Transient CD4+ T cell depletion during suppressive ART reduces the HIV reservoir in humanized mice.

Lifelong treatment is required for people living with HIV as current antiretroviral therapy (ART) does not eradicate HIV infection. Latently infected cells are essentially indistinguishable from uninfected cells and cannot be depleted by currently available approaches. This study evaluated antibody mediated transient CD4+ T cell depletion as a strategy to reduce the latent HIV reservoir. Anti-CD4 antibodies effectively depleted CD4+ T cells in the peripheral blood and tissues of humanized mice. We then demonstrate that antibody-mediated CD4+ T cell depletion of HIV infected ART-suppressed animals results in substantial reductions in cell-associated viral RNA and DNA levels in peripheral blood cells over the course of anti-CD4 antibody treatment. Recovery of CD4+ T cells was observed in all tissues analyzed except for the lung 26 days after cessation of antibody treatment. After CD4+ T cell recovery, significantly lower levels of cell-associated viral RNA and DNA were detected in the tissues of anti-CD4 antibody-treated animals. Further, an 8.5-fold reduction in the levels of intact HIV proviral DNA and a 3.1-fold reduction in the number of latently infected cells were observed in anti-CD4-antibody-treated animals compared with controls. However, there was no delay in viral rebound when ART was discontinued in anti-CD4 antibody-treated animals following CD4+ T cell recovery compared with controls. Our results suggest that transient CD4+ T cell depletion, a long-standing clinical intervention that might have an acceptable safety profile, during suppressive ART can reduce the size of the HIV reservoir in humanized mice.

APOBEC3G and APOBEC3F Act in Concert To Extinguish HIV-1 Replication.

UNLABELLED: The multifunctional HIV-1 accessory protein Vif counters the antiviral activities of APOBEC3G (A3G) and APOBEC3F (A3F), and some Vifs counter stable alleles of APOBEC3H (A3H). Studies in humanized mice have shown that HIV-1 lacking Vif expression is not viable. Here, we look at the relative contributions of the three APOBEC3s to viral extinction. Inoculation of bone marrow/liver/thymus (BLT) mice with CCR5-tropic HIV-1JRCSF(JRCSF) expressing a vif gene inactive for A3G but not A3F degradation activity (JRCSFvifH42/43D) displayed either no or delayed replication. JRCSF expressing a vif gene mutated to inactivate A3F degradation but not A3G degradation (JRCSFvifW79S) always replicated to high viral loads with variable delays. JRCSF with vif mutated to lack both A3G and A3F degradation activities (JRCSFvifH42/43DW79S) failed to replicate, mimicking JRCSF without Vif expression (JRCSFΔvif). JRCSF and JRCSFvifH42/43D, but not JRCSFvifW79S or JRCSFvifH42/43DW79S, degraded APOBEC3D. With one exception, JRCSFs expressing mutant Vifs that replicated acquired enforced vif mutations. These mutations partially restored A3G or A3F degradation activity and fully replaced JRCSFvifH42/43D or JRCSFvifW79S by 10 weeks. Surprisingly, induced mutations temporally lagged behind high levels of virus in blood. In the exceptional case, JRCSFvifH42/43D replicated after a prolonged delay with no mutations in vif but instead a V27I mutation in the RNase H coding sequence. JRCSFvifH42/43D infections exhibited massive GG/AG mutations in pol viral DNA, but in viral RNA, there were no fixed mutations in the Gag or reverse transcriptase coding sequence. A3H did not contribute to viral extinction but, in combination with A3F, could delay JRCSF replication. A3H was also found to hypermutate viral DNA. IMPORTANCE: Vif degradation of A3G and A3F enhances viral fitness, as virus with even a partially restored capacity for degradation outgrows JRCSFvifH42/43D and JRCSFvifW79S. Unexpectedly, fixation of mutations that replaced H42/43D or W79S in viral RNA lagged behind the appearance of high viral loads. In one exceptional JRCSFvifH42/43D infection, vif was unchanged but replication proceeded after a long delay. These results suggest that Vif binds and inhibits the non-cytosine deaminase activities of intact A3G and intact A3F, allowing JRCSFvifH42/43D and JRCSFvifW79S to replicate with reduced fitness. Subsequently, enhanced Vif function is acquired by enforced mutations. In infected cells, JRCSFΔvif and JRCSFvifH42/43DW79S are exposed to active A3F and A3G and fail to replicate. JRCSFvifH42/43D Vif degrades A3F and, in some cases, overcomes A3G mutagenic activity to replicate. Vif may have evolved to inhibit A3F and A3G by stoichiometric binding and subsequently acquired the ability to target these proteins to proteasomes.

