The Enterics for Global Health (EFGH) Shigella Surveillance Study in Pakistan.

Background: The Enterics for Global Health (EFGH) Shigella surveillance study is a longitudinal multicountry study that aims to estimate incidence rates and document consequences of Shigella diarrhea within 7 countries in Africa, Asia, and Latin America. In addition to a high incidence of childhood diarrhea, Pakistan is facing a problem of antimicrobial resistance in urban and peri-urban areas of Karachi. Methods: In Pakistan, EFGH will be conducted in Karachi, which is one of the metropolitan cities bordering the Arabian Sea and has a diverse population of 1.6 million according to the 2017 population census. The study aims to enroll 1400 children aged 6-35 months over 2 years (2022-2024) from 6 health care facilities (Abbasi Shaheed Hospital, Khidmat-e-Alam Medical Centre, Sindh Government Hospital Korangi 5, Sindh Government Hospital Ibrahim Hyderi, Ali Akbar Shah VPT Center, and Bhains Colony VPT Center) situated in Nazimabad and Bin-Qasim town. Moreover, population enumeration and health care utilization surveys from a defined catchment area of health facilities will be conducted to estimate the Shigella diarrhea incidence rates. Conclusions: The study will provide critical data to policy-makers about the burden of Shigella and antimicrobial resistance, which is essential for planning Shigella vaccine trials.

Effectiveness of typhoid conjugate vaccine against culture-confirmed typhoid in a peri-urban setting in Karachi: A case-control study.

BACKGROUND: Enteric fever, caused by Salmonella Typhi and S. Paratyphi, is a cause of high morbidity and mortality among children in South Asia. Rising antimicrobial resistance presents an additional challenge. Typhoid Conjugate Vaccines (TCV) are recommended by the World Health Organization for use among people 6 months to 45 years old living in endemic settings. This study aimed to assess the effectiveness of TCV against culture-confirmed S. Typhi in Lyari Town, Karachi, Pakistan. This peri-urban town was one of the worst affected by the outbreak of extensively drug resistant (XDR) typhoid that started in November 2016. METHODS: A matched case-control study was conducted following a mass immunization campaign with TCV at three key hospitals in Lyari Town Karachi, Pakistan. Children aged 6 months to 15 years presenting with culture-confirmed S. Typhi were enrolled as cases. For each case, at least 1 age-matched hospital control and two age-matched community controls were enrolled. Adjusted odds ratios with 95% confidence intervals (CIs) were calculated using conditional logistic regression. RESULTS: Of 82 typhoid fever patients enrolled from August 2019 through December 2019, 8 (9·8%) had received vaccine for typhoid. Of the 164 community controls and 82 hospital controls enrolled, 38 (23·2%) community controls and 27 (32·9%) hospital controls were vaccinated for typhoid. The age and sex-adjusted vaccine effectiveness was found to be 72% (95% CI: 34% - 88%). The consumption of meals prepared outside home more than once per month (adjusted odds ratio: 3·72, 95% CI: 1·55- 8·94; p-value: 0·003) was associated with the development of culture-confirmed typhoid. CONCLUSION: A single dose of TCV is effective against culture confirmed typhoid among children aged 6 months to 15 years old in an XDR typhoid outbreak setting of a peri-urban community in Karachi, Pakistan.

Butyrylcholinesterase inhibitory activity of testosterone and some of its metabolites.

Testosterone and ten of its metabolites were examined as inhibitors of butyrylcholinesterase. A significant enzyme inhibition activity (IC(50) = 1.55 microM) was observed for androst-4-en-3,7-dione. The kinetic parameters of butyrylcholinesterase inhibition were determined and molecular docking was carried out in order to develop a better understanding of the inhibitor-enzyme interactions. The results showed that the inhibition was non-competitive, stabilized mainly by hydrogen bonds and hydrophobic interactions between the inhibitor and butyrylcholinesterase.

Bioactive 5alpha-pregnane-type steroidal alkaloids from Sarcococca hookeriana.

