One Health intervention for elimination of anthrax in an endemic district of Odisha: A baseline and endline study

Background

This study was to compare a baseline and endline survey which were conducted to assess the changes in knowledge, attitude and practices about anthrax disease among the communities after One Health intervention for the elimination of human anthrax in an endemic district of Odisha.

Methods

A total of 2670 respondents were interviewed during the baseline and 2511 for the endline survey using a structured questionnaire by multi-stage sampling method. Descriptive statistics were used and logistic regression was performed to estimate the relationship between the variables and knowledge of anthrax.

Results

Out of the total participants in the study, males were about 76.25% in baseline and 72.08% in endline and about half of the total respondents were illiterate. Majority of the respondents had reported agriculture as their main occupation during both surveys. More than 50% of the respondents had livestock in their houses and farming was the main purpose for keeping them in both surveys. Around 20.26% of respondents knew about anthrax in baseline which raised to 53.64% after One Health intervention. Almost 21.29% of livestock owners had vaccinated their animals against anthrax disease throughout baseline, which increased to 66.5% during the endline survey.

Conclusion

This study highlights a significant surge in both knowledge and practices related to anthrax within the community after the implementation of intervention packages based on the One Health approach. The outcome of our study signified the importance of One Health interventions to address the health challenges related to zoonotic diseases in tribal communities. The data could be useful for local Governments to incorporate such an approach in their health policy to eliminate human anthrax.

Social and biological evaluation of antimicrobial resistance (SOBEAR) in rural India: a study protocol

Background

Antimicrobial resistance (AMR) has been one of the biggest global health threats in recent years, mostly in low- and middle-income countries, which requires urgent research using a multidisciplinary research approach. The use of large quantities of antimicrobial drugs inappropriately for humans, poultry and agriculture has been recognized as a leading cause of antibiotic resistance and the predominance of drug-resistance pathogens in the environment. This protocol aims to describe the use/misuse of antibiotics (ABs) in the community and evaluate clinical samples from healthcare settings to detect genes associated with antimicrobial resistance.

Methods

We will conduct a community-level survey in different villages of the Tigiria block to assess knowledge and awareness on ABs and AMR. We will conduct in-depth interviews (IDIs) with doctors, pharmacists, nurses and drug sellers, as well as focus group discussions (FGDs) with ASHA and ANM workers who are involved in antibiotic supplies to the community. Quantitative data from the community survey and qualitative data of IDIs and FGDs will be linked and analyzed using statistical modeling and iterative thematic content analysis. Specimens (stool, urine, blood and wound/pus) will be collected from clinically diagnosed patients of different healthcare centers of Tigiria block. The samples will be cultured for bacterial isolation and antibiotic sensitivity testing. Genomic DNA will be isolated from positive bacterial cultures and sequenced using PCR to evaluate high-threat multi-drug resistance organisms (MDROs), screening of plasmid-mediated quinolone resistance (PMQR) genes, antimicrobial genes responsible for MDR and quinolone resistance-determining regions (QRDRs).

Conclusion

This is the community-based protocol to evaluate the knowledge, attitudes, awareness and practices regarding ABs and AMR. The study protocol establishes a foundation for evaluating population-based prevalence and risk factors for AMR and MDROs in rural areas of the Odisha state, India.

SARS-CoV-2 seroprevalence in patients with autoimmune rheumatic diseases versus family controls: a multi-city cross-sectional survey

There is uncertainty regarding the effect of the SARS-CoV-2 infection on patients with autoimmune rheumatic diseases (AIRD) who are on immunosuppressive drugs. We did a multicity cross-sectional seroprevalence study conducted in five different cities in India before COVID-19 immunization. Patients with a diagnosis of AIRD and DMARDs were included. Relatives of the patients, preferably staying in the same household with no known rheumatic diseases served as controls. Serum IgG antibodies to SARS-CoV-2 Receptor Binding Domain (RBD) of the spike protein and nucleoprotein (NP) were assayed in eight hundred and eighty nine sera (subjects with disease = 379 and in subjects without disease = 510). IgG antibodies to either RBD and/or NP were positive in 135 (36%) subjects with AIRD as compared to 196 (38%) controls. The seroprevalence of anti-RBD and anti-NP varied between different cities but was not significantly different between subjects with and without disease in Mumbai, Ahmedabad, Bengaluru and Bhubaneswar. However, the occurrence of IgG antibodies to RBD was significantly (p < 0.05) lower in subjects with disease (28/65;43%) as compared to subjects without disease (42/65;65%) in Kolkata, where the positivity rate was lower in connective tissue disease group than in inflammatory arthritis group. Overall, patients with rheumatic diseases on DMARDs have IgG antibodies to RBD and NP of SARSCoV-2 at a comparable level with that of subjects without disease, but the level of antibodies to RBD is lower in patients with connective tissue disease on immunosuppressive drugs in one centre.

Investigation of human anthrax outbreak in Koraput district of Odisha, India

BACKGROUND

Anthrax is a zoonotic infection resulting from the bacteria Bacillus anthracis. Humans contract cutaneous anthrax by coming into contact, and gastrointestinal (GI) anthrax by consumption of infected animals or animal products. An outbreak investigation was conducted to confirm the occurrence of the anthrax outbreak, comprehend its extent, understand the epidemiological characteristics, identify the outbreak's cause, and propose control measures.

METHODS

A descriptive epidemiology was carried out for this outbreak investigation. We defined a suspected human cutaneous anthrax case as appearance of skin lesions and symptoms (itching/redness/swelling) and a suspected case of GI anthrax as appearance of diarrhoea/abdominal pain/vomiting in a resident of Koraput district after being associated with slaughtering and/or consumption of carcass during 5th April to 15th May 2023. The etiological hypothesis was formulated using descriptive epidemiological methods. Laboratory confirmation was performed by real-time polymerase chain reaction (RT-PCR). Statistical analyses were conducted using SPSS 25.

RESULTS

A total of 47 clinically suspected anthrax cases were identified during the outbreak in five villages of Koraput district in Odisha. The epidemic curve indicated multiple point-source exposures starting from 13th April 2023. About 10 cases were identified by RT-PCR testing as confirmed cases of anthrax. No death was recorded in this outbreak investigation.

CONCLUSIONS

Based on a thorough examination of epidemiological survey results and laboratory findings, we conclude that the outbreak was of human cutaneous and GI anthrax. Exposures from handling dead animals were associated with cutaneous anthrax, whereas eating uncooked meat of dead sheep was associated with gastrointestinal anthrax.

