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1.
BMC Microbiol ; 24(1): 74, 2024 Mar 07.
Article in English | MEDLINE | ID: mdl-38454332

ABSTRACT

OBJECTIVE: Multi-drug resistance (MDR) has notably increased in community acquired uropathogens causing urinary tract infections (UTIs), predominantly Escherichia coli. Uropathogenic E. coli causes 80% of uncomplicated community acquired UTIs, particularly in pre-menopausal women. Considering this high prevalence and the potential to spread antimicrobial resistant genes, the current study was conducted to investigate the presence of clinically important strains of E. coli in Pakistani women having uncomplicated cystitis and pyelonephritis. Women belonging to low-income groups were exclusively included in the study. Seventy-four isolates from urine samples were processed, phylotyped, and screened for the presence of two Single Nucleotide Polymorphisms (SNPs) particularly associated with a clinically important clonal group A of E. coli (CgA) followed by antibiotic susceptibility testing and genome sequence analysis. RESULTS: Phylogroup B2 was most prevalent in patients and 44% of isolates were positive for the presence of CgA specific SNPs in Fumarate hydratase and DNA gyrase subunit B genes. Antibiotic susceptibility testing showed widespread resistance to trimethoprim-sulfamethoxazole and extended-spectrum beta-lactamase production. The infection analysis revealed the phylogroup B2 to be more pathogenic as compared to the other groups. The genome sequence of E. coli strain U17 revealed genes encoding virulence, multidrug resistance, and host colonization mechanisms. CONCLUSIONS: Our research findings not only validate the significant occurrence of multidrug-resistant clonal group A E. coli (CgA) in premenopausal Pakistani women suffering from cystitis and pyelonephritis but also reveal the presence of genes associated withvirulence, and drug efflux pumps. The detection of highly pathogenic, antimicrobial-resistant phylogroup B2 and CgA E. coli strains is likely to help in understanding the epidemiology of the pathogen and may ultimately help to reduce the impact of these strains on human health. Furthermore, the findings of this study will particularly help to reduce the prevalence of uncomplicated UTIs and the cost associated with their treatment in women belonging to low-income groups.


Subject(s)
Cystitis , Escherichia coli Infections , Pyelonephritis , Urinary Tract Infections , Uropathogenic Escherichia coli , Humans , Female , Escherichia coli , Escherichia coli Infections/diagnosis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Pakistan/epidemiology , Urinary Tract Infections/diagnosis , Drug Resistance, Multiple , Cystitis/drug therapy
2.
Curr Microbiol ; 80(11): 349, 2023 Sep 21.
Article in English | MEDLINE | ID: mdl-37733140

ABSTRACT

Pseudomonas aeruginosa infection in seriously ill patients is a major concern due to its ability to form biofilm and secrete effector toxins. There is little information on the prevalence of T3SS effector toxins and biofilm production in clinical isolates of P. aeruginosa from Nigeria. The goal of this study is to evaluate the prevalence of T3SS toxins and biofilm production among isolates from selected tertiary hospitals in Nigeria. This study examined 430 clinical isolates from our previous work, comprising 181 MDR (multidrug-resistant) and 249 non-MDR isolates. Biofilm production and type III secretion toxins were determined using colorimetric microtiter plate assay and polymerase chain reaction, respectively. Carbapenem-resistant isolates were typed using REP-PCR and BOX-PCR. Biofilm production was detected in 386/430 (89.8%) of the isolates. Out of 386 biofilm producers, 167 (43.3%) were multidrug-resistant isolates. PCR identified four T3SS virulence types among 430 isolates, including 78 (18.1%) exoU+/exoS- isolates, 343 (79.8%) exoU-/exoS + isolates, 5 (1.2%) exoU+/exoS + isolates, and 4 (0.9%) exoU-/exoS- isolates. Both REP- and BOX-PCR consist of eight clusters. On the REP-PCR dendrogram, ExoU+/ExoS- isolates majorly occupied cluster IV. Clusters IV, VII, and VIII consist of isolates from wounds on BOX-PCR dendrogram. There was a positive association between strong biofilm production and multidrug resistance in our P. aeruginosa isolates. This study identified multidrug-resistant, biofilm-producing P. aeruginosa strains that secrete cytotoxic effectors which are significant virulence factors in P. aeruginosa. This poses a severe risk to our healthcare system and highlights the importance of continuous surveillance to prevent infectious disease outbreaks.


