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1.
Emerg Infect Dis ; 30(4): 803-805, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38526236

ABSTRACT

Primary amebic meningoencephalitis caused by Naegleria fowleri is a rare but nearly always fatal parasitic infection of the brain. Globally, few survivors have been reported, and the disease has no specific treatment. We report a confirmed case in Pakistan in a 22-year-old man who survived after aggressive therapy.


Subject(s)
Central Nervous System Protozoal Infections , Naegleria fowleri , Male , Humans , Young Adult , Adult , Central Nervous System Protozoal Infections/diagnosis , Central Nervous System Protozoal Infections/drug therapy , Brain , Pakistan/epidemiology , Survivors
2.
Mycoses ; 67(1): e13677, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37990393

ABSTRACT

BACKGROUND: Recent reports of the emergence of fluconazole resistance in Candida parapsilosis species complex poses a challenge, more specifically in settings where echinocandin-based treatment regime is not feasible. OBJECTIVE: This study reported emergence of fluconazole resistance in C. parapsilosis species complex strains isolated from blood cultures. MATERIALS AND METHODS: This retrospective observational study was conducted from 2018 to 2020 at a tertiary care laboratory from Pakistan. Fluconazole-resistant C. parapsilosis species complex fungemia cases were identified from laboratory database and clinical details were collected. Identification of C. parapsilosis species complex was done using API 20C AUX and Cornmeal Tween80 agar morphology. Minimum inhibitory concentrations (MICs) were determined using Sensititre YeastONE and interpretation was done with CLSI M60 ED1:2017. ERG11 gene region was amplified and sequenced by Sanger sequencing and analysed by MEGA 11 Software. RESULTS: A total of 13 (8.5%) fluconazole-resistant isolates were identified from 152 C. parapsilosis species complex candidemia cases. Fluconazole MICs of resistant isolates ranged between 8 and 256 µg/mL. Analysis of ERG11 gene revealed nonsynonymous mutations at position Y132F in 86% of the fluconazole-resistant isolates. Diabetes and hospitalization were important risk factors for candidemia with fluconazole-resistant C. parapsilosis complex. CONCLUSION: This is the first report of the emergence and molecular mechanisms of fluconazole resistance in C. parapsilosis species complex from Pakistan. Y132F mutation in the ERG11 gene was the most common mutation in fluconazole-resistant strains. These findings are concerning and necessitate better diagnostics, newer antifungals, ongoing surveillance and further insights on resistance mechanisms in the country.


Subject(s)
Candidemia , Fluconazole , Humans , Fluconazole/pharmacology , Fluconazole/therapeutic use , Candida parapsilosis/genetics , Candidemia/drug therapy , Pakistan/epidemiology , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Mutation , Microbial Sensitivity Tests , Drug Resistance, Fungal/genetics
3.
Gates Open Res ; 7: 102, 2023.
Article in English | MEDLINE | ID: mdl-37795041

ABSTRACT

Stillbirth, one of the most common adverse pregnancy outcomes, is especially prevalent in low and middle-income countries (LMICs). Understanding the causes of stillbirth is crucial to developing effective interventions. In this commentary, investigators working across several LMICs discuss the most useful investigations to determine causes of stillbirths in LMICs. Useful data were defined as 1) feasible to obtain accurately and 2) informative to determine or help eliminate a cause of death. Recently, new tools for LMIC settings to determine cause of death in stillbirths, including minimally invasive tissue sampling (MITS) - a method using needle biopsies to obtain internal organ tissue from deceased fetuses for histology and pathogen identification in those tissues have become available. While placental histology has been available for some time, the development of the Amsterdam Criteria in 2016 has provided a useful framework to categorize placental lesions. The authors recommend focusing on the clinical history, the placental evaluation, the external examination of the fetus, and, when available, fetal tissue obtained by MITS, especially of the lung (focused on histology and microbiology) and brain/cerebral spinal fluid (CSF) and fetal blood (focused on microbiological analysis). The authors recognize that this approach may not identify some causes of stillbirth, including some genetic abnormalities and internal organ anomalies, but believe it will identify the most common causes of stillbirth, and most of the preventable causes.

