Low-level Infection Research Articles

The study of chaotic dynamics of an eco-epidemiological predator-prey model with alternative food

Parasites can alter the quality and quantity of participants. On the other hand, the spread of diseases between individuals or species is an important research topic. Here we consider a tritrophic food model in which bacteria spread among the animal's environment where other nutrients are present. We analyze the local stability of the model around the efficiency of the equation. We also report significant numbers of offspring in terms of ecology and disease and use these numbers to analyze community structure of the sample. We started from this situation as a model. Our numerical results show that at low infection level the body causes conflict, but at high infection level conflict prioritizes safety. Our findings therefore challenge previous models’ predictions that the parasite has a negative impact. We also looked at the impact of other foods on chaotic dynamics. When other nutrients increase, stress does not change, but when other nutrients decrease, chaos disappears and the disease among animals is eliminated from the body.

Intestinal parasitic infections and their potential risk factors among prison inmates in Valencia, Spain

BackgroundDespite the fact that prison inmates are a population at higher risk than other groups of suffering from intestinal parasite infections in relation to their living conditions, information about these diseases in prison environments is still scarce. Herein, we analyze the status of intestinal parasite infections in a Spanish prison.MethodsA cross-sectional study involving 528 inmates was conducted from April to June 2022 among inmates at Centro Penitenciario Picassent (Valencia, Spain). Stool specimens were examined using the direct wet mount technique, the formol-ether concentration technique, and the Ziehl-Neelsen staining method. We used STATA 16.1 for data analysis. We consider a p-value less than 0.05 significant at a 95% confidence level.ResultsOf the 528 inmates (471 men and 57 women; a mean age of 41.94 years) enrolled in the study, 83 (15.7%) were infected. Only six species of protozoa were detected. The gut potential microeukaryotic pathobiont Blastocystis sp. was the predominant parasite, accounting for 37 (44.6%) of the infections. Gut parasite amebas (6.6%) and pathobionts (5.3%) were more prevalent than flagellates (2.3%). The prevalence of infection with pathogenic species (8.9%) was similar to that of non-pathogenic species (8.7%). Infection among men (15.2%) was higher than in women (0.6%) (p < 0.0001). In multivariate analysis, the country of birth (AOR = 0.31, 95% CI = 0.18–0.52) and the time spent in prison (AOR = 1.83, 95% CI = 1.06–3.14) were statistically significant associated to intestinal parasite infections (p < 0.0001 and p = 0.028, respectively).ConclusionThis study found low levels of intestinal parasite infections in the CPP which could be indicative of the implementation of sanitary measures in prison environments in Spain. The less time spent in prison favor the risk of having infection while the Spanish nationality of inmates could reduce the risk of infection. The main recommendation would be to introduce routine parasitological tests upon foreigners entering prison.

Mycobacterium tuberculosis β-lactamase variant reduces sensitivity to ampicillin/avibactam in a zebrafish-Mycobacterium marinum model of tuberculosis

The β-lactamase of Mycobacterium tuberculosis, BlaC, hydrolyzes β-lactam antibiotics, hindering the use of these antibiotics for the treatment of tuberculosis. Inhibitors, such as avibactam, can reversibly inhibit the enzyme, allowing for the development of combination therapies using both antibiotic and inhibitor. However, laboratory evolution studies using Escherichia coli resulted in the discovery of single amino acid variants of BlaC that reduce the sensitivity for inhibitors or show higher catalytic efficiency against antibiotics. Here, we tested these BlaC variants under more physiological conditions using the M. marinum infection model of zebrafish, which recapitulates hallmark features of tuberculosis, including the intracellular persistence of mycobacteria in macrophages and the induction of granuloma formation. To this end, the M. tuberculosis blaC gene was integrated into the chromosome of a blaC frameshift mutant of M. marinum. Subsequently, the resulting strains were used to infect zebrafish embryos in order to test the combinatorial effect of ampicillin and avibactam. The results show that embryos infected with an M. marinum strain producing BlaC show lower infection levels after treatment than untreated embryos. Additionally, BlaC K234R showed higher infection levels after treatment than those infected with bacteria producing the wild-type enzyme, demonstrating that the zebrafish host is less sensitive to the combinatorial therapy of β-lactam antibiotic and inhibitor. These findings are of interest for future development of combination therapies to treat tuberculosis.