Subject(s)
Pseudomonas aeruginosa , Type III Secretion Systems , Humans , Nigeria , Prevalence , Type III Secretion Systems/genetics , Pseudomonas aeruginosa/genetics , Biofilms
3.
Curr Microbiol ; 79(3): 83, 2022 Feb 05.
Article in English | MEDLINE | ID: mdl-35122538

ABSTRACT

Infections during pregnancy can culminate in adverse pregnancy outcomes, including preterm birth (PTB). Pakistan is among the top ten nations with high PTB-associated neonatal mortality rates, where access to prenatal as well as neonatal care is only afforded by the privileged few. Societal stigma further discourages women seeking healthcare for minor infections. Microbial pathogens associated with genitourinary infections can lead to gestational complications culminating in earlier onset of labor. In this study, association of Escherichia coli (E. coli) with PTB in Pakistani women of low-socioeconomic status is examined. 57 paired vaginal swabs and placenta samples from mothers with full term and preterm deliveries were collected and processed for isolation and molecular characterization of extraintestinal pathogenic E. coli (ExPEC). ExPEC isolated from vaginal swabs and placenta showed phylotype B2 being most prevalent (Vagina n = 3 (9), 33%) (Placenta n = 4 (12), 33%) in preterm cases followed by phylotype B1 (Vagina n = 2 (9), 22%) (Placenta n = 3 (12), 25%) and untypeable strains. Antibiotic susceptibility profiling showed a large percentage of resistant isolates to multiple antibiotics, including carbapenem and included extended-spectrum beta-lactamase (ESBL) producers. Our study is the first to report different phylotypes of E. coli from placental tissues in preterm deliveries which may be a cause for concern for maternal and neonatal health. ExPEC from vaginal swabs and placental of females delivering preterm shows the pathogenic phylotype B2 dominance with a large percentage of isolates resistant to multiple antibiotics, including carbapenem and included ESBL producers. The placental isolates may indicate ascending infection from vagina or urinary tract which may lead to preterm birth.


Subject(s)
Escherichia coli Infections , Premature Birth , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Female , Humans , Infant, Newborn , Pakistan/epidemiology , Placenta , Pregnancy , Pregnant Women , Socioeconomic Factors , beta-Lactamases/genetics
4.
Curr Microbiol ; 79(7): 195, 2022 May 20.
Article in English | MEDLINE | ID: mdl-35593885

ABSTRACT

Helicobacter pullorum is a human zoonotic pathogen transmitted through poultry where it is associated with vibrionic hepatitis and colitis. Hemolysin co-regulated protein (Hcp) is an important structural as well as effector protein of type six secretory system; however, its role in H. pullorum invasion and pathogenesis has not been elucidated. In this study, we predicted the Helicobacter pullorum Hcp (HpuHcp) structure and identified Campylobacter jejuni Hcp (CjHcp) as its nearest homologue. Analysis of the predicted structure shows several common bacterial Hcp motifs like Protein kinase C phosphorylation site, Casein kinase II phosphorylation site, N-myristoylation site, cAMP-and cCGMP-dependent protein kinase phosphorylation site, N-glycosylation site. The presence of unique microbodies C-terminal targeting signal domain was present in HpuHcp which was seen for the first time in CjHcp. This could indicate that Hcp is a structural protein as well as a secretory protein. Moreover, the presence of a deamidase domain, similar to the tecA of Burkholderia cenocepacia an opportunistic pathogen, may help in bacterial internalization as it depolymerises the membranous actin by deamidation of the host cell Rho GTPases cdc42 and Rac1, which was supported by increased invasion of hepatocytes by Hcp-positive isolates.


Subject(s)
Burkholderia cenocepacia , Campylobacter jejuni , Helicobacter , Bacterial Proteins/metabolism , Burkholderia cenocepacia/metabolism , Helicobacter/metabolism , Hemolysin Proteins/metabolism
5.
J Pak Med Assoc ; 72(12): 2381-2385, 2022 Dec.
Article in English | MEDLINE | ID: mdl-37246652

