Association between drinking water fluoride and the serum alkaline phosphatase and phosphate levels in pregnant women and newborn infants.

BACKGROUND: Endemic fluorosis (skeletal and dental) is a serious public health problem in many parts of the world, especially in India. Age, sex, dietary calcium (Ca), the hormonal status, the dose and duration of the fluoride intake, and renal efficiency in handling fluoride all influence fluoride metabolism. OBJECTIVES: The aim of the study was to evaluate the effect of the fluoride present in drinking water on the serum alkaline phosphatase (ALP) and phosphate levels in pregnant women and newborn infants. MATERIAL AND METHODS: In the present cross-sectional study, the participants were categorized into 2 groups based on a fluoride concentration in their drinking water: the low/optimum-fluoride group (<1 ppm); and the high-fluoride group (≥1 ppm). Each group was comprised of 90 pregnant women who were recruited from the hospital at the time of admission for delivery. Fluoride was measured in their drinking water, urine, maternal serum, and cord blood. The ALP and phosphate levels were measured in serum using a fully automated analyzer. RESULTS: The drinking water consumed by the pregnant women contained fluoride, which was significantly positively correlated with the urine and blood serum fluoride levels. There were significant differences in the ALP levels between the 2 groups in both maternal serum and cord blood. The level of phosphate in maternal serum was significantly higher in the high-fluoride group. The results of both simple and multivariate regression analyses revealed that the fluoride content in drinking water was significantly associated with the ALP level in cord blood and the phosphate level in maternal serum. CONCLUSIONS: The ALP levels were negatively associated with drinking water fluoride concentrations in both maternal serum and cord blood. The phosphate levels in maternal serum were positively associated with drinking water fluoride concentrations.

Online practical assessment in biochemistry designed on Bloom's taxonomy to assess the student's competency: Prior exposure of the students to online tools beneficial.

Online assessments are needed during the prevailing pandemic situation to continue educational activities while ensuring safety. After conducting the online practical assessment (OPrA) in Biochemistry, we analyzed the students' responses. The blueprint of the OPrA was prepared by the faculty, referring to the various levels and domains of Bloom's taxonomy. Four components were chosen for the online assessment: digital spotters, enumerating the steps of objective structured practical examination, interpretation of quantitative estimation, and case discussion. Each faculty assessed about 12-13 students in separate breakout rooms over 15-20 min on all four components. Feedback on the conduct of the examination was collected from the students and faculty anonymously and analyzed. Out of the 200 students who attended the online assessment, only one scored less than 50%, majority of them scored between 71% and 90%. Under the individual exercises, the average score of students in "Spotters" was 9.8 out of 10; in "OSPE," 8.7 out of 10; in "Quantitative experiments," 15.2 out of 20 and in "Case discussion," 22.4 out of 30. Around 20% had previous experience attending the OPrA. They differed in their opinion from the rest of the students on five aspects; time allotted for the assessment (p value = 0.02, χ2  = 5.07), students using unfair means during the online viva (p value = 0.02, χ2  = 5.57), their computing skills (p value = 0.001, χ2  = 19.82), their performance (p value = 0.001, χ2  = 8.84), and overall conduct of the examination (p value = 0.001, χ2  = 15.55). OPrA tools may be designed referring to Bloom's taxonomy, and prior exposure to the online tools may benefit the students.

Analysis of JAK2V617F Tyrosine Kinase Mutation in Blood Donors with Erythrocytosis - A Pilot Study in a Tertiary Care Teaching Hospital of South India.

Purpose: Transfusion services and blood centers provide immediate medical evaluation to blood donors by physical examination and hemoglobin (Hb) screening. Screening for Hb value before every blood donation is mainly aimed to rule out anemia. However, it is not uncommon to defer the donors for high Hb value which can be due to primary or secondary polycythemia. This study aimed to analyze the frequency of JAK2V617F mutation among blood donors with a high Hb of >18 g/dl. Patients and Methods: A prospective study was conducted over a period of 18 months involving blood donors with a persistently high Hb value of >18 g/dl. Complete blood count (CBC), JAK2V617F gene mutation and Serum Erythropoietin (EPO) levels in study donors were analyzed. Descriptive statistical analysis was performed using SPSS, version 24 (IBM, USA). Results: Of 13,798 screened donors, 48 donors (0.34%) had persistent erythrocytosis with a high Hb value of >18 g/dl. Their age ranged between 20-50 years with a mean of 31.2 ± 6.66. The CBC parameters including red blood cell (RBC) count, Hb%, hematocrit (Hct), white blood cell (WBC) count and the platelet count ranged from 4.35-8.43 million/µL (6.2 ± 0.6), 18.6-24.4 g/dl (19 ± 0.94), 51.9-83.3% (58 ± 5.02), 3.99-10.8 × 103/µL (7.8 ± 1.5), and 120-450 × 103/µL (227 ± 57.2), respectively. Estimated mean EPO value was 8.29 mIU/± 0.04. JAK2V617F mutation was detected in 2 donors (4.1%). Conclusion: The prevalence of persistent erythrocytosis among blood donors was 0.34% and among them, two donors (4.1%) harbored the JAK2V617F mutation. Thus, blood centers play an important role in the primary screening of donors with high hemoglobin leading to early detection and management of polycythemia vera (PV).

Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far.

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Role of NRF2 cascade in determining the differential response of cervical cancer cells to anticancer drugs: an in vitro study.

BACKGROUND: Cervical cancers are usually treatable if detected in early stages by a combination of therapies. However, the prognosis of cervical cancer patients with metastasis remains unfavorable due to the fact that most of the cervical carcinomas are either resistant to anticancer drugs or show signs of relapse after initial treatment. Therefore, it is important to control the chemoresistance as it is the key to develop effective treatment options for cervical cancer. OBJECTIVE: The current study aimed at evaluating the differential responses of cervical cancer cells to anti-cancer drugs and assessed whether the differences in the expression profiles of antioxidant genes regulated by nuclear factor erythroid-2-related factor 2 (NRF2), led to the variations in the sensitivities of the cancer cells to treatment. METHODOLOGY: Three cervical cancer cell lines were investigated for their differences in NRF2 pathway by measuring the gene expression and enzyme activity. The differences in the sensitivity to anti-cancer drugs and variation in ROS profile was also evaluated. The addition of exogenous drugs to manipulate the intracellular ROS and its effect on NRF2 pathway genes was also investigated. RESULTS: HeLa and SiHa cells were more sensitive to cisplatin and oxaliplatin treatment than C33A cells. HeLa and SiHa cells had significantly lower NRF2 gene levels, NQO1 enzyme activity and basal GSH levels than C33A cells. Levels of ROS induced were higher in HeLa than C33A cells. CONCLUSION: Overall, the differences in the cellular levels of antioxidant regulatory genes led to the differential response of cervical cancer cells to anti-cancer drugs.

Phytochemical fractions from Annona muricata seeds and fruit pulp inhibited the growth of breast cancer cells through cell cycle arrest at G0/G1 phase.

INTRODUCTION: Annona muricata (L.) (AM), commonly known as Soursop and Lakshmanaphala/Hanumaphala in India, has been extensively used in ethnomedicine for treating tuberculosis, urinary tract infections (UTIs) and cancers. The fruit is a rich source of antioxidants and antitumor agents. METHODS: In this study, we have extracted phytochemicals that exhibited anti-cancer property from the (a) fruit pulp using methanol (AMPM) and water (AMPW); and (b) seeds using methanol (AMSM). Qualitative phytochemical analysis showed the presence of phenolics, tannins, alkaloids, flavonoids, sterols, terpenoids, carbohydrates and proteins in AMPM and AMPW. All three extracts were first checked for in vitro antioxidant and anti-inflammatory properties and then tested for efficacy against MCF-7 and MDA-MB-231. RESULTS: Among these three extracts, AMSM showed the highest antioxidant power as well as ~80% inhibition at 320µg/ml concentration in both cell lines upon treatment for 24h. However, only about 40% inhibition was observed with 320µg/ml AMPM treatment, despite its highest anti-inflammatory potential. Water extract AMPW exhibited about 80% growth inhibition at 50% dilution. Since fruit pulp is the one consumed, the extracts AMPM and AMPW were further tested for apoptosis induction and cell cycle arrest. Analysis of the data showed increased apoptosis and G0/G1 cell cycle arrest upon exposure to AMPM and AMPW.

Urinary Intestinal Fatty Acid Binding Protein for Diagnosis of Necrotizing Enterocolitis.