Evaluating the Effectiveness of Geriatric-Specific Cancer Rehabilitation Programs on Patient Health Outcomes.

OBJECTIVE: This study evaluated a specialized rehabilitation program's impact on senior cancer patients' quality of life. METHODS: one hundred and thirty patients aged ≥65 years with various cancer types undergoing/recovering from treatment were enrolled in oncology clinics in Al-Ahsa, Saudi Arabia. The intervention arm (n=65) participated in a tailored geriatric cancer rehabilitation program. The control group (n=65) received standard oncology care. The Functional Assessment of Cancer Therapy-General (FACT-G) tool assessed the quality of life across physical, social, emotional, and functional domains. T-tests and multivariate regression analyses compared outcomes. RESULT: Total FACT-G scores showed a significantly higher quality of life for the geriatric cancer rehabilitation group versus standard care. Rehabilitation patients also demonstrated meaningful improvements across physical, social, and functional subscales. Rehabilitation involvement was the most predictive factor for optimized outcomes. CONCLUSION: Specialized geriatric cancer rehabilitation meaningfully improved several quality of life domains in older patients over standard care. Despite persistent barriers, rehabilitation programming optimized older cancer patients' physical and psychosocial health. Oncology and geriatrics must collaborate to ensure evidence-based rehabilitation access meets older cohorts' unique needs.

Loss of In Vivo Replication Fitness of HIV-1 Variants Resistant to the Tat Inhibitor, dCA.

HIV resistance to the Tat inhibitor didehydro-cortistatin A (dCA) in vitro correlates with higher levels of Tat-independent viral transcription and a seeming inability to enter latency, which rendered resistant isolates more susceptible to CTL-mediated immune clearance. Here, we investigated the ability of dCA-resistant viruses to replicate in vivo using a humanized mouse model of HIV infection. Animals were infected with WT or two dCA-resistant HIV-1 isolates in the absence of dCA and followed for 5 weeks. dCA-resistant viruses exhibited lower replication rates compared to WT. Viral replication was suppressed early after infection, with viral emergence at later time points. Multiplex analysis of cytokine and chemokines from plasma samples early after infection revealed no differences in expression levels between groups, suggesting that dCA-resistance viruses did not elicit potent innate immune responses capable of blocking the establishment of infection. Viral single genome sequencing results from plasma samples collected at euthanasia revealed that at least half of the total number of mutations in the LTR region of the HIV genome considered essential for dCA evasion reverted to WT. These results suggest that dCA-resistant viruses identified in vitro suffer a fitness cost in vivo, with mutations in LTR and Nef pressured to revert to wild type.

Diversity and prevalence of gastrointestinal parasites of Black Bengal goats in Natore, Bangladesh.

