Entomopathogenic fungi-based silver nanoparticles: a potential substitute of synthetic insecticides to counter behavioral and physiological immunity in Aedes aegypti mosquito (Diptera: Culicidae).

Excessive use of synthetic insecticides has resulted in environmental contamination and adverse effects on humans and other non-target organisms. Entomopathogenic fungi offer eco-friendly alternatives; however, their application for pest control requires significant advancement owing to limitations like slow killing time and effectiveness only when applied in higher amounts, whereas exposure to UV radiation, high temperature, and humidity can also reduce their viability and shelf-life. The nanoparticles synthesized using fungal extracellular extracts provide a new approach to use fungal pathogens. Our study focused on the synthesis of Metarhizium anisopliae-based silver nanoparticles (AgNPs) and evaluation of their efficiency on various physiological and behavioral parameters of the mosquito Aedes aegypti. The synthesis, size (27.6 d.nm, PDI = 0.209), zeta potential (- 24.3 mV), and shape of the AgNPs were determined through dynamic light scattering, scanning and transmission electron microscopic, and UV-visual spectroscopic analyses (432 nm). Our results showed significantly reduced survival (100% decrease in case of 3.2 and 1.8 µL/cm2 volumes, and 60% decrease in case of 0.8 µL/cm2 volume), phenoloxidase activity (t = 39.91; p = 0.0001), and gut microbiota, with increased oxidative stress and cell apoptosis in AgNPs-challenged mosquitoes. Furthermore, the AgNPs-exposed mosquitoes presented a concentration-specific decrease in flight locomotor activity (F = 17.312; p < 0.0001), whereas no significant changes in antifungal activity, self-grooming frequencies, or time spent were found. These findings enhance our understanding of mosquito responses to AgNPs exposure, and offer a more efficient mosquito control strategy using entomopathogenic fungi.

Entomopathogenic fungal infection following immune gene silencing decreased behavioral and physiological fitness in Aedes aegypti mosquitoes.

Entomopathogenic fungi are a promising category of biocontrol agents with mosquitocidal properties. Prior studies have proved their potential to reduce fecundity, human biting and vector competence, all of them together determine vectorial capacity of the mosquitoes. Unfortunately, conventional vector control strategies are inadequate with growing problem of insecticide resistance and environmental deterioration. Therefore, alternate vector control measures are immediately needed and to accomplish that, an improved understanding of behavioral and physiological defense mechanisms of the mosquitoes against fungal infection is essential. In this study, fitness was considered with respect to different behavioral (self-grooming and flight), physiological (antifungal activity and antimicrobial peptides) parameters and survival rates as compared to the control group. We found a significant upregulation in CLSP2, TEP22, Rel1 and Rel2 genes at multiple time periods of fungal infection, which indicates the successful fungal infection and activation of Toll and IMD pathways in mosquitoes. RNAi-mediated silencing of Rel1 and Rel2 genes (transcription factors of Toll and IMD pathways, respectively) significantly reduced the survival, self-grooming frequencies and durations, and flight locomotor activity among adult Ae. aegypti female mosquitoes. Moreover, Rel1 and Rel2 knockdown significantly decreased antifungal activity and antimicrobial peptides expression levels in target mosquitoes. These results indicate an overall decrease in fitness of the mosquitoes after fungal challenge following Rel1 and Rel2 silencing. These findings provide an improved understanding of behavioral and physiological responses in mosquitoes with altered immunity against entomopathogenic fungal infections which can guide us towards the development of novel biocontrol strategies against mosquitoes.

Composition of gut and oropharynx bacterial communities in Rattus norvegicus and Suncus murinus in China.

BACKGROUND: Rattus norvegicus and Suncus murinus are important reservoirs of zoonotic bacterial diseases. An understanding of the composition of gut and oropharynx bacteria in these animals is important for monitoring and preventing such diseases. We therefore examined gut and oropharynx bacterial composition in these animals in China. RESULTS: Proteobacteria, Firmicutes and Bacteroidetes were the most abundant phyla in faecal and throat swab samples of both animals. However, the composition of the bacterial community differed significantly between sample types and animal species. Firmicutes exhibited the highest relative abundance in throat swab samples of R. norvegicus, followed by Proteobacteria and Bacteroidetes. In throat swab specimens of S. murinus, Proteobacteria was the predominant phylum, followed by Firmicutes and Bacteroidetes. Firmicutes showed the highest relative abundance in faecal specimens of R. norvegicus, followed by Bacteroidetes and Proteobacteria. Firmicutes and Proteobacteria had almost equal abundance in faecal specimens of S. murinus, with Bacteroidetes accounting for only 3.07%. The family Streptococcaceae was most common in throat swab samples of R. norvegicus, while Prevotellaceae was most common in its faecal samples. Pseudomonadaceae was the predominant family in throat swab samples of S. murinus, while Enterobacteriaceae was most common in faecal samples. We annotated 33.28% sequences from faecal samples of S. murinus as potential human pathogenic bacteria, approximately 3.06-fold those in R. norvegicus. Potential pathogenic bacteria annotated in throat swab samples of S. murinus were 1.35-fold those in R. norvegicus. CONCLUSIONS: Bacterial composition of throat swabs and faecal samples from R. norvegicus differed from those of S. murinus. Both species carried various pathogenic bacteria, therefore both should be closely monitored in the future, especially for S. murinus.

