Association of Serum Magnesium Level with Severity of Neurological Disability in Patients with Acute Ischemic Stroke

Magnesium (Mg) has important effects on vascular system and deficiency of this cation is thought to be a risk factor for cerebrovascular atherosclerosis and complications. The study was planned to find out the association of serum magnesium level with severity of neurological disability in patient with acute ischemic stroke. This cross-sectional descriptive study was conducted in the department of Neurology and Medicine at Mymensingh Medical College & Hospital, Mymensingh from June, 2018 to October, 2019. Patients with acute ischemic stroke were evaluated following informed written consent. Diagnosis was confirmed by neuroimaging of brain. Moreover, serum magnesium assay was done for each patient. Data were collected by interview, clinical examination and laboratory investigations of patients using a case record form and analysis was carried out by using the SPSS 22.0 (IBM Inc., Armonk, NY, USA). Mean age of acute ischemic stroke patients was 63.94±13.93 years with male predominance (58.30%). Majority of the respondents (70.2%) had NIH Stroke Scale (NIHSS) score 5-15 (moderate stroke), 13.1% had score 1-5 (minor stroke), 13.1% had score15-20 (Moderate to severe stroke) and 3.6% had score 21-42 (severe stroke). Mean serum magnesium level was 1.83±0.283mg/dl. Hypomagnesaemia was present in 28(33.3%) patients and it was related with higher NIHSS scoring (p<0.05). Multiple regression showed that among the risk factors, serum magnesium level was independently associated with severity of neurological disability of the acute ischemic stroke (p<0.001). In this study, the correlation coefficient between serum magnesium level and NIHSS score was found as r= - 0.667 which showed negative relationship between serum magnesium and NIHSS score. Lower serum magnesium level is associated with the severity of neurological disability of acute ischemic stroke patient. Further case-control studies are required to validate this finding.

Development and Validation of MRI Imaging Biomarkers for Prostate Cancer Using Deep Learning

PURPOSE/OBJECTIVE(S)

Given the increasing number of treatment options for patients with localized prostate cancer (PCa), there is a need for biomarkers to aid in risk stratification. Specifically, novel biomarkers can aid in the identification of high-risk phenotypes among similar patients in traditional NCCN risk groupings. One promising area for development is using pre-treatment prostate MRI to identify imaging biomarkers to identify prostate cancer patients at highest risk for recurrence. We hypothesized that deep learning could be leveraged to identify imaging biomarkers of aggressive PCa from pre-treatment prostate MRIs.

MATERIALS/METHODS

Our study included 1,020 patients treated at our institution between 2010-2022. Given pathologic extraprostatic extension (EPE) and seminal vesicle invasion (SVI) are associated with higher risk of treatment failure, we hypothesized that deep learning models which identified radiographic EPE and SVI would provide non-invasive imaging biomarkers associated with PCa prognosis. We trained two separate deep learning models using convolutional neural networks to predict SVI and EPE respectively. The model inputs were T2W prostate MRIs (n = 894) and models consisted of 8 convolutional layers. Dropout, L2 regularization, and data augmentation were used to improve model generalizability and reduce overfitting. Discriminatory ability of each model was measured using AUC on a blinded external test set of 221 patients. To assess the clinical utility of our imaging biomarkers, log-rank tests were used to evaluate biochemical free survival (BFS) for patients classified as high risk to patients classified as low risk. Biochemical failure was defined as post-treatment PSA >0.1 for patients who underwent radical prostatectomy (RP) or PSA >2ng/ml above nadir for patients receiving radiation therapy.

RESULTS

Within our cohort of 1,020 patients the median age was 66 with a median follow up of 4 years. 49.3% (n = 503) underwent RP and 50.7% (n = 517) received EBRT. 4% (n = 41) were low risk, 62.4% (n = 636) were intermediate risk, and 33% (n = 337) were high risk based on NCCN criteria. Deep learning models showed good discriminatory ability for both EPE (AUC 0.66) and SVI (AUC 0.74). Both imaging biomarkers showed prognostic ability to identify high risk prostate phenotypes. Patients deemed high risk based on EPE classifier had worse BFS (median 5 vs 9 years, p<.001). Similarly, patients classified as high risk based on SVI also showed worse BFS (median 5 vs 9 years, p = 0.024). Among intermediate risk patients, EPE biomarker showed an ability to identify high risk phenotypes (median 6 vs 9 years, p = 0.024).

CONCLUSION

Deep learning classifiers of prostate MRIs demonstrated the ability to stratify high-risk prostate cancer phenotypes beyond traditional risk paradigms. Imaging biomarkers represent a non-invasive method to help aid in the personalization of treatment for patients with localized prostate cancer and identify patients who potentially require treatment escalation.

Quality of Life of Bangladeshi Doctors in the COVID-19 era: Are We Taking Good Care of Our Carers?

The Coronavirus pandemic has been affecting our healthcare professionals physically as well as psychologically since March 2020. Whilst various measures have been taken to protect their physical health, their mental wellbeing has not been brought into attention. We aimed to assess the well-being of Bangladeshi doctors and identify the high-risk group using a core-10 validated form. We performed an observational cross-sectional survey among Bangladeshi healthcare professionals. One hundred one (101) doctors filled out the core-10 form. We collected data over a 1-month-period during the first peak of COVID-19. According to our data, majority of the participants (49%) felt anxious or nervous at some point. Thirty one percent (31%) felt hopeless, unhappy even panic attacks but most significant finding was that 21% participants had at least once thought about ending their lives. This is a matter of concern and the workplaces should identify the vulnerable professionals so that they can be supported better mentally and socially. More than half of the participants (55%) were found to have moderate to severe depression in the first peak of COVID 19 pandemic. This is not over yet; more waves are coming. Therefore, it is really important that we address this issue before it is too late and ensure regular counselling, better childcare for working parents, safety measures to protect their families and financial security. Otherwise, we might exhaust our carers to a level where even they cannot help us survive this global challenge.