The Use of CBD and Its Synthetic Analog HU308 in HIV-1-Infected Myeloid Cells.

Currently, there is no cure for human immunodeficiency virus type 1 (HIV-1) infection. However, combined antiretroviral therapy (cART) aids in viral latency and prevents the progression of HIV-1 infection into acquired immunodeficiency syndrome (AIDS). cART has extended many lives, but people living with HIV-1 (PLWH) face lifelong ailments such as HIV-associated neurocognitive disorders (HAND) that range from asymptomatic HAND to HIV-1-associated dementia. HAND has been attributed to chronic inflammation and low-level infection within the central nervous system (CNS) caused by proinflammatory cytokines and viral products. These molecules are shuttled into the CNS within extracellular vesicles (EVs), lipid bound nanoparticles, and are released from cells as a form of intercellular communication. This study investigates the impact of cannabidiol (CBD), as a promising and potential therapeutic for HAND patients, and a similar synthetic molecule, HU308, on the EVs released from HIV-1-infected myeloid cells as well as HIV-1-infected 3D neurospheres. The data shows that both CBD and HU308 decrease non-coding and coding viral RNA (TAR and env) as well as proinflammatory cytokines as IL-1β and TNF-α mRNA. This decrease in viral RNA occurs in in vitro differentiated primary macrophages, in EVs released from HIV-1-infected cells monocytes, and infected neurospheres. Furthermore, a 3D neurosphere model shows an overall decrease in proinflammatory mRNA with HU308. Finally, using a humanized mouse model of HIV-1 infection, plasma viral RNA was shown to significantly decrease with HU308 alone and was most effective in combination with cART, even when compared to the typical cART treatment. Overall, CBD or HU308 may be a viable option to decrease EV release and associated cytokines which would dampen the virus spread and may be used in effective treatment of HAND in combination with cART.

Comparison of Mini-FLOTAC, Flukefinder® and sedimentation techniques for detection and quantification of Fasciola hepatica and Calicophoron daubneyi eggs using spiked and naturally infected bovine faecal samples

BackgroundFasciolosis (Fasciola hepatica) and paramphistomosis (Calicophoron daubneyi) are two important infections of livestock. Calicophoron daubneyi is the predominant Paramphistomidae species in Europe, and its prevalence has increased in the last 10–15 years. In Italy, evidence suggests that the prevalence of F. hepatica in ruminants is low in the southern part, but C. daubneyi has been recently reported at high prevalence in the same area. Given the importance of reliable tools for liver and rumen fluke diagnosis in ruminants, this study evaluated the diagnostic performance of the Mini-FLOTAC (MF), Flukefinder® (FF) and sedimentation (SED) techniques to detect and quantify F. hepatica and C. daubneyi eggs using spiked and naturally infected cattle faecal samples.MethodsBriefly, negative bovine faecal samples were artificially spiked with either F. hepatica or C. daubneyi eggs to achieve different egg count levels: 10, 50 and 100 eggs per gram (EPG) of faeces. Moreover, ten naturally infected cattle farms from southern Italy with either F. hepatica and/or C. daubneyi were selected. For each farm, the samples were analysed individually only with MF technique and as pools using MF, FF and SED techniques. Bayesian latent class analysis (LCA) was used to estimate sensitivity and accuracy of the predicted intensity of infection as well as the infection rate in the naturally infected farms.ResultsThe outcome of this study showed that the highest number of eggs (F. hepatica and C. daubneyi) recovered was obtained with MF, followed by FF and SED in spiked infected samples at 50 and 100 EPG, while at lower infection levels of 10 EPG, FF gave the best results. Moreover, the sensitivity for all the techniques included in the study was estimated at > 90% at infection levels > 20 EPG for both F. hepatica and C. daubneyi eggs. However, MF was the most accurate of the three techniques evaluated to estimate fluke infection intensity. Nevertheless, all three techniques can potentially estimate infection rate at farm level accurately.ConclusionsOptimization and standardization of techniques are needed to improve the FEC of fluke eggs.Graphical

Greater rate of nitrogen fertilizer application increases root rot caused by Phytophthora cinnamomi and P. plurivora in container‐grown rhododendron