Objectives: The objective of this work was to estimate the diversity of gastrointestinal (GI) parasite species, their prevalence, and risk factors in Black Bengal goats (BBGs) of Natore, Bangladesh. Materials and Methods: Fecal samples from randomly selected 260 BBGs were processed through Stoll's ova counting method, floatation, and simple sedimentation method. Microscopy-based identification of parasitic eggs, cysts, or oocysts was made. A semi-structured questionnaire-based data on host and management practices were collected from the owner. Data analysis was done using Statistical Package for Social Sciences. Results: The overall prevalence of GI parasites in BBGs was 65.4%, with an individual prevalence of 8.5% for Fasciola gigantica, 21.5% for Paramphistomum spp., 20% for Haemonchus spp., 34.2% for Strongyloides spp., 8.5% for Trichuris spp., and 9.2% for Eimeria spp. No significant effect of host age, gender, body condition, animal rearing system, or housing floor type was observed on parasitism. Animals of young age, female, poorly body-conditioned, living in a free-range system, and housed on a muddy floor had a relatively higher susceptibility to infection. Deworming had a significant impact on reducing the frequency of caprine GI parasitism. Conclusions: Despite the significant effect of anthelmintic, the elevated prevalence of GI parasites in BBGs suggests a critical need for developing effective strategies to prevent caprine parasitoses.

Prevalence of hookworm infections among stray dogs and molecular identification of hookworm species for the first time in Bangladesh.

Hookworms are the most common and voracious blood-sucking parasites of the small intestines of mammalian hosts such as dogs, cats, ruminants and humans. Canine hookworms are endemic in the Southeast Asian countries including Bangladesh. There is scarcity of information on the prevalence of hookworms of stray dogs in Bangladesh. The present study determined the prevalence of canine hookworms using fecal examination followed by morphometric and molecular identification. Fecal samples were collected from 320 stray dogs living in rural areas of Mymensingh district (Gauripur upazila, Mymensingh sadar upazila and Tarakanda upazila) and hookworm eggs were identified using the flotation techniques. The overall prevalence of hookworm was 79.1% through microscopic examination. Estimated fecal prevalence was higher in Gauripur upazila (89.7%) followed by Mymensingh sadar upazila (84.8%) and Tarakanda upazila (53.2%). Five hookworm species were identified based on the morphometric examination, namely, Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma tubaeforme, Ancylostoma braziliense and Ancylostoma duodenale, respectively. Polymerase Chain Reaction (PCR) was performed with the genomic DNA by targeting the 5.8S rRNA (~ 404 bp) and Cytochrome oxidase-1 (Cox 1, ~ 450 bp) and confirmed the identification for the first time in Bangladesh. This study reveals that stray dogs may act as reservoir hosts of human hookworm infection. Further detail molecular study is warranted to explore the genetic diversity of hookworms that infect both dogs and human in Bangladesh.

A large-scale epidemiological investigation on trematode infections in small ruminants in Bangladesh.

BACKGROUND: The important trematode species in small ruminants: Paramphistomum sp., Fasciola spp. and Schistosoma spp. seriously affect the productivity of domestic ruminants in endemic areas. METHODS: In the present study, we identified the potential risk factors associated with trematodes infections in small ruminants in seven topographic zones of Bangladesh using simple sedimentation and modified Stoll' ova counting technique. RESULTS: A total of 2440 samples were examined, where 965 were found positive with one or more trematode species with an overall prevalence of 39.5% (95% CI, 37.6%-41.5%) and intensity of infection was 264.77 ± 9.86 egg per gram of faeces. Three trematode species were identified namely Paramphistomum sp. (34.1%, 32.2%-36.0%), Fasciola spp. (7.5%, 6.5%-8.6%) and Schistosoma spp. (2.7%, 2.1%-3.5%). Prevalence of co-infection was 4.8%. The spatial distribution of trematode infections varied from 29.5% to 53.6%. Univariate analysis revealed that physiological condition of females, body condition, farming system, deworming and season were significantly (p < 0.05) associated with trematodes infections in small ruminants. By multiple logistic regression model, three factors such as physiological condition of females (pregnant and lactating), poor body condition and animals without deworming were identified as potential risk factors for trematodes infection in small ruminants. CONCLUSION: Trematode infections are prevalent in the study areas and Paramphistomum sp. is most common in different areas among the identified trematodes species. Government should take necessary action to appraise an effective control strategy of trematode infections in small ruminants.