FeedMaster: A least-cost feed formulation App for minimizing the cost and maximizing milk yield

Objective: The study aimed to develop and assess an Android app designed for farmers with a low educational status that can formulate a least-cost ration. Materials and Methods: First, a computer-android-based app named BLRI FeedMaster was developed to guide users in formulating a balanced ration at the least cost. A survey was conducted on 30 livestock officers and 18 farmers with 50 cattle to evaluate its efficacy at the field level. The study outcomes were milk yield, feeding cost, milk composition, time, and cost for management before and after using the BLRI FeedMaster app. Descriptive statistics and paired sample t-tests were used to analyze the data. Results: After adopting the BLRI FeedMaster app, a significant increase was observed in daily average milk yield (9.39 ± 0.32 l from 8.37 ± 0.36 l), while a considerable decrease was observed in daily average feed quantity (4.88 ± 0.15 kg from 5.60 ± 0.17 kg) and feed cost (BDT 28.00 ± 0.50 from BDT 29.75 ± 0.49). Besides, the number of visits, time, and cost for seeking professional services regarding feed, health care, and other information was significantly minimized. The number of visits decreased to 0.36 ± 013 from 3.07 ± 0.38, and the consumed time was reduced from 270 ± 34.30 to 235.71 ± 59.42 min (p < 0.05) after adopting the app. Conclusion: Hence, this app was very beneficial for farmers with a low economic and educational background and may ultimately help farmers with profitable animal farming and sustainable pro¬duction in the least developed countries like Bangladesh.

Prevalence of Hepatitis B Virus Infection among Children with Liver Disease Admitted In Mymensingh Medical College Hospital

Hepatitis B virus infection is an important cause of liver disease. Hepatitis B Virus may present with varying degree of severity. In older children, 5-10% cases leading to chronic liver disease, cirrhosis and hepatocellular carcinoma. This descriptive cross sectional study was done to assess the prevalence of Hepatitis B Virus infection among hospitalized children with liver disease in pediatric department of Mymensingh Medical College Hospital, Bangladesh from December 2015 to October 2016. All the children of both sexes having age between six months to twelve years admitted in the pediatric ward with acute or chronic liver disease were included in this study by purposive sampling. A written consent was obtained from legal guardian of children before inclusion. Ethical clearance was obtained from competent authority. A detailed history was taken from parents in each case according to pre-designed questionnaire about demography of the patients and the risk factors of the liver disease. A thorough clinical examination and available relevant investigations like serological testing for HBV infection was done in all patients. We had figure out the seropositivity of HBV among patients having liver disease by doing HBsAg and Anti-HBc IgM. Progress of the patient was monitored by daily clinical examinations and by investigating HBsAg and Anti-HBc IgM. Finally data analysis was done by SPSS version 21.0. Among total 100 patients most (44%) patients were in 7-10 years old and most (62%) of the participants were male. Acute liver disease was 58% cases and chronic liver disease was 42% cases. HBsAg was positive in 1 case among acute liver disease and 5 cases among chronic cases. Total 6 (six) patients were found positive for HBsAg. Anti HBc IgM was positive in 4 patients among acute liver disease. Among these Anti HBc IgM positive (4) patients only one had both HBsAg and Anti HBc IgM positive. So, four patients were confirming suffered from acute viral hepatitis because they had anti HBc IgM positive. On the contrary 5 patients suffered from chronic hepatitis by hepatitis B because they were only HBsAg positive. So, in this study 9 patients (9%) were confirming suffered from HBV infection. Possible transmission factors of hepatitis B were history of (H/O) blood transfusion/trauma/parenteral injection, H/O umbilical sepsis, H/O maternal illness/infection during pregnancy. HBV still is a major cause of morbidity. All the children with liver disease should be routinely tested for HBV.

Status and conservation needs of Cycas pectinata Buch.-Ham. in its natural habitat at Baroiyadhala National Park, Bangladesh

The widespread cycad Cycas pectinata was first discovered in the Bengal region by William Griffith in Baroiyadhala forest of Chattogram in 1838. In Bangladesh, this species is confined to a few hills at Baroiyadhala, Sitakunda upazila of Chattogram district. Though the Baroiyadhala forests were declared a national park in 2010, the loss of this native gymnosperm from this forest is alarming. The present study aimed to assess the status of C. pectinata populations in its native range, identify the drivers responsible for ongoing losses, and identify locations of C. pectinata occurrence in Baroiyadhala National Park suitable for in situ conservation. A random quadrat survey with 21 sample plots of 100 × 100 m was conducted during April–June 2018 in Baroiyadhala National Park. Population and growth data for C. pectinata were collected from each sample plot, along with observations of disturbances. Four focus group discussions (FGDs) were conducted with adjacent local people. The study revealed presence of 12 C. pectinata individuals per hectare and five seedlings per hectare in the study area, and significant numbers of dead and burned Cycas were also found in some sites. Based on density, five C. pectinata hotspots were identified for in situ conservation programs. Habitat destruction, indiscriminate fire, and unsustainable harvesting of leaves and male and female cones are responsible for rapid declines in C. pectinata populations in its wild habitat. Measures for protection and restoration of the species are creating awareness among the local people about ecological importance of this species; enhancing protection; banning trade of Cycas; creating opportunities of sustainable livelihood for local people to reduce dependency on forests.

272 Morbid Obesity in Lower Limb Arthroplasty: Short Length of Stay and Favourable One-Year Outcomes

Introduction

There are concerns that BMI is associated with a greater length of stay (LOS) and perioperative complications in lower limb arthroplasty.