Serosurveys to detect SARS-CoV-2 antibodies among high-risk groups in six urban cities of Odisha, India

INTRODUCTION

Personnel involved in essential services or residing in high-risk areas during the COVID-19 pandemic are at increased risk of getting infected. We evaluated the proportion of personnel infected in several high-risk groups in Odisha using seroprevalence studies.

METHODOLOGY

During July to November, 2020, individuals from multiple high-risk groups in 6 urban cities (Bhubaneswar, Berhampur, Cuttack, Malkangiri, Paralakhemundi, and Rourkela) in Odisha, India, were recruited to the study after obtaining written informed consent. Blood samples collected from the study participants were tested for IgG antibodies against COVID-19 in Roche Cobas e441 (Roche Diagnostics, Rotkreuz, Switzerland). Information on socio-demographic variables, association with a confirmed or suspected case, and other details were collected using an electronic data capture tool and analysed with a statistical software.

RESULTS

The overall COVID-19 seroprevalence was 34.9% (95%CI 33.6-36.2) among the 5434 individuals. The seroprevalence varied from 21.8% (95% CI, 19.6-24.1) in Rourkela to 54.9% (95% CI, 51.5-58.2) in Bhubaneswar. Seropositivity was maximum among prisoners (47.7%), followed by municipality/ sanitation staff (43.5%), and other office going staff (40.8%). Multivariate logistic regression indicated that participants aged 18-29 years, 30-44 years, residents of slums and vending zone, municipality staff, prisoners, residents of urban cities Malkangiri, Cuttack, Paralakhemundi, Bhubaneswar and those with previous history of COVID-19 were independent co-relates of seropositivity.

CONCLUSIONS

The risk of COVID-19 varied among the high-risk groups of Odisha. Periodic seroprevalence studies in future are essential to protect the high-risk personnel involved in frontline activities during the pandemic.

COVID-19 vaccine hesitancy among school children aged 12-14 years: A cross-sectional study from Bhubaneswar, Odisha, India

INTRODUCTION

Universal coverage of COVID-19 vaccines is of paramount importance for the prevention and control of the pandemic. World Health Organization (WHO) in 2019 declared vaccine hesitancy as one of the top ten global health threats. The study aims to find out the COVID-19 vaccine hesitancy among school children along with their parent's perspectives.

METHODOLOGY

A cross-sectional study was conducted among school children (aged 12-14 years) at two schools in Bhubaneswar, Odisha. Data were collected via web-based links using a semi-structured questionnaire among students and their parents.

RESULTS

Of 343 children, 79% (271) showed a strong willingness to get vaccinated. Around 91.8% (315) of parents agreed to get their children vaccinated. Fear of side effects (65.2%) was the most common reason for unwillingness.

CONCLUSIONS

With only 1/5th of the children not willing to get vaccinated, policymakers should create a multi-centric effort for the universal coverage of the COVID-19 vaccination.

Perception and determinants leading to antimicrobial (mis)use: A knowledge, attitude, and practices study in the rural communities of Odisha, India

Background

Antimicrobial resistance (AMR) has emerged as one of the major public health issues globally. This cross-sectional study determined knowledge, attitudes and practices (KAP) regarding antimicrobial use and AMR among rural communities of Tigiria (Odisha), India.

Methods

A semi-structured questionnaire based on socio-demographic characteristics, antibiotics usage, awareness of antimicrobial resistance, healthcare utilization and quality of life were asked to the participants using an electronic device with Open Data Kit. Descriptive statistics, independent t-test and ANOVA were performed to analyze the variables.

Results

A total of 1,003 participants were surveyed in the study from 25 villages of Tigiria. About 44.47% (95% CI: 41.36-47.60) of study participants have heard about antimicrobial medicines and 14.75% (95% CI: 12.65-17.13) of participants were involved in buying antibiotics without prescription over the counter. Around 20.14% (95% CI: 17.72-22.78) of participants, stopped taking antibiotics before completing the full course. The physical domain was the most affected with low scores compared to other domains of quality of life (QOL). The QOL scores were found significant (p < 0.05) across age, gender, education and ethnicity.

Conclusion

The study documented a significant level of KAP regarding antimicrobial (mis)use in the study. It is essential that antimicrobial stewardship programs for various stakeholders and educational programmes must be initiated to increase awareness of people on antimicrobial resistance.

Scrub typhus seroprevalence from an eastern state of India: findings from the state-wide serosurvey

BACKGROUND

Scrub typhus is a mite-borne infectious disease caused primarily by the obligate intracellular bacteria Orientia tsutsugamushi, which is transmitted by chigger mites. The objective of this study was to determine the prevalence of scrub typhus among adults in Odisha, an eastern state of India.

METHODS

A descriptive cross-sectional study was conducted to analyse 1840 serum samples from five districts (Khordha, Cuttack, Ganjam, Malkangiri and Sundargarh) of Odisha collected during 2020-2021. Both immunoglobulin G (IgG) and IgM antibodies against scrub typhus were tested using commercial enzyme-linked immunosorbent assay kits. Point estimates of the 95% confidence interval and adjusted odds ratio were calculated.

RESULTS

Of 1840 participants, the prevalence of IgG positivity was 1034 (56.19%) and that of IgM was 523 (28.42%). The majority of participants were in the 18-45 y age group (53.7%). Cuttack had the highest IgG positivity (64.54%) and Malkangiri had the lowest (29.32%). The highest and lowest positivity for IgM were found in Malkangiri (40.84%) and Cuttack (25.30%), respectively.

CONCLUSIONS

With an increasing number of infections detected in the state, scrub typhus is emerging as a public health threat. Increasing awareness among the general public and healthcare professionals through health education campaigns regarding scrub typhus is essential. Early detection of the disease through the establishment of a laboratory surveillance system is required to control the transmission of scrub typhus.