ABSTRACT

OBJECTIVE: To investigate the existence of genetically diverse vibrio cholerae variant strains in a rural Sindh district, and to find out the phylogenetic relationship of indigenous vibrio cholerae strains. METHODS: The cross-sectional study was conducted from April 2014 to May 2016 in Khairpur, Pakistan, and comprised stool samples/rectal swabs collected from the main and city branches of the Khairpur Medical College Teaching Hospital, and the Pir Abdul Qadir Shah Jeelani Institute of Medical Sciences, Gambat. The samples were identified using standard microbiological, biochemical, serological techniques and polymerase chain reaction targeting the ompW gene. Whole genome sequencing and bioinformatics tool MUMmer 3.2.3 was used to compare indigenous and contemporary vibrio cholerae strains circulating in the province of Sindh. Neighbour-joining tree method was used to construct the phylogenic tree. RESULTS: Of the 360 samples, 76(21.11%) were found positive for vibrio cholera strains. The species-specific ompW gene was amplified at the correct size of 588bp. The isolates belonged to serogroup Inaba, O1, biotype El Tor. Unique sequences with same genomic coordinates showed that test strains were not similar to the reference sequence. Conserved genome sequences showed that 12 Out of 16 (75%) of the test strains were similar to each Other except the 3 strains isolated from Khairpur and 1 from Karachi. Multiple sequence alignment of the regions translated into protein showed that 13 out of 16 (81.25%) test strains were similar except 2 strains from Khairpur and 1 From Karachi. The phylogenetic tree showed that all isolated strains descended from the same ancestor along with the reference strain. CONCLUSIONS: Vibrio cholerae O1 El Tor variant existed in Khairpur.


Subject(s)
Cholera , Vibrio cholerae O1 , Humans , Vibrio cholerae O1/genetics , Cholera/epidemiology , Cholera/microbiology , Phylogeny , Cross-Sectional Studies , Pakistan/epidemiology , Disease Outbreaks
6.
Apoptosis ; 26(1-2): 7-8, 2021 02.
Article in English | MEDLINE | ID: mdl-33512610

ABSTRACT

Some viruses are known to be associated with increased apoptosis. Apoptotic cell death triggered by these viruses has a complex role in host antiviral immunity, and might facilitate the viral clearance or act as a mechanism for virus-induced tissue injury and disease progression. The induction of apoptosis is a hallmark of SARS-CoV-2 infection. Accumulating evidence suggests that there is a direct relationship between apoptosis rate and COVID-19 pathogenicity/severity. Targeting virus-induced apoptosis could be a promising strategy in the treatment of SARS-CoV-2 virus infection.


Subject(s)
Antiviral Agents/therapeutic use , Apoptosis , COVID-19 Drug Treatment , COVID-19/pathology , SARS-CoV-2/pathogenicity , Drug Delivery Systems , Humans
7.
Arch Microbiol ; 203(7): 3793-3802, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34120200

ABSTRACT

It has been long understood that the vaginal microflora is crucial in maintaining a normal physiological environment for the host and its involvement is deemed indispensable for reproductive success. A global concept of normalcy vs. dysbiosis of vaginal microbiome is debatable as women of different races have a unique vaginal microflora with regional variations. Vaginal microflora is a dynamic microenvironment affected by gestational status, menstrual cycle, sexual activity, age, and contraceptive use. Normal vaginal flora is dominated by lactobacilli especially in women of European descent vs. African American women. These microbes confer the host vagina protection from potentially pathogenic microbes that may lead to urinary tract infections and sexually transmitted diseases. Changes in the vaginal microbiota including reduced lactobacilli abundance and increased facultative and anaerobic organism populations result in bacterial vaginosis, that predisposes the host to several conditions like low birth weight and increased risk of contracting bacterial infections. On the other hand, the vaginal microbiome is also reshaped during pregnancy, with less microbial diversity with a dominance of Lactobacillus species. However, an altered vaginal microbiota with low lactobacilli abundance especially during pregnancy may result in induction of excessive inflammation and pre-term labor. Since the vaginal microbiome plays an important role during embryo implantation, it is not surprising that bacterial vaginosis is more common in infertile women and associated with reduced rates of conception. Probiotic has great success in treating bacterial vaginosis and restoring the normal microbiome in recent. This report, reviewed the relationships between the vaginal microbiome and women's reproductive health.


Subject(s)
Dysbiosis , Microbiota , Vagina , Dysbiosis/microbiology , Female , Humans , Pregnancy , Vagina/microbiology , Vaginosis, Bacterial
8.
Int Microbiol ; 24(1): 123-124, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32875426

ABSTRACT

Until now, there is no current vaccine or treatment against SARS-CoV-2. There are previous successful RNAi studies performed on SARS-CoV. Therefore, similar line of investigation against SARS-CoV-2 could be successful.