Method

We analysed data from a six-month period to see if there was a correlation between BMI and LOS. We performed a subgroup analysis for patients with morbid obesity (BMI &gt;40).

Results

285 TKRs and 195 THRs were analysed. For TKRs, the average length of stay was 2.7 days. There was no significant correlation between BMI and LOS (r=-0.0447, p = 0.2267). The morbidly obese category (n = 33) had the shortest LOS (2.5 days) compared to other BMI categories. 30-day readmission rate was 6%. 90-day re-admission rate was 12%. Six patients had minor wound issues requiring no intervention or antibiotics only. The was one prosthetic joint infection, one stitch abscess, one DVT and one patellar tendon injury.

For THRs, the average LOS was 2.9 days. There was no significant correlation between BMI and LOS (r = 0.007, p = 0.4613). The morbid obese category (n = 9) had the shortest LOS (1.9 days) compared to other BMI categories. No patients were readmitted within 90 days or had documented complications.

Conclusions

Increased BMI is not associated with increased LOS. The morbidly obese had the shortest LOS, and commendable complication and re-admission rates.

Relation between Serum Magnesium Level and Migraine

Migraine is one of the most disabling types of headache. It affects 4-6% of men and 13-18% of women; more than 80% of them are under 30 years. Many theories to explain mechanism of migraine are present; role of serum magnesium is one of them. This Cross-sectional analytical study was designed to see serum magnesium level status of migraine patients in Bangladesh and to find out any relation. The study was carried out in Outpatient Department of Neurology of Mymensingh Medical College Hospital, Mymensingh, Bangladesh from July 2017 to September 2018. Seventy (70) patients between 18-60 years of both sexes with headache fulfilling the criteria for migraine were enrolled as migraine group. Patients with headache who did not fulfill the criteria of migraine enrolled as non migraine group. Patients were included in both groups after exclusion of structural lesions, magnesium containing drug intake, pregnancy, menstruation, alcoholism, renal or GIT problems. Serum magnesium levels were studied in both groups and compared with each other. All related factors such as age, sex, family history of migraine, occupation were assessed. Fifty one (51) of 70 patients (72.85%) was female and 19(27.15%) were male in migraine group. Thirty eight (54.28%) of cases were between 18 and 30 years old. Thirty nine (55.71%) of migraine patients had history of similar headache in their family. Severe headache in 51.43% of migraine patients and 30% had more than three attacks per month. Mean serum magnesium level was 1.70 mg/dl in migraine group and 1.85 mg/dl in non migraine group (p=0.001). Serum magnesium level was also lower in severe migraine headache in comparison to mild to moderate headache (p=0.01). No significant difference was found in serum magnesium level compared according to age, sex, frequency of attack and presence or absence of aura. The study concludes that serum magnesium in migraine patients was significantly lower than non migraine group. It was also lower in migraine patient having severe headache in comparison with mild to moderate headache, though in both conditions they were within normal range.

A multi-centre, cross-sectional study on coronavirus disease 2019 in Bangladesh: clinical epidemiology and short-term outcomes in recovered individuals

Coronavirus disease 2019 (COVID-19) rapidly became a global pandemic. This study aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) -associated epidemiology and clinical outcomes in Bangladesh in order to understand the future course of the COVID-19 pandemic and develop approaches to prevention. A cross-sectional study based on retrospective interviews was conducted on 1021 individuals with RT-PCR-confirmed COVID-19 admitted in six different hospitals in Bangladesh and who recovered 4 weeks before the interview date. Of the 1021 patients, 111 (10.9%) were asymptomatic and the other 910 (89.1%) were symptomatic. Higher prevalence of COVID-19 was found in the male population (75%), in cohorts with B-positive blood group (36.3%) and in the 31-40 years age group. Common symptoms observed in our study participants were fever (72.4%), cough (55.9%), loss of taste (40.7%) and body ache (40%); whereas among the biochemical parameters, neutrophil count (46.4%), D-dimer (46.1%) and ferritin (37.9%) levels were elevated. Among the recovered individuals, short-term outcomes including pains and aches (31.8%), weakened attention span (24.4%) and anxiety or depression (23.1%) were also significantly prevalent in the symptomatic cases with comorbidities. Our study showed that in Bangladesh, adult males aged between 31 and 40 years were more vulnerable to developing COVID-19. It also indicated a rising trend of asymptomatic cases as the pandemic progressed. As a consequence, deployment of interventions to curb further spread of community infection is necessary to avoid grave outcomes of COVID-19 in Bangladesh.

Ornamental fish: a potential source of pathogenic and multidrug-resistant motile Aeromonas spp

Aeromonas spp. are ubiquitous bacteria that cause diseases in fish and other aquatic animals. They are the natural inhabitants of different aquatic environments, such as freshwater, brackishwater and marinewater. Extrinsic stressors, such as crowding, unhygienic handling, poor water quality, polluted feeding and inadequate nutrition, can predispose fish to Aeromonas infection. In ornamental fish, motile Aeromonas spp. are known as aetiological agents of motile aeromonad infections, which cause significant mortality in fish and economic loss in the ornamental fish industry. The existence of different virulence factors leads to the virulence potential of motile Aeromonas spp. There are several antimicrobials used to treat bacterial infections in ornamental fish. However, the extensive use of antimicrobials in the ornamental fish industry causes multidrug resistance. This article reviewed a multitude of virulence factors that are related to the ornamental fish-borne Aeromonas pathogenicity and the antimicrobial resistance determinants related to the multidrug resistance phenotypes of motile Aeromonas spp. in ornamental fish.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

FRI0438 POST-CHIKUNGUNYA CHRONIC ARTHRITIS - SHARING OF BANGLADESH EXPERIENCE OVER ONE YEAR FOLLOW UP OF 60 PATIENTS

Background:

Chikungunya virus (CHIKV) infection is an emerging disease which is responsible for several epidemics around the world1. Systematic review and meta-analysis had shown that approximately 25% of cases of Chikungunya(CHIK) would develop CHIK-Chronic Inflammatory Rheumatism and 14% would develop persistent arthritis (or spondylitis)2.