Hepatitis B virus infection among the tribal and particularly vulnerable tribal population from an eastern state of India: Findings from the serosurvey in seven tribal dominated districts, 2021-2022

The Global Health Sector Strategy on viral hepatitis (2016-2021) endorsed by the World Health Assembly in 2016, called for the elimination of viral hepatitis as a public health threat by 2030. Odisha, an eastern state of India, has the third-highest percentage of tribal population in the country and limited information is available regarding the prevalence of HBsAg among them. The present study was undertaken to estimate the seroprevalence of hepatitis B surface antigen as well as HBV DNA almost after 12 years of the first prevalence study of HBsAg among the tribal community of Odisha. The present study attempted to estimate the prevalence of HBsAg among the 35 Scheduled tribal (ST) communities and 5 Particularly Vulnerable Tribal Group (PVTG) using the 2,737 number of sera collected as part of a statewide COVID-19 serosurvey, among the tribal populations of Odisha (residing in 7 districts) aged 6-75 years. HBsAg positivity ranged between 1.79 and 2.94% across various age groups. 42.9% of HBsAg positive individuals showed the presence of HBV DNA and the high viral load was 0.10 × 10²-6.84 × 10⁸ IU/mL, indicating a high potential to transmit the virus. The HBsAg positivity was 14.18 and 6.06% among the PVTGs, Kutia Khond and Paudi Bhuyan, who were first time surveyed for HBsAg prevalence. The present study documents the prevalence of HBsAg among the major tribal population residing in the eastern state of the country and highlights the need for a statewide survey of Hepatitis B infection and risk factors, coverage and impact of the Hepatitis B vaccination program introduced in 2010-2011 in Odisha among the ST and PVTG population of the state.

Seroprevalence of human brucellosis among the tribal and non-tribal population residing in an eastern state of India: Findings from the state-wide serosurvey

BACKGROUND

Brucellosis is a neglected zoonotic disease found predominantly in lower- and middle-income countries (LMICs), causing significant public health concern in India. The objective of this study was to assess the prevalence of human brucellosis in Odisha, India among community members involved in animal husbandry as a common practice.

METHOD

This cross-sectional study included 817 adult participants from 11 districts in Odisha. Four districts from the Northern division, four districts from the Central division, and three districts from the Southern division were selected for the study. Blood samples were collected during a COVID-19 serosurvey in Odisha conducted from 1st to 17th September 2021. Immunoglobulin-G (IgG) antibodies were measured against Brucella using a commercial ELISA kit. Point estimates at 95% confidence intervals (CIs) and adjusted odds ratio were calculated.

RESULTS

The overall prevalence of anti-Brucella IgG antibodies was calculated at 16.65% (95% CI: 14.19-19.42). The highest seropositivity was found in Sambalpur district (29.73%; 95% CI: 16.43-47.16) and the lowest was determined in Mayurbhanj district (4.44%; 95% CI: 0.99-15.60). Compared to males, females were more prone to contracting the disease (AOR: 1.13; 95% CI: 1.05-1.67). Participants from rural settings had higher prevalence of anti-Brucella IgG antibodies than urban dwellers (AOR: 4.53; 95% CI: 1.73-11.86).

CONCLUSION

This study revealed that human brucellosis was associated with sociodemographic factors like gender, living settings, and household numbers. To prevent brucellosis, screening should be initiated, infected humans should be treated early, and the public should be educated about risk factors and preventive measures.

Dynamicity and persistence of severe acute respiratory syndrome coronavirus-2 antibody response after double dose and the third dose with BBV-152 and AZD1222 vaccines: A prospective, longitudinal cohort study

Introduction

Vaccines are available worldwide to combat coronavirus disease-19 (COVID-19). However, the long-term kinetics of the vaccine-induced antibodies against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have not been sufficiently evaluated. This study was performed to investigate the persistence and dynamicity of BBV-152 (Covaxin)- and AZD1222 (Covishield)-induced immunoglobulin-G (IgG) antibodies over the year and neutralizing antibodies’ status after 1-month of booster dose.

Materials and methods

This 52-week longitudinal cohort study documented antibody persistence and neutralizing antibodies status among 304 healthcare workers (HCWs) from six hospitals and research facilities in Odisha, enrolled during January 2021 and continued till March 2022. IgG antibodies against spike receptor-binding domain (RBD) of SARS-CoV-2 were quantified in an automated chemiluminescence immune assay-based (CLIA) platform and a surrogate virus neutralization test (sVNT) was performed by enzyme-linked immunosorbent assay (ELISA).

Results

Among these 304 HCWs vaccinated with double doses, 154 HCWs (50.66%) were Covaxin recipients and the remaining 150 (49.34%) were Covishield recipients. During the follow-ups for seven times, a total of 114 participants were identified as vaccine breakthrough cases. In 190 non-infected HCWs, the median antibody titer was significantly waned from DD2 to DD10, both for Covaxin (231.8 vs. 42.7 AU/ml) and Covishield (1,884.6 vs. 369.2 AU/ml). No statistically significant differences in antibody titers were observed based on age, gender, comorbidities, and blood groups. The median inhibition activity of sVNT increased from 23.8 to 91.3% for Covaxin booster recipients and from 41.2 to 96.0% for Covishield booster recipients. Among 146 booster dose recipients, 48 were breakthrough cases after booster and all were contracted by the omicron variant.

Conclusion

This year-long follow-up study found a 7- and 5-fold antibody waning in Covaxin and Covishield recipients, respectively, without any breakthrough infection history. However, individuals with booster breakthrough had mild symptoms and did not require hospital admission. The data also indicate the possible escape of omicron variants despite the presence of vaccine-induced neutralizing antibodies.

Trend in seroprevalence of SARS-CoV-2 (IgG antibody) among tribal-dominated population: Findings from Jharkhand, India

Background & objectives

Serosurvey of COVID-19 provides a better estimation of people who have developed antibodies against the infection. Undertaking such a serosurvey in certain districts of India which are densely populated with prominent tribes can provide valuable information regarding seropravelance of SARS-CoV-2 antibodies among such indigenous populations. In this context, two rounds of population-based, cross-sectional serosurveys for SARS-CoV-2 IgG antibody were carried out in Jharkhand, a tribal-dominated State of India, to compare the seroprevalence of SARS-CoV-2 infection and to determine the associated demographic risk factors.

Methods

The surveys were carried out in June 2020 and February 2021 in ten districts of the State of Jharkhand. Blood samples were collected from the residents of the selected districts by random sampling and tested for anti-SARS-CoV-2 antibodies using an automated chemiluminescence immunoassay platform. A total of 4761 and 3855 eligible participants were included in round 1 and round 2, respectively.

Results

The age- and gender-standardized seroprevalence for COVID-19 during round 1 was 0.54 per cent (0.36-0.80) that increased to 41.69 per cent (40.16-43.22) during round 2 with a gap of eight months in between. The seropositivity among male and female participants was 0.73 and 0.45 per cent, respectively, during the first round and 51.35 and 33.70 per cent, respectively, during the second round. During the first round, 17.37 per cent of the participants were tribal with seropositivity of 0.24 per cent (0.02-0.87), and during the second round, 21.14 per cent were tribal with seropositivity of 39.14 per cent (35.77-42.59). Compared to tribal group, non-tribal participants had an adjusted odds of 1.24 (95% confidence interval=1.04-1.48) for SARS-CoV-2 seropositivity.