The bioassay-guided phytochemical investigation of Sarcococca hookeriana with respect to cholinesterase inhibitory properties has yielded two new 5alpha-pregnane-type steroidal alkaloids, hookerianamides J (1) and K (2), along with eight known compounds (3-10). The structures of 1 and 2 were elucidated by spectroscopic methods. These compounds displayed good to moderate activities in vitro against the enzymes acetylcholinesterase (IC 50 8.1-48.5 microM) and butyrylcholinesterase (IC 50 0.4-4.0 microM). Compounds 1-10 were also tested in vitro for their leishmanicidal activity against Leishmania major and for their antibacterial activities against Bacillus subtilis, Micrococcus luteus, Streptococcus faecalis, and Pseudomonas pallida.

In vitro anticholinesterase activity of various alkaloids.

In the current study, a number of alkaloids including retamine, cytisine, and sparteine (quinolizidine-type), yohimbine and vincamine (indole-type), scopolamine and atropine (tropane-type), colchicine (tropolone-type), allantoin (imidazolidine-type), trigonelline (pyridine-type) as well as octopamine, synephrine, and capsaicin (exocyclic amine-type) were tested in vitro for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at 1 mg/ml concentration by the Ellman method using an ELISA microplate reader. Among the alkaloids tested, only capsaicin exerted a remarkable inhibitory effect towards both AChE and BChE [(62.7 +/- 0.79)% and (75.3 +/- 0.98)%, respectively]. While the rest of the alkaloids did not show any significant inhibition against AChE, three of the alkaloids, namely retamine, sparteine, and yohimbine, exerted a noteworthy anti-BChE effect as compared to galanthamine, the reference drug.

Leishmanicidal and cholinesterase inhibiting activities of phenolic compounds from Allanblackia monticola and Symphonia globulifera.

In a preliminary antiprotozoal screening of several Clusiaceae species, the methanolic extracts of Allanblackia monticola and Symphonia globulifera showed high in vitro leishmanicidal activity. Further bioguided phytochemical investigation led to the isolation of four benzophenones: guttiferone A (1), garcinol (2), cambogin (3) and guttiferone F (4), along with three xanthones: allanxanthone A (5), xanthone V1 (6) and globulixanthone C (7) as active constituents. Compounds 1 and 6 were isolated from S. globulifera leaves, while compounds 2-5 were obtained from A. monticola fruits. Guttiferone A (1) and F (4) showed particulary strong leishmanicidal activity in vitro, with IC50 values (0.2 microM and 0.16 microM, respectively) comparable to that of the reference compound, miltefosine (0.46 microM). Although the leishmanicidal activity is promising, the cytotoxicity profile of these compounds prevent at this state further in vivo biological evaluation. In addition, all the isolated compounds were tested in vitro for their anticholinesterase properties. The four benzophenones showed potent anticholinesterase properties towards acetylcholinesterase (AChE) and butylcholinesterase (AChE). For AChE, the IC50 value (0.66 microM) of garcinol (2) was almost equal to that of the reference compound galanthamine (0.50 microM). Furthermore, guttiferone A (1) and guttiferone F (4) (IC50 = 2.77 and 3.50 microM, respectively) were more active than galanthamine (IC50 = 8.5) against BChE.

Cholinesterase inhibiting and antiplasmodial steroidal alkaloids from Sarcococca hookeriana.

Bioguided phytochemical investigation of Sarcococca hookeriana with respect to the cholinesterase enzyme inhibitory assay yielded two new pregnane-type steriodal alkaloids hookerianamide H (1) and hookerianamide I (2), along with three known alkaloids N(a)-methylepipachysamine D (3), sarcovagine C (4) and dictyophlebine (5). Their structures were determined with the aid of extensive spectroscopic analysis. All compounds showed good inhibitory activities against the enzymes acetylcholinesterase (IC(50) 2.9-34.1 microM) and butyrylcholinesterase (IC(50) 0.3-3.6 microM). These compounds also showed moderate antiplasmodial activity (IC(50) 2.4-10.3 microM) against the Plasmodium falciparum chloroquine resistant W2 strain.