Objectives:

To describe the frequency of the clinical patterns of chronic arthritis & to characterize the clinical symptoms in a Bangladeshi cohort of CHIK patients 12months post-infection.

Methods:

In 2017, a Chikungunya outbreak occurred in Dhaka, Bangladesh, during which a prospective cohort of CHIK patients with confirmed diagnosis was constituted. A longitudinal follow up of 60 patients from an initial cohort of 142 patients, attending the out-patient department of Rheumatology, BSMMU, was done. Patients having arthritis/ arthralgia or both lasting more than 3 months were considered as chronic cases. Their baseline and follow-up symptoms at 3m, 6m and 12months were evaluated. Functional status was assessed with the Bengali Version Health Assessment Questionnaire (HAQ).

Results:

Of the initial 142 patients enrolled in the study, 135(95.1%) had CHIKV-IgM and 29(20.4%) had IgG positive. Patients that followed up in-person were predominantly adult (age 43.73 ± 11.09 years) and female 34 (56.7%). The majority of the patients 35 (58.3%) had undifferentiated arthritis. After three months, 8 (16.3%) had oligoarthralgia, 26 (53.1%) had polyarthralgia and 8 (16.3%) had polyarthralgia with oligoarthritis. At the end of one year, 13 (21.7%) patients underwent complete remission. Among the 47 patients, 21 had joint involvement where 11(52.4%) had polyarthralgia, 5(23.8%) had polyarthralgia with oligoarthritis, 5 (23%) had oligoarthralgia and 4 (19%) had monoarthralgia. Among the 47 patients, mild, moderate and severe functional disability was present in 89.4%, 6.4% and 4.3% patients respectively.

Conclusion:

After one year of follow up, one-third of the patients remained symptomatic. Polyarthralgia was the predominant clinical feature. Mild functional disability was also observed in a significant number of patients.

References:

[1]Ali Ou Alla S, Combe B. Arthritis after infection with Chikungunya virus. Best Pract Res Clin Rheumatol. 2011;25(3):337-46.

[2]Rodríguez-Morales AJet al.Prevalence of Post-Chikungunya Infection Chronic Inflammatory Arthritis: A Systematic Review and Meta-Analysis.Arthritis. Care. Res. 68(12), 1849-1858 (2016).

Table 1.

Socio-demographic and clinical pattern of patients with Chronic CHK arthritis (n=60)

Variablesn(%)Age (in years)Mean ±SD43.73 ±11.1SexFemale34 (56.7)Male26 (43.3)First joint involvementGeneralized34 (56.7)Ankle12 (20.0)Knee6 (10.0)Wrist5 (8.3)Others (MTP, shoulder, neck and axial plane)3 (5.0)Clinical patternUndifferentiated35(58.3)Spondyloarthritis10 (16.7)Rheumatoid Arthritis7 (11.7)Pre-existing Spondyloarthritis6(10.2)Pre-existing Rheumatoid Arthritis1(1.7)Pre-existing Osteo-arthritis Arthritis1(1.7)Table 2.

Joint involvement of patients with Chronic CHIK arthritis

Joint characteristics3 m (n=49)6 m (n=36)1yr (n=21)f(%)f(%)f(%)Type of involvement in persistent painJoint only33 (55.0)28 (46.7)20 (33.3)Both joint & soft-tissue16 (26.7)8 (13.3)1 (1.7)Joint involvementMonoarthralgia1 (2.0)5 (13.9)4 (19.0)Oligoarthralgia8 (16.3)6 (16.7)5 (23.0)Polyarthralgia26 (53.1)18 (50.0)11 (52.4)Monoarthritis1 (2.0)0(0.0)0(0.0)Oligoarthritis6 (12.2)3 (8.3)0(0.0)Polyarthritis7 (14.3)9 (11.1)1 (4.8)Oligoarthralgia & monoarthritis1 (2.0)0 (0.0)0 (0.0)Polyarthralgia & monoarthritis0 (0.0)1 (2.8)0 (0.0)Polyarthralgia & oligoarthritis8 (16.3)4 (11.1)5 (23.8)Polyarthralgia & Polyarthritis1 (2.0)0 (0.0)0 (0)

Disclosure of Interests:

None declared

0353 Objectively Measured Sleep and Components of Metabolic Syndrome in Well-Functioning Older Adults

Introduction

Prior studies tying sleep to metabolic syndrome in older adults have mostly used self-report sleep measures. We investigated the association between actigraphic sleep parameters and metabolic syndrome components in well-functioning older adults.

Methods

We studied 434 participants in the Baltimore Longitudinal Study of Aging (aged 71.1±12.8 years, 41.4% women) with 6.6±1.0 nights of wrist actigraphy and data on metabolic syndrome components: blood triglyceride (TG) level &gt;150 mg/dL; high density lipoprotein (HDL) &lt;50 mg/dL; and waist circumference (WC) &gt;88.9 cm for women and &gt;101.6 cm for men. Sleep parameters were the primary predictors and metabolic syndrome components the outcomes. Logistic regression was performed, and results are expressed as odds ratio (OR) with p-values.