Subject(s)
COVID-19/therapy , COVID-19/virology , RNA Interference , SARS-CoV-2/genetics , Animals , Gene Expression Regulation, Viral , Genome, Viral , Humans , SARS-CoV-2/physiology , Viral Proteins/genetics , Viral Proteins/metabolism
9.
Curr Microbiol ; 79(1): 27, 2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34905085

ABSTRACT

Pseudomonas aeruginosa, resistant to multiple antibacterial agents including carbapenems, is of great global public health concern. There is limited data available regarding incidence of Metallo-Beta Lactamase producing P. aeruginosa, their molecular basis of resistance in particular carbapenem resistance and any genetic relatedness among circulating clinical isolates in Southwest Nigeria. Four hundred and thirty P. aeruginosa isolates were collected from seven tertiary care hospitals (predominantly from wound, ear, and urinary tract infections) and verified by PCR targeting oprI and oprL. Antibiotic susceptibility using 16 selected antibiotics and MBL screening was performed. The integrons (class 1, 2 and 3) and carbapenemase genes- blaGES, blaNMC-A, blaBIC-1, blaSME, blaIMP, blaVIM, blaSPM, blaNDM, blaAIM, blaDIM, blaSIM, blaGIM, blaOXA-48, blaOXA-58 were detected by PCR and were sequenced. Quantitative real-time polymerase chain reaction was used to quantify expression levels of eight efflux pump genes, ampC cephalosporinase and outer membrane porin, oprD. The isolates were genotyped using Enterobacterial Repetitive Intergenic Consensus sequence Polymerase Chain Reaction (ERIC-PCR). Four hundred and thirty P. aeruginosa isolates were subjected to antibiotic susceptibility testing, revealing that 109 (25.4%) isolates were multidrug-resistant, 47 (10.9%) were extensively drug-resistant and 25 (5.8%) were pandrug-resistant. MBL was seen in 17.0% (73/430) isolates. MBL-encoding genes; blaVIM-5 and blaNDM-1 were detected in 86.3% (63/73) isolates, with blaVIM-5 and blaNDM-1 in 35.6% (26/73) and 38.4% (28/73), respectively, whereas co-occurrence of blaVIM-5 and blaNDM-1 was found in 12.3% (9/73). Forty-one (56.2%) carbapenem-resistant P. aeruginosa strains carried class 1 integrons, while co-occurrence of class 1 and 2 integrons was seen in 12.3%. qPCR results indicated that MexXY-OprM was highly expressed pump in 58.9%, ampC upregulated in 26.0%, while oprD porin was downregulated in 65.8% isolates. ERIC-PCR results suggest that carbapenem-resistant strains exhibit genetic heterogeneity. The high incidence of MBL-encoding genes and integrons in diversified clinical P. aeruginosa from southwestern Nigeria is of great concern. The co-occurrence of blaVIM-5 and blaNDM-1 as well as resistance in general manifesting a gradient based on genotypic variation suggests that there is a strong need for efficient surveillance programs and antibiotic stewardship.


Subject(s)
Pseudomonas Infections , Pseudomonas aeruginosa , Bacterial Proteins , Humans , Incidence , Microbial Sensitivity Tests , Nigeria , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/genetics , Tertiary Healthcare , beta-Lactamases/genetics
10.
J Pak Med Assoc ; 71(1(A)): 47-50, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33484517

ABSTRACT

OBJECTIVE: To isolate and characterise multidrug resistant strains of Staphylococcus aureus from healthcare workers who are at potential risk of nosocomial infections. METHODS: The observational, cross-sectional study was conducted from November 2014 to April 2015 at different hospitals of Haripur and Abbottabad, Pakistan, and comprised ward and operation theatre staff. The isolates were identified on the basis of microbiological and biochemical tests and further confirmed by polymerase chain reaction. Disc diffusion method was used for antibiotic sensitivity testing, and panton valentine leukocidin and methicillin resistance mecA genes were detected using polymerase chain reaction. RESULTS: Of 208 isolates, 108(52%) were from the ward staff and 100(48%) were from the operation theatre staff. Overall, 167(80.3%) isolates were positive for Staphylococcus aureus, and 75(36%) were methicillin-resistant Staphylococcus aureus. The number of antibiotic-resistant isolates was 75(45%) cefoxitin, 60(36%) ofloxacin, 152(91%) erythromycin, 52(31%) doxycycline, 127(76%) lincomycin, 53(32%) amoxicillin-clavulanate, 67(40%) ciprofloxacin, and 89(53%) ceftriaxone. CONCLUSIONS: A high number of hospital staff, including those working in operation theatres, were found to be carrying methicillin-resistant Staphylococcus aureus and multidrug resistant strains in their nasal passage that may be a source of infection to patients.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Anti-Bacterial Agents/pharmacology , Bacterial Proteins , Cross-Sectional Studies , Humans , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Pakistan/epidemiology , Personnel, Hospital , Staphylococcal Infections/drug therapy , Staphylococcal Infections/epidemiology
11.
Microb Pathog ; 135: 103645, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31356927