4.
BJOG ; 130 Suppl 3: 43-52, 2023 11.
Article in English | MEDLINE | ID: mdl-37671586

ABSTRACT

OBJECTIVE: To examine inflammatory lesions in placentas of stillbirths, preterm neonatal deaths and term controls in India and Pakistan. DESIGN: Prospective, observational study. SETTING: Three hospitals in India and a large maternity hospital in Pakistan. POPULATION: The enrolled participants with placentas available for histology evaluation included stillbirths (n = 814), preterm live births who died within 28 days of birth (n = 618) and term live birth controls (n = 201). From this same population, polymerase chain reaction (PCR) analysis for pathogens was performed on 809 stillbirth placentas, 614 neonatal death placentas and the placentas of 201 term controls. Placentas from preterm infants who lived beyond day 28 (n = 1432) were only available from India. METHODS: A prospective observational study of placental inflammatory lesions defined by the Amsterdam criteria and on the same placentas, multiplex PCR evaluation for 75 pathogens using TaqMan Array Cards. MAIN OUTCOME MEASURES: Any placental inflammatory lesions, including chorioamnionitis, funisitis, villitis and intervillitis and their association with various pathogens. RESULTS: In the Indian liveborn preterm infants, placental inflammation of any kind was present in 26.2% of those who died versus 16.6% of those who lived (p = 0.0002). Chorioamnionitis was present in 25.8% of those who died versus 16.3% of those who lived (p = 0.0002) and funisitis was present in 4.1% of those who died versus 1.5% of those who lived, (p = 0.005). Across all three sites, in the placentas of the 201 term controls, 18.9% had any inflammation, 16.9% had chorioamnionitis, 5.5% had funisitis, 0.5% had intervillitis and none had villitis. Overall, for stillbirths, any inflammation was observed in 30.2%, chorioamnionitis in 26.9%, funisitis in 5.7%, intervillitis in 6.0% and villitis in 2.2%. For the neonatal deaths, any inflammation was present in 24.9%, chorioamnionitis in 23.3%, funisitis in 8.1%, intervillitis in 1.9% and villitis in 0.5%. Compared with the placentas of term controls, in neonatal deaths, only chorioamnionitis was significantly increased (23.3% versus 16.9%, p = 0.05). Among stillbirths, the rates of any inflammation, chorioamnionitis, intervillitis and villitis were similar across the birthweight groups. However, funisitis was more common in the placentas of stillborn fetuses weighing 2500 g or more (13.8%) compared with 1.0% for those weighing less than 1000 g and 4.8% for stillborn fetuses weighing 1000-2499 g. In the PCR studies, Ureaplasma spp. were by far the most common pathogens found and generally were more commonly found in association with inflammatory lesions. CONCLUSIONS: Chorioamnionitis was the most common type of placental inflammatory lesion regardless of whether the placentas evaluated were from term controls, stillbirths or neonatal deaths. For stillbirths, inflammation in each inflammation category was more common than in the term controls and significantly more so for any inflammation, chorioamnionitis, intervillitis and villitis. For neonatal deaths, compared with the placentas of term controls, all inflammation categories were more common, but only significantly so for chorioamnionitis. Ureaplasma spp. were the most common organisms found in the placentas and were significantly associated with inflammation.


Subject(s)
Chorioamnionitis , Perinatal Death , Premature Birth , Female , Pregnancy , Infant, Newborn , Humans , Placenta/pathology , Chorioamnionitis/epidemiology , Stillbirth/epidemiology , Prospective Studies , Asia, Southern , Infant, Premature , Inflammation/pathology , Premature Birth/epidemiology , Premature Birth/pathology
5.
BJOG ; 130 Suppl 3: 36-42, 2023 11.
Article in English | MEDLINE | ID: mdl-37530629

ABSTRACT

OBJECTIVE: To compare placental findings in women with and without pre-eclampsia. DESIGN: The PURPOSe study included women with stillbirths, women with preterm births and women at term as controls. The placenta of each case was evaluated using the Amsterdam criteria. SETTING: Two sites and five tertiary care hospitals of south Asia (Three in India and two in Pakistan). POPULATION: Pregnancies in India and Pakistan with placental histology including women with documented hypertension and documented proteinuria and women with neither hypertension nor proteinuria. METHODS: We compared the placental findings of the two groups using the Amsterdam criteria and further evaluated the placental findings in women with and without pre-eclampsia who had a stillbirth, preterm live birth, or term live birth (control). MAIN OUTCOME MEASURES: The main outcome measures were the frequency of maternal and fetal vascular malperfusion and the frequency of placental inflammation and its components, chorioamnionitis, funisitis, villitis and intervillitis in women with and without pre-eclampsia. RESULTS: A total of 733 women had pre-eclampsia and 2334 women had neither hypertension nor proteinuria. In the placentas of women with pre-eclampsia, 57.3% had maternal vascular malperfusion compared with 37.1% in women without pre-eclampsia (p < 0.0001). There was not a significant difference in the prevalence of fetal vascular hypertension between mothers with (17.1%) and without (14.8%, p = 0.6118) pre-eclampsia. When placentas were classified as 'histologically normal' or not, 61.3% of those from pre-eclamptic pregnancies were classified as abnormal, whereas if there was no pre-eclampsia, only 45.0% were classified as histologically abnormal (p < 0.0001). We also considered rates of placental maternal vascular malperfusion in women with and without pre-eclampsia with stillbirth, preterm neonatal death, and term live birth. In women at term with no pre-eclampsia, 16.7% of the placentas had features of maternal vascular malperfusion. This occurred in 79.9% of women with stillbirths with pre-eclampsia compared with 51.8% of those without pre-eclampsia. Maternal vascular malperfusion was present in 49.7% of preterm live births with pre-eclampsia compared with 33.8% without pre-eclampsia. We also evaluated the inflammatory lesions by whether the mother had or did not have pre-eclampsia. When all inflammatory lesions were considered, women with pre-eclampsia had significantly fewer inflammatory lesions than those women without pre-eclampsia (17.1% versus 23.6% p = 0.001). Each of the specific inflammatory lesions was less common in placentas of women with pre-eclampsia than those with chorioamnionitis (16.1% versus 21.9%, p = 0.004) and funisitis (1.5% versus. 5.1%, p = 0.0004). CONCLUSIONS: Of placental lesions in women with pre-eclampsia, maternal vascular malperfusion was the most common. Inflammatory lesions were less common in women with pre-eclampsia.