Comparisons of microbiological characteristics and antibiotic resistance of Klebsiella pneumoniae isolates from urban rodents, shrews, and healthy people.

BACKGROUND: The comparisons of molecular characterization and antibiotic resistance of Klebsiella pneumoniae (KP) isolates from humans and other animal hosts are not well studied. Our goal was to compare the molecular epidemiology of KP strains that were isolated from urban rodents, shrews, and healthy people. RESULTS: K. pneumoniae (KP) isolates were isolated from fecal samples of rodents, shrews and healthy adults in 2015 in southern China. In total, 465 fecal samples were collected, of which 85 from rodents, 105 from shrews, and 275 from healthy adults. Antimicrobial susceptibility and production of extended-spectrum ß-lactamases (ESBL) of the isolates were tested. PCR-based methods were used to detect specific genes, including ESBL genes (blaTEM, blaSHV, and blaCTX-M) in ESBL-producing isolates, capsular serotypes (K1, K2, K5, K20, K54, and K57) in hypervirulent KPs (hvKPs), and virulence genes (magA, wcaG, rmpA, uge, kfu, and aerobactin) in hvKP isolates. Multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to exclude the homology of these isolates. The carriage rate of KP in urban rodents and shrews (78.42%) was higher than that in healthy adults (66.18%) (χ2 = 8.206, P = 0.004). The prevalence rates of ESBL-producing isolates among rodents, shrews, and humans were 7.94, 12.79, and 17.03%, respectively. The positive rates of CTX-M, TEM and SHV types in ESBL-producing isolates were 29.79, 27.66, and 17.02%, respectively. Serotype K1, K5, K20, and K57 were detected in both small mammals and humans. PFGE typing revealed thirty-six clusters. PFGE cluster A was clustered by samples of shrews and healthy adult, with a similarity of 88.4%. MLST typing revealed thirty-eight types. ST23 and ST35 were detected in samples of shrews and healthy adults. ST37 was detected in samples of 2 rodents and a healthy adult. CONCLUSIONS: Overlapping serotypes of hvKP were observed in both the animals and humans. The same PFGE or MLST types were also found in isolates derived humans, rodents and shrews. Therefore, urban rodents and shrews might play a certain role in the transmission of drug-resistant and hypervirulent KP.

Methicillin-resistant Staphylococcus aureus among urban rodents, house shrews, and patients in Guangzhou, Southern China.

BACKGROUND: The transmission of methicillin-resistant Staphylococcus aureus (MRSA) between humans and animals has been identified in a number of countries. In this study, MRSA in urban rodents and shrews in a community was investigated. Further, comparisons of MRSA isolates from rodents, shrews, and humans were conducted to evaluate the relationships of these isolates from different origins. RESULTS: Between 2015 and 2016, 397 oropharynx samples from 212 rodents and 185 shrews, and 8 MRSA isolates from hospital patients were collected. Twelve MRSA were isolated from the small mammals (3.0, 95%CI: 1.3-4.7%), including 11 isolates from rodents and one from a shrew. Three MRSA isolates from Rattus norvegicus were PVL-positive, and seven isolates were IEC-negative (one from Suncus murinus, five from Rattus norvegicus, and one from a patient). The spa type, MLST, and antimicrobial resistance patterns showed that the MRSA retrieved from rodents and shrews are likely related to human strains. CONCLUSION: MRSA derived from rodent shares similar antimicrobial resistance and molecular characteristics to those from humans, suggesting that urban rodents may play as maintenance host or vectors for MRSA which is important to human health.