Results

After adjusting for age, sex, race and education, higher sleep efficiency (SEFF; per 10%) was associated with a lower odds of high WC (SEFF OR=0.60, p=0.01) and, compared to participants in the intermediate total sleep time tertile (5.5 to 6.8 h), those in the shortest tertile (&lt;5.5 h) had a slightly lower odds of high WC (TST OR=0.98, p=0.02). In adjusted models, greater wake after sleep onset (WASO; per 30 min), greater average wake bout length (WBL; per min), and lower SEFF (per 10%) were associated with a greater odds of poor HDL level (&lt;50 mg/dL) (WASO OR=1.37, p=0.05; WBL OR=1.49, p=0.007; SEFF OR=0.72, p=0.04). After further adjustment for BMI and depressive symptoms, only the association between longer WBL and poor HDL level remained significant (OR=1.48, p=0.01). There were no associations between sleep parameters and TG level.

Conclusion

Among well-functioning older adults, greater WASO but lower TST and SE are associated with poorer metabolic syndrome components. Longitudinal research is needed to evaluate the temporal associations of objectively measured poor sleep and metabolic syndrome components and evaluate the roles of BMI and depressive symptoms in these associations.

Support

The first author is supported by a Postdoctoral Fellowship by the Intramural Research Program (IRP) at the National Institute on Aging (NIA). This study was supported in part by National Institute on Aging (NIA) grant R01AG050507, the NIA Intramural Research Program (IRP), and Research and Development Contract HHSN-260-2004-00012C.

Species identification, virulence markers and antimicrobial resistance profiles of Aeromonas sp. isolated from marketed hard-shelled mussel (Mytilus coruscus) in Korea

Hard-shelled mussel (Mytilus coruscus) is a popular seafood in Korea. This study aimed to determine the virulence markers and antimicrobial resistance patterns of 33 Aeromonas strains isolated from mussels. The isolates were identified as A. salmonicida (n = 14), A. veronii (n = 9), A. enteropelogenes (n = 4), A. caviae (n = 3), A. allosaccharophila (n = 2) and A. bivalvium (n = 1) by gyrB gene sequencing. The sequence divergence between and within the species ranged from 3·70 to 10·40% and 0-1·50% respectively. Every species formed a distinct group in a neighbour-joining phylogenetic tree. The DNase, gelatinase, caseinase, β-haemolysis, biofilm and lipase activities were observed in 33 (100·00%), 31 (93·93%), 30 (90·90%), 27 (81·81%), 21 (63·63%) and 17 (51·51%) isolates respectively. The virulence genes were detected by PCR in the following frequencies: fla (90·09%), aer (87·88%), hlyA (87·88%), ahyB (81·19%), gcaT (75·76%), ser (69·70%), lip (66·67%), alt (57·58%), ast (51·51%) and act (21·21%). Every isolate was resistant to at least three of 18 antimicrobials in the disk diffusion test. The multiple antimicrobial resistance index values ranged from 0·11 to 0·44 among the isolates. Our study suggests that mussels can be a potential reservoir of virulent and multidrug-resistant Aeromonas sp. SIGNIFICANCE AND IMPACT OF THE STUDY: Aeromonas sp. are known as common pathogenic bacteria isolated from seafood. The virulence factors and antimicrobial resistance profiles of mussel-borne Aeromonas sp. are poorly understood. This study demonstrated for the first time the existence of virulence markers and antimicrobial resistance of Aeromonas sp. from mussels in Korea. Majority of the isolates were positive for phenotypic virulence characteristics and harboured several virulence genes which reveal the potential virulence of mussel-borne Aeromonas sp. Multiple antimicrobial resistance was also observed among the isolates. Our study highlights the importance of food safety standards in mussel consumption.

Prevalence of virulence and antimicrobial resistance genes in Aeromonas species isolated from marketed cockles (Tegillarca granosa) in Korea

This study aimed to examine incidence, virulence and antimicrobial properties in Aeromonas spp. isolated from cockles (Tegillarca granosa) in Korea. Firstly, genomic DNA was extracted from 32 Aeromonas spp. isolates, and PCR screening for virulence, antimicrobial resistance genes was carried out. The disk diffusion assay was used to examine antimicrobial susceptibility. Aeromonas spp. isolates comprised, A. hydrophila (n = 8), A. veronii (n = 15), A. media (n = 2), A. salmonicida (n = 2), A. allosaccharophila (n = 1), A. bestiarum (n = 1), A. culicicola (n = 1), A. enteropelogenes (n = 1) and A. rivipollensis (n = 1). High prevalence of virulence-related genes reported as; act (69%), alt (47%), ast (41%), aerA (56%), lip (50%), ahyB (47%), ser (28%), fla (66%), gcat (44%), ascV (50%) and hlyA (72%). All isolates were multidrug resistant, while highest resistance level observed for ampicillin (100%), followed by imipenem (81%), rifampicin (78%), cephalothin (72%), piperacillin (47%) and Colistin sulfate (31%). The presence of bla_SHV , bla_CTX , tetE, aac(6')-Ib, strA-strB, qnrS, qnrB and IntI1 genes were reported in varying combinations. Nevertheless, bla_TEM , bla_IMP , tetA, tetB, qnrA, qnrB and aphAI-IAB genes and the class1 integron were not detected. The high occurrence of virulence and antimicrobial resistance genes in cockles reveals that it can be a potential health risk source for consumers.