OBJECTIVE: This study was conducted to compare the urinary levels of intestinal fatty acid binding protein (I-FABP) and I-FABP: Cr (creatinine) between neonates with necrotising enterocolitis and gestation matched healthy controls. METHODS: 24 neonates with stage 1, 25 with stage 2 and 3 necrotizing enterocolitis, and 25 gestation matched (32.9 wk) controls were compared. Single spot urine sample was collected for estimating the IFABP and creatinine levels. RESULTS: Median (IQR) value of urinary I-FABP were higher in those with stage 2, 3 NEC [2773 (2417.7- 2820)] than stage 1 NEC [1164 pg/mL (1341.5 - 2213.4)] and controls [413 (113 - 729.7); pg/mL] (P<0.001). Urinary I-FABP: Cr levels of 3.6 pg/mmoL had a sensitivity and specificity of 96% and 99.5%, respectively in diagnosing stage 2/3 NEC. CONCLUSION: Urinary IFABP: Creatine ratio of 3.6 pg/mmoL is highly specific for stage 2 and 3 NEC.

NRF2, p53, and p16: Predictive biomarkers to stratify human papillomavirus associated head and neck cancer patients for de-escalation of cancer therapy.

Patients with HPV associated (HPV+ve) head and neck squamous cell carcinoma (HNSCC), particularly oropharyngeal cancer, show better treatment response, higher survival rates, and lower risks of recurrence as compared to HPV-ve HNSCC patients. Despite increased sensitivity to treatment modality, HPV+ve HNSCC patients are subjected to the same intensive anti-cancer therapy as HPV-ve HNSCC patients and thus subjecting them to unwarranted long-term toxicity. To identify predictive biomarkers for risk-stratification, we have analyzed the mutational spectrum, and the evidence suggests that gain-of-function mutations in the NRF2 pathway are highly prevalent in HPV-ve HNSCC. At the same time, it is rare in HPV+ve HNSCC tumors. We have reviewed the importance of gain-of-NRF2 function and loss of p53 in the prognosis of HNSCC patients and discussed a predictive scoring system using a combination of HPV status (p16), NRF2 pathway and p53 to stratify HPV+ve HNSCC into good versus poor responders, which could immensely help in guiding future de-escalation treatment approaches in patients with HPV+ve HNSCC.

Impact of experiential learning among medical undergraduates: A randomized controlled trial.

BACKGROUND: Experiential learning sessions as a teaching aid have been applied early in the medical undergraduate curriculum to improve the knowledge and inculcate research interest. We compared the ability of 1st-year medical undergraduates to answer the molecular biology questions among those who had attended the experiential learning sessions of molecular biology techniques versus those who did not attend. SUBJECTS AND METHODS: A randomized controlled trial was carried out with 200 1st-year medical undergraduates, among whom 69 students were selected by simple random sampling for the demonstration of the molecular biology techniques, such as isolation of genomic DNA, polymerase chain reaction, cell culture techniques, western blotting, and high-performance liquid chromatography for 1-week duration. Student's feedback was collected on a five-point Likert sc ale at the end of the session to understand how they agree or disagree with a particular statement. The content validity rate (CVR) and content validity index (CVI) of the questionnaire were determined, and its internal consistency was examined by Cronbach's alpha. The internal assessment marks of these students, valued by faculty who were blinded to their training sessions, were compared with the rest of the 131 students by independent t-test to know the outcome of these experiential learning sessions. RESULTS: On CVR and CVI assessment, all the questions scored more than 0.70 and 0.85, respectively. Cronbach's alpha for the whole questionnaire was 0.85. Student's feedback indicated that these sessions did complement the cognitive skills acquired for these techniques. We also found a statistically significant improvement (P = 0.006) in the examination performance between the students who attended versus those who did not attend the experiential learning sessions. CONCLUSION: Experiential learning, through demonstration and hands-on experience, enhance d the learning of molecular biology techniques among 1st-year medical undergraduates.

DNA extraction from archived hematoxylin and eosin-stained tissue slides for downstream molecular analysis.