Interpretation & conclusions

COVID-19 seroprevalence was found to be low during the first round (0.54%) of the survey, possibly due to the travel restrictions during lockdown better adherence to social distancing and wearing of face masks among the people. Understanding the dynamics of SARS-CoV-2 transmission and the susceptibility to infection at the individual as well as community level will inform decision and help policy makers to design and implement effective public health strategies to mitigate the pandemic in this State.

Serological survey for SARS-CoV-2 antibodies among tribal communities of Odisha post-second wave

Background & objectives

Serial national level serosurveys in India have provided valuable information regarding the spread of COVID-19 pandemic in the general population, but the impact of the ongoing pandemic on the tribal population in India is not well understood. In this study, we evaluated the seroprevalence of COVID-19 antibodies in the tribal population of Odisha post-second wave (September 2021).

Methods

A population-based, age-stratified, cross-sectional study design was adopted for the survey, carried out in seven tribal districts of Odisha from 30^th August to 16^th September 2021. A multistage random sampling method was used where serum samples were tested for antibodies against the SARS-CoV-2 nucleocapsid (N) protein in each district, and a weighted seroprevalence with 95 per cent confidence interval (CI) was estimated for each district.

Results

A total of 2855 study participants were included from the seven tribal districts of Odisha in the final analysis. The overall weighted seroprevalence was 72.8 per cent (95% CI: 70.1-75.3). Serological prevalence was the highest among 18-44 yr (74.4%, 95% CI: 71.3-77.3) and from Sambalpur district [75.90% (66.90-83.10)]. Among participants, 41.93 per cent had received at least one dose of any COVID-19 vaccine. Kandhamal district had the highest number of fully immunized participants (24.78%), and in Sundergarh district, most of the study participants (58.1%) were unimmunized.

Interpretation & conclusions

This study found high seroprevalence against SARS-CoV-2 in the tribal population of Odisha. The vaccination coverage is at par with the general population, and efforts to address some knowledge gaps may be needed to improve the coverage in the future.

Assessment of socio-behavioural correlates and risk perceptions regarding anthrax disease in tribal communities of Odisha, Eastern India

BACKGROUND

This study is a baseline survey to assess the knowledge, attitude and practices with regards to the anthrax disease among the communities before demonstrating a One Health approach for elimination of human anthrax in an endemic district of Odisha. A total of 2670 respondents from 112 villages of 14 blocks were interviewed for the study using a structured questionnaire by multi-stage sampling method. Descriptive statistics were reported and logistic regression was performed to estimate the relationship between the variables and knowledge of anthrax.

RESULT

Out of 2670 participants in the study, 76.25% were male and about half were illiterate. Most of the respondents (54.19%) were involved in agriculture as an occupation. 71% of the respondents had livestock in their houses and farming was the main purpose for keeping the livestock. Only one-fifth of the respondents (20.26%) knew about anthrax and a majority of them have come across the disease during community outbreaks. Almost 25.9% of livestock owners had knowledge about vaccination against anthrax disease although 83.4% of the livestock owners disposed the animal carcass by burial method.

CONCLUSION

The study findings indicated that the community members had poor knowledge of cause, symptoms, transmission and prevention of anthrax disease which may be improved by a One Health approach.

Persistence of Antibodies Against Spike Glycoprotein of SARS-CoV-2 in Healthcare Workers Post Double Dose of BBV-152 and AZD1222 Vaccines

Purpose: We investigated the persistence of the vaccine-induced immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers (HCWs) in Odisha who received a complete dose of either Covaxin or Covishield vaccine.

Methods: This 24-week longitudinal cohort study was conducted from January to July 2021 with participants from 6 healthcare and research facilities of Odisha to understand the dynamicity of the vaccine-induced IgG antibodies against SARS-CoV-2 after the complete dose of vaccines.

Results: Serum samples were collected from 614 participants during each follow-up and were tested in two chemiluminescent microparticle immunoassay (CLIA)-based platforms to detect SARS-CoV-2 antibodies both qualitatively and quantitatively. Among these participants, 308 (50.2%) participants were Covishield recipients and the rest 306 (49.8%) participants took Covaxin. A total of 81 breakthrough cases were recorded and the rest 533 HCWs without any history of postvaccination infection showed significant antibody waning either from T3 (Covaxin recipient) or T4 (Covishield recipient). The production of vaccine-induced IgG antibodies is significantly higher (p < 0.001) in Covishield compared with Covaxin. Covishield recipients produced higher median anti-S IgG titer than Covaxin. No statistically significant differences in antibody titers were observed based on age, gender, comorbidities, and blood groups.

Conclusion: This 6-month follow-up study documents a 2-fold and 4-fold decrease in spike antibody titer among Covishield and Covaxin recipients, respectively. The clinical implications of antibody waning after vaccination are not well understood. It also highlights the need for further data to understand the long-term persistence of vaccine-induced antibody and threshold antibody titer required for protection against reinfection.

SARS-CoV-2 IgG antibody responses in rt-PCR-positive cases: first report from India

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody responses remain poorly understood and the clinical utility of serological testing is still unclear.

Aim

To understand the relationship between the antibody response to SARS-CoV-2 infection and the demographics and cycle threshold (C_t) values of confirmed RT-PCR patients.

Methodology

A total of 384 serum samples were collected from individuals between 4–6 weeks after confirmed SARS-CoV-2 infection and tested for the development of immunoglobulin class G (IgG) against SARS-CoV-2. The C_t values, age, gender and symptoms of the patients were correlated with the development of antibodies.

Results

IgG positivity was found to be 80.2 % (95 % CI, 76.2–84.2). Positivity increased with a decrease in the C_t value, with the highest (87.6 %) positivity observed in individuals with C_t values <20. The mean (±sd) C_t values for IgG positives and negatives were 23.34 (±6.09) and 26.72 (±7.031), respectively. No significant difference was found for demographic characteristics such as age and sex and symptoms and antibody response. The current study is the first of its kind wherein we have assessed the correlation of the RT-PCR C_t with the development of IgG against SARS-CoV-2.

Conclusion

Although C_t values might not have any relation with the development of symptoms, they are associated with the antibody response among SARS-CoV-2-infected individuals.