Phylogenetic relationships, virulence and antimicrobial resistance properties of Klebsiella sp. isolated from pet turtles in Korea

Klebsiella sp. are responsible for a multitude of infectious diseases in both humans and animals. In this study, phylogenetic relationships, virulence and antimicrobial resistance gene properties of 16 Klebsiella sp. isolated from 49 pet turtles were investigated. The isolates including Klebsiella oxytoca (n = 13) and Klebsiella pneumoniae (n = 3) were identified using 16S rRNA gene sequencing and each species formed distinct clusters in the neighbour-joining phylogenetic tree. The prevalence of virulence genes including ureC (100%) and kfu (68·75%) was observed among the isolates using Polymerase chain reaction (PCR) assay. The fimH, mrkD and rmpA genes were detected in all K. pneumoniae while these were absent in every K. oxytoca isolate. In antimicrobial susceptibility testing, high resistance rates were observed against ampicillin (100%) and cephalothin (62·50%). The resistance rates against imipenem, tetracycline, trimethoprim/sulfamethoxazole, nalidixic acid and ciprofloxacin were 12·50, 12·50, 12·50, 6·25 and 6·25% respectively. The presence of antimicrobial resistance genes such as plasmid-mediated quinolone resistance (PMQR) [qnrB (37·50%), qnrA (31·25%), qnrS (12·50%) and aac(6')-Ib-cr (12·50%)], extended-spectrum β-lactamase (ESBL) [bla_CTX-M (18·75%)], β-lactamase [bla_SHV-1 (18·75%)] and tetracycline resistance [tetE (12·50%)] was observed. The results revealed that pet turtle-borne Klebsiella sp. may carry different types of virulence and antimicrobial resistance genes which represents a potential threat to public health. SIGNIFICANCE AND IMPACT OF THE STUDY: Klebsiella sp. are nonmotile Gram-negative bacteria that are found in different environments. The virulence and antimicrobial resistance properties of pet turtle-borne Klebsiella sp. have not been studied before. Phylogenetic relationships, virulence traits and antimicrobial resistance profiles of pet turtle-borne Klebsiella sp. were characterized for the first time in Korea. Multiple virulence and antimicrobial resistance genes were observed among the isolates. The occurrence of virulence and antimicrobial resistance determinants in Klebsiella sp. may represent a potential threat to public health.

Manila clam (Ruditapes philippinarum) marketed in Korea as a source of vibrios harbouring virulence and β-lactam resistance genes

The present study assessed the occurrence, virulence determinants and antimicrobial susceptibility patterns of Vibrio spp. isolated from live Manila clam (Ruditapes philippinarum). A total of 31 Vibrio spp. including 27 V. diabolicus, two V. fluvialis, one V. alginolyticus and one V. antiquarius were isolated and identified. Phenotypic detection of DNase, lipase, phospholipase, amylase and caseinase activities was 100%; and 87% gelatinase, 45% slime production and 6% haemolysin activities were also observed. The prevalence of toxin-related virulence genes for collagenase (94%), toxR (100%), tlh (68%), and VPI (71%) was detected by PCR. Additionally, two V. fluvialis isolates carried F-toxR and hupo genes. Moreover, 61% of the isolates showed multiple antimicrobial resistance indices >0·2. The resistance rates of ampicillin, piperacillin, colistin sulfate, rifampicin, and cephalothin were 100, 81, 71, 77 and 68% respectively. The prevalence of blaCTX-M (87%), blaTEM (55%) and Int1 (90%) genes was observed, whereas blaSHV, strA-strB, tetA, tetB, and aadA2 gene cassette were reported in varying combinations. However, armA, aac(3)-IIa and quinolone resistance genes (qnrA, qnrB, qnrS) were not amplified. Thus, the virulence along with extended-spectrum β-lactamases (ESBLs) and other antimicrobial resistance genes in multidrug-resistant Manila clam-borne vibrios may pose a public health threat for consumers. SIGNIFICANCE AND IMPACT OF THE STUDY: In Korea, eating raw seafood is considered a great delicacy. This has negatively affected the public by increasing health issues over the years due to the ingestion of vibrios. For the first time, we could identify Vibrio diabolicus and Vibrio antiquarius in marketed Manila clams in Korea. The prevalent Vibrio diabolicus isolates demonstrated the Vibrio parahaemolyticus and Vibrio cholerae homologous virulence genes (toxR, tlh, and VPI). Additionally, the abundance of extended-spectrum β-lactamases (ESBLs) and integron (IntI1) harboured by Manila clam-borne vibrios elucidate the potential health risk for consumers and may complicate health treatments in the case of infection.

Prevalence of virulence and extended-spectrum β-lactamase (ESBL) genes harbouring Vibrio spp. isolated from cockles (Tegillarca granosa) marketed in Korea

The present study aimed to investigate the incidence, virulence and antibiotic properties in Vibrio spp. isolated from cockles (Tegillarca granosa) marketed in Korea. A total of 32 Vibrio spp. isolates including V. parahaemolyticus (n = 4), V. alginolyticus (n = 11), V. diabolicus (n = 14) and V. harveyi (n = 3) were detected using gyrB sequencing. The phenotypic pathogenicity revealed that the DNase, amylase and phospholipase activities were 100%, while lipase, slime production, gelatinase and caseinase were detected in 72, 88, 88 and 81% of the isolates respectively. The PCR amplification for the detection of V. parahaemolyticus species-specific tdh, tlh, trh and toxR genes were positive in 4 (13%), 16 (50%), 0 (0%) and 4 (13%) isolates respectively. The V. alginolytuicus species-specific tdh, tlh, trh, toxR and vac genes were carried by 15 (47%), 29 (91%), 0 (0%), 15 (47%) and 25 (78%) of the isolates respectively. In addition, multidrug resistance was observed by 27 (84%) isolates, whereas higher resistant rates were observed against ampicillin, piperacillin, streptomycin and cephalothin. The occurrence of bla_CTX (78%), bla_TEM (40%), bla_SHV (22%) and aac(6')-Ib (94%) were prevalent, while strAB, tetB, aphAI-IAB, intl1 and aadA1 gene cassettes were also detected. The results signify the potential health risks resulting from the consumption of raw cockles in Korea. SIGNIFICANCE AND IMPACT OF THE STUDY: Vibrios are well known to cause human infections following consumption of raw or undercooked seafood. This phenomenon has undoubtedly increased the number of health issues over the past few years in Korea. Among the identified Vibrio spp., we could detect V. diabolicus and V. harveyi for the first time in marketed cockles in Korea. The presence of species-specific genes (tdh-VA, tlh-VP, tlh-VA and toxR-VA) in V. diabolicus exhibits the close genetic affinity among V. parahaemolyticus and V. alginolyticus. Furthermore, the prevalence of extended-spectrum β-lactamases (ESBLs) and other antibiotic resistance genes along with multidrug resistance signifies the potential threat for consumers.