ABSTRACT

Vibrio cholerae O1 infections mainly are responsible for significant mortality and morbidity amongst children, however, non-O1/non-O139 V. cholerae have also been reported to cause mild to severe infections because of their virulence potential. The pathogenic mechanisms of non-O1, non-O139 isolates are not as clearly understood as for that of O1 and O139 isolates. Type three secretion system (TTSS) is also considered one of the important virulent factors and during the current study, we investigated the role of TTSS in association with non-O1/non-O139 clinical isolates. We report that the presence of TTSS in non-O1/non-O139 V. cholerae clinical isolate (D13) from a child confers more virulence compared to the one lacking it (D15) in another clinical case during the small cholera epidemic. Moreover, the antibiotic susceptibility profiles of D13 and D15 indicate that they are multiple drug resistance (MDR) isolates. The sequence analysis for TTSS cluster was carried out for D13 and compared with the TTSS positive reference Vibrio parahaemolyticus RIMD2210633 and V. cholerae AM19226 non-O1/non-O139. Furthermore, the pathogenic potential of D13 & D15 was also explored in simple and economical invertebrate host model, Galleria mellonella and the results revealed that TTSS+ve isolate (D13) was more virulent compared to TTSS-ve isolate (D15). We suggest that this distinct genetic difference, seen in natural variants D13 and D15, is also reflected by the clinical picture of the former in contributing towards the severity of disease symptoms and this finding was further validated by assessing virulence potential of both isolates using inexpensive G. mellonella infection model.


Subject(s)
Type III Secretion Systems/metabolism , Vibrio cholerae non-O1/metabolism , Virulence Factors , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Child , Cholera , Disease Models, Animal , Drug Resistance, Bacterial , Genotype , Humans , Moths , Multigene Family , Type III Secretion Systems/genetics , Vibrio cholerae O1 , Vibrio cholerae non-O1/drug effects , Vibrio cholerae non-O1/genetics , Vibrio cholerae non-O1/isolation & purification , Virulence , Virulence Factors/genetics , Whole Genome Sequencing
12.
BMC Infect Dis ; 19(1): 978, 2019 Nov 21.
Article in English | MEDLINE | ID: mdl-31752744

ABSTRACT

BACKGROUND: Acute diarrhea is a leading cause of morbidity and mortality in children particularly in developing countries of Asia and Africa. The present study was conducted to detect the two most important pathogens, rotavirus and Campylobacter Jejuni in children suffering with diarrhea in Rawalpindi and Islamabad, Pakistan in 2014. The clinical and epidemiological aspects of the disease were also investigated. METHODS: A total of 500 stool samples were collected from children presented with clinical signs and symptoms of acute diarrhea. The samples were initially screened for the presence of rotavirus A (RVA) via ELISA (Enzyme-linked immunosorbent assay) and RT-PCR (Reverse Transcriptase PCR) and then were analysed for C. jejuni by using species specific PCR assay. RESULTS: The detection rate of RVA was 26.4% (132/500) while, Campylobacter was detected in 52% (260/500) of samples with C. jejuni accounted for 48.2% (241/500) of all study cases. Co-infection of C. jejuni with RVA was identified in 21.8% of all cases. Children with RVA and C. jejuni co-infection showed a higher probability (p = 0.01) to be dehydrated. A significant association (p = 0.02) was found between C. jejuni positive status and fever in children. The median age of children with both RVA and C. jejuni infection was 6-11 months. The RVA detection rate was high in winter months of the year while, C. jejuni infections were documented high in summer over 1 year study period. CONCLUSIONS: The overall results have demonstrated the high prevalence of C. jejuni in Rawalpindi, Islamabad, Pakistan in 2014. The results of present study will not only help to calculate disease burden caused by C. jejuni and rotavirus but also will provide critical information to health authorities in planning public health care strategies against these pathogens.