Subject(s)
Chorioamnionitis , Hypertension , Pre-Eclampsia , Premature Birth , Infant, Newborn , Pregnancy , Female , Humans , Placenta/blood supply , Chorioamnionitis/epidemiology , Stillbirth/epidemiology , Pre-Eclampsia/epidemiology , Pre-Eclampsia/pathology , Prospective Studies , Pakistan/epidemiology , Premature Birth/epidemiology , Premature Birth/pathology , Proteinuria/epidemiology , Proteinuria/etiology
6.
PLOS Glob Public Health ; 3(6): e0001896, 2023.
Article in English | MEDLINE | ID: mdl-37262051

ABSTRACT

COVID-19 resulted in extensive morbidity and mortality worldwide. SARS-CoV-2 evolved rapidly, with increasing transmission due to Variants of Concern (VOC). Identifying VOC became important but genome submissions from low-middle income countries (LMIC) remained low leading to gaps in genomic epidemiology. We demonstrate the use of a specific mutation RT-PCR based approach to identify VOC in SARS-CoV-2 positive samples through the pandemic in Pakistan. We selected 2150 SARS-CoV-2 PCR positive respiratory specimens tested between April 2021 and February 2022, at the Aga Khan University Hospital Clinical Laboratories, Karachi, Pakistan. Commercially available RT-PCR assays were used as required for mutations in Spike protein (N501Y, A570D, E484K, K417N, L452R, P681R and deletion69_70) to identify Alpha, Beta, Gamma, Delta, and Omicron variants respectively. Three pandemic waves associated with Alpha, Delta and Omicron occurred during the study period. Of the samples screened, VOC were identified in 81.7% of cases comprising mainly; Delta (37.2%), Alpha (29.8%) and Omicron (17.1%) variants. During 2021, Alpha variants were predominant in April and May; Beta and Gamma variants emerged in May and peaked in June; the Delta variant peaked in July and remained predominant until November. Omicron (BA.1) emerged in December 2021 and remained predominant until February 2022. The CT values of Alpha, Beta, Gamma and Delta were all significantly higher than that of Omicron variants (p<0.0001). We observed VOC through the pandemic waves using spike mutation specific RT-PCR assays. We show the spike mutation specific RT-PCR assay is a rapid, low-cost and adaptable for the identification of VOC as an adjunct approach to NGS to effectively inform the public health response. Further, by associating the VOC with CT values of its diagnostic PCR we gain information regarding the viral load of samples and therefore the level of transmission and disease severity in the population.

7.
J Pak Med Assoc ; 73(2): 396-398, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36800735

ABSTRACT

Naegleria fowleri causes acute fatal primary amoebic meningoencephalitis in adults and children with a history of exposure to aquatic activities. However, several cases of Primary Amoebic Meningoencephalitis (PAM) have been reported from Karachi with no history of aquatic recreational activities suggesting the presence of N. fowleri in domestic water. This study reports a case of co-infection of N. fowleri with Streptococcus pneumoniae in an elderly hypertensive male.