Efficacy of clinically used anthelmintics against toxocariasis of buffalo calves in Bangladesh.

Toxocariasis is a paramount parasitic disease having > 50% prevalence among newborn buffalo calves in Bangladesh. The objective of this study was to compare the efficacy of clinically used anthelmintics and their subsequent effect on the haematological parameters and body weight in buffalo calves in commercial buffalo farms in coastal region. Thirty-two buffalo calves below 3 months of age with clinical Toxocara infection had been selected and treated with albendazole (ABZ), levamisole (LVM) and ivermectin (IVM). The EPG counts, hematological parameters and initial body weight of buffalo calves were recorded on the day of anthelmintic treatment (day 0). Fecal samples were collected on day 14 and 28 including hematological parameters and body weight were recorded on day 28 post-treatment. The efficacy (%) of anthelmintics were estimated by fecal egg count reduction test (FECRT). The parameters like Hb, PCV, ESR, TEC, TLC were analyzed from the blood samples. The FECRT revealed 96.83% efficacy for IVM followed by 94.23% and 85.84% for LVM and ABZ, respectively. Anthelmintic treated calves showed significant (p < 0.01) increase in Hb, PCV, TEC and body weight, and decrease in ESR and TLC as a result of worm expulsion from buffalo calves after 28 days of post-treatment. Among the tested anthelmintics, IVM was found to be more effective against toxocariasis in buffalo calves. This is a novel information on anthelmintics efficacy in buffalo calves in Bangladesh. Details study is recommended on the efficacy of anthelmintics in different buffalo management systems by in vitro egg hatch assay (EHA) test.

Ubc9 mediates nuclear localization and growth suppression of BRCA1 and BRCA1a proteins.

BRCA1 gene mutations are responsible for hereditary breast and ovarian cancers. In sporadic breast tumors, BRCA1 dysfunction or aberrant subcellular localization is thought to be common. BRCA1 is a nuclear-cytoplasm shuttling protein and the reason for cytoplasmic localization of BRCA1 in young breast cancer patients is not yet known. We have previously reported BRCA1 proteins unlike K109R and cancer-predisposing mutant C61G to bind Ubc9 and modulate ER-α turnover. In the present study, we have examined the consequences of altered Ubc9 binding and knockdown on the subcellular localization and growth inhibitory function of BRCA1 proteins. Our results using live imaging of YFP, GFP, RFP-tagged BRCA1, BRCA1a and BRCA1b proteins show enhanced cytoplasmic localization of K109 R and C61G mutant BRCA1 proteins in normal and cancer cells. Furthermore, down-regulation of Ubc9 in MCF-7 cells using Ubc9 siRNA resulted in enhanced cytoplasmic localization of BRCA1 protein and exclusive cytoplasmic retention of BRCA1a and BRCA1b proteins. These mutant BRCA1 proteins were transforming and impaired in their capacity to inhibit growth of MCF-7 and CAL51 breast cancer cells. Interestingly, cytoplasmic BRCA1a mutants showed more clonogenicity in soft agar and higher levels of expression of Ubc9 than parental MCF7 cells. This is the first report demonstrating the physiological link between cytoplasmic mislocalization of mutant BRCA1 proteins, loss of ER-α repression, loss of ubiquitin ligase activity and loss of growth suppression of BRCA1 proteins. Thus, binding of BRCA1 proteins to nuclear chaperone Ubc9 provides a novel mechanism for nuclear import and control of tumor growth.

Prevalence and factors influencing gastrointestinal parasitic infections in sheep in Bangladesh.