Subject(s)
Campylobacter Infections/microbiology , Campylobacter jejuni/isolation & purification , Diarrhea/microbiology , Diarrhea/virology , Rotavirus Infections/virology , Rotavirus/isolation & purification , Campylobacter Infections/epidemiology , Campylobacter jejuni/classification , Campylobacter jejuni/genetics , Child, Preschool , Cities , Coinfection/epidemiology , Coinfection/microbiology , Coinfection/virology , Diarrhea/epidemiology , Feces/microbiology , Feces/virology , Female , Humans , Infant , Male , Pakistan/epidemiology , Prevalence , Rotavirus/classification , Rotavirus/genetics , Rotavirus Infections/epidemiology
13.
Avian Pathol ; 48(6): 557-563, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31294635

ABSTRACT

Helicobacter pullorum is an emerging zoonotic pathogen that causes gastroenteritis in chickens and inflammatory bowel disease in humans ingesting contaminated meat. However, the mechanism by which the bacterium causes disease is unclear. Type six secretion system (T6SS) plays a major role in bacterial pathogenesis and adaptation. Haemolysin coregulated protein (Hcp) plays a central role in the structure of the T6SS pilus and acts as effector protein in certain bacteria. In this study, H. pullorum isolated from 156 caecal samples of broiler chickens was screened for the presence of T6SS Hcp gene via PCR amplification. 30.7% of caecal and 18.3% of liver samples tested positive for presence of H. pullorum. From these positive samples, 29.7% possessed the T6SS gene. In bacterial co-culture experiments, significant loss of viability (81.6-39.1%) was observed for H. pullorum-infected hepatocytes and presence of Hcp did not contribute to the loss of cell viability. Nevertheless, infection of erythrocytes with Hcp-positive isolates was associated with greater haemolytic activity compared to infection with Hcp-negative isolates. Therefore, presence of T6SS could be indicative of virulent strains meriting further studies to characterize this virulence factor in H. pullorum infection.


Subject(s)
Chickens/microbiology , Helicobacter Infections/veterinary , Helicobacter/pathogenicity , Inflammatory Bowel Diseases/microbiology , Poultry Diseases/microbiology , Type VI Secretion Systems/genetics , Animals , Bacterial Proteins/genetics , Cecum/microbiology , Helicobacter/genetics , Helicobacter Infections/microbiology , Humans , Virulence , Virulence Factors/genetics , Zoonoses
14.
World J Microbiol Biotechnol ; 36(1): 9, 2019 Dec 19.
Article in English | MEDLINE | ID: mdl-31858269

ABSTRACT

Campylobacter jejuni is the one of the leading cause of bacterial food borne gastroenteritis. PglB, a glycosyltransferase, plays a crucial role of mediating glycosylation of numerous periplasmic proteins. It catalyzes N-glycosylation at the sequon D/E-X1-N-X2-S/T in its substrate proteins. Here we report that the PglB itself is a glycoprotein which self-glycosylates at N534 site in its DYNQS sequon by its own catalytic WWDYG motif. Site-directed mutagenesis, lectin Immunoblot, and mobility shift assays confirmed that the DYNQS is an N-glycosylation motif. PglB's N-glycosylation motif is structurally and functionally similar to its widely studied glycosylation substrate, the OMPH1. Its DYNQS motif forms a solvent-exposed crest. This motif is close to a cluster of polar and hydrophilic residues, which form a loop flanked by two α helices. This arrangement extremely apposite for auto-glycosylation at N534. This self-glycosylation ability of PglB could mediate C. jejuni's ability to colonize the intestinal epithelium. Further this capability may also bear significance for the development of novel conjugated vaccines and diagnostic tests.


Subject(s)
Campylobacter jejuni/enzymology , Glycoproteins/chemistry , Hexosyltransferases/chemistry , Membrane Proteins/chemistry , Amino Acid Sequence , Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins/genetics , Glycosylation , Hexosyltransferases/genetics , Hexosyltransferases/immunology , Membrane Proteins/genetics , Membrane Proteins/immunology , Models, Molecular , Mutagenesis, Site-Directed , Phylogeny , Protein Conformation , Sequence Alignment , Sequence Analysis, Protein , Vaccines
15.
Medicina (Kaunas) ; 55(5)2019 May 23.
Article in English | MEDLINE | ID: mdl-31126058

