile salts sucrose agar and then incubated at 37°C for 18–24 h. The presumptive V. mimicus isolates were confirmed by biochemical characterization and molecularly with vmh gene-specific for V. mimicus. Results The study revealed that the prevalence of V. mimicus is 5.6% in the total of samples screened. The highest occurrence was observed in brackis...

Research paper thumbnail of Prevalence, Virulence Characterization, AMR Pattern and Genetic Relatedness of Vibrio parahaemolyticus Isolates From Retail Seafood of Kerala, India

Frontiers in Microbiology, 2020

Narayanan et al. V. parahaemolyticus With Pathogenic Potential in Seafood The conventional method... more Narayanan et al. V. parahaemolyticus With Pathogenic Potential in Seafood The conventional methods used to identify the pathogenic V. parahaemolyticus would be good for clinical isolates, but a more elaborate method is recommended for the detection of tdh gene in environmental isolates. This is the first comprehensive study on pathogenic V. parahaemolyticus in Kerala, India and demonstrates for the first time, the isolation of potentially pathogenic V. parahaemolyticus, carrying tdh gene from seafood collected from retail markets in Kerala.

Research paper thumbnail of Isolation and characterization of sulphur oxidizing bacteria (Halothiobacillus sp.) from aquaculture farm soil

Journal of Environmental Biology, 2019

Isolation and characterization of Halothiobacillus sp. from the shrimp aquaculture farm soil and ... more Isolation and characterization of Halothiobacillus sp. from the shrimp aquaculture farm soil and their sulphur oxidation ability and utilization of H S in in-vitro model. 2 Starkeys mineral salt medium was used to screen autotrophic sulphur oxidizing bacteria. For the qualitative screening, bacterial isolates were inoculated in mineral salt medium containing bromo phenol blue indicator to monitor change in pH. The isolates were studied further for their sulphate ion production, sulphur oxidase enzyme production and utilization of Na S. Identification was carried out by 2 conventional biochemical and molecular methods. Fifty isolates showed distinct sulphur oxidizing ability on the mineral salt medium. The pH reduction test revealed that out of fifty isolates six could efficiently reduce the pH of the medium to 3.0 from an o-1 initial pH of 7 within 96 hr of incubation at 30 C. Maximum sulphate ion (12.65 mg ml) and sulphur oxidase-1-1 enzyme (16.64 mM sulphate hr ml) was produced by a bacterial isolate, Halothiobacillus sp. strain rk3. All the six isolates efficiently utilized Na S in in-vitro conditions. Conventional and molecular identification (16S 2 rRNA sequence analysis) revealed that the sulphur oxidizing bacterial isolates belonged to Halothiobacillus spp. Furthermore, sequencing similarity calculation showed an average nucleotide identity (ANI) values higher than 99% which suggests that the isolates were not genetically different. The present investigation revealed the presence of Halothiobacillus sp. as natural microflora of farm soils in shrimp aquaculture.

Research paper thumbnail of Multidrug-resistant phenotypes among biofilm-producing staphylococcal isolates from farm-raised fish: a molecular scrutiny

Journal of Applied Microbiology

Aims To describe the molecular characteristics of methicillin-resistant Staphylococcus aureus (MR... more Aims To describe the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates from farm-raised fish. Methods and results Fish samples (n = 180) collected from aquaculture farms in three major districts of Kerala, yielded 45 methicillin-resistant staphylococci (MRS) (25%) isolates. All of the isolates were resistant to tested beta-lactams, and 19 (42.22%) were resistant to flouroquinolones. According to the resistance profile of each isolate, 33 of 45 (73.33%) are identified as multidrug-resistant (MDR) isolates, with an average multiple antibiotic resistance (MAR) index of 0.41 ± 0.09. Notably, virulence determinants such as classical enterotoxin (sea & seb), and SE-like toxin (seg & sei) genes co-existed with Antimicrobial Resistance Genes (ARGs) in isolates studied. Regardless of the isolates being strong biofilm producers, only 23 (51.1%) harbored icaA and icaD genes. The heterogeneity of MRSA (n = 17) clones were evident as the species belonged to...