Breakthrough SARS-CoV-2 infections among BBV-152 (COVAXIN®) and AZD1222 (COVISHIELDTM ) recipients: Report from the eastern state of India

In this study, we attempted to record the breakthrough cases reported through passive and voluntary reporting at various healthcare facilities from different districts of Odisha, their clinical presentation, requirement of hospitalization postinfection, and antibody titer against spike antigen. Nasopharyngeal swab and serum samples alongwith demographic, clinical presentation and requirement of hospitalization postinfection were collected from vaccinated individuals through passive and voluntary reporting to various healthcare facilities of Odisha state to detect the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) virus infection and quantitative estimation of antibody titers. A total of 274 samples were found to be positive after 14 days of receiving complete doses of the vaccines. More than 83.2% of the individuals were found to be symptomatic with 9.9% of those required hospitalization. The seropositivity in individuals receiving Covishield (96.7%) was significantly higher than in Covaxin (77.1%). Hospitalized patients were having less median antibody titers than individuals in home isolation. The median age for breakthrough infection among the referred cases was 47.0 years (interquartile range [IQR]: 28.0) with a significantly older age group among Covishield recipients. The median spike receptor binding domain IgG titer values for Covaxin and Covishield recipients were 213.5 AU/ml (IQR: 537.5) and 647.5 AU/ml (IQR: 1645.1), respectively. The results reported here highlight the need for systematic data capture for the breakthrough infections to monitor the emergence of any vaccine escape variants and to plan the next steps in the coronavirus disease‐19 (COVID‐19) vaccine development by understanding the link between clinical protection and measured immunity against SARS‐CoV‐2 infection.

IgG antibody response against nucleocapsid and spike protein post-SARS-CoV-2 infection

Objectives

Coronavirus disease-19 (COVID-19) pandemic became the greatest public health challenge globally. Study of dynamicity and durability of naturally developed antibodies against SARS-CoV-2 are of great importance from an epidemiological viewpoint.

Methods

In this observational cohort study, we have followed up the 76 individuals who tested positive for SARS-CoV-2 infection by real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) for 16 weeks (post-enrolment) to record the periodic changes in titre, concentration, clinical growth and persistence of naturally developed SARS-CoV-2 antibodies. We collected serum samples from these individuals for 16 weeks with a frequency of weekly and fortnightly during each follow-up and tested them in two CLIA-based platforms (Abbott Architect i1000SR and Roche Cobas e411) for testing SARS-CoV-2 antibodies both qualitatively and quantitatively.

Results

We recorded the antibody magnitude of these individuals 10 times between September 2020 and February 2021. We found a waning of antibodies against nucleocapsid antigen protein but not a complete disappearance by the end of 16 weeks. Out of 76 cases, 30 cases (39.47%) became seronegative in qualitative assay, although all the sera samples (100%) remained positive when tested in quantitative assay.

Conclusion

The lower persistence of anti-nucleocapsid SARS-CoV-2 antibody may not be the exact phenomenon as those cases were still seropositive against spike protein and help in neutralising the virus.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01651-4.

Pooled testing for SARS-CoV-2 infection in an automated high-throughput platform

BACKGROUND

Active detection of SARS-CoV-2 infection through testing is elementary for the control of COVID-19 pandemic. The implementation of large-scale RT-PCR testing has led to a rise in the demand for testing kits whose availability is always a concern.

OBJECTIVE

To find out the feasibility of pooled testing in a high-throughput platform.

METHODOLOGY

Pooled testing was conducted in Roche cobas 6800 in 2 methods. Firstly, the simple two-stage testing algorithm was conducted for 1410 samples individually and then as pooled samples. Secondly, we evaluated the sensitivity of cobas 6800 for the detection of a single positive sample within a pool of negative samples.

RESULTS

Implementing the five-sample Dorfman pooling to test 1410 samples, we identified 42 (2.9%) individual SARS-CoV-2-positive samples and 27 (9.5%) positive pool samples. The pooling strategy precisely identified all the positive samples. All individually negative samples were also accurately determined by pooling. There was 100% sensitivity of detecting positive samples in a pool of negative samples even up to 1:64 dilution. There was a threefold increase in total throughput in one-third of the cost per day.

CONCLUSION

A high-throughput platform such as Cobas 6800 can effectively increase the testing capacity by twofold to threefold by adopting the pooled testing strategy for successful management of SARS-CoV-2 and helping in the containment of community transmission.

A qualitative exploratory study using One Health approach for developing an intervention package for elimination of human anthrax in an endemic district of Odisha, India

Background & objectives:

Anthrax is a zoonotic disease of public health concern in India. One of the key predisposing factors is linked to the behaviour of the community. This study was nested within a baseline survey to understand the risk perception, attitude, socio-cultural and behavioural practices among different communities in an anthrax endemic tribal district of Odisha, India. It was aimed to explore the systemic gaps from the officials of different departments while addressing the animal and human anthrax cases and the knowledge, attitude, and behavioural practices among the tribal communities with regards to both animal and human anthrax signs, symptoms, and transmission from animal to human.

Methods:

A qualitative exploratory study was carried out in the district of Koraput, Odisha. Insights from eight focus group discussions (FGDs) and 42 in-depth-interviews (IDIs) with the stakeholders from health, veterinary, forest, general administrative departments and community were collected and analyzed thematically.

Results:

Major themes that emerged were inter-departmental coordination, livestock vaccination, surveillance network, laboratory facilities, prevention and control strategies with regards to the animal and human anthrax cases. The study also emphasized setting up the surveillance system as per the standard guidelines, and strengthening the diagnostic facilities for timely detection of confirmed cases. It also highlighted the current needs and the gaps among inter-sectoral coordination, collaboration, and sensitization among Health, Veterinary, Forest, Education, Nutrition, and Tribal Welfare Departments at various levels to reduce the prevalence and control the outbreaks of anthrax in the district and State.

Interpretation & conclusions:

The coordination gaps, financial burden, insufficient relevant knowledge and information among the concerned stakeholders were the issues found in this study in addition to non-availability of proper diagnostic facility. The coordination among different departments adapting One Health approach may be one of the best possible ways for the elimination of anthrax cases in an endemic region.