BACKGROUND: Histopathologically stained archived tissue slides are stored in hospital archives for years to decades. They are the largest available source of biological materials and are a potentially useful resource that can be used for retrospective epidemiological studies. DNA recovered from the slides can be used for several downstream molecular processes including polymerase chain reaction, single nucleotide polymorphism analysis, and whole genome sequencing. The DNA from these slides can be utilized to compare gene signatures of normal and diseased tissues. However, extraction of high-quality DNA from archived stained hematoxylin and eosin (H&E) slides remains challenging. AIM: To standardize a new protocol for extracting DNA from archived H&E-stained tissue slides for further molecular assays. METHODS: A total of 100 archived H&E-stained cancer slides were subjected to a total of five methods of DNA extraction. Methods were varied in the deparaffinization step, tissue rehydration, duration of lysis, and presence or absence of proteinase K. The extracted DNA was quantified using a NanoDrop spectrophometer and the quality was analyzed by agarose gel electrophoresis. Then each sample was subjected to polymerase chain reaction (PCR) to amplify the internal control gene GAPDH, thereby confirming the DNA intactness, which could be further utilized for other downstream applications. RESULTS: Of the five different methods tested, the third method wherein xylene was used for tissue deparaffinization followed by 72 h of digestion and without proteinase K inactivation yielded the highest amount of DNA with good purity. The yield was significantly higher when compared to other methods. In addition, 90% of the extracted DNA showed amplifiable GAPDH gene. CONCLUSION: Here we present a step-by-step, cost-effective, and reproducible protocol for the extraction of PCR-friendly DNA from archived H&E-stained cancer tissue slides that can be used for further downstream molecular applications.

Detection of Human Papilloma Virus and Risk Factors among Patients with Head and Neck Squamous Cell Carcinoma Attending a Tertiary Referral Centre in South India

Background: Head and Neck Squamous Cell Carcinomas (HNSCC) is the sixth most common cancer globally. In India, on an average 25-30% of all cancer cases affect the head and neck. The etiological factors associated with HNSCC are tobacco, alcohol and environmental carcinogens. However there are few cases, where there are no obvious risk factors involved. In western counties, there are many reports of human papilloma virus (HPV) association with HNSCC. Hence, we conducted a study to determine the role of HPV infection and risk factors among patients with HNSCC. Materials and Methods: A prospective, cross-sectional study was conducted in a tertiary referral centre from January 2014 to March 2016. 88 patients were enrolled in the study. Socio- demographic, behavioural data, site and subsite involvement, histopathology, staging and treatment were documented. Polymerase chain reaction (PCR) was performed to detect the presence of HPV DNA using consensus primers MY 09/11 and GP5+/GP6+ and further the samples were subjected to PCR for detecting HPV type 16 and 18. Results: The study included 88 participants with HNSCC. 57 had oral and oropharyngeal squamous cell carcinoma, 11 with laryngeal malignancy and 20 involving hypopharynx. Among the participants buccal mucosa (n=22) was the most common subsite involved, majority (50%) had moderately differentiated squamous cell carcinoma and 53.4% presented in stage IV. 2 (2.6%) cases were positive for HPV consensus and both were positive for HPV 16, one case each in larynx and hypopharynx. There was statistical significance in the association between betel nut chewing, cigarette smoking and alcohol intake as risk factors in the carcinogenesis of HNSCC. Conclusion: In our setting in South India, HPV does not play a major role in the carcinogenesis of HNSCC but betel nut chewing, tobacco exposure and alcohol consumption remain major risk factors for HNSCC.

Evaluation of Protein Kinase Cß and PPARγ Activity in Diabetic Rats Supplemented with Momordica charantia.

INTRODUCTION: The present study was taken up to compare and evaluate the effect of Momordica charantia supplementation with pioglitazone on PKC-ß and PPAR-γ activity in kidneys of diabetic rats. The hypoglycaemic and lipid lowering effect of Momordica charantia were screened in laboratory animal model and its potency was compared with a Thiazolidinedione (TZD) group antidiabetic drug like pioglitazone. MATERIALS AND METHODS: Adult healthy albino rats of Wistar strain aged 3-4months, weighing between 170-250gm of either sex were divided into 4 groups; Group 1 (normal controls), Group 2 (diabetic controls), Group 3 (diabetic rats treated with pioglitazone) and Group 4 (diabetic rats treated with bitter melon juice). Type 1 Diabetes was induced in rats by intraperitoneal injection of streptozotocin at a dose of 55 mg/kg body weight, following which glucose levels were estimated by Accu chek- active glucometer on day 0, 7, 14, 21 and 28 days to assess the efficacy of Bitter Melon Juice (BMJ) and pioglitazone. After 28 days of treatment, the rats were sacrificed and blood collected from abdominal vena cava was used for estimation of triglycerides by Glycerol 3 phosphate oxidase phenol aminophenazone method and cholesterol by Cholestrol oxidase phenol aminophenazone method. PKC-ß and PPAR-γ were estimated in the dissected kidneys by using double sandwich ELISA based kits on an automated plate reader. RESULTS: BMJ significantly reduced blood glucose levels in group 4 as compared to diabetic controls (p<0.001). Total cholesterol and triglycerides were significantly reduced in both group 3 and 4. In Group 4, there was reduction in PKC-ß levels, when compared to Group 3(p=0.004). PPAR-γ levels were increased in both Group 3 and 4, when compared to Group 2. CONCLUSION: The results suggest that BMJ has hypoglycaemic and lipid lowering effect in diabetic animal models. BMJ increases PPAR-γ activity and decreases PKC-ß activity in kidneys of diabetic rats, thereby preventing the complications of diabetes mellitus. Fresh BMJ mimics action of pioglitazone belonging to TZD group thus showing a potential for further research in identifying the active molecules responsible for glucose and lipid lowering action.