Research paper thumbnail of Evolution, Characteristics, and Clonal Expansion of Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA): Global Perspectives

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of AMR Global Scourge: Literacy as an End-to-End Containment Measure

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Status of AMR in Food Sector: Implications for Food Safety and Food Security with Special Reference to Fisheries

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Economic Impact of Antimicrobial Resistance and Projected Future Trends

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Genome Characterization and Infectivity Potential of Vibriophage-ϕLV6 with Lytic Activity against Luminescent Vibrios of Penaeus vannamei Shrimp Aquaculture

Viruses

Shrimp aquaculture, especially during the hatchery phase, is prone to economic losses due to infe... more Shrimp aquaculture, especially during the hatchery phase, is prone to economic losses due to infections caused by luminescent vibrios. In the wake of antimicrobial resistance (AMR) in bacteria and the food safety requirements of farmed shrimp, aqua culturists are seeking alternatives to antibiotics for shrimp health management, and bacteriophages are fast emerging as natural and bacteria-specific antimicrobial agents. This study analyzed the whole genome of vibriophage-ϕLV6 that showed lytic activity against six luminescent vibrios isolated from the larval tanks of P. vannamei shrimp hatcheries. The Vibriophage-ϕLV6 genome was 79,862 bp long with 48% G+C content and 107 ORFs that coded for 31 predicted protein functions, 75 hypothetical proteins, and a tRNA. Pertinently, the vibriophage-ϕLV6 genome harbored neither AMR determinants nor virulence genes, indicating its suitability for phage therapy. There is a paucity of whole genome-based information on vibriophages that lyse lumines...

Research paper thumbnail of Antimicrobial Resistance in Fisheries

Handbook on Antimicrobial Resistance, 2023

Research paper thumbnail of Handbook on Antimicrobial Resistance

Handbook on Antimicrobial Resistance

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

Research paper thumbnail of Comparison of single and multi-host enrichment approach for harnessing lytic phages against antimicrobial-resistant E. coli: Repurposing the enrichment step

Biologia

Escherichia coli has been enlisted as a pathogen of antimicrobial resistance (AMR) importance pos... more Escherichia coli has been enlisted as a pathogen of antimicrobial resistance (AMR) importance posing a threat to human health. In the wake of the widespread AMR, lytic bacteriophages remain a promising alternative to antibiotics for controlling the multidrug-resistant (MDR) pathogens. However, the major hindrance for phage therapy is the lack of a rapid procedure to harness broad host range phages. Hitherto in vogue, lytic phage isolation methods are based on conventional single host enrichment (M1). Limitation to the available methods includes a higher number of steps, additional instrumentation, cost and time involved in the screening of samples and more recovery of narrow host range phages.To improve the conventional method of isolation, a multiple host enrichment approach (modified method; M2) is developed and validated with a classical approach using 24 MDR extended-spectrum β-lactamase producing (ESBL) E. coli and universal coliphage host E. coli NCIM 2089. A total of 58 phages were isolated using both the methods (27 phages from M1 and 31 phages from M2) and were categorized, based on the DNA restriction digestion pattern, to 25 groups with a maximum host range of 17 in host range analysis. Even though there is no significant difference (P > 0.01) in recovering number of phages between M1 and M2 methods, excepting in one occasion where MFB13 host yielded 3 more morphologically distinct phages in M2 (p ≤ 0.05), the M2 approach was better in terms of reduction in time (4.72%) and cost (23.5%) and same instrumentation requirement. This emphasizes that the proposed method has the potential to yield broad host range lytic phages against localized strain repository of AMR E. coli which can be leading to its application in food, food contact surfaces as well as phage therapy.