Subject(s)
Central Nervous System Protozoal Infections , Meningoencephalitis , Naegleria fowleri , Adult , Child , Aged , Humans , Male , Streptococcus pneumoniae , Pakistan , Central Nervous System Protozoal Infections/diagnosis , Meningoencephalitis/diagnosis
8.
BJOG ; 130(4): 366-376, 2023 03.
Article in English | MEDLINE | ID: mdl-36504437

ABSTRACT

OBJECTIVES: To determine COVID-19 antibody positivity rates over time and relationships to pregnancy outcomes in low- and middle-income countries (LMICs). DESIGN: With COVID-19 antibody positivity at delivery as the exposure, we performed a prospective, observational cohort study in seven LMICs during the early COVID-19 pandemic. SETTING: The study was conducted among women in the Global Network for Women's and Children's Health's Maternal and Newborn Health Registry (MNHR), a prospective, population-based study in Kenya, Zambia, the Democratic Republic of the Congo (DRC), Bangladesh, Pakistan, India (two sites), and Guatemala. POPULATION: Pregnant women enrolled in an ongoing pregnancy registry at study sites. METHODS: From October 2020 to October 2021, standardised COVID-19 antibody testing was performed at delivery among women enrolled in MNHR. Trained staff masked to COVID-19 status obtained pregnancy outcomes, which were then compared with COVID-19 antibody results. MAIN OUTCOME MEASURES: Antibody status, stillbirth, neonatal mortality, maternal mortality and morbidity. RESULTS: At delivery, 26.0% of women were COVID-19 antibody positive. Positivity increased over the four time periods across all sites: 13.8%, 15.4%, 21.0% and 40.9%. In the final period, positivity rates were: DRC 27.0%, Kenya 33.1%, Pakistan 32.8%, Guatemala 37.0%, Zambia 37.8%, Bangladesh 47.2%, Nagpur, India 57.4% and Belagavi, India 62.4%. Adjusting for site and maternal characteristics, stillbirth, neonatal mortality, low birthweight and preterm birth were not significantly associated with COVID-19. The adjusted relative risk (aRR) for stillbirth was 1.27 (95% CI 0.95-1.69). Postpartum haemorrhage was associated with antibody positivity (aRR 1.44; 95% CI 1.01-2.07). CONCLUSIONS: In pregnant populations in LMICs, COVID-19 antibody positivity has increased. However, most adverse pregnancy outcomes were not significantly associated with antibody positivity.


Subject(s)
COVID-19 , Premature Birth , Child , Pregnancy , Female , Infant, Newborn , Humans , Pregnancy Outcome/epidemiology , Stillbirth/epidemiology , Child Health , Developing Countries , Prospective Studies , COVID-19 Testing , Pandemics , Premature Birth/epidemiology , COVID-19/epidemiology , Women's Health , Infant Mortality
9.
Clin Infect Dis ; 76(3): e1004-e1011, 2023 02 08.
Article in English | MEDLINE | ID: mdl-36104850

ABSTRACT

BACKGROUND: We identified pathogens found in internal organs and placentas of deceased preterm infants cared for in hospitals in India and Pakistan. METHODS: Prospective, observational study conducted in delivery units and neonatal intensive care units. Tissue samples from deceased neonates obtained by minimally invasive tissue sampling and placentas were examined for 73 different pathogens using multiplex polymerase chain reaction (PCR). RESULTS: Tissue for pathogen PCR was obtained from liver, lung, brain, blood, cerebrospinal fluid, and placentas from 377 deceased preterm infants. Between 17.6% and 34.1% of each type of tissue had at least 1 organism identified. Organism detection was highest in blood (34.1%), followed by lung (31.1%), liver (23.3%), cerebrospinal fluid (22.3%), and brain (17.6%). A total of 49.7% of the deceased infants had at least 1 organism. Acinetobacter baumannii was in 28.4% of the neonates compared with 14.6% for Klebsiella pneumoniae, 11.9% for Escherichia coli/Shigella, and 11.1% for Haemophilus influenzae. Group B streptococcus was identified in only 1.3% of the neonatal deaths. A. baumannii was rarely found in the placenta and was found more commonly in the internal organs of neonates who died later in the neonatal period. The most common organism found in placentas was Ureaplasma urealyticum in 34% of the samples, with no other organism found in >4% of samples. CONCLUSIONS: In organ samples from deceased infants in India and Pakistan, evaluated with multiplex pathogen PCR, A. baumannii was the most commonly identified organism. Group B streptococcus was rarely found. A. baumannii was rarely found in the placentas of these deceased neonates.