ABSTRACT

Background and Objective: Vibrio cholerae continues to emerge as a dangerous pathogen because of increasing resistance to a number of antibiotics. This paper provides a solution to emerging antibiotic resistance by introducing novel proteins as vaccine candidates against cholera. Materials and Methods: Vibrio cholerae genome versatility is a hurdle for developing a vaccine to combat diarrhoeal infection, so its core gene information was used to determine a potential vaccine candidate. Whole genome sequence data of more than 100 Vibrio cholerae strains were used simultaneously to get core genome information. The VacSol pipeline based on reverse vaccinology was selected to address the problem of safe, cheap, temperature-stable, and effective vaccine candidates which can be used for vaccine development against Vibrio cholerae. VacSol screens vaccine candidates using integrated, well-known, and robust algorithms/tools for proteome analysis. The proteomes of the pathogens were initially screened to predict homology using BLASTp. Proteomes that are non-homologous to humans are then subjected to a predictor for localization. Helicer predicts transmembrane helices for the protein. Proteins failing to comply with the set parameters were filtered at each step, and finally, 11 proteins were filtered as vaccine candidates. Results: This selected group of vaccine candidates consists of proteins from almost all structural parts of Vibrio cholerae. Their blast results show that this filtered group includes flagellin A protein, a protein from the Zn transporter system, a lipocarrier outer membrane protein, a peptidoglycan-associated protein, a DNA-binding protein, a chemotaxis protein, a tRNA Pseuriudine synthase A, and two selected proteins, which were beta lactamases. The last two uncharacterized proteins possess 100% similarity to V. albensis and Enterobacter, respectively. Tertiary structure and active site determination show a large number of pockets on each protein. Conclusions: The most interesting finding of this study is that 10 proteins out of 11 filtered proteins are introduced as novel potential vaccine candidates. These novel vaccine candidates can result in the development of cost-effective and broad-spectrum vaccines which can be used in countries where cholera is a major contributor to diarrheal disease.


Subject(s)
Vaccinology/methods , Vibrio cholerae/isolation & purification , Cholera/drug therapy , Cholera/prevention & control , Humans , Pakistan , Vaccinology/trends , Vibrio cholerae/genetics
16.
Crit Rev Microbiol ; 44(4): 504-521, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29513060

ABSTRACT

Emerging infectious diseases remain among the leading causes of global mortality. Traditional laboratory diagnostic approaches designed to detect and track infectious disease agents provide a framework for surveillance of bio threats. However, surveillance and outbreak investigations using such time-consuming approaches for early detection of pathogens remain the major pitfall. Hence, reasonable real-time surveillance systems to anticipate threats to public health and environment are critical for identifying specific aetiologies and preventing the global spread of infectious disease. The current review discusses the growing need for monitoring and surveillance of pathogens with the same zeal and approach as adopted by microbial forensics laboratories, and further strengthening it by integrating with the innovative nanotechnology for rapid detection of microbial pathogens. Such innovative diagnostics platforms will help to track pathogens from high risk areas and environment by pre-emptive approach that will minimize damages. The various scenarios with the examples are discussed where the high risk associated human pathogens in particular were successfully detected using various nanotechnology approaches with potential future prospects in the field of microbial forensics.


Subject(s)
Communicable Diseases, Emerging/diagnosis , Forensic Medicine/methods , Nanotechnology/methods , Animals , Communicable Diseases, Emerging/epidemiology , Disease Outbreaks , Forensic Medicine/instrumentation , Forensic Medicine/trends , Humans , Nanotechnology/instrumentation , Nanotechnology/trends
17.
Rev Med Virol ; 27(1)2017 01.
Article in English | MEDLINE | ID: mdl-27597296

ABSTRACT

Dengue fever is regarded as one of the most prominent emerging arboviral infections in Pakistan since its first epidemic almost 2 decades ago. Interplay between potential vectors, susceptible host, and lax environmental conditions may promote the infection, leading to an epidemic. These factors may indeed have played a major role in the spread of the disease in the country, which was limited to Karachi till 2006. With recent natural disasters such as the earthquake in 2005 and flooding in 2010, 2011 and 2012, numbers of vector-borne diseases and outbreaks including dengue fever are on the rise in Pakistan. Therefore, it is a major concern for health sector workers and of utmost importance to have some understanding of the factors affecting disease outbreak for better risk assessment in the region. In the following report we review the climatic as well as host- and vector-associated factors involved in the outbreak of dengue epidemics in Pakistan and highlight high-risk zones in the country.