Carboxylic acid modified pH-responsive composite polymer particles

pH-responsive polymers are attracting much interest from researchers because of their wide application potentials in areas like biosensor, bioseparator, bioreactor, biocatalysis, drug delivery, and water treatments. In this investigation a two-step process is evaluated to prepare carboxyl(–COOH) functional submicrometer-sized pH-responsive composite polymer particles. First, submicrometer-sized polystyrene (PS) particles are prepared by a modified conventional dispersion polymerization. In the second step, PS/poly(methacrylic acid-acrylamide-ethylene glycol dimethacrylate) [PS/P(MAA-AAm-EGDMA)] composite polymer particles are synthesized by seeded co-polymerization of methacrylic acid, acrylamide, and ethylene glycol dimethacrylate in the presence of PS seed particles. The size distributions and morphologies analyzed by electron micrographs suggested that seeded copolymerization smoothly occurred without formation of any secondary tiny copolymer particles. The surface composition and functionality are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. The hydrodynamic diameter increased with the increase in pH values as part of the carboxyl groups are deprotonated, which favored the swelling of copolymer layer formed around the surface of PS particles. The adsorption of cationic and anionic surfactants at two different pH values showed that adsorption of cationic surfactant is favored at higher pH value whereas that of anionic surfactant is favored at lower pH value.

Antibiotic and heavy metal resistance genes in Aeromonas spp. isolated from marketed Manila Clam (Ruditapes philippinarum) in Korea

AIMS

Manila clam (Ruditapes philippinarum) is one of the most popular seafood in Korea, owing to their unique taste and nutritional value. This study aimed to disclose the antibiotic and heavy metal resistance characteristics of Aeromonas spp. isolated from marketed Manila clam in Korea.

METHODS AND RESULTS

A total of 36 Aeromonas spp. strains were isolated and subjected to two tests: an antibiotic disk diffusion test to determine their resistance to antibiotics, and a broth dilution test to determine their resistance to heavy metals. PCR-based amplification was performed to detect the resistance genes. A high level of resistance to ampicillin (100%) and cephalothin (89%) was observed, while 42, 39, 36 and 36% of the isolates were resistant to oxytetracycline, imipenem, nalidixic acid and tetracycline respectively. In addition, among the tested heavy metals, cadmium (Cd) recorded the highest resistance rate (61%), followed by chromium (Cr) (50%), lead (Pb) (47%) and copper (Cu) (37%). However, mercury (Hg) resistance was not observed. PCRs revealed the occurrence of bla_TEM , bla_SHV , bla_CTX-M , qnrS, tetB, tetE, aac(6')-Ib, strA-strB and intI1 genes among 100, 31, 31, 78, 78, 89, 25, 50 and 72% of the isolates respectively. Moreover, heavy metal resistance genes, copA, merA and czcA were detected in 25, 47 and 61% of the isolates respectively.

CONCLUSIONS

The results suggest the importance of multi-drug and heavy metal-resistant aeromonads in Manila clam to assess the consumer safety and public health.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first to elaborate on the importance of multi-drug and heavy metal-resistant aeromonads in Manila clam. Particularly, the presence of extended-spectrum-β-lactamase genes and other antibiotic resistance genes intensifies the possible health risks and may complicate therapeutic treatments upon infection, while heavy metal resistance suggests possible heavy metal exposure.

Incidence of antimicrobial resistance genes and class 1 integron gene cassettes in multidrug-resistant motile Aeromonas sp. isolated from ornamental guppy (Poecilia reticulata)

Aeromonas sp. are opportunistic pathogenic bacteria which are associated with various diseases in ornamental fish, aquaculture raised species and wild fisheries. In our study, antimicrobial resistance patterns, antimicrobial resistance genes and class 1 integron gene cassettes of 52 guppy-borne Aeromonas sp. were examined. The isolates were identified as A. veronii (n = 34), A. dhakensis (n = 10), A. hydrophila (n = 3), A. caviae (n = 3) and A. enteropelogenes (n = 2) by gyrB gene sequencing. Every isolate was resistant to at least four antimicrobials in disc diffusion test. The resistance to amoxicillin, nalidixic acid and oxytetracycline was 100% among the tested isolates. 92·30, 76·92, 71·15, 51·92, 51·92 and 50·00% of the isolates were resistant to ampicillin, rifampicin, imipenem, cephalothin, tetracycline and trimethoprim respectively. The multiple antibiotic resistance index values ranged from 0·28 to 0·67. PCR amplification of antimicrobial resistance genes implied the occurrence of tetracycline resistance (tetA (65·39%), tetE (25·00%) and tetB (15·38%)), plasmid-mediated quinolone resistance (qnrS (26·92%) and qnrB (17·31%)) and aminoglycoside resistance (aphaAI-IAB (7·69%) and aac (6')-Ib (3·84%)) genes in the isolates. The IntI gene was positive for 36·54% of the isolates and four class 1 integron gene cassette profiles (aadA2, qacE2-orfD, aadA2-catB2 and dfrA12-aadA2) were identified. These data suggest that ornamental guppy can be a reservoir of multidrug-resistant Aeromonas sp. which comprise different antimicrobial resistance genes and class 1 integrons. SIGNIFICANCE AND IMPACT OF THE STUDY: Antimicrobial resistance genes and integron gene cassettes of ornamental fish-borne aeromonads are poorly studied. The antimicrobial resistance patterns, antimicrobial resistance genes and class 1 integron gene cassettes of Aeromonas sp. isolated from ornamental guppy were characterized for the first time in Korea. The incidence of different antimicrobial resistance genes and class 1 integron gene cassettes were observed in multidrug-resistant Aeromonas isolates. This result suggests that better management practices are necessary to prevent and address the serious consequences of indiscriminate and inappropriate antimicrobial use, and the distribution of multidrug-resistant bacteria.