Subject(s)
Perinatal Death , Infant , Pregnancy , Female , Infant, Newborn , Humans , Infant, Premature , Prospective Studies , Pakistan/epidemiology , Multiplex Polymerase Chain Reaction , Escherichia coli
10.
Mycoses ; 66(1): 52-58, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36106428

ABSTRACT

INTRODUCTION: The gradual increase in caspofungin usage in Pakistan raises a concern of emergence of echinocandin resistance in local Candida glabrata strains. We sequenced and determined mutations in fks1 and fks2 genes in invasive Candida glabrata strains from Pakistan. MATERIAL AND METHODS: Thirty-six invasive C. glabrata strains were selected with median (min-max) minimum inhibitory concentrations (MICs) of 0.06 (0.015-0.25) mg/L for caspofungin, 0.015 (0.008-0.06) mg/L for micafungin and 0.06 (0.015-0.12) mg/L for anidulafungin. fks1 and fks2 gene fragments were sequenced using Sanger methodology. Sequences were analysed with MEGA-6 software to identify specific single-nucleotide polymorphisms (SNP) against wild-type sequences of C. glabrata. RESULTS: In fks1 gene, non-synonymous mutation D632H was observed in one isolate with caspofungin MIC of 0.25 mg/L. Synonymous mutation at position A742 was observed in 26/36 (72%) of the isolates. 34/36 (94.5%) isolates analysed for fks2 gene were observed as wild type. A novel non-synonymous mutation at I661T was observed in fks2 gene in one isolate with caspofungin MIC of 0.12 mg/L and anidulafungin and micafungin MIC of 0.06 and 0.015 mg/L, respectively. Novel fks2 synonymous mutations at position T647, K652 and I706 were observed in 16/36 (44%), 25/36 (69%) and 23/36 (63%) isolates, respectively. CONCLUSION: Low frequencies of both non-synonymous and synonymous polymorphisms were observed in invasive C. glabrata strains. Since S663P in fks2 gene is associated with caspofungin resistance, a novel mutation at 661 codon identified in our study needs correlation with treatment outcome data and mandates periodic genomic surveillance.


Subject(s)
Antifungal Agents , Candida glabrata , Humans , Micafungin/pharmacology , Anidulafungin , Caspofungin/pharmacology , Pakistan , Antifungal Agents/pharmacology , Glucosyltransferases/genetics , Fungal Proteins/genetics , Echinocandins/pharmacology , Microbial Sensitivity Tests , Mutation , Drug Resistance, Fungal/genetics
11.
Virus Evol ; 8(1): veac020, 2022.
Article in English | MEDLINE | ID: mdl-35462736

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to emerge, and their identification is important for the public health response to coronavirus disease 2019 (COVID-19). Genomic sequencing provides robust information but may not always be accessible, and therefore, mutation-based polymerase chain reaction (PCR) approaches can be used for rapid identification of known variants. International travelers arriving in Karachi between December 2020 and February 2021 were tested for SARS-CoV-2 by PCR. A subset of positive samples was tested for S-gene target failure (SGTF) on TaqPathTM COVID-19 (Thermo Fisher Scientific) and for mutations using the GSD NovaType SARS-CoV-2 (Eurofins Technologies) assays. Sequencing was conducted on the MinION platform (Oxford Nanopore Technologies). Bayesian phylogeographic inference was performed integrating the patients' travel history information. Of the thirty-five COVID-19 cases screened, thirteen had isolates with SGTF. The travelers transmitted infection to sixty-eight contact cases. The B.1.1.7 lineage was confirmed through sequencing and PCR. The phylogenetic analysis of sequence data available for six cases included four B.1.1.7 strains and one B.1.36 and B.1.1.212 lineage isolate. Phylogeographic modeling estimated at least three independent B.1.1.7 introductions into Karachi, Pakistan, originating from the UK. B.1.1.212 and B.1.36 were inferred to be introduced either from the UK or the travelers' layover location. We report the introduction of SARS-CoV-2 B.1.1.7 and other lineages in Pakistan by international travelers arriving via different flight routes. This highlights SARS-CoV-2 transmission through travel, importance of testing, and quarantine post-travel to prevent transmission of new strains, as well as recording detailed patients' metadata. Such results help inform policies on restricting travel from destinations where new highly transmissible variants have emerged.