Gastrointestinal (GI) parasites are major contributors to decrease productivity in livestock over the world. A cross-sectional study was conducted in different areas of Bangladesh to determine the prevalence of GI parasitic infections and their association with the biotic and abiotic factors in sheep. A total of 572 faecal samples were collected from the selected areas of Bangladesh and microscopic examination was performed for the identification of parasites using flotation and sedimentation technique. Out of 572, 441 animals were found infected with one or more species of GI parasites with an overall prevalence of 77.1%. Nine types of parasites from four different classes were detected namely Strongyles (42.1%), Strongyloides sp. (27.1%) and Trichuris sp. (1.0%), Moniezia sp. (2.4%), Paramphistomum cervi (32.5%), Fasciola gigantica (6.1%) and Schistosoma sp. (3.5%), coccidia (16.6%) and Balantidium coli (7.9%). Nematodes infections (56.8%) were significantly highest among trematodes (37.9%), protozoa (24.4%) and cestode (2.4%). In the present study, all the biotic factors including sex, age, physiological condition of female and body condition score (BCS) of animals were insignificantly (p>0.05) associated with the prevalence of GI parasitic infection in sheep but among the abiotic factors, muddy housing of animals, rainy season, having no knowledge about GI parasites and illiteracy of farmers were significantly (p<0.05) associated with the GI parasitic infections. This epidemiological investigation will assist to build a suitable control program against GI parasites in sheep and thus, help to prevent production loss and increase livelihood of small holder farmers.

Prevalence and risk factors of Toxocara vitulorum infection in buffalo calves in coastal, northeastern and northwestern regions of Bangladesh.

Buffalo (Bubalus bubalis) is popularly known as the black gold of South Asia, consisting of 97% of the world buffalo population. Among the parasitic infections, Toxocara vitulorum is one of the most common and harmful parasites of buffalo calves in Bangladesh. A cross-sectional study was conducted to explore the prevalence and associated risk factors of T. vitulorum infection of buffalo calves in four regions of Bangladesh. A total of 1751 fecal samples were collected and examined using flotation followed by the McMaster technique for counting the eggs per gram of feces (EPG) of T. vitulorum. The overall prevalence of T. vitulorum infection in buffalo calves was 22.9%. Significantly (p < 0.001) higher prevalence was found in the Barishal coastal area (35.7%) followed by Chattogram coastal area (29.2%), northeastern region (15.5%) and northwestern region (8.3%). Buffalo calves aged 1-3 months were heavily infected with T. vitulorum (51.7%) which was statistically different (p < 0.001) compared to those >3-6 months (27.6%) and > 6-12 months (6.5%). According to univariate analysis, coastal regions, rainy season, young age, gender, indigenous river type, buffalo calves with poor body condition and soft feces were found significantly associated with T. vitulorum infections. Coastal regions, rainy season and young age were identified as the risk factors of T. vitulorum infection in buffalo calves by final logistic regression model. This study reveals that T. vitulorum infection is endemic in Bangladesh and widely distributed in the coastal regions. Therefore, attention to buffalo calves regarding in-depth clinical effects and current therapeutic approaches against this nematode should be evaluated along with the economic impact of infection. Exploring the genetic diversity of T. vitulorum may help to reveal the host-parasite relationship in the future.

Multiple anthelmintic resistance in gastrointestinal nematodes of small ruminants in Bangladesh.

Anthelmintic resistance (AR) against gastrointestinal nematodes (GINs) of sheep and goats is a global concern. To address the problem, this study assessed the status of AR in different government and private sheep and goat farms in Bangladesh. We conducted fecal egg count reduction test (FECRT) and Egg hatch assay (EHA) experiments. For the detection of resistant larvae, pooled fecal samples from treated and non-treated groups were subjected to coproculture. Furthermore, 195 adult Haemonchus parasites were genotyped to ascertain benzimidazole (BZ) resistance allele from seven topographic zones of Bangladesh using allele specific PCR (AS-PCR). In FECRT, the percentage reduction along with 95% confidence intervals indicated that GINs were resistant to albendazole (ABZ), levamisole (LEV) and ivermectin (IVM). Coproculture revealed that Haemonchus spp., Oesophagostomum spp. and Trichostrongylus spp. were resistant to anthelmintics. ABZ resistance was also confirmed by in vitro EHA in all the farms except the private goat farm in Mymensingh. The genotype frequencies were 6% for homozygous resistant (rr), 59% for heterozygous (rS) and 35% for homozygous susceptible (SS) among different topographic zones. The allelic frequency of the mutation conferring resistance (r) ranged from 25% to 47% signifying resistance to BZ in nematodes of sheep/goats. The genotype frequencies (rr, rS and SS) and allelic frequencies (r and S) varied significantly (p˂0.05) in different zones in Bangladesh. Overall, the data suggest an alarming condition created by multiple AR in Bangladesh.

