Genetic variation and virulence of Streptococcus pneumoniae

Streptococcus pneumoniae or pneumococcus is included among major human pathogens and is responsible for a number of diseases including life-threatening conditions such as pneumonia, meningitis and sepsis. Though pneumococcal vaccines are available, they provide limited coverage against infections as pneumococcus shows extensive variation, which also allows escape from vaccines and antibiotic resistance. It is armed with several virulence factors including capsule, surface proteins, enzymes and toxins, which are variably expressed and altogether determine pneumococcal virulence. The aim of this project was to study pneumococcal genetic variation and its effect on virulence, with a focus on pneumococcal capsule, which is considered the major determinant of virulence and is involved in interaction with host immune system. It is the target for current vaccines and at least 93 pneumococcal serotypes are known, which differ in pathogenicity. To study the effect of capsule on the pneumococcal virulence, capsule-switch mutants were constructed in three genetic backgrounds; TIGR4 (serotype 4, virulent), 403 (serotype 4, avirulent) and D39 (serotype 2, virulent) and were studied for variation in their in vivo and in vitro characteristics. These mutants were compared with their parent strains and other mutants for effects of capsule switching on their growth, formation of capsular polysaccharide, capsular thickness, chain formation and virulence in murine models of infection using MF1 mice. Significant differences were observed in behaviour of parent and mutant strains. To develop a broader insight into pneumococcal virulence, avirulent derivative of strain TIGR4, 403 was genome sequenced and compared with TIGR4 for genetic mutations. To study differences in gene expression both the strains were also compared using microarrays. Genome analysis revealed only few mutations in strain 403 but microarray experiments showed 288 genes to be expressed differently in strain 403. Strain 403 was also tested as live attenuated vaccine to see if it could provide protection against the same and different serotypes, as it can be used as a vehicle for delivery of different polysaccharides to the host body along with the whole set of pneumococcal antigenome. Vaccine trials of 403 were not very fruitful as it failed to provide any protection through intranasal route though partial protection was observed in mice vaccinated intraperitoneally with significant differences in levels of bacteraemia, survival, weight and temperature losses on challenging with homologous strain

Mutational Frequencies in Mycobacterial rpoB gene using GeneXpert/MTB Rif Assay in Rifampicin Resistant patients at a tertiary care setting in Urban Sindh, Pakistan: Analysis from a Five-Year Period

Objectives: To assess the mutational frequencies in Mycobacterial rpoB gene using GeneXpert/MTB Rif Assay in rifampicin resistant patients during 2013-2017 at a tertiary care setting in Urban Sindh, Pakistan.&#x0D; Methods: This Retrospective Descriptive Cross-Sectional Study was conducted at the TB laboratories, Ojha Institute of Chest Diseases, Dow University of Health Sciences. The record of 713 positive cases of Rifampicin Resistant Tuberculosis from January 2013 to December 2017 were analysed. These were diagnosed using GeneXpert® that detects mutations in the 81 base pair region of rpoB gene with the help of five molecular probes A, B, C, D and E. All invalid and extra pulmonary samples were excluded.&#x0D; Results: In total, 713 cases were found to be rifampicin resistant during the five-year period, among which 374 (52.45%) were males while 339 (47.55%) were females. Among the five standard probes A, B, C, D and E, 97.48% of the cases had a single mutation. Among these, mutations in Probe E (66.48%) were the most common, followed by Probe B (14.3%) and Probe D (11.08%). Only 13 cases (1.82%) of double mutations and five cases (0.7%) of triple mutations were detected.&#x0D; Conclusion: The rpoB gene Probe E region 529-533 appears the most potent site for a mutation and development of rifampicin resistance in the rpoB gene in Mycobacterium tuberculosis, that encodes the β-subunit of RNA polymerase. The most affected age-group in both males and females is 19-45 Years.&#x0D; doi: https://doi.org/10.12669/pjms.37.4.3875&#x0D; How to cite this:Alamgir M, Sajjad M, Baig MS, Noori MY. Mutational Frequencies in Mycobacterial rpoB gene using GeneXpert/MTB Rif Assay in Rifampicin Resistant patients at a tertiary care setting in Urban Sindh, Pakistan: Analysis from a Five-Year Period. Pak J Med Sci. 2021;37(4):1151-1154. doi: https://doi.org/10.12669/pjms.37.4.3875&#x0D; This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</jats:p