Association between Dietary Isoflavones in Soy and Legumes and Endometrial Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Epidemiologic studies have reported conflicting findings between soy- and legume-derived dietary isoflavones and risk of endometrial cancer. OBJECTIVE: The aim of the present meta-analysis was to quantitatively investigate the association between daily intake of soy- and legume-derived isoflavones and risk of endometrial cancer. DESIGN: A broad search was conducted in the following electronic databases: PubMed, EMBASE, Google Scholar, the Cochrane Library, the China Knowledge Resource Integrated Database, and the Chinese Biomedical Database based on combinations of the key words endometrial cancer, isoflavone, soy, and legume for epidemiologic studies that focused on relationships between dietary isoflavones and endometrial cancer risk. A fixed-effect or random-effect model was used to pool study-specific risk estimates. RESULTS: A total of 13 epidemiologic studies were included in the present meta-analysis, consisting of three prospective cohort studies and 10 population-based case-control studies. The final results indicated that higher dietary isoflavone levels from soy products and legumes were associated with a reduced risk of endometrial cancer (odds ratio [OR] 0.81, 95% CI 0.74 to 0.89). Low heterogeneous bias was observed (I2=11.7%; P=0.327). Subgroup analyses were conducted based on study design, source of dietary isoflavones, and study region. When restricted to study design, dietary isoflavones from soy and legumes played a role in prevention of endometrial cancer in case-control studies (OR 0.81, 95% CI 0.73 to 0.90). However, there did not appear to be an association between dietary isoflavones and endometrial cancer in cohort studies (OR 0.81, 95% CI 0.66 to 1.00). Significant associations were found between dietary isoflavones from soy products (OR 0.82, 95% CI 0.72 to 0.92) and legumes (OR 0.84, 95% CI 0.74 to 0.96) and endometrial cancer. Dietary isoflavones were associated with reduced incidence of endometrial cancer, both in Asian countries (OR 0.78, 95% CI 0.66 to 0.93) and non-Asian countries (OR 0.82, 95% CI 0.73 to 0.92). CONCLUSIONS: The findings suggest a weak inverse association between higher consumption of dietary isoflavones from soy products and legumes and endometrial cancer risk. However, there is still a need for large, prospective epidemiologic studies that provide a higher level of evidence to verify these findings.

Serological Prevalence Against Japanese Encephalitis Virus-Serocomplex Flaviviruses in Commensal and Field Rodents in South China.

BACKGROUND: Japanese encephalitis caused by Japanese encephalitis virus (JEV) is an endemic zoonotic disease of high public health importance in the Asian Pacific region. The aim of this study was to investigate the presence of JEV infection in commensal and field rodents in South China. MATERIALS AND METHODS: RNA copies of JEV were detected in brain samples of rodents using real-time RT-PCR. Detection of serum against JEV-reactive antibodies was performed using indirect enzyme-linked immunosorbent assay and microneutralization test. RESULTS: In total, 198 rodents were collected from Guangzhou City and Xiamen City between November 2013 and May 2014. JEV RNA was not detected in 188 brain samples. Forty-four in 96 serum samples (45.8%) were positive for JEV-reactive IgG antibodies. The prevalence of neutralizing antibodies to against JEV-reactive in these serum samples was 61.5% (24/39), with titers ranging from 1:10 to 1:56. CONCLUSION: Rodents are not known to play a role in transmission of JEV in Asia, nor is there an evidence to support a role for rodents in transmission of other related flaviviruses in China. However, in the current study, we detected evidence of JEV-reactive antibodies in large numbers of Rattus norvegicus and Rattus losea Swinhoe. Further studies of rodents as potential hosts of JEV or other related flaviviruses are warranted.

[Investigation of antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates from rat-like animals around a hospital in Guangzhou].

OBJECTIVE: To investigate antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates in fecal samples from rat-like animals. METHODS: Rat-like animals were captured using cages around a hospital and the neighboring residential area between March and October, 2015. K. pneumoniae and P. aeruginosa were isolated from the fecal samples of the captured animals. Antimicrobial susceptibility test was performed according to the guidelines of Clinical and Laboratory Standards Institute (2014). RESULTS: A total of 329 rat-like animals were captured, including 205 Suncus murinus, 111 Rattus norvegicus, 5 Rattus flavipectus and 8 Mus musculus. The positivity rates of K. pneumoniae and P. aeruginosa were 78.4% and 34.7% in the fecal samples from the captured animals, respectively. K. pneumoniae isolates from Suncus murinus showed a high resistance to ampicillin, cephazolin, nitrofurantoin, piperacillin and cefotaxime (with resistance rates of 100%, 51.2%, 44.2%, 37.2%, and 23.3%, respectively), and K. pneumoniae isolates from Rattus spp. showed a similar drug-resistance profile. The prevalence rates of multidrug resistance and ESBLs were 40.9% and 10.7%, respectively. P. aeruginosa from both Suncus murinus and Rattus spp. exhibited the highest resistance rates to aztreonam (12.4% and 16.0%, respectively), followed by penicillins and fluoroquinolones. P. aeruginosa isolates were susceptible to cephems, aminoglycosides and carbapenems (with resistance rates below 5%). CONCLUSION: K. pneumoniae and P. aeruginosa isolated from rat-like animals showed drug-resistance profiles similar to those of the strains isolated from clinical patients, suggesting that the possible transmission of K. pneumoniae and P. aeruginosa between rat-like animals and human beings.