One Health approach for elimination of human anthrax in a tribal district of Odisha: Study protocol

BACKGROUND

Anthrax is a major but neglected zoonotic disease of public health concern in India with Odisha contributing a major share to the disease burden. Bacillus anthracis spores can be found naturally in soil and commonly affect both animals and humans around the world. Domestic and wild animals such as cattle, sheep, goats, and deer can become infected when they inhale or ingest spores from contaminated soil, plants, or water. Anthrax can be fatal if patients are not treated promptly with antibiotics. This protocol aims to describe the implementation and evaluation of the 'One Health' intervention model based on the principles of Theory of Change (ToC) to eliminate human anthrax from a tribal district in Odisha, India.

METHODS

This study would test the effectiveness of a complex public health intervention package developed using the ToC framework for the elimination of human anthrax in Koraput district by a comparative analysis of baseline and end-line data. We plan to enroll 2640 adults across 14 geographically divided blocks in Koraput district of Odisha for baseline and end-line surveys. After baseline, we would provide capacity building training to stakeholders from the department of health, veterinary, forest, academic and allied health institutions followed by workshops on sensitization and awareness through IEC (Information Education Communication)/BCC (Behavior Change Communication) activities in the community. We would establish a state-level laboratory facility as a robust system for timely diagnosis and management of human anthrax cases. Surveillance network will be strengthened to track the cases in early stage and risk zoning will be done for focused surveillance in endemic areas. Advocacy with district level administration will be done for maximizing the coverage of livestock vaccination in the entire district. Interdepartmental coordination would be established for the effective implementation of the intervention package.

CONCLUSION

This would be a first study applying One Health concept for the elimination of human anthrax in India. The findings from this study will offer important insights for policy-making and further replication in other endemic regions of the state and country.

TRIAL REGISTRATION

The authors confirm that all ongoing and related trials for this intervention are prospectively registered with the Clinical Trials Registry of India [CTRI/2020/05/025325] on 22 May 2020.

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys

The study aims to estimate and compare the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence, the fraction of asymptomatic or subclinical infections in the population, determine the demographic risk factors and analyse the antibody development at different time points among adults in Bhubaneswar city, India. This was a serial three-round cross-sectional, community-based study where participants were selected from the residents of Bhubaneswar city using multi-stage random sampling. Blood samples were collected during household visits along with demographic and clinical data from every participant. Total anti-SARS-CoV-2 antibody present in serum was assessed using the electro-chemiluminescence immunoassay platform. Temporal comparisons of the community seroprevalence were performed against the detected number of cumulative cases, active cases, recoveries and deaths. A total of 3693 participants were enrolled in this study with a cumulative non-response rate of 18.33% in all the three rounds. The gender-weighted seroprevalence for the city in the first round was 1.55% (95% confidence interval (CI) 0.84-2.58), second round was 5.27% (95% CI 4.13-6.59) and in the third round was 49.04% (95% CI 46.39-51.68). In the first round, the seroprevalence was found to be highest in the elderly population, whereas the seroprevalence for the second and third phases was highest in the age group of 30-39 years. Seroprevalence showed an increasing trend over the three time periods, with the highest seropositivity rates among individuals sampled between 16 and 18 September 2020. By the third round, 93.93% of those who had previously been tested positive by real-time reverse transcription polymerase chain reaction had seroconversion and 46.57% of those who had been tested negative also showed seroconversion. Infection to case ratio during first round was 27.05, for second round and third round it was 5.62 and 17.91, respectively.

Diagnostic accuracy comparison of three fully automated chemiluminescent immunoassay platforms for the detection of SARS-CoV-2 antibodies

Background

Serological test is an essential surveillance tool to track down the extensiveness of SARS-CoV-2 transmission and subsequently to move out from the enforced lockdown stage.

Objective

The study measures the diagnostic accuracy of three popular chemiluminescent immunoassay (CLIA) based automated platforms for the detection of anti-SARS-CoV-2 antibodies and compares their agreements.

Study design

Serum samples of 594 COVID-19 positive patients and 100 samples from pre-COVID cases were tested by three CLIA based automated platforms: Abbott architect i2000SR, Roche cobas e411 and Yhlo iFlash 1800 and their diagnostic accuracy were compared by the area under the curves (AUC) value obtained from receiver operator characteristic (ROC) curves. Cohen’s kappa statistic and McNemar’s test were used to interpret the agreement between the platforms.

Results

All three platforms showed high specificity as claimed by the manufacturer. Sensitivity was calculated as 64.48 % (58.67–70.3) for Abbott, 80.48 % (76.62–84.34) for Roche and 76.94 % (72.65–81.23) for Yhlo. AUC was maximum for Roche (0.929). The Cohen’s kappa value was determined in between 0.69−0.89 as the inter-rater agreements.

Conclusion

The overall statistical analysis demonstrated cobas e411 as the diagnostically most accurate platform among the three.

COVID-19 in children in Odisha state, India: a retrospective review

We retrospectively analysed the swab samples tested for COVID-19 from 7 March 2020 to 17 August 2021 at the Indian Council of Medical Research-Regional Medical Research Centre, Bhubaneswar, Odisha. 553 763 nasopharyngeal swabs were collected from individuals suspected with COVID-19 in Odisha state. 75 190 (13.6%) samples were positive by reverse transcription-PCR. There were 5988 (8%) cases in children and young people under 18 years old. Odisha reported 996 153 COVID-19 cases which resulted in 6985 deaths in adults and 36 in children and young people under 18 years old.

Saliva for diagnosis of SARS-CoV-2: First report from India

There are very few studies in search of an alternate and convenient diagnostic tool which can substitute nasopharyngeal swab (NPS) specimen for detection of SARS-CoV-2. In the study we analyzed, the comparison and agreement between the feasibility of using the saliva in comparison to NPS for diagnosis of SARS-CoV-2. A total number of 74 patients were enrolled for this study. We analyzed and compared the NPS and saliva specimen collected within 48 h after the symptom onset. We carried out real-time quantitative polymerase chain reaction, gene sequencing for the detection and determination SARS-CoV-2 specific genes. Phylogenetic tree was constructed to establish the isolation of viral RNA from saliva. We used the Bland-Altman model to identify the agreement between two specimens. This study showed a lower cycle threshold (C_T ) mean value for the detection of SARS-CoV-2 ORF1 gene (mean, 27.07; 95% confidence interval [CI], 25.62 to 28.52) in saliva methods than that of NPS (mean 28.24; 95% CI, 26.62 to 29.85) specimen although the difference is statistically nonsignificant (p > .05). Bland-Altman analysis produced relatively smaller bias and high agreement between these two clinical specimens. Phylogenetic analysis with the RdRp and S gene confirmed the presence of SARS-CoV-2 in the saliva samples. Saliva represented a promising tool in COVID-19 diagnosis and the collection method would reduce the exposure risk of frontline health workers which is one of the major concerns in primary healthcare settings.