AbstractPhytophthora root rot, caused by many Phytophthora species, decreases the health of rhododendrons produced in nurseries. Optimizing nitrogen (N) fertilizer is often used to improve nursery stock quality, but there is little information on how N fertilizers influence root rot caused by these pathogens. To understand the impact of N fertilizer and pathogen species on root rot development, rhododendrons were grown with no (0 g N/pot), low (1.04 g N/pot) or high (3.12 g N/pot) rates of N and inoculated with either P. cinnamomi or P. plurivora. Noninoculated plants at low and high N rates had greater biomass, leaf greenness and enhanced N, potassium, magnesium, phosphorus, sulphur and manganese uptake compared to plants grown with no N. When either Phytophthora species was present, N application increased aboveground disease symptoms (wilting, chlorosis, reduced stomatal conductance and biomass), but had no effect on root rot severity belowground. In addition, P. cinnamomi restricted uptake of several nutrients while P. plurivora had less influence on nutrient uptake. Nurseries frequently apply high amounts of N to promote fast growth. However, our results show that this can exacerbate root rot when P. cinnamomi or P. plurivora is present. Although decreasing N can reduce the number of overtly symptomatic plants, this may conversely increase the risk for selling apparently asymptomatic plants with low levels of infection. Additional studies are needed to determine how N fertilization influences Phytophthora root rot for a broader range of rhododendron cultivars and nursery crop species.

Assessing the acceptability and feasibility of reactive drug administration for malaria elimination in a Plasmodium vivax predominant setting: a qualitative study in two provinces in Thailand

BackgroundReactive case detection (RACD) or testing and treatment of close contacts of recent malaria cases, is commonly practiced in settings approaching malaria elimination, but standard diagnostics have limited sensitivity to detect low level infections. Reactive drug administration (RDA), or presumptive treatment without testing, is an alternative approach, but better understanding regarding community acceptability and operational feasibility are needed.MethodsA qualitative study was conducted as part of a two-arm cluster randomized-controlled trial evaluating the effectiveness of RDA targeting high-risk villages and forest workers for reducing Plasmodium vivax and P. falciparum malaria in Thailand. Key informant interviews (KIIs) and focus group discussions (FGDs) were conducted virtually among key public health staff, village health volunteers (VHVs), and household members that implemented or received RDA activities. Transcriptions were reviewed, coded, and managed manually using Dedoose qualitative data analysis software, then underwent qualitative content analysis to identify key themes.ResultsRDA was well accepted by household members and public health staff that implemented it. RDA participation was driven by fear of contracting malaria, eagerness to receive protection provided by malaria medicines, and the increased access to health care. Concerns were raised about the safety of taking malaria medicines without having an illness, particularly if underlying health conditions existed. Health promotion hospital (HPH) staff implementing RDA noted its operational feasibility, but highlighted difficulty in traveling to remote areas, and requested additional travel resources and hiring more VHVs. Other challenges were highlighted including the need for additional training for VHVs on malaria activities and the inability of HPH staff to conduct RDA due to other health priorities (e.g., Covid-19). More training and practice for VHVs were noted as ways to improve implementation of RDA.ConclusionsTo maximize uptake of RDA, regular education and sensitization campaigns in collaboration with village leaders on the purpose and rationale of RDA will be critical. To alleviate safety concerns and increase participant safety, a rigorous pharmacovigilance program will be important. To accelerate uptake of RDA, trust between HPH staff and VHVs and the communities they serve must continue to be strengthened to ensure acceptance of the intervention.Trial registrationThis study was approved by the Committee on Human Research at the University of California San Francisco (19–28,060) and the local Ethics Committee for Research in Human Subjects at Tak Provincial Health office (009/63) and Kanchanaburi Provincial health office (Kor Chor 0032.002/2185). Local authorities and health officers in the provinces, districts, and villages agreed upon and coordinated the implementation of the study. All methods in this study were carried out in accordance with relevant guidelines and regulations.

Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the ‘gold standard’ for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/μL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

Long-term prevalence follow-up (1967-2022) of HTLV-2 among vulnerable indigenous populations in the Amazon region of Brazil.