Molecular Detection and Phylogenetic Characteristics of Herpesviruses in Rectal Swab Samples from Rodents and Shrews in Southern China.

Herpesviruses (HVs) can cause asymptomatic, benign, or fatal infections in a variety of animal species. However, the prevalence and phylogenetic characteristics of HVs in rodents and shrews in China are poorly understood. We thus performed a molecular detection and phylogenetic analysis of rat and shrew HVs in southern China between 2012 and 2014. Seventeen (6.7%) of 255 rectal swab specimens from rats and six (6.7%) of 90 rectal swab specimens from shrews tested positive for HVs. Phylogenetic analysis revealed that rodent and shrew HVs detected in this study were species specific, clustering in the Betaherpesvirinae and Gammaherpesvirinae clade. Novel Macavirus was detected in Rattus norvegicus (RN/13YX52/24 and RN/14HC50) and gammaherpesviruses in Suncus murinus (SM/14BY7/16/20/97/99/106).These findings have contributed to our understanding of the taxonomy, phylogeny, and biology of HVs.

Molecular Detection and Phylogenetic Characterization of Bat and Human Adenoviruses in Southern China.

Several novel adenoviruses (AdVs) have recently been identified in humans and other animal species. In this study, we report the molecular detection of and phylogenetically characterize bat and human AdVs detected in fecal or rectal swab samples collected in southern China. To detect AdVs, a 252-261 bp fragment of the DNA polymerase (DPOL) gene was amplified using nested PCR. A total of 520 rectal swab samples were collected from eight bat species in four geographic regions of southern China (Guangzhou, Yunfu, Huizhou, and Haikou city). Thirty-six (6.9%) samples from the following species tested positive for AdVs: Myotis ricketti, Miniopterus schreibersii, Scotophilus kuhlii, Taphozous melanopogon, Rhinolophus blythi, and Cynopterus sphinx. Eight novel AdVs were detected in 13.3% of the samples from C. sphinx. Of 328 fecal samples from patients with diarrhea, 16 (4.9%) were positive for classical human AdVs. Phylogenetic analysis showed that human AdVs shared low similarity (57.1-69.3%) with bat AdVs in deduced amino acid sequences of the AdV DPOL region. Thus, our study indicated that bat AdVs and human AdVs are species specific. As such, there is no evidence of cross-species transmission of AdV between bats and humans based on current data.

Detection of novel adenoviruses in fecal specimens from rodents and shrews in southern China.

The prevalence and phylogenetic characteristics of AdVs in rodents and shrews in China are still unknown. To explore the epidemiological characteristics of rodent and shrew AdVs in southern China, 255 fecal samples derived from four rodent species and 90 from shrews were collected in Xiamen and Guangzhou city of southern China. Amplification of a 314-324-bp fragment from the DNA polymerase gene of AdVs was attempted by using a nested PCR. Twenty-nine (11.4 %) specimens from rodents and one (1.1 %) specimen from shrews were tested positive for AdVs. Phylogenetic analysis revealed that nine samples from Rattus norvegicus in Guangzhou city between 2012 and 2013 might be the genuine AdV of R. norvegicus. The same putative AdV sequences were derived from samples of different host species from different/same places. A novel adenovirus was detected in Suncus murinus Linnaeus (SML/14GDGZ72) for the first time. Our findings provide new data on the prevalence and diversity of AdVs in rodents and shrews.

Maternal autoimmune diseases and the risk of autism spectrum disorders in offspring: A systematic review and meta-analysis.