Role of Multidrug Resistance Proteins in Nonresponders to Immunomodulatory Therapy for Noninfectious Uveitis

Purpose

Nearly a third to half of patients with noninfectious uveitis (NIU) fail to achieve control with immunomodulatory therapy (IMT). Multidrug resistance (MDR) proteins are transmembrane proteins that allow efflux of intracellular drugs, leading to drug resistance. The aim of our study was to compare MDR protein function in blood CD4⁺ cells between responders and nonresponders to IMT.

Methods

We included NIU patients on IMT for ≥6 months and corticosteroid dose ≤10 mg/d. Nonresponders to treatment were those with worsening (two or more steps) of inflammation in the past 3 months on full-dose immunosuppressive therapy. MDR function was assessed by Rhodamine-123 dye retention in blood CD4⁺ cells. Three nonresponders were treated with adjunctive oral cyclosporine A (CSA, MDR inhibitor) therapy for 2 months and reevaluated.

Results

Fourteen NIU patients were recruited. Most (n = 8) had Vogt-Koyanagi-Harada disease. These included nine nonresponders and five responders to IMT. Nonresponders produced significantly higher MDR function and proinflammatory cytokines (interferon γ, tumor necrosis factor α, interleukin 17, and Granulocyte Macrophage Colony Stimulating Factor (GM-CSF)) than responders. In vitro CSA treatment of CD4⁺ cells inhibited MDR expression and proinflammatory cytokine production while increasing Foxp3. Finally, adjunctive oral CSA therapy led to improvement in clinical inflammatory scores with a concurrent decrease in MDR function and proinflammatory cytokine secretion.

Conclusions

MDR function is significantly higher in CD4⁺ T cells of nonresponders to IMT. Adjunctive CSA therapy may decrease MDR function and allow improvement in treatment response to IMT.

Translational Relevance

Our study highlights the need for MDR inhibition strategies in NIU patients not responding to IMT for improving the efficacy of anti-inflammatory therapy.

Naringin sensitizes the antibiofilm effect of ciprofloxacin and tetracycline against Pseudomonas aeruginosa biofilm

The study aims to explore the combinatorial effect of naringin with antibiotics, ciprofloxacin and tetracycline on Pseudomonas aeruginosa biofilms. The antibiofilm efficacy of selected treatment regimes against P. aeruginosa biofilm were quantified by crystal violet assay, MTT assay, Congo red binding assay, and were visualized by confocal laser scanning microscopy and scanning electron microscopy. All the assays reflected antibiofilm activities, however, combinatorial performances of naringin with antibiotics were found to be more significant. A significant reduction in swimming and swarming motilities along with pellicle formation and altered colony morphology were observed as a result of combinatorial effect. The cytotoxicity of naringin and its antibiotic combinations was assayed on murine macrophage cell line. The applicability of such combinations was tested for their relative eradication against pre-formed biofilm on urinary catheter surface. This finding indicated that naringin potentiates the efficacy of both ciprofloxacin and tetracycline on P. aeruginosa biofilm in comparison to their solo treatment. The finding would help to open hitherto unexplored possibilities of establishing naringin as a potential antibiofilm agent and suggest on the possibility of its use in drug-herb combinations for managing biofilm-associated bacterial infections.

Antimicrobial Peptides: An Approach to Combat Resilient Infections

BACKGROUND

It was apparent by the end of 1980s that the success against the threats of bacterial pathogens on public health was an illusion, with the rapid development of resistant strains more than the discovery of new drugs. As a consequence, the remedial services were in the backfoot position of being on the losing side of this never-ending evolutionary war. The quest for new antibiotics to overcome resistance problems has long been a top research priority for the researchers and the pharmaceutical industry. However, the resistance problems remain unresolved due to the abrupt misuse of antibiotics by common people, which has immensely worsened the scenario by disseminating antibiotic-resistant bacterial strains around the world.

OBJECTIVE

Thus, immediate action is needed to measure emerging and re-emerging microbial diseases having new resistance mechanisms and to manage their rapid spread among the common public by means of novel alternative metabolites.

CONCLUSION

Antimicrobial Peptides (AMPs) are short, cationic peptides evolved in a wide range of living organisms and serve as the essential part of the host innate immunity. For humans, these effector molecules either can directly kill the foreign microbes or modulate the host immune systems so that the human body could develop some resistance against the microbial infections. In this review, we discuss their history, structural classifications, modes of action, and explain their biological roles as anti-infective agents. We also scrutinize their clinical potentiality, current limitations in various developmental stages and strategies to overcome for their successful clinical applications.

Reserpine attenuates biofilm formation and virulence of Staphylococcus aureus

This study investigated the effects of reserpine, the main bioactive compound of Rauwolfia serpentina, on biofilm formation and biofilm-associated virulence factors production in a Gram-positive pathogen, Staphylococcus aureus. Crystal violet assay, MTT assay, Congo red binding, CLSM studies were performed to assess the antibiofilm activity. Molecular docking was performed to explain the possible mode of action, catheter model was used to evaluate its application potential and the combinatorial study was performed in search of an improved therapeutic formulation. Reserpine affected biofilm formation, EPS production, biofilm cell viability and virulence factor production. It could eradicate 72.7% biofilm at ½ × MIC dose and could also stop the metabolic activity of 50.6% bacterial cells in a biofilm. Staphylococcus aureus biofilm- and virulence-regulatory proteins like AgrA, AtlE, Bap, IcaA, SarA and SasG were found to interact with reserpine which might lead to the attenuation of its pathogenicity. Reserpine along with other commercial antibiotics could generate a hightened antibiofilm response, and also eradicated a good percentage of bacterial biofilm from a urinary catheter model. These findings suggested reserpine as a good alternative entity to generate new improved therapeutic formulations.

Effect of reserpine on Pseudomonas aeruginosa quorum sensing mediated virulence factors and biofilm formation

This study aimed to evaluate the effect of reserpine, a plant-derived indole-alkaloid, against Pseudomonas aeruginosa PAO1 biofilms. The anti-biofilm activity of reserpine was evaluated by crystal violet staining, MTT assay, confocal laser scanning microscopy and scanning electron microscopy. Reserpine effects were also assessed by qRT-PCR of quorum sensing (QS)-regulated genes and biochemical quantification of the QS-mediated virulence factors pyocyanin, rhamnolipids, proteases and elastases. Reserpine reduced biofilm formation, cell motility, virulence factor production, and QS-controlled gene expression. Additionally, molecular docking analysis for AHL synthase LasI and QS transcriptional regulators LasR/MvfR revealed a plausible molecular mechanisms of reserpine QS inhibition. These findings provide insights into the underlying mode of action of reserpine, which may be useful in the development of new drugs against biofilm-related infections.