An Assessment of the Contact History of Multi-Drug Resistant Tuberculosis Patients from Sindh: A Gender based comparison

The purpose of this project was to evaluate the pattern of transmission in patients suffering from Multidrug resistant (MDR) Tuberculosis by assessing their contact information. Data were obtained and analyzed from 164 individuals suffering from MDR TB. Records were scanned to evaluate the presence ofa close contact with known history of Tuberculosis. Tabulations and analysis were performed in Microsoft Excel® and online calculators. Analysis of contact data showed that only 36% of the patients had a close contact with a known Tuberculosis patient. Chi-square test did not show any association between history ofpresence of a contact and the patients’ gender (p&gt;0.5). Among the cases with established exposure with a TB patient among close contacts, 17.5% females and 12.5% males reported exposure with a contact outside the close family. Majority of patients were unaware of the presence of a known contact in their vicinity. There was no association between knowledge about exposure and patients’ gender. The study shows that efforts of active case finding should be employed to find the hidden cases of Tuberculosis in the society to stop the spread by those patients, who are unaware of their disease.</jats:p

A comparative study of Conventional methods and GeneXpert Mycobacterium tuberculosis Rifampicin (MTB/RIF) assay for diagnosis of childhood pulmonary tuberculosis

Abstract Background Diagnosis of childhood TB (tuberculosis) is challenging because its symptoms resemble other diseases, very few (less than five) mycobacteria are capable of causing the disease and children do not or rarely expectorate. These peculiar attributes make childhood TB different from adult TB but it is still not being dealt differently from adult TB .Despite evidences from national, international data and WHO recommendation for use of Gene expert/TB/RIF assay, decision to start the treatment is based mostly on Chest X ray, tuberculin skin test, history of contact and clinical sign and symptoms .Therefore, we planned this study to find best available choices of diagnostic tests for early case detection of childhood TB particularly MDR TB Methods: This comparative analytical study of 15 months was done at PHRC, SRCCH, NICH and Provincial TB Lab Ojha Institute of chest diseases Karachi. Our study population comprised of 143 probable cases of pulmonary TB below the age of 15 years. After taking written consent from parent/guardian, a Performa was filled with contact no, address, clinical history, scoring chart and diagnostic tests suggested by attending clinician. ZN staining for smear microscopy GeneXpert Mycobacterium tuberculosis Rifampicin (Xpert MTB/RIF) assay, Culture on Lowenstein–Jensen (L.J) media and Mycobacterium Growth Indicator Tube (MGIT) was done for every sample according to standard operating procedures of WHO and results were entered and analyzed on SPSS statistical package for social sciences. Results Out of 143 samples 7 (5%) were positive for MTB via Xpert MTB/RIF assay while 3(2.09) were positive through AFB microscopy, LJ culture and MGIT. When compared with gold standard blood culture sensitivity and negative predictive value of Xpert MTB/RIF were 100% and 97.14% while specificity and positive predictive value were 97.14% and 43% respectively. Conclusion Xpert MTB/RIF is a rapid test that can aid in timely diagnosis of peds TB, facilitating the timely treatment. However, specificity and PPV need to be taken into account. Key words: AFB microscopy, LJ and MGIT, Xpert MTB/RIF, Peds TB.</jats:p

Relationship of neutrophil lymphocyte ratio, monocyte lymphocyte ratio and neutrophil monocyte ratio with treatment response in pulmonary tuberculosis patients during intensive phase treatment