Although inherited and immune disorder factors are known to be involved in autism spectrum disorders (ASD), controversy still exists as to whether maternal autoimmune disease is an independent risk of ASD in offspring. We aimed to quantitatively summarize the risk of ASD in offspring in relation to maternal autoimmune diseases. A literature search in Pubmed, Web of science, Embase, and China national knowledge internet was conducted to identify relevant studies. Pooled odd ratio (OR) and its 95% confidence interval (CI) were computed by STATA version 12.0. Nine case-control studies and one cohort studies comprising 9775 cases and 952,211 controls were included in this study. A positive association between maternal autoimmune diseases and the risk of ASD in offspring was identified assuming a fixed effect model (pooled OR, 1.34; 95% CI, 1.23-1.46; I(2), 27.9%). There were statistically significant associations between maternal autoimmune diseases developed during pregnancy or maternal thyroid disease and the risk of ASD in offspring (pooled OR, 1.30, 1.29, respectively). Maternal autoimmune disease is likely to be an independent risk factor of ASD in offspring.

High prevalence and diversity of viruses of the subfamily Gammaherpesvirinae, family Herpesviridae, in fecal specimens from bats of different species in southern China.

Several studies have reported the detection of herpesviruses (HVs) in bats. However, the prevalence and phylogenetic characteristics of HVs in bats are still poorly understood. To elucidate the epidemiological characteristics of bat HVs in southern China, 520 fecal samples from eight bat species were collected in four geographic regions of southern China. Of these samples, 73 (14.0 %) tested positive for HVs using nested polymerase chain reaction assay. Phylogenetic analysis revealed a high degree of molecular diversity of HVs in bats of different species from different geographic regions. Our study provides evidence for co-evolution of bats and HVs.

A meta-analysis of confocal laser endomicroscopy for the detection of neoplasia in patients with Barrett's esophagus.

BACKGROUND AND AIMS: Barrett's esophagus (BE) is considered the most important risk factor for development of esophageal adenocarcinoma. Confocal laser endomicroscopy (CLE) is a recently developed technique used to diagnose neoplasia in BE. This meta-analysis was performed to assess the accuracy of CLE for diagnosis of neoplasia in BE. METHODS: We searched EMBASE, PubMed, Cochrane Library, and Web of Science to identify relevant studies for all articles published up to June 27, 2015 in English. The quality of included studies was assessed using QUADAS-2. Per-patient and per-lesion pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio with 95% confidence intervals (CIs) were calculated. RESULTS: In total, 14 studies were included in the final analysis, covering 789 patients with 4047 lesions. Seven studies were included in the per-patient analysis. Pooled sensitivity and specificity were 89% (95% CI: 0.82-0.94) and 83% (95% CI: 0.78-0.86), respectively. Ten studies were included in the per-lesion analysis. Compared with the PP analysis, the corresponding pooled sensitivity declined to 77% (95% CI: 0.73-0.81) and specificity increased to 89% (95% CI: 0.87-0.90). Subgroup analysis showed that probe-based CLE (pCLE) was superior to endoscope-based CLE (eCLE) in pooled specificity [91.4% (95% CI: 89.7-92.9) vs 86.1% (95% CI: 84.3-87.8)] and AUC for the sROC (0.885 vs 0.762). CONCLUSION: Confocal laser endomicroscopy is a valid method to accurately differentiate neoplasms from non-neoplasms in BE. It can be applied to BE surveillance and early diagnosis of esophageal adenocarcinoma.

[Detection of serum antibodies against Japanese encephalitis virus in bats in Hainan and Guangdong Provinces of China].

OBJECTIVE: To investigate the prevalence of serum antibodies against Japanese encephalitis virus (JEV) in bats. METHODS: Blood samples from the heart were obtained from bats captured in Guangdong and Hainan Provinces in 2013. The anti-JEV antibodies in bat sera were tested using indirect ELISA and virus neutralization test. RESULTS: A total of 201 bat serum samples were tested, in which the total positivity rate of anti-JEV antibodies was 46.27% (93/201). The positive rate of anti-JEV antibodies in bats from Hainan and Guangdong Provinces was 88.89% (48/54) and 30.61% (45/147), respectively. All the samples from Rousettus leschenaultia, Miniopterus schreibersii, Pipistrellus abramus, and Rhinolophus macrotis were positive for anti-JEV antibodies, and up to 95.56% (43/45) of the samples from Miniopterus schreibersii (from Hainan Province) yielded positive results. Of the 28 samples with positive results by indirect ELISA, 15 showed positive results in virus neutralization test (53.57%) with neutralization antibody titers ranging from 1:10 to 1:28.22. CONCLUSION: Bats from different regions and of different species can be naturally infected with JEV and have a high prevalence of anti-JEV antibodies in their sera. The role of bats in the natural cycle of JEV awaits further study.