12.
BMC Microbiol ; 22(1): 62, 2022 02 25.
Article in English | MEDLINE | ID: mdl-35209842

ABSTRACT

BACKGROUND: Mutations in the Rv0678, pepQ and atpE genes of Mycobacterium tuberculosis (MTB) have been reported to be associated with reduced antimycobacterial susceptibility to bedaquiline (BDQ). Resistance conferring mutations in treatment naïve MTB strains is likely to have implications for BDQ based new drug regimen that aim to shorten treatment duration. We therefore investigated the genetic basis of resistance to BDQ in MTB clinical isolates from BDQ naïve TB patients from Pakistan. In addition, mutations in genes associated with efflux pumps were investigated as an alternate mechanism of resistance. METHODS: Based on convenience sampling, we studied 48 MTB clinical isolates from BDQ naïve TB patients. These isolates (from our strain bank) included 38 MDR/pre-XDR/XDR (10 BDQ resistant, 8 BDQ intermediate and 20 BDQ susceptible) and 10 pan drug susceptible MTB isolates. All strains were subjected to whole genome sequencing and genomes were analysed to identify variants in Rv0678, pepQ, atpE, Rv1979c, mmpLS and mmpL5 and drug resistance associated efflux pump genes. RESULTS: Of the BDQ resistant and intermediate strains 44% (8/18) had variants in Rv0678 including; two reported mutations S63R/G, six previously unreported variants; L40F, R50Q and R107C and three frameshift mutations; G25fs, D64fs and D109fs. Variants in efflux pumps; Rv1273c (G462K), Rv0507c (R426H) and Rv1634c (E198R) were found to be present in drug resistant isolates including BDQ resistant and intermediate isolates. E198R in efflux pump gene Rv1634c was the most frequently occurring variant in BDQ resistant and intermediate isolates (n = 10). CONCLUSION: We found RAVs in Rv0678 to be commonly associated with BDQ resistance. Further confirmation of the role of variants in efflux pump genes in resistance is required so that they may be incorporated in genome-based diagnostics for drug resistant MTB.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Antitubercular Agents/pharmacology , Diarylquinolines , Humans , Microbial Sensitivity Tests , Mutation , Mycobacterium tuberculosis/genetics , Pakistan , Tuberculosis, Multidrug-Resistant/microbiology
13.
J Antimicrob Chemother ; 77(4): 1005-1011, 2022 03 31.
Article in English | MEDLINE | ID: mdl-35137072

ABSTRACT

BACKGROUND: Plasmodium falciparum strains that are resistant to standard-dose chloroquine can be treated by higher chloroquine concentrations maintained for a longer time in vivo. OBJECTIVES: To determine the relative importance of chloroquine concentrations versus exposure time for elimination of chloroquine-susceptible and -resistant P. falciparum in vitro. METHODS: Chloroquine-susceptible (3D7) and -resistant (FCR3) strains were exposed in vitro to 1, 2, 4, 8, 16 or 32 times their respective 90% inhibitory chloroquine concentrations for 3, 5, 7 or 14 days and then followed until recrudescence, or not, by 42 days after the end of exposure. RESULTS: Exposure to chloroquine appeared to eliminate susceptible and resistant parasites, leaving small pyknotic apparently dead parasites. Chloroquine-susceptible and -resistant parasites recrudesced after 3 and 5 days of chloroquine exposure. Recrudescence occurred in one out of four 7 day exposure series but not after 14 days exposure. The median time to recrudescence was 13 to 28 days with a range of 8 to 41 days after the end of exposure. Time to recrudescence after the end of exposure increased with duration of exposure for susceptible and resistant strains (P < 0.001). Time to recrudescence did not correlate with concentrations greater than 1× IC90. CONCLUSIONS: Chloroquine-susceptible and -resistant P. falciparum probably become dormant. Elimination of dormant parasites is primarily dependent upon the duration of chloroquine exposure. Exposure to effective drug concentrations for 7 days eliminates most parasites in vitro. The results support in vivo data indicating that elimination of chloroquine-resistant P. falciparum correlates with Day 7 chloroquine concentrations.


Subject(s)
Antimalarials , Malaria, Falciparum , Antimalarials/pharmacology , Antimalarials/therapeutic use , Chloroquine/pharmacology , Chloroquine/therapeutic use , Drug Resistance , Humans , Malaria, Falciparum/drug therapy , Plasmodium falciparum
14.
Sci Rep ; 11(1): 22958, 2021 11 25.
Article in English | MEDLINE | ID: mdl-34824360

ABSTRACT

Understanding key host protective mechanisms against SARS-CoV-2 infection can help improve treatment modalities for COVID-19. We used a blood transcriptome approach to study biomarkers associated with differing severity of COVID-19, comparing severe and mild Symptomatic disease with Asymptomatic COVID-19 and uninfected Controls. There was suppression of antigen presentation but upregulation of inflammatory and viral mRNA translation associated pathways in Symptomatic as compared with Asymptomatic cases. In severe COVID-19, CD177 a neutrophil marker, was upregulated while interferon stimulated genes (ISGs) were downregulated. Asymptomatic COVID-19 cases displayed upregulation of ISGs and humoral response genes with downregulation of ICAM3 and TLR8. Compared across the COVID-19 disease spectrum, we found type I interferon (IFN) responses to be significantly upregulated (IFNAR2, IRF2BP1, IRF4, MAVS, SAMHD1, TRIM1), or downregulated (SOCS3, IRF2BP2, IRF2BPL) in Asymptomatic as compared with mild and severe COVID-19, with the dysregulation of an increasing number of ISGs associated with progressive disease. These data suggest that initial early responses against SARS-CoV-2 may be effectively controlled by ISGs. Therefore, we hypothesize that treatment with type I interferons in the early stage of COVID-19 may limit disease progression by limiting SARS-CoV-2 in the host.