Human T-lymphotropic virus 2 (HTLV-2) has been described for more than 30 years as an endemic infection in Brazilian indigenous populations, with its occurrence varying by age and sex, maintained mainly by sexual intercourse and mother-to-child transmission, favoring intrafamilial aggregation. The epidemiological scenario of HTLV-2 infection has been described among communities of the Amazon region of Brazil (ARB), with the number of retrospective positive blood samples increasing for more than 50 years. Five publications were selected that showed the presence of HTLV-2 in 24 of 41 communities; the prevalence of infection was described among 5,429 individuals at five points in time. Among the Kayapó villages, the prevalence rates were described according to age and sex and reached up to 41.2%. Three communities (Asurini, Araweté, and Kaapor) were kept virus free for 27 to 38 years of surveillance. Low, medium and high prevalence levels of infection were defined, and two pockets of high endemicity were shown in the state of Pará, pointing to the Kikretum and Kubenkokrê Kayapó villages as the epicenter of HTLV-2 in the ARB. The prevalence rates over the years have shown a decline among the Kayapó (from 37.8 to 18.4%) and an apparent change to a higher prevalence among females, but not during the first decade of life, usually associated with transmission from mother to child. Sociocultural and behavioral aspects, as well as public health policies directed toward sexually transmitted infections, might have positively influenced the decline in HTLV-2 infections.

Investigating intestinal parasitic infections with emphasis on molecular identification of Strongyloides stercoralis and Trichostrongylus colubriformis in north of Iran

Currently, parasitic infections are one of the important health problems in the world, especially in developing countries. This study aims to investigate intestinal parasites with an emphasis on molecular identification through the analysis of mitochondrial COX1 and ITS2 gene sequences of Strongyloides stercoralis (S. stercoralis) and Trichostrongylus spp. in north of Iran. Five hundred forty stool samples were collected from medical diagnostic laboratories affiliated with Mazandaran University of Medical Sciences in Sari city, north of Iran. First, all the samples were examined using direct smear, formalin-ether sedimentation, and trichrome staining technique. Suspected samples of Strongyloides larvae were cultured in agar plate. Then, DNA was extracted from samples containing Trichostrongylus spp. eggs and Strongyloides larvae. To amplify DNA, PCR was performed and the samples with a sharp band in electrophoresis were sequenced by Sanger method. Overall, the prevalence of parasitic infections in the study population was 5.4%. The highest and the lowest level of infection was observed with Trichostrongylus spp. and S. stercoralis at 3% and 0.2%, respectively. No traces of live Strongyloides larvae were seen in the culture medium of the agar plate. The six isolates obtained from the amplification of the ITS2 gene of Trichostrongylus spp. were sequenced, all of which were Trichostrongylus colubriformis. The sequencing results of COX1 gene indicated S. stercoralis. In the present study, the prevalence of intestinal parasitic infections in north of Iran has relatively decreased that its main reason can be due to the coronavirus epidemic and compliance with health principles. However, the prevalence of Trichostrongylus parasite was relatively high that it requires special attention to apply appropriate control and treatment strategies in this field.

Influence of Human Behavior on COVID-19 Dynamics Based on a Reaction-Diffusion Model.

To investigate the influence of human behavior on the spread of COVID-19, we propose a reaction-diffusion model that incorporates contact rate functions related to human behavior. The basic reproduction number is derived and a threshold-type result on its global dynamics in terms of is established. More precisely, we show that the disease-free equilibrium is globally asymptotically stable if ; while there exists a positive stationary solution and the disease is uniformly persistent if . By the numerical simulations of the analytic results, we find that human behavior changes may lower infection levels and reduce the number of exposed and infected humans.

Prevalence of Cryptosporidium infection in children from China: a systematic review and meta-analysis

Cryptosporidium is an important zoonotic pathogen that causes diarrhea in humans and animals, and a leading cause of diarrhea morbidity and mortality in children under 5 years old. However, the meta-analysis of Cryptosporidium infection in children in China has not been published. We searched the databases for articles published on the prevalence of Cryptosporidium infection in children in China since the inception of these databases to 31 October 2022. The prevalence of Cryptosporidium infection in children was estimated using a random effects model. The results showed that 111 datasets from 24 provinces were selected for the final quantitative analysis. The estimated pooled Cryptosporidium infection prevalence in children in China was 2.9% (3300/126,381). The highest prevalence rate was in southwestern China (4.8%, 365/7766). Subgroup analysis indicated that the Cryptosporidium infection rate in children aged < 3 years (4.9%, 330/8428) was significantly higher than that in children aged 3–6 years (2.5%, 609/26,080) and >6 years (2.6%, 647/27,586). Six Cryptosporidium species were detected in children in China from the selected studies. C. hominis was the dominant species (77.1%, 145/188) and the proportions of subgenotype IaA14R4 of C. hominis was highest (42.8%, 62/145). The findings suggest that Chinese children is in a low level of Cryptosporidium infection, however, the geographical distribution of the infection is extensive. We suggest that measures should be taken to ensure the healthy growth of Chinese children by improving the water environment, increasing public health facilities, strengthening children's health education, and developing sound Cryptosporidium infection control programs.