Research paper thumbnail of Gene sequencing analysis of tailed phages identified diverse (Kayfunavirus and Berlinvirus) coliphages in aquatic niche against AMR Escherichia coli

Research paper thumbnail of Multi-drug resistance, integron and transposon-mediated gene transfer in heterotrophic bacteria from Penaeus vannamei and its culture environment

Environmental Science and Pollution Research

Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food pr... more Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food production avenues including aquaculture. One hundred and sixty out of 2304 bacterial isolates from shrimp farm samples (n = 192) of Andhra Pradesh, India, were MDR. Based on biochemical identification and 16S rRNA sequencing, they were grouped into 35 bacterial species with the predominance of Vibrio parahaemolyticus (12.5%). The MDR isolates showed highest resistance toward oxytetracycline (89%) with more than 0.2 MAR (multiple antibiotic resistance), demonstrates a high-risk source. The most prevalent antibiotic-resistance gene (ARG) and mobile genetic element (MGE) detected were tetA (47.5%) and int1 (46.2%), respectively. In conjugation experiments, overall transfer frequency was found to be in the range of 1.1 × 10−9 to 1.8 × 10−3 with the transconjugants harbouring ARGs and MGEs. This study exposed the wide distribution of MDR bacteria in shrimp and its environment, which can further aggravate the already raised concerns of antibiotic residues in the absence of proper mitigation measures.

Research paper thumbnail of Iron-Enriched Fish Powder Improved Haemoglobin Levels in Adolescent Girls of West Jaintia Hills District of Meghalaya, India

Biological Trace Element Research

This study was carried out to assess the efficacy of sodium iron EDTA (NaFeEDTA) salt-enriched fi... more This study was carried out to assess the efficacy of sodium iron EDTA (NaFeEDTA) salt-enriched fish powder in addressing iron deficiency in adolescent anaemic girls. This was a 60-day randomised double-blinded, controlled intervention trial involving 123 girls age ranging from 10 to 19 years in three villages of West Jaintia Hills District of State of Meghalaya in India using soup made out of sodium iron EDTA (NaFeEDTA)-enriched fish powder (250 mg/100 g). The influence of the iron-enriched powder on blood haemoglobin levels and serum iron was determined. The research also analysed the food consumed by the study subjects during the study period and it was found that there were no significant differences between the iron-enriched and control groups. The results indicated that the girls predominantly consumed cereals with little fruits, vegetables and meat. On an average, 100 ml of soup prepared out of 10 g of fish powder per day was consumed that theoretically provided about 25 mg of iron each day. Following intervention, all the participants in the group that consumed soup made out of NaFeEDTA-enriched fish powder had significantly higher haemoglobin levels and serum iron and a lower prevalence of anaemia than the control group. The effects of NaFeEDTA salt-enriched fish powder were statistically significant and it can be inferred that NaFeEDTA-enriched fish powder was highly effective in controlling iron deficiency and reducing the prevalence of iron-deficiency anaemia among the adolescent girls.

Research paper thumbnail of A revisited two-step microtiter plate assay: Optimization of in vitro multiplicity of infection (MOI) for Coliphage and Vibriophage

Journal of Virological Methods, 2021

A 2-step microtiter plate assay was developed to simultaneously check wide values of MOIs of bact... more A 2-step microtiter plate assay was developed to simultaneously check wide values of MOIs of bacteriophages, ranging between MOI-0.0001 and MOI-10000 in the first step and optimize the most suitable MOI (lowest quantity of phage) for inhibiting the growth of the target bacteria in the second step. The results of the first step revealed that the effective MOI of coliphage-ɸ5 for controlling the growth of antimicrobial resistant (AMR) E. coli was between 4.36 and 43.6 for E.coli-EC-3; between 38.2 and 382 for E.coli-EC-7 and between 81.5 and 815 for E.coli-EC-11. The optimum MOI of coliphage-ɸ5 determined in the second step was 17.44, 191 and 326 for controlling the growth of E.coli-EC-3; E.coli-EC-7 and E.coli-EC-11, respectively. The effective MOI of vibriophage-ɸLV6 for controlling luminescent Vibrio harveyi in the first step was found to be between 18.3 and 183 and the optimum MOI as determined in the second step was 79. The sequential 2-step microtiter plate method yielded faster optimization of MOI and was economical compared to the conventional flask method. The measurement of OD values at 550 nm and 600 nm showed similar trend and replicate data from 5-wells and 3-wells yielded identical pattern indicating that the measuring absorbance data in 3-replicate wells at either OD550 or OD600 is sufficient to generate quantifiable phage lysis data. The 2-step microtiter plate assay finds application in phage therapy in human health care, agriculture and animal agriculture for determining the optimum MOIs for selected bacteriophages.