Andrographolide induces oxidative stress-dependent cell death in unicellular protozoan parasite Trypanosoma brucei

African sleeping sickness is a parasitic disease in humans and livestock caused by Trypanosoma brucei throughout sub-Saharan Africa. Absence of appropriate vaccines and prevalence of drug resistance proclaim that a new way of therapeutic interventions is essential against African trypanosomiasis. In the present study, we have looked into the effect of andrographolide (andro), a diterpenoid lactone from Andrographis paiculata on Trypanosoma brucei PRA 380. Although andro has been recognized as a promosing anti-cancer drug, its usefulness against Trypanosoma spp remained unexplored. Andro showed promising anti-trypanosomal activity with an IC₅₀ value of 8.3μM assessed through SYBR Green cell viability assay and also showed no cytotoxicity towards normal murine macrophages. Cell cycle analysis revealed that andro could induce sub-G₀/G₁ phase arrest. Flow cytometric analysis also revealed that incubation with andro caused exposure of phosphatidyl serine to the outer leaflet of plasma membrane in T. brucei PCF. This event was preceded by andro-induced depolarization of mitochondrial membrane potential (Δym) and elevation of cytosolic calcium. Andro also caused elevation of intracellular reactive oxygen species (ROS) as well as lipid peroxidation level, and depletion in reduced thiol levels. Taken together, these data indicate that andro has promising antitrypanosomal activity mediated by promoting oxidative stress and depolarizing the mitochondrial membrane potential and thereby triggering an apoptosis-like programmed cell death. Therefore, this study merits further investigation to the therapeutic possibility of using andro for the treatment of African trypanosomiasis.

Attenuation of Pseudomonas aeruginosa quorum sensing, virulence and biofilm formation by extracts of Andrographis paniculata

Quorum-sensing (QS) is known to play an essential role in regulation of virulence factors and toxins during Pseudomonas aeruginosa infection which may frequently cause antibiotic resistance and hostile outcomes of inflammatory injury. Therefore, it is an urgent need to search for a novel agent with low risk of resistance development that can target QS and inflammatory damage prevention as well. Andrographis paniculata, a herbaceous plant under the family Acanthaceae, native to Asian countries and also cultivated in Scandinavia and some parts of Europe, has a strong traditional usage with its known antibacterial, anti-inflammatory, antipyretic, antiviral and antioxidant properties. In this study, three different solvent extracts (viz., chloroform, methanol and aqueous) of A. paniculata were examined for their anti-QS and anti-inflammatory activities. Study was carried out to assess the effect on some selected QS-regulatory genes at transcriptional level using Real Time-PCR. In addition, ability to attenuate MAPK pathways upon P. aeruginosa infection was performed to check its potential anti-inflammatory activity. Chloroform and methanol extracts showed significant reduction (p < 0.05) of the QS-controlled extracellular virulence factors in P. aeruginosa including the expression of pyocyanin, elastase, total protease, rhamnolipid and hemolysin without affecting bacterial viability. They also significantly (p < 0.05) reduced swarming motility and biofilm formation of P. aeruginosa. The chloroform extract, which was found to be more effective, decreased expression of lasI, lasR, rhlI and rhlR by 61%, 75%, 41%, and 44%, respectively. Moreover, chloroform extract decreased activation of p-p38 and p-ERK1/2 expression levels in MAPK signal pathways in P. aeruginosa infected macrophage cells. As the present study demonstrates that A. paniculata extracts inhibit QS in P. aeruginosa and exhibit anti-inflammatory activities, therefore it represents itself as a prospective therapeutic agent against P. aeruginosa infection.

Andrographolide: antibacterial activity against common bacteria of human health concern and possible mechanism of action

Increasing bacterial resistance to common drugs is a major public health concern for the treatment of infectious diseases. Certain naturally occurring compounds of plant sources have long been reported to possess potential antimicrobial activity. This study was aimed to investigate the antibacterial activity and possible mechanism of action of andrographolide (Andro), a diterpenoid lactone from a traditional medicinal herb Andrographis paniculata. Extent of antibacterial action was assessed by minimal bactericidal concentration method. Radiolabeled N-acetyl glucosamine, leucine, thymidine, and uridine were used to determine the effect of Andro on the biosyntheses of cell wall, protein, DNA, and RNA, respectively. In addition, anti-biofilm potential of this compound was also tested. Andro showed potential antibacterial activity against most of the tested Gram-positive bacteria. Among those, Staphylococcus aureus was found to be most sensitive with a minimal inhibitory concentration value of 100 μg/mL. It was found to be bacteriostatic. Specific inhibition of intracellular DNA biosynthesis was observed in a dose-dependent manner in S. aureus. Andro mediated inhibition of biofilm formation by S. aureus was also found. Considering its antimicrobial potency, Andro might be accounted as a promising lead for new antibacterial drug development.

Effect of Bacoside A on growth and biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa

The goal of this study was to evaluate the antibiofilm and antimicrobial activities of Bacoside A, a formulation of phytochemicals from Bacopa monnieri, against Staphylococcus aureus and Pseudomonas aeruginosa, which are known to form biofilms as one of their virulence traits. The antimicrobial effects of Bacoside A were tested using the minimum inhibitory concentration and minimum bactericidal concentration assays. A cell membrane disruption assay was performed to find its possible target site. MTT assay, crystal violet assay, and microscopic studies were performed to assess the antibiofilm activity. Bacoside A showed antimicrobial activity against both test organisms in their planktonic and biofilm states. At a subminimum inhibitory concentration of 200 μg·mL^-1, Bacoside A significantly removed ∼88%-93% of bacterial biofilm developed on microtiter plates. Biochemical and microscopic studies suggested that the eradication of biofilm might be due to the loss of extracellular polymeric substances and to a change in cell membrane integrity of the selected bacterial strains treated with Bacoside A. These results indicate that Bacoside A might be considered as an antimicrobial having the ability to disrupt biofilms. Thus, either alone or in combination with other therapeutics, Bacoside A could be useful to treat biofilm-related infections caused by opportunistic bacterial pathogens.