Subject(s)
COVID-19/immunology , Carrier State/immunology , Interferon Type I/immunology , Adult , Aged , Antiviral Agents , COVID-19/genetics , Computational Biology/methods , Female , Gene Expression/genetics , Gene Expression Regulation/genetics , Humans , Interferon Type I/genetics , Interferon Type I/metabolism , Male , Middle Aged , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Severity of Illness Index , Up-Regulation
15.
PLoS One ; 16(8): e0256451, 2021.
Article in English | MEDLINE | ID: mdl-34464419

ABSTRACT

BACKGROUND: We investigated the genome diversity of SARS-CoV-2 associated with the early COVID-19 period to investigate evolution of the virus in Pakistan. MATERIALS AND METHODS: We studied ninety SARS-CoV-2 strains isolated between March and October 2020. Whole genome sequences from our laboratory and available genomes were used to investigate phylogeny, genetic variantion and mutation rates of SARS-CoV-2 strains in Pakistan. Site specific entropy analysis compared mutation rates between strains isolated before and after June 2020. RESULTS: In March, strains belonging to L, S, V and GH clades were observed but by October, only L and GH strains were present. The highest diversity of clades was present in Sindh and Islamabad Capital Territory and the least in Punjab province. Initial introductions of SARS-CoV-2 GH (B.1.255, B.1) and S (A) clades were associated with overseas travelers. Additionally, GH (B.1.255, B.1, B.1.160, B.1.36), L (B, B.6, B.4), V (B.4) and S (A) clades were transmitted locally. SARS-CoV-2 genomes clustered with global strains except for ten which matched Pakistani isolates. RNA substitution rates were estimated at 5.86 x10-4. The most frequent mutations were 5' UTR 241C > T, Spike glycoprotein D614G, RNA dependent RNA polymerase (RdRp) P4715L and Orf3a Q57H. Strains up until June 2020 exhibited an overall higher mean and site-specific entropy as compared with sequences after June. Relative entropy was higher across GH as compared with GR and L clades. More sites were under selection pressure in GH strains but this was not significant for any particular site. CONCLUSIONS: The higher entropy and diversity observed in early pandemic as compared with later strains suggests increasing stability of the genomes in subsequent COVID-19 waves. This would likely lead to the selection of site-specific changes that are advantageous to the virus, as has been currently observed through the pandemic.


Subject(s)
COVID-19/epidemiology , Genome, Viral , SARS-CoV-2/genetics , 5' Untranslated Regions/genetics , COVID-19/virology , Genetic Variation , Humans , Mutation , Nasopharynx/virology , Pakistan/epidemiology , Pandemics , Phylogeny , RNA-Dependent RNA Polymerase/genetics , SARS-CoV-2/classification , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/genetics , Whole Genome Sequencing
16.
Malar J ; 20(1): 176, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33827592

ABSTRACT

BACKGROUND: K13 propeller (k13) polymorphism are useful molecular markers for tracking the emergence and spread of artemisinin resistance in Plasmodium falciparum. Polymorphisms are reported from Cambodia with rapid invasion of the population and almost near fixation in south East Asia. The study describes single nucleotide polymorphisms in Kelch protein propeller domain of P. falciparum associated with artemisinin resistance from Southern Pakistan. METHODS: Two hundred and forty-nine samples were collected from patients with microscopy confirmed P. falciparum malaria attending Aga Khan University Hospital during September 2015-April 2018. DNA was isolated using the whole blood protocol for the QIAmp DNA Blood Kit. The k13 propeller gene (k13) was amplified using nested PCR. Double-strand sequencing of PCR products was performed using Sanger sequencing methodology. Sequences were analysed with MEGA 6 and Bio edit software to identify specific SNP combinations. RESULTS: All isolates analysed for k13 propeller allele were observed as wild-type in samples collected post implementation of ACT in Pakistan. C580Y, A675V, Y493H and R539T variants associated with reduced susceptibility to artemisinin-based combination therapy (ACT) were not found. Low frequency of M476I and C469Y polymorphisms was found, which is significantly associated with artemisinin resistance. CONCLUSION: Low frequencies of both nonsynonymous and synonymous polymorphisms were observed in P. falciparum isolates circulating in Southern Pakistan. The absence of known molecular markers of artemisinin resistance in this region is favourable for anti-malarial efficacy of ACT. Surveillance of anti-malarial drug resistance to detect its emergence and spread need to be strengthened in Pakistan.