Research paper thumbnail of Predominance of genetically diverse ESBL Escherichia coli identified in resistance mapping of Vembanad Lake, the largest fresh-cum-brackishwater lake of India

Environmental Science and Pollution Research, 2021

Antimicrobial resistance (AMR) burden in Escherichia coli along the 90 km stretch of Vembanad Lak... more Antimicrobial resistance (AMR) burden in Escherichia coli along the 90 km stretch of Vembanad Lake, Kerala, India was assessed. Seventy-seven percent of water samples drawn from different stations of the Lake harbored E. coli. Antibiotic susceptibility test performed on 116 E. coli isolates revealed 81% were resistant to ≥ one antibiotic with 39 AMR profiles, 30% multidrug resistant, 32% extended spectrum  lactamase (ESBL) producers as per CLSI.The probability of isolating cefotaxime resistant E. coli was the highest 0.7 (P ≤ 0.05) in the Lake. Genetically diverse ESBL types blaTEM-116,blaCTX-M-152, blaCTX-M-27,blaCTX-M-55, blaCTX-M-205, and blaSHV-27 were identified. Molecular typing (ERIC PCR, MLST and PBRT) confirmed the diversity among E. coli between and within the stations. ST11439 and Single and Double Loci Variants of ST443, ST4533 were identified in Multi locus sequence typing (MLST) analysis. Inc plasmids (B/O, F, W, I1, FIIA, HI1, P-1, K/B and N) identified in the Lake evidences the transmission potential. Low multiple antibiotic resistance index (average < 0.2) indicating lower risk to the human population albeit, an emerging concern of ESBL resistance in the Lake. The occurrence of genetically variant ESBL E. coli in Vembanad Lake signals health hazards and necessitates pragmatizing strategic control measures.

Research paper thumbnail of Antimicrobial resistance in Vibrios of shrimp aquaculture: Incidence, identification schemes, drivers and mitigation measures

Aquaculture Research, 2021

Research paper thumbnail of Antibiotic resistance of culturable heterotrophic bacteria isolated from shrimp (Penaeus vannamei) aquaculture ponds

Marine Pollution Bulletin, 2021

Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage ... more Shrimp aquaculture is one of the fastest growing food-producing avenues, where antibiotics usage has become an issue of great concern due to the development of antimicrobial resistance in bacteria. A total of 2304 bacterial isolates from 192 samples (sediment, water, shrimp, and source water) from Andhra Pradesh, India were screened. Antibiotic resistance of bacterial isolates was highest for oxytetracycline (23.4%) followed by erythromycin (12.7%), co-trimoxazole (10%) ciprofloxacin (9.6%), and chloramphenicol (6%), of which 11.9% isolates were multi-drug resistant. Bacterial isolates from shrimp (26.7%), water (23.9%), and sediment (19.6%) samples exhibited more resistance (p ≤ 0.05) towards oxytetracycline. Higher antibacterial resistance was observed from samples of southern Andhra Pradesh (locations L6 and L7). Gram negative bacteria were more prevalent (64%) and showed significantly (p ≤ 0.01) higher resistance. This study indicated the wider distribution of antibiotic-resistant bacteria in shrimp aquaculture ponds with potential risk to humans and the environment.

Research paper thumbnail of Role of Natural Additives on Quality and Shelf Life Extension of Fish and Fishery Products

Natural Food Additives, 2021

Fish and fishery products have drawn greater attention due to their high nutritional value owing ... more Fish and fishery products have drawn greater attention due to their high nutritional value owing to the presence of cheap superior quality proteins, essential fatty acids, and macro and micronutrients. But higher water content, non- protein nitrogen, and post mortem pH (6–7) in fish favor rapid spoilage by autolysis or putrefaction, and can result in health risk as well as economic loss. Moreover, the quality of fish is affected by species, harvesting season, handling and method of processing. Thus, application of food additives become necessary to maintain the shelf life, nutritional content, texture and flavor of the raw material as well as processed products. Considerable research is being done on applications of natural additives after the emergence of the concept ‘Green consumerism’ which resulted in decreased consumer preference for using synthetic food additives. In this background, this chapter will review the natural additives used for quality maintenance and shelf life ext...