Natural nodular worm infection in goats induces eosinophil extracellular DNA trap (EET) formation.

Extracellular DNA Trap (ET) formation by granulocyte is a strong innate immune machinery that plays crucial roles in trapping and killing of pathogens. Here, we show Eosinophil Extracellular DNA Trap (EET) formation in goats naturally infected with nodular worms (Oesophagostomum columbianum, Strongyloidae: Nematoda). By a slaughterhouse based survey, we found that 60% goats were infected with nodular worms. We detected numerous, hard and pale yellow to dark black nodules of variable sizes (0.25-2 cm) in the large intestine and the number of nodules were significantly (p < .05) higher in the cecum (21.7 ± 17.9) than in the colon (10.1 ± 9.9). Histologically, pink colored circumscribed caseous mass was surrounded by a dense zone of infiltration and fibrous proliferation along with massive infiltration of eosinophils in and around the necrotic mass. DAPI staining revealed huge accumulation of extracellular DNA, which formed wide ridge like structure surrounding the necrotic zone. Massive release of eosinophils cationic proteins (ECP), a helmintho-toxic substance, was found into the lesions. Collectively, our results suggest that nodular worm infection induces EETosis and ECP release, and is one of the major parasitic problem affecting Black Bengal goats that causes distortion of normal architecture of the gut wall.

Gastro-intestinal nematodes in goats in Bangladesh: A large-scale epidemiological study on the prevalence and risk factors.

Goats greatly influence the economic sustainability of rural communities. However, parasitic diseases, especially gastrointestinal nematodes (GINs) are a major constraint on profitable small ruminants' production worldwide. During July- 2015 to June- 2016, we conducted a cross sectional study within seven topographic zones of Bangladesh to explore the level of infection and associated risk factors of GINs infections of goats. The study followed standard flotation and modified McMaster techniques. Among 1998 samples from goats; 1241 (62.1%) were found to be infected with one or more species of GINs by fecal examination for nematode eggs. The identified nematodes were strongyles (51.9%), Strongyloides sp. (19.0%) and Trichuris spp. (2.9%). By coproculture, we identified Haemonchus spp., Oesophagostomum spp., Trichostrongylus spp. and Bunostomum spp. in the different topographic zones. According to univariate analysis; young age, other breed than Black Bengal, animals in poor condition, backyard rearing system, muddy housing, illiterate farmers and rainy season were found significantly associated with GINs infections. Besides, other breed than Black Bengal, animals in poor condition, backyard rearing system, muddy housing and illiterate farmers were identified as the risk factors of GINs infections in goats. This is the first detailed epidemiological investigation of GINs of goats in Bangladesh. The epidemiological findings are expected to help formulate effective control strategies against GINs infections in goats by improving health status of animals, management system and education level of the farmers.

Mitochondrial localization, ELK-1 transcriptional regulation and growth inhibitory functions of BRCA1, BRCA1a, and BRCA1b proteins.