The prevalence of soil transmitted helminths and its influential factors in Shandong Province, China: an analysis of surveillance data from 2016 to 2020

BackgroundSoil-transmitted helminths (STHs) were previously endemic in Shandong Province, China. This study aimed to analyze the STHs prevalence trend and the natural, social, and human cognitive and behavioural factors influencing the discrepancies between high and low infection levels from 2016 to 2020 in Shandong Province in eastern China.MethodsSTHs surveillance data of Shandong Province from 2016 to 2020 were obtained from China Information Management System for Prevention and Control of Parasitic Diseases. STHs infections were detected by modified Kato–Katz method. Comprehensive information on the natural and social factors, STHs-related knowledge and behaviours were collected through questionnaire surveys. Retrospective spatial scan analysis was performed using SaTScan v10.1 to evaluate any identified spatial clusters of STHs infection for statistical significance and Bayes discriminant analysis was used to discriminate the high or low infection groups of the villages.ResultsIn total, 72,160 participants were involved in our survey from 2016 to 2020. The overall STHs prevalence rate was 1.13%, with the eastern region of Shandong Province having the highest rate (2.02%). The predominant species was T. trichiura, with the prevalence rate of 0.99% and the ≥ 70-year age group possessed the highest rate of 2.21%. The STHs prevalence rate showed an annual linear downward trend from 2016 to 2020 (chi_{{{text{trend}}}}^{2} = 127.600, P < 0.001). Respondents aged ≥ 60 years had the lowest awareness level of STHs-related prevention knowledge (all P < 0.05), and were the most likely to adopt the practice of fertilizing with fresh stool (χ2 = 28.354, P < 0.001). Furthermore, the southern region demonstrated the highest temperature and rainfall level and the lowest GNP and annual net income per capita (all P < 0.05).ConclusionsThere is a remarkable declining in STHs prevalence in Shandong Province from 2016 to 2020. However, the prevalence rates of STHs especially T. trichiura in the southern and eastern regions were still high, and the elderly were more susceptible to be infected with STHs owning to their low awareness level of STHS-related prevention knowledge and high adoption rate of dangerous production and living behaviours. Integrated approaches of health education, environment improvement and behaviour change should be strengthened to obtain a further reduction of STHs prevalence in China.

Single-Nucleus Sequencing of Fat Body Reveals Distinct Metabolic and Immune Response Landscapes in Silkworm Larvae after Bombyx mori Nucleopolyhedrovirus Infection.

The fat body plays a central role in the regulation of the life cycle of insects and acts as the major site for detoxification, nutrient storage, energy metabolism, and innate immunity. However, the diversity of cell types in the fat body, as well as how these cell subsets respond to virus infection, remains largely unknown. We used single-nucleus RNA sequencing to identify 23 distinct clusters representing adipocyte, hemocyte, epithelial cell, muscle cell, and glial cell types in the fat body of silkworm larvae. Further, by analysis of viral transcriptomes in each cell subset, we reveal that all fat body cells could be infected by Bombyx mori nucleopolyhedrovirus (BmNPV) at 72 h postinfection, and that the majority of infected cells carried at least a medium viral load, whereas most cells infected by BmNPV at 24 h postinfection had only low levels of infection. Finally, we characterize the responses occurring in the fat body cell clusters on BmNPV infection, which, on one hand, mainly reduce their metabolic functions, involving energy, carbohydrates, lipids, and amino acids, but, on the other hand, initiate a strong antiviral response. Our single-nucleus RNA sequencing analysis reveals the diversity of insect fat body cells and provides a resource of gene expression profiles for a systems-level understanding of their response to virus infection.