Subject(s)
Dengue/epidemiology , Disease Outbreaks , Mosquito Vectors/growth & development , Humans , Pakistan/epidemiology , Seasons , Temperature
18.
Genet Mol Biol ; 41(3): 570-577, 2018.
Article in English | MEDLINE | ID: mdl-30044465

ABSTRACT

Paraoxonase 1 (PON1) is a serum enzyme associated with high density lipoprotein (HDL) regulation through its paraoxonase and arylesterase activity. PON1 inhibits the oxidation of HDL and low density lipoprotein (LDL), and is involved in the pathogenesis of a variety of diseases including atherosclerosis. Conversely, mutations in the low density lipoprotein receptor (LDLR) result in failure of receptor mediated endocytosis of LDL leading to its elevated plasma levels and onset of familial hypercholesterolemia (FH). In the current study we investigated the role of PON1 polymorphisms rs662; c.575A > G (p.Gln192Arg) and rs854560; c.163T > A (p.Leu55Met) in a large family having FH patients harboring a functional mutation in LDLR. Genotypes were revealed by RFLP, followed by confirmation through Sanger sequencing. PON1 activity was measure by spectrophotometry. Our results show significantly reduced serum paraoxonase and arylesterase activities in FH patients compared with the healthy individuals of the family (p < 0.05). PON1 QQ192 genotype showed a significantly higher association with FH (p=0.0002). PON1 Q192 isoform was associated with reduced serum paraoxonase activity by in silico analysis and PON1 R192 exhibited higher serum paraoxonase and arylesterase activity than the other polymorphs. Our results highlight that the combination of LDLR mutations and PON1 MMQQ genotypes may lead to severe cardiac events.

19.
J Pak Med Assoc ; 68(4): 642-645, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29808058

ABSTRACT

Multidrug resistance (MDR) in gram-negative pathogens is the emerging threat to clinicians. The current study was designed to determine the prevalence and pattern of multidrug resistance in gram-negative clinical isolates. It was conducted at the COMSATS Institute of Information Technology, Islamabad, Pakistan, from June to October 2014. Of the 8, 300 samples collected, 729(8.8%) clinically important gram-negative pathogens were retrieved. These pathogens were subjected to phenotypic and biochemical detection and were further processed for multidrug resistance pattern. It was observed that gram-negative pathogens were simultaneously resistant to many antibiotics. The prevalence of extended spectrum b-lactamase phenomenon was 220(100%) in Klebsiella pneumoniae, 195(75%) in Escherichia coli. Resistance to carbapenem was 174(79%) in Klebsiella pneumoniae and 14(5.4%) in Escherichia coli. Resistance against fluoroquinolones also displayed an escalating trend. The current study found that resistance against antibiotics was displaying a drastic increase in chronic renal patients.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/isolation & purification , Renal Insufficiency, Chronic/microbiology , Carbapenems/pharmacology , Cross-Sectional Studies , Escherichia coli/drug effects , Fluoroquinolones/pharmacology , Humans , Kidney Transplantation , Klebsiella pneumoniae/drug effects , Renal Insufficiency, Chronic/surgery , beta-Lactam Resistance
20.
J Pak Med Assoc ; 67(5): 688-697, 2017 May.
Article in English | MEDLINE | ID: mdl-28507352

ABSTRACT

OBJECTIVE: To determine Candida colonisation/infection in renal transplant patients and to determine the resistance pattern against antifungal drugs. METHODS: This prospective, observational study was conducted at Al-Sayyed Hospital, Rawalpindi, Pakistan, from January to October 2014, in collaboration with the Microbiology and Public Health Laboratory's, Islamabad campus..The clinical specimens investigated included respiratory tract secretions, blood, urine, high vaginal swab, skin scrapings, and plastic devices samples. RESULTS: Of the 7,850 samples, 164(2.08%) were positive for Candida. Candida albicans were most prevalent as they were found in 114(69%) samples. Besides, 56(34%) of the positive samples were resistant to one or more antifungal agents. Highest resistance was obtained against fluconazole. We found only 5(3.04%) positive samples of Candida glabrata; of them, 3(60%)were resistant. In case of Candida spp, 27(48%) resistance was observed. In Candida albicans, 23(41%) of the samples were found to be resistant. Most of the Candida isolates was recovered from bronchial alveolar lavage. CONCLUSIONS: Although Candida albicans remained the main responsible species for Candida infections, but non-albican Candida species are also emerging.


Subject(s)
Antifungal Agents/pharmacology , Candidiasis/epidemiology , Drug Resistance, Fungal , Kidney Failure, Chronic/surgery , Kidney Transplantation , Amphotericin B/pharmacology , Candida albicans/drug effects , Candida albicans/isolation & purification , Candida glabrata/drug effects , Candidiasis/microbiology , Cross-Sectional Studies , Fluconazole/pharmacology , Humans , Ketoconazole/pharmacology , Microbial Sensitivity Tests , Pakistan/epidemiology , Prevalence , Prospective Studies , Tertiary Care Centers , Voriconazole/pharmacology
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