Abstract Objective To determine the relationship of Neutrophil Lymphocyte Ratio (NLR), Monocyte Lymphocyte Ratio (MLR), and Neutrophil Monocyte Ratio (NMR) with treatment response in Pulmonary Tuberculosis (PTB) patients during intensive phase treatment (IPT). Methods This analytical cross-sectional study was conducted at Ojha Institute of Chest Diseases (OICD), Dow University of Health Sciences, from February to December 2021. 100 patients were enrolled using purposive sampling technique. Both male and female of age 18 and above, rifampicin sensitive newly diagnosed cases of PTB by Acid Fast Bacilli (AFB) microscopy and Gene Xpert MTB/RIF were included. SPSS version 26 was used to analyze data. Numerical data was expressed in median and interquartile range and categorical data was expressed in frequencies and percentages. Results Out of total 100 patients, 81% (n = 81) showed treatment response with negative AFB Sputum Smear Microscopy (SSM) after 2nd month. Out of 81% (n = 81) of the patients who achieved treatment response, 83.9% (n = 68) also had decreased NLR, 85.2% (n = 69) had decreased MLR and 83.9% (n = 68) had decreased NMR from baseline. However 19% (n = 19) did not achieved treatment response with positive AFB SSM after 2nd month of ATT (Anti tuberculosis treatment), among them 10.52% (n = 2) were INH resistant with no decrease in all the ratios after 2nd month. Conclusion Leukocyte ratios decreased significantly from baseline as PTB was treated in patients who achieved treatment response with negative AFB SSM after two months of ATT and hence these ratios could be used as markers to monitor the treatment response

Islamic economics: a survey of the literature

A central thesis of this paper is that social science is the study of human experience, and hence is strongly conditioned by history. Modern Western political, economic and social structures have emerged as a consequence of the repudiation of religion associated with the Enlightenment and are based on secular principles. Many of these are inimical to Islamic principles, and cannot be adapted to an Islamic society. Muslim societies achieved freedom from colonial rule in the first half of the twentieth century and have sought to construct institutions in conformity with Islam. The development of Islamic economics is part of this process of transition away from Western colonial institutions. This paper is a survey of the literature on Islamic economics, which focuses on the contrasts between Western economic theories and Islamic approaches to the organization of economic affairs

Global treatment of haemorrhoids—A worldwide snapshot audit conducted by the International Society of University Colon and Rectal Surgeons

Aim: There is no universally accepted treatment consensus for haemorrhoids, and thus, management has been individualized all over the world. This study was conducted to assess a global view of how surgeons manage haemorrhoids. Methods: The research panel of the International Society of University Colon and Rectal Surgeons (ISUCRS) developed a voluntary, anonymous questionnaire evaluating surgeons' experience, volume and treatment approaches to haemorrhoids. The 44 multiple-choice questionnaire was available for one month via the ISUCRS email database and the social media platforms Viber and WhatsApp. Results: The survey was completed by 1005 surgeons from 103 countries; 931 (92.6%) were in active practice, 819 (81.5%) were between 30 and 60 years of age, and 822 (81.8%) were male. Detailed patient history (92.9%), perineal inspection (91.2%), and digital rectal examination (91.1%) were the most common assessment methods. For internal haemorrhoids, 924 (91.9%) of participants graded them I–IV, with the degree of haemorrhoids being the most important factor considered to determine the treatment approach (76.3%). The most common nonprocedural/conservative treatment consisted of increased daily fibre intake (86.9%), increased water intake (82.7%), and normalization of bowel habits/toilet training (74.4%). Conservative treatment was the first-line treatment for symptomatic first (92.5%), second (72.4%) and third (47.3%) degree haemorrhoids; however, surgery was the first-line treatment for symptomatic fourth degree haemorrhoids (77.6%). Rubber band ligation was the second-line treatment in first (50.7%) and second (47.2%) degree haemorrhoids, whereas surgery was the second-line treatment in third (82.9%) and fourth (16.7%) degree symptomatic haemorrhoids. Rubber band ligation was performed in the office by 645(64.2%) of the participants. The most common surgical procedure performed for haemorrhoids was an excisional haemorrhoidectomy for both internal (87.1%) and external (89.7%) haemorrhoids – with 716 (71.2%) of participants removing 1, 2 or 3 sectors as necessary. Conclusion: Although there is no global haemorrhoidal treatment consensus, there are many practice similarities among the different cultures, resources, volume and experience of surgeons around the world. With additional studies, a consensus statement could potentially be developed