Prevalence of Varroa destructor in Honeybee (Apis mellifera) Farms and Varroosis Control Practices in Southern Italy.

The majority of honeybee farms in industrialized countries currently base their Varroa destructor control programs on the use of acaricides in conjunction with other management practices. However, the outcomes of these practices are often misunderstood and have only been studied to a limited extent. Better yields are guaranteed by having hives with low infection levels in the spring. Therefore, it is crucial to understand which beekeeping practices can result in increased control effectiveness. This study aimed to analyze the potential effects of environmental factors and beekeeping practices on the dynamics of V. destructor population. Experimental evidence was obtained by interpolating percentage infestation data from diagnoses conducted on several apiaries in the Calabria region (Southern Italy) with data acquired from a questionnaire on pest control strategies. Data on climatic temperature during the different study periods were also taken into account. The study was conducted over two years and involved 84 Apis mellifera farms. For each apiary, the diagnosis of infestation was made on a minimum of 10 hives. In total, 840 samples of adult honeybees were analyzed in the field to determine the level of infestation. In 2020, 54.7% of the inspected apiaries tested positive for V. destructor, and in 2021, 50% tested positive, according to a study of the field test findings (taking into account a threshold of 3% in July). A significant effect of the number of treatments on parasite prevalence was found. The results showed a significant reduction in the infestation rate in apiaries that received more than two treatments each year. Furthermore, it was shown that management practices, such as drone brood removal and frequent queen replacement, have a statistically significant impact on the infestation rate. The analysis of the questionnaires revealed some critical issues. In particular, only 50% of the interviewed beekeepers diagnosed infestation on samples of adult bees, and only 69% practiced drug rotation. In conclusion, it is only possible to maintain the infestation rate at an acceptable threshold by implementing integrated pest management (IPM) programs and using good beekeeping practices (GBPs).

HIV-1 tropism in low-level viral load HIV-1 infections during HAART in Guangdong, China.

Since only a few studies have been conducted on the factors associated with different HIV-1 tropisms in low-level viral load HIV-1 infections in China, we investigated the sequences of HIV-1 V3 loop in prevalent HIV-1 subtypes and factors related to HIV-1 tropism and immune recovery in HIV-1 infections after 6 months of highly active antiretroviral therapy (HAART) in Guangdong, China. Plasma samples with HIV-1 RNA of 400-999 copies/mL were collected. We analyzed the amino acid sequence of the V3 loop by in silico prediction algorithms. Mann-Whitney and Chi-square tests were used for statistical comparison. Furthermore, logistic regression and multiple linear regression were used, respectively, for factors associated with 351 HIV-1 tropism and immune recovery of 67 cases with continued CD4+ T cell count during HAART. There was a lower percentage of HIV-1 R5-tropic virus in CRF01_AE (66.3%) (p < 0.0001) and CRF55_01B (52.6%) (p < 0.0001) compared with both CRF07_BC (96.1%) and CRF08_BC (97.4%), respectively. Compared with the R5-tropic virus, higher proportions of IIe8/Val8, Arg11/Lys11, and Arg18/His18/Lys18 were observed in the X4-tropic virus of CRF01_AE and CRF07_BC (p < 0.0001). The baseline CD4+ T cell count (p < 0.0001) and baseline CD4+ T/CD8+ T ratio (p = 0.0006) of all R5-tropic infections were higher than those in the X4-tropic infection. The baseline CD4+ T cell count (odds ratio [OR] 0.9963, p = 0.0097), CRF07_BC (OR 0.1283, p = 0.0002), and CRF08_BC (OR 0.1124, p = 0.0381) were associated with less HIV-1 X4-tropism. The baseline CD4+ T cell count was a positive factor (p < 0.0001) in the recovery of CD4+ T cell count during HAART. R5-tropism represented the majority in low-level viral load HIV-1 infections receiving HAART for more than 6 months in Guangdong, China. The baseline immune level in the HIV-1 R5-tropic infections was higher than that in the X4-tropic infections. The amino acids of the 8th, 11th, and 18th of the HIV-1 V3 loop were more variable in the X4-tropic HIV-1. CRF01_AE, CRF55_01B, and lower baseline CD4+ T cell count were associated with more HIV-1 X4-tropism. The immune recovery during HAART was positively related to baseline CD4+ T cell count.