BRCA1 is a tumor suppressor gene that is mutated in families with breast and ovarian cancer. Several BRCA1 splice variants are found in different tissues, but their subcellular localization and functions are poorly understood at the moment. We previously described BRCA1 splice variant BRCA1a to induce apoptosis and function as a tumor suppressor of triple negative breast, ovarian and prostate cancers. In this study we have analyzed the function of BRCA1 isoforms (BRCA1a and BRCA1b) and compared them to the wild-type BRCA1 protein using several criteria like studying expression in normal and tumor cells by RNase protection assays, subcellular localization/fractionation by immunofluorescence microscopy and Western blot analysis, transcription regulation of biological relevant proteins and growth suppression in breast cancer cells. We are demonstrating for the first time that ectopically expressed GFP-tagged BRCA1, BRCA1a, and BRCA1b proteins are localized to the mitochondria, repress ELK-1 transcriptional activity and possess antiproliferative activity on breast cancer cells. These results suggest that the exon 9, 10, and 11 sequences (aa 263-1365) which contain two nuclear localization signals, p53, Rb, c-Myc, gamma-tubulin, Stat, Rad51, Rad50 binding domains, angiopoietin-1 repression domain are not absolutely required for mitochondrial localization and growth suppressor function of these proteins. Since mitochondrial dysfunction is a hallmark of cancer, we can speculate that the mitochondrial localization of BRCA1 proteins may be functionally significant in regulating both the mitochondrial DNA damage as well as apoptotic activity of BRCA1 proteins and mislocalization causes cancer. J. Cell. Physiol. 219: 634-641, 2009. (c) 2009 Wiley-Liss, Inc.

Genetic diversity patterns of Haemonchus contortus isolated from sheep and goats in Bangladesh.

Haemonchus contortus is the most prevalent parasitic nematode among the Trichostrongylids causing severe health hazards leading to production losses in small ruminants around the world. This study was conducted to explore genetic variation within and among H. contortus populations from seven topographic zones of Bangladesh in small ruminants using second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA and the mitochondrial nicotinamide dehydrogenase subunit 4 (nad4) genes. To do this, a total of 95 adult H. contortus were collected from abomasa of slaughtered sheep and goats from seven different geographic zones of Bangladesh. After the extraction of DNA, ITS-2 of nuclear ribosomal DNA and partial region of the mitochondrial nad4 genes were amplified and sequenced for 95 and 85 worms, respectively. After editing and alignment, sequences were employed for analysis to determine sequence variation, genetic diversity and population genetic structure. Genetic analysis defined 19 distinct ITS-2 genotypes and 77 unique nad4 haplotypes among the H. contortus isolates. The nucleotide diversities were 0.0098 and 0.025 for ITS-2 and nad4 gene, respectively. Phylogenetic analysis (neighbor joining, maximum likelihood and maximum parsimony) of haplotypes indicated the existence of two populations without marked specification of host and locations within H. contortus populations in Bangladesh. By population genetic analysis, 93.67% of genetic variance was partitioned within the population. Very low genetic differentiation but high gene flow was observed among different populations of H. contortus in Bangladesh. This is the first study on genetic variability of H. contortus isolates of small ruminants in Bangladesh. Our study could be the basis for further molecular epidemiological studies, using more discriminative markers and tracing possible changes in the population structure of H. contortus.

Emergence of carbapenemase-producing urinary isolates at a tertiary care hospital in Dhaka, Bangladesh.

OBJECTIVES: A growing incidence of pathogens producing carbapenemases has been observed in many countries including Bangladesh. The present study was carried out to determine the presence of carbapenemase producers among uropathogens. MATERIALS AND METHODS: A total of 138 Gram-negative uropathogens were isolated and identified by conventional methods and were screened for carbapenemase production using imipenem discs. Phenotypic identification of carbapenemase production was done by the double disc synergy test, combined disc assay, and modified Hodge test. The minimum inhibitory concentration of imipenem was determined by the agar dilution method. Genes encoding blaNDM-1, blaIMP, blaVIM, blaKPC and blaOXA-48/blaOXA-181 were identified by polymerase chain reaction. RESULTS: Twenty (14.49%) imipenem resistant strains were detected among 138 Gram-negative uro-pathogens. The most common isolates were Escherichia coli and Klebsiella spp. Among 20 imipenem resistant strains, 16 (80%) carbapenemase producers were detected by polymerase chain reaction, 13 (65%) by double disc synergy, 15 (75%) by combined disc assay, and seven (35%) by modified Hodge test. The blaNDM-1 gene was most prevalent (55%), followed by blaOXA-48/OXA-181, blaKPC (20%), blaVIM (15%), and blaIMP (10%). More than one carbapenemase gene was present in nine (45%) of the isolates. The minimum inhibitory concentration of imipenem of the carbapenemase producers ranged from ≥128 µg/mL to 4 µg/mL. Overall, carbapenemase encoding genes were detected in 11.6% (16/138) of the studied Gram-negative uropathogens. All (100%) of the carbapenemase-producing organisms were resistant to all tested antibiotics apart from colistin. CONCLUSION: The study shows a significant rate of urinary isolates were carbapenemase producers, including a high prevalence of blaNDM-1, in Bangladesh.