Serotyping & molecular characterization for study of genetic diversity among seafood associated nontyphoidal Salmonella serovars.

BACKGROUND & OBJECTIVES: Infections due to seafood associated Salmonella serovars are great risk to public health. Different phenotypic characteristics have been used previously for epidemiological investigation of Salmonella. Beyond the phenotypic characterization, a reliable genetic level discriminatory method is required. Therefore, this study was attempted to use different phenotypic and molecular fingerprinting methods for investigation of genetic diversity among seafood associated nontyphoidal Salmonella serovars. METHODS: Fifty eight seafood associated Salmonella isolates were included in this study. All isolates were serotyped and epidemiological investigation was carried out using molecular fingerprinting methods, random amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus sequence based-PCR (ERIC-PCR) along with whole cell protein profiling using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) in our study. RESULTS: Among the 58 Salmonella isolates, S. Weltevreden was observed to be the most predominant serovar. Typing of Salmonella serovars using RAPD and ERIC-PCR suggested the existence of a genetic diversity. Though both PCR based techniques were found to have a good discriminatory index, a better discriminatory ability was observed when the results obtained by the two techniques were combined and taken for composite analysis. Protein profiling of whole cells using SDS-PAGE demonstrated the presence of several bands with two bands of sizes 38 kDa and 46 kDa common among all 58 isolates. INTERPRETATION & CONCLUSIONS: Our study shows that use of protein profiling in combination with established typing methods such as RAPD and ERIC-PCR may provide useful information in typing of non-typhoidal Salmonella isolates associated with seafood and to develop strategies to protect public from Salmonella infections.

Environmental lead levels in a coastal city of India: the lead burden continues.

BACKGROUND: Urbanization, rapid industrialization, increased vehicular traffic, and consequent increase in the use of petroleum fuels in India are constantly emitting lead along with other pollutants into the environment. Apart from atmospheric lead, this element is the most widely used in everyday life. Although infants and children are the most susceptible to the effects of lead, adults are also affected to varying degrees and it had ranked as one of the most serious environmental threats to human health. Hence, we must understand the benefits of preventing lead exposure as it reduces treatment costs, increases productivity in industry, and also reduces infant mortality. These are good enough reasons for a nation wide program to prevent lead poisoning. OBJECTIVES: In the view of elevated blood lead levels (BLL) in majority of the school children in the city of Mangalore, we aimed to identify the potential sources of lead in the environment which would have probably caused the elevated BLL. MATERIALS AND METHODS: More than 600 readings were taken throughout the city of Mangalore using X-ray fluorimeter. RESULTS: Our results showed that there were elevated levels of lead in the environment surrounding the battery repair shops, battery recyclers, automotive workshops, and tyre retreaders, but interestingly, the soil around the petrol bunks did not show elevated levels of lead. Among the paints, the yellow paint showed high levels of lead. CONCLUSION: Similar surveys would be useful elsewhere in India and in other developing countries in order to identify the potential sources of lead and to prevent lead poisoning.

Development of monoclonal antibody based sandwich ELISA for the rapid detection of pathogenic Vibrio parahaemolyticus in seafood.

Thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) are considered important virulence factors of Vibrio parahaemolyticus and strains producing either of these or both are considered pathogenic. In this study, we generated monoclonal antibodies (mAbs) against purified TRH recombinant protein of pathogenic V. parahaemolyticus. Sandwich enzyme-linked immunosorbent assays (ELISA) using the hybridoma clone 4B10 showed higher sensitivity of detection compared to other clones. Using mAb 4B10 based sandwich ELISA, we could detect pathogenic V. parahaemolyticus in 41.18% (14 out of 34) of the seafood samples analyzed. PCR targeting the toxR gene showed the presence of V. parahaemolyticus in 64.7% (22 out of 34) seafood samples. Further, PCR targeting the virulence genes showed that 6 seafood samples harboured the tdh gene while 9 harboured the trh gene indicating the presence of pathogenic V. parahaemolyticus. Our results show that mAb 4B10 sandwich ELISA developed in this study could be used as a rapid method for screening seafood samples for the presence of pathogenic V. parahaemolyticus.

Presence of Salmonella pathogenicity island 2 genes in seafood-associated Salmonella serovars and the role of the sseC gene in survival of Salmonella enterica serovar Weltevreden in epithelial cells.

The type III secretion system encoded by the Salmonella pathogenicity island 2 (SPI-2) has a central role in the pathogenesis of systemic infections by Salmonella. Sixteen genes (ssaU, ssaB, ssaR, ssaQ, ssaO, ssaS, ssaP, ssaT, sscB, sseF, sseG, sseE, sseD, sseC, ssaD and sscA) of SPI-2 were targeted for PCR amplification in 57 seafood-associated serovars of Salmonella. The sseC gene of SPI-2 was found to be absent in two isolates of Salmonella enterica serovar Weltevreden, SW13 and SW39. Absence of sseC was confirmed by sequencing using flanking primers. SW13 had only 66 bp sequence of the sseC gene and SW39 had 58 bp sequence of this gene. A clinical isolate, S. Weltevreden--SW3, 10:r:z6--was used to construct a deletion mutant for the sseC gene. Significant reduction in the survival of SW3, 10:r:z6 ΔsseC and natural mutants SW13 and SW39 in HeLa cells suggests that sseC has a crucial role in the intracellular survival of S. Weltevreden. Expression of sseC was upregulated during the intracellular phase of both S. enterica serovar Typhimurium and clinical isolate S. Weltevreden SW3, 10:r:z6, suggesting a crucial role for this gene in the survival of S. Weltevreden inside host cells.

gcpA (stm1987) is critical for cellulose production and biofilm formation on polystyrene surface by Salmonella enterica serovar Weltevreden in both high and low nutrient medium.

Biofilm formation by Salmonella is a serious concern in the food-processing industry and the persistence of the organism in biofilms becomes a constant source of contamination. Since there is zero tolerance for Salmonella in foods, it is important to understand the mechanism of biofilm formation and to prevent the formation. Therefore, this study aimed at investigating the biofilm-forming ability of seafood isolates of Salmonella enterica serovar Weltevreden (S. Weltevreden) under two different nutrient conditions (normal strength trypticase soy broth (TSB) and 1:100 diluted TSB). The role of cellulose production in biofilm formation and in the expression of multicellular behavior (rough, dark, red morphotype: rdar) was investigated. Fourteen isolates of seafood associated S. Weltevreden were studied for biofilm production in polystyrene microtitre plates. Only one (SW49) of 14 was a strong biofilm former on polystyrene template and was able to produce biofilm in both undiluted TSB and 1:100 diluted TSB at 24h. All others produced moderate or weak biofilms which was higher in 1:100 diluted TSB compared to undiluted medium. All the isolates except one were positive by PCR for the three genes, gcpA (stm1987), adrA (yaiC) and csgD. Gene expression of gcpA, adrA and csgD was studied by real-time PCR with the one strong (SW49) and one representative weak (SW30) biofilm former. In SW49 at 24h of incubation, the expression of gcpA from biofilm cells was 33 and 36 times higher than from planktonic cells grown in TSB and diluted TSB respectively and at 72h the expression from biofilm cells was 57 and 61 times higher than that from planktonic cells. Quantification of gene expression did not reveal any significant difference in the expression of csgD and adrA gene. Deletion of gcpA in SW49 resulted in its inability to produce cellulose and consequent inability to bind calcoflour, inability to form rdar colony on Congo Red-agar plates and failure to produce biofilm on polystyrene substrate. The data indicated that, in case of S. Weltevreden, gcpA is critical for activating cellulose synthesis and biofilm formation both in undiluted and diluted TSB. The results of this study suggest the existence of an alternative biofilm regulatory pathway in S. Weltevreden. Role of adrA in cellulose production in nutrient rich medium is known but role of gepA in the above phenomenon is proved in this study. An understanding of the genes involved would help in looking at strategies of repression of the gene to control formation of biofilm.