Hyper‐IgE syndrome presenting with early life craniosynostosis in monozygotic twin sisters

<scp>Hyper‐IgE</scp> syndrome presenting with early life craniosynostosis in monozygotic twin sisters

Epidemiological survey of gastrointestinal infections by gastrointestinal nematodes and coccidia in cattle in the semiarid region of Northeastern Brazil

The aim of the present study was to carry out an epidemiological survey on gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, northeastern Brazil. A total of 832 cattle were sampled, of both sexes and different ages, on 21 farms in 21 municipalities in the state of Paraíba, Brazil. Fecal samples were collected individually to perform eggs per gram (EPG) and oocysts per gram (OoPG) counts in feces, and to perform fecal cultures. To assess factors associated with nematode and coccidia infections, epidemiological survey forms were applied to the farmers. The total frequency of infections by nematodes was 59.6% (496/832) and it was 36.9% (307/832) for coccidia. The levels of infection by nematodes and coccidia were most frequently low (EPG &lt; 300; OoPG &lt; 1,000), in 72.4% (359/496) and 75.2% (231/307), respectively. The most frequent nematode genera was Haemonchus spp. (78.8%). The risk factors for nematode infections in cattle were beef production trait (odds ratio = 2.99) and extensive rearing system (odds ratio = 3.8); the factors for coccidia were age ≤ 12 months (odds ratio = 2.9) and body score between 1 and 2 (odds ratio = 5.2). These results prove that there are high frequencies of gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, with predominantly low levels of infection. However, given the importance of subclinical infections, adjustments to sanitary management measures can contribute to reduction of parasite indices and better performance among the animals, thus generating greater profitability for farmers.

Screening germplasm lines for identification of resistant source against gray mold disease (Amphobotrys ricini (N.F. Buchw.) Hennebert) of castor

The present study was aimed to screen castor germplasm lines varying in wax content against gray mold disease for the identification of resistance source under in vitro conditions using detached spike and detached capsule technique. Out of thirty-three lines screened against gray mold under in vitro conditions six lines with low wax content viz., RG-1754 (0.24 µg/mg), RG-1875 (0.12 µg/mg), RG-1915 (0.21 µg/mg), RG-1919 (0.24 µg/mg), RG-1972 (0.08 µg/mg) and RG-1926 (0.08 µg/mg) recorded significantly low levels of infection ranging from 10 to 20 per cent 7 days after inoculation. Whereas the susceptible cultivar DCH -519 has recorded disease severity of more than 90 %. The pearman's rank correlation analysis showed a strong positive relation between disease severity and capsule wax content, with p &lt; 0.01 and r = 0.884.

Effects of Low-Level Persistent Infection on Maintenance of Immunity by CD4 T Cell Subsets and Th1 Cytokines.

CD4 T cells are required, along with antibodies, for complete protection from blood-stage infection with Plasmodium spp., which cause malaria. Without continuous exposure, as on emigration of people from endemic areas, protection from malaria decays. As in other persistent infections, low-level Plasmodium chabaudi infection protects the host from reinfection at 2 months postinfection, a phenomenon termed premunition. Premunition is correlated with T cell responses, rather than antibody levels. We previously showed that while both effector T cells (Teff) and memory T cells (Tmem) are present after infection, Teff protect better than Tmem. Here, we studied T cell kinetics post-infection by labeling dividing Ifng+ T cells with 5-bromo-2'-deoxyuridine (BrdU) in infected Ifng reporter mice. Large drops in specific T cell numbers and Ifng+ cells upon clearance of parasites suggest a mechanism for decay of protection. Although protection decays, CD4 Tmem persist, including a highly differentiated CD27- effector memory (Tem) subset that maintains some Ifng expression. In addition, pretreatment of chronically infected animals with neutralizing antibody to interferon gamma (IFN-γ) or with clodronate liposomes before reinfection decreases premunition, supporting a role for Th1-type immunity to reinfection. A pulse-chase experiment comparing chronically infected to treated animals showed that recently divided Ifng+ T cells, particularly IFN-γ+ TNF+ IL-2- T cells, are promoted by persistent infection. These data suggest that low-level persistent infection reduces CD4+ Tmem and multifunctional Teff survival, but promotes IFN-γ+ TNF+ IL-2- T cells and Ifng+ terminally differentiated effector T cells, and prolongs immunity.