Detection of extended spectrum ß-lactamase in Pseudomonas spp. isolated from two tertiary care hospitals in Bangladesh.

BACKGROUND: Extended spectrum ß-lactamases (ESBLs) represent a major group of lactamases responsible for resistance, mostly produced by gram-negative bacteria, to newer generations of ß-lactam drugs currently being identified in large numbers worldwide. The present study was undertaken to see the frequency of ESBL producing Pseudomonas spp. isolated from six hundred clinical specimens (wound, pus, aural, urine, sputum, throat and other swabs) collected over a period of three years from two tertiary care hospitals in Bangladesh. FINDINGS: Aerobic bacterial culture was performed on aseptically collected swabs and only growth of Pseudomonas was considered for further species identification and ESBL production along with serotyping of Pseudomonas aeruginosa. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer agar diffusion method and ESBL production was detected on Mueller Hinton agar by double-disk synergy technique using Amoxicillin-Clavulanic acid with Ceftazidime, Cefotaxime, Ceftriaxone and Aztreonam. Culture yielded 120 Pseudomonas spp. and 82 of them were biochemically characterized for species. Pseudomonas aeruginosa was found to be the predominant (90.2%) species. Of 82 isolates tested for ESBL, 31 (37.8%) were ESBL positive with 29 (93.5%) as Pseudomonas aeruginosa, the remaining 2 (6.5%) were Stenotrophomonas maltophilia and Ralstonia pickettii. Antibiogram revealed Imipenem as the most effective drug (93.3%) among all antimicrobials used against Pseudomonas spp. followed by Aminoglycosides (63.7%). CONCLUSION: ESBL producing Pseudomonas spp. was found to be a frequent isolate from two tertiary care hospitals in Bangladesh, showing limited susceptibility to antimicrobials and decreased susceptibility to Imipenem in particular, which is a matter of great concern.

New approach for generation of neutralizing antibody against human T-cell leukaemia virus type-I (HTLV-I) using phage clones.

We have screened a phage peptide library to address whether clones binding to a monoclonal antibody (mAb) could be isolated and if the selected phage particles would be able to elicit an in vivo immune response against the original antigen. A phage peptide library, consisting of seven random amino acids inserted in the minor coat protein (pIII), was screened for specific binding to a rat mAb LAT-27, which is capable of neutralizing human T-cell leukaemia virus type-I (HTLV-I) by binding to its envelope gp46 epitope, (amino acids LPHSNL). Total 37 clones were selected from the library and one clone named 4-2-22 was tested for its immunogenicity in three rabbits. The all rabbit immune sera showed strong binding activity to a gp46 peptide carrying the neutralization sequence, stained gp46-expressing cells and neutralized HTLV-I in vitro as determined by cell fusion inhibition assay. These results show that the selected phage clone was capable of mimicking the epitope recognized by a HTLV-I neutralizing mAb, and it can be used as an immunogen to induce protective immune response against HTLV-I. Thus, the present methodology could be one of the approaches to develop vaccines against infectious agents in a simple and inexpensive way.