Subject(s)
Antimalarials/pharmacology , Artemisinins/pharmacology , Drug Resistance/genetics , Plasmodium falciparum/genetics , Polymorphism, Single Nucleotide , Protozoan Proteins/genetics , Pakistan , Plasmodium falciparum/drug effects , Protozoan Proteins/metabolism
17.
Trop Doct ; 48(1): 52-54, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28792284

ABSTRACT

Plasmodium vivax is the most common specie causing malaria outside Africa with approximately 13.8 million reported cases worldwide. We report case of P. vivax infection with cerebral involvement. A nine year old boy presented with high grade fever accompanied by projectile vomiting and abnormal behavior later he developed seizures, shock, and unconsciousness. P. vivax monoinfection was diagnosed based on peripheral smears and PCR. After antimalarial therapy, patient made full recovery. Current case highlights increasing trend of cerebral complications caused by P. vivax.


Subject(s)
Malaria, Cerebral/diagnosis , Malaria, Vivax/diagnosis , Plasmodium vivax/isolation & purification , Antimalarials/therapeutic use , Child , Fever/drug therapy , Humans , Male , Pakistan , Plasmodium vivax/genetics , Polymerase Chain Reaction , Seizures/etiology , Vomiting/etiology
19.
J Pak Med Assoc ; 67(4): 627-629, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28420929

ABSTRACT

To determine the perception of pathology as a future career choice among medical students of a private medical school from Karachi, Pakistan. A descriptive cross-sectional study was conducted at the Aga Khan University, Karachi, Pakistan. A total of 201 students participated in this study. All Students were approached randomly to participate. A total of 201 students participant survey forms were evaluated in this study. The overall satisfaction level with pathology was observed in 61.8% of the students. Majority of the students understood subspecialties which were a part of clinical medicine. Over half of the students thought pathology as a specialty should be highlighted in a more integrated manner (59.2%) with a minority favouring a separate pathology rotation (11.9%). In conclusion, this study indicates that majority of students have a positive approach towards the field of pathology and favour incorporating it in an integrative way into the medical school curriculum.


Subject(s)
Attitude , Career Choice , Curriculum , Pathology/education , Students, Medical , Cross-Sectional Studies , Female , Humans , Male , Pakistan , Perception , Schools, Medical , Surveys and Questionnaires , Young Adult
20.
J Microbiol Immunol Infect ; 48(2): 213-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-24681005

ABSTRACT

BACKGROUND: Various factors determine the outcome of Plasmodium falciparum infection such as parasite load, sequestration, adhesion molecules, and immune mediators. P. falciparum merozoite surface protein-1 (msp-1) and msp-2 genotypes were also found associated with severe disease. We investigated the association between msp-1 and msp-2 genotypes in patients with uncomplicated malaria (UM) and severe malaria (SM). METHODS: Twenty-two malaria patients with microscopy-confirmed P. falciparum infection and eight healthy endemic controls were selected for analysis. Nested polymerase chain reaction (PCR) was used to identify P. falciparum genotypes. The plasma concentration of cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interferon-gamma (IFN-γ)] and chemokines [chemokine (C-X-C motif) ligand 9 (CXCL9) and CXCL10] were evaluated using enzyme-linked immunosorbent assay (ELISA). RESULTS: TNF-α levels were significantly higher in both UM (389 pg/mL, p = 0.020) and SM (771 pg/mL, p = 0.004) compared with healthy controls, while they were greater in SM (p = 0.012) as compared to UM. CXCL9 levels were significantly raised in SM as compared to UM and negative controls (NCs). CXCL10 levels were raised in UM (550 pg/mL, p = 0.001) and SM (1480 pg/mL, p = 0.01) as compared with NCs. Increased levels of IL-6 were found in patients carrying the FC27 allelic type of msp-2. A higher prevalence of MAD 20 and K1 msp-1 alleles was observed in the SM group compared to UM. CONCLUSION: Overall, a greater prevalence of MAD 20 alleles and increased serum TNF-α and CXCL9 levels were associated with severe outcome in malaria. Understanding the diversity of malaria genotypes is important for predicting disease-related outcomes of P. falciparum infection in endemic areas.


Subject(s)
Malaria, Falciparum/pathology , Malaria, Falciparum/parasitology , Merozoite Surface Protein 1/genetics , Plasmodium falciparum/genetics , Adolescent , Adult , Aged , Antigens, Protozoan/genetics , Child , Cytokines/blood , Enzyme-Linked Immunosorbent Assay , Female , Genotype , Humans , Male , Middle Aged , Pakistan , Plasmodium falciparum/isolation & purification , Polymerase Chain Reaction , Protozoan Proteins/genetics , Young Adult
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