Incidence of antibiogram, antibiotic resistance genes and class 1 and 2 integrons in tribe Proteeae with IMP27 gene for the first time in Providencia sp. isolated from pet turtles

Proteeae is a tribe which consists of three genera: Proteus, Providencia and Morganella. The objective of this study was to determine antimicrobial resistance profile, virulence genotype and class 1 and 2 integrons in Proteeae isolated from pet turtles and to determine the impact of antibiotic resistance on virulence and antimicrobial resistance genes. Integron-positive isolates were used to detect their gene cassette array. Sixty four Proteeae were isolated and all were resistant to macrolides (100%). Among 64 isolates 56, 52, 36 and 25 were resistant to nitrofurans, β-lactams, tetracycline and aminoglycoside respectively. Sixteen (25%) isolates were positive for intI1 while 14 (21·87%) were positive for integrase 2 (intI2). Eleven (17·18%) isolates were positive for class 1 variable region while 7 (10·93%) were positive for class 2 variable region. IMP27, a novel metallo β-lactamase gene was found in Providencia isolates. Proteus sp. were positive for every tested virulence genes and UreC gene was detected in 48·44% followed by zapA (17·19%), mrpA (17·19%) and hlyA (14·06%) genes. In this study, integron associated-antibiotic resistance genes have been identified in Proteeae isolates in a considerable range representing clear threats to public health. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, multidrug-resistant Proteeae isolates had several antibiotic resistance genes. Integrons are important contributors to the development and dissemination of antibiotic resistance. We could detect both class 1 and 2 integrons and several gene cassette arrays in class 1 integron. The gene cassette arrays of the Class 2 integrons contained IMP27-dfrA1-aadA1-catB2-ybeA-ybgA in two isolates. To the best of our knowledge this is the first study to report detection of IMP27 in Providencia rettgeri isolates. All results indicate that healthy pet turtles act as potential reservoirs for Proteeae species with zoonotic potential.

Comparison of virulence genes in Proteus species isolated from human and pet turtle

The current study was aimed to investigate the prevalence of ureC, rsbA, zapA and mrpA virulence genes using polymerase chain reaction (PCR) in Proteus spp. isolated from 5 commercially popular species of pet turtles and comparison of the mrpA gene sequences of Proteus mirabilis isolates with human clinical isolates. A total of 24 isolates in pet turtles were identified, comprised of P. mirabilis (15), Proteus vulgaris (7) and Proteus hauseri (2). The prevalence of ureC, rsbA, zapA and mrpA genes among all identified Proteus spp. isolates were 91.7%, 50%, 45.8% and 45.8%, respectively. The average percentage similarities of mrpA gene sequence of pet turtle P. mirabilis isolates to human urinary and respiratory isolates were 96.35% and 94.85%, respectively. The prevalence of virulence genes and high similarity of mrpA gene sequences between pet turtles and human P. mirabilis isolates revealed that though pet turtles are healthy, these animals may pose a potential risk of urinary and respiratory infections to humans.

Effect of boundary conditions on the evolution of lattice strains in a polycrystalline austenitic stainless steel

The effect of boundary conditions (constant load, constant strain and elastic follow-up) on lattice strain evolution during creep in a polycrystalline austenitic stainless steel was studied using in situ neutron diffraction at 550 °C. The lattice strains were found to remain constant under constant load control. However, under constant strain and elastic follow-up control, the lattice strains relaxed the most in the elastically softest lattice plane {200} and the least in the elastically stiffest lattice plane {111}. The intergranular stresses created between different grain families were constant during creep tests irrespective of the boundary conditions with the initial applied stresses of 250 MPa.

IMPACT OF CLINICAL MASTITIS IN DAIRY FARMING AT KESHABPUR UPAZILLA IN JESSORE IN BANGLADESH

The study was conducted at upazilla veterinary hospital, Keshabpur, Jessore during the period of March 2013 to August 2013 to estimate the impact of clinical mastitis in dairy cows. Clinical mastitis was diagnosed on the basis of clinical signs and strip cup test (SCT). A total of 432 cases of dairy animals were recorded among them 65 cases were mastitis. The overall prevalence of mastitis was 15.05%. The prevalence of mastitis was 12.04% and 3.01% in cows and does respectively. In doe, the prevalence was 7.14% in Jamunapari goat and 4.46% in Black Bengal goat. Reproductive stages enhanced the prevalence of mastitis. The prevalence of mastitis was also significantly affected by floor conditions where 10.42% in cows and 8.04% in does in the farms with brick-block floor and 6.51% in cows and 3.57% in does with soil floor. The efficacy of Ceftriaxone and amoxicillin was better than gentamicin and streptomycin. Hygienic condition showed lower prevalence of mastitis 1.63% and 1.79% in cow and does respectively than the unhygienic farm.