Research paper thumbnail of Prevalence of Vibrio mimicus in Fish, Fishery Products, and Environment of South West Coast of Kerala, India

Journal of AOAC INTERNATIONAL, 2021

Background Vibrio mimicus is a seafood-borne bacterium involved in incidences of human infections... more Background Vibrio mimicus is a seafood-borne bacterium involved in incidences of human infections following consumption of raw or undercooked seafood. Regular monitoring of seafood for V.mimicus is necessary for risk assessment and to establish mitigation measures. Method During the period 2017–2020, a total of 250 samples comprising finfish, shellfish, water, ice, and sediment samples were collected from fish markets, fish landing centers, and fish farms in the Ernakulum district on the Southwest coast of Kerala, India. V. mimicus was isolated using enrichment in alkaline peptone water for 18 h followed by plating on thiosulfate citrate bile salts sucrose agar and then incubated at 37°C for 18–24 h. The presumptive V. mimicus isolates were confirmed by biochemical characterization and molecularly with vmh gene-specific for V. mimicus. Results The study revealed that the prevalence of V. mimicus is 5.6% in the total of samples screened. The highest occurrence was observed in brackis...

Research paper thumbnail of Prevalence, Virulence Characterization, AMR Pattern and Genetic Relatedness of Vibrio parahaemolyticus Isolates From Retail Seafood of Kerala, India

Frontiers in Microbiology, 2020

Narayanan et al. V. parahaemolyticus With Pathogenic Potential in Seafood The conventional method... more Narayanan et al. V. parahaemolyticus With Pathogenic Potential in Seafood The conventional methods used to identify the pathogenic V. parahaemolyticus would be good for clinical isolates, but a more elaborate method is recommended for the detection of tdh gene in environmental isolates. This is the first comprehensive study on pathogenic V. parahaemolyticus in Kerala, India and demonstrates for the first time, the isolation of potentially pathogenic V. parahaemolyticus, carrying tdh gene from seafood collected from retail markets in Kerala.

Research paper thumbnail of Isolation and characterization of sulphur oxidizing bacteria (Halothiobacillus sp.) from aquaculture farm soil

Journal of Environmental Biology, 2019

Isolation and characterization of Halothiobacillus sp. from the shrimp aquaculture farm soil and ... more Isolation and characterization of Halothiobacillus sp. from the shrimp aquaculture farm soil and their sulphur oxidation ability and utilization of H S in in-vitro model. 2 Starkeys mineral salt medium was used to screen autotrophic sulphur oxidizing bacteria. For the qualitative screening, bacterial isolates were inoculated in mineral salt medium containing bromo phenol blue indicator to monitor change in pH. The isolates were studied further for their sulphate ion production, sulphur oxidase enzyme production and utilization of Na S. Identification was carried out by 2 conventional biochemical and molecular methods. Fifty isolates showed distinct sulphur oxidizing ability on the mineral salt medium. The pH reduction test revealed that out of fifty isolates six could efficiently reduce the pH of the medium to 3.0 from an o-1 initial pH of 7 within 96 hr of incubation at 30 C. Maximum sulphate ion (12.65 mg ml) and sulphur oxidase-1-1 enzyme (16.64 mM sulphate hr ml) was produced by a bacterial isolate, Halothiobacillus sp. strain rk3. All the six isolates efficiently utilized Na S in in-vitro conditions. Conventional and molecular identification (16S 2 rRNA sequence analysis) revealed that the sulphur oxidizing bacterial isolates belonged to Halothiobacillus spp. Furthermore, sequencing similarity calculation showed an average nucleotide identity (ANI) values higher than 99% which suggests that the isolates were not genetically different. The present investigation revealed the presence of Halothiobacillus sp. as natural microflora of farm soils in shrimp aquaculture.