Application of biofilm dispersion-based nanoparticles in cutting off reinfection.

Bacterial biofilms commonly cause chronic and persistent infections in humans. Bacterial biofilms consist of an inner layer of bacteria and an autocrine extracellular polymeric substance (EPS). Biofilm dispersants (abbreviated as dispersants) have proven effective in removing the bacterial physical protection barrier EPS. Dispersants are generally weak or have no bactericidal effect. Bacteria dispersed from within biofilms (abbreviated as dispersed bacteria) may be more invasive, adhesive, and motile than planktonic bacteria, characteristics that increase the probability that dispersed bacteria will recolonize and cause reinfection. The dispersants should be combined with antimicrobials to avoid the risk of severe reinfection. Dispersant-based nanoparticles have the advantage of specific release and intense penetration, providing the prerequisite for further antibacterial agent efficacy and achieving the eradication of biofilms. Dispersant-based nanoparticles delivered antimicrobial agents for the treatment of diseases associated with bacterial biofilm infections are expected to be an effective measure to prevent reinfection caused by dispersed bacteria. KEY POINTS: • Dispersed bacteria harm and the dispersant's dispersion mechanisms are discussed. • The advantages of dispersant-based nanoparticles in bacteria biofilms are discussed. • Dispersant-based nanoparticles for cutting off reinfection in vivo are highlighted.

Enhancement of dissolution rate and oral bioavailability of poorly soluble drug florfenicol by using solid dispersion and effervescent disintegration technology.

OBJECTIVE: Florfenicol(FF) is an excellent veterinary antibiotic, limited by poor solubility and poor bioavailability. SIGNIFICANCE: Here in, we aimed to explore the applicability of fast disintegrating tablets compressed from Florfenicol-loaded solid dispersions (FF-SD-FDTs) to improve the dissolution rate and oral bioavailability of Florfenicol. METHODS: Utilizing selecting appropriate preparation methods and carriers, the solid dispersions of Florfenicol (FF-SDs) were prepared by solvent evaporation and the fast disintegrating tablets (FF-SD-FDTs) were prepared by the direct compression (DC) method. RESULTS: The tablet properties including hardness, friability, disintegration time, weight variation, etc. all met the specifications of Chinese Veterinary Pharmacopeia(CVP). FF-SD-FDTs significantly improved drug dissolution and dispersion of FF in vitro compared to florfenicol conventional tablets (FF-CTs). A pharmacokinetics study in German shepherd dogs proved the AUC0-∞ and Cmax values of FF-SD-FDTs are 1.38 and 1.38 times more than FF-CTs, respectively. CONCLUSIONS: Overall, it can be concluded that FF-SD-FDTs with excellent disintegration and dissolution properties were successfully produced, which greatly improved the oral bioavailability of the poorly soluble drug FF, and the study provided a new idea for a broader role of FF in pet clinics.

New insights into the interactions between Blastocystis, the gut microbiota, and host immunity.

The human gut microbiota is a diverse and complex ecosystem that is involved in beneficial physiological functions as well as disease pathogenesis. Blastocystis is a common protistan parasite and is increasingly recognized as an important component of the gut microbiota. The correlations between Blastocystis and other communities of intestinal microbiota have been investigated, and, to a lesser extent, the role of this parasite in maintaining the host immunological homeostasis. Despite recent studies suggesting that Blastocystis decreases the abundance of beneficial bacteria, most reports indicate that Blastocystis is a common component of the healthy gut microbiome. This review covers recent finding on the potential interactions between Blastocystis and the gut microbiota communities and its roles in regulating host immune responses.

Blood metabolomics reveals the therapeutic effect of Pueraria polysaccharide on calf diarrhea.

BACKGROUND: Neonatal calf diarrhea (NCD) is typically treated with antibiotics, while long-term application of antibiotics induces drug resistance and antibiotic residues, ultimately decreasing feed efficiency. Pueraria polysaccharide (PPL) is a versatile antimicrobial, immunomodulatory, and antioxidative compound. This study aimed to compare the therapeutic efficacy of different doses of PPL (0.2, 0.4, 0.8 g/kg body weight (BW)) and explore the effect of plasma metabolites in diarrheal calves by the best dose of PPL. RESULTS: PPL could effectively improve the daily weight gain, fecal score, and dehydration score, and the dosage of 0.4 g/kg BW could reach curative efficacy against calf diarrhea (with effective rates 100.00%). Metabolomic analysis suggested that diarrhea mainly affect the levels of taurocholate, DL-lactate, LysoPCs, and intestinal flora-related metabolites, trimethylamine N-oxide; however, PPL improved liver function and intestinal barrier integrity by modulating the levels of DL-lactate, LysoPC (18:0/0:0) and bilirubin, which eventually attenuated neonatal calf diarrhea. It also suggested that the therapeutic effect of PPL is related to those differential metabolites in diarrheal calves. CONCLUSIONS: The results showed that 0.4 g/kg BW PPL could restore the clinical score of diarrhea calves by improving the blood indexes, biochemical indexes, and blood metabolites. And it is a potential medicine for the treatment of calf diarrhea.

Experimental colonization with Blastocystis ST4 is associated with protective immune responses and modulation of gut microbiome in a DSS-induced colitis mouse model.

BACKGROUND: Blastocystis is a common gut protistan parasite in humans and animals worldwide, but its interrelationship with the host gut microbiota and mucosal immune responses remains poorly understood. Different murine models of Blastocystis colonization were used to examine the effect of a common Blastocystis subtype (ST4) on host gut microbial community and adaptive immune system. RESULTS: Blastocystis ST4-colonized normal healthy mice and Rag1-/- mice asymptomatically and was able to alter the microbial community composition, mainly leading to increases in the proportion of Clostridia vadinBB60 group and Lachnospiraceae NK4A136 group, respectively. Blastocystis ST4 colonization promoted T helper 2 (Th2) response defined by interleukin (IL)-5 and IL-13 cytokine production, and T regulatory (Treg) induction from colonic lamina propria in normal healthy mice. Additionally, we observed that Blastocystis ST4 colonization can maintain the stability of bacterial community composition and induce Th2 and Treg immune responses to promote faster recovery from experimentally induced colitis. Furthermore, fecal microbiota transplantation of Blastocystis ST4-altered gut microbiome to colitis mice reduced the severity of colitis, which was associated with increased production of short-chain fat acids (SCFAs) and anti-inflammatory cytokine IL-10. CONCLUSIONS: The data confirm our hypothesis that Blastocystis ST4 is a beneficial commensal, and the beneficial effects of Blastocystis ST4 colonization is mediated through modulating of the host gut bacterial composition, SCFAs production, and Th2 and Treg responses in different murine colonization models.

Trichosporon asahii PLA2 Gene Enhances Drug Resistance to Azoles by Improving Drug Efflux and Biofilm Formation.

Trichosporon asahii is an opportunistic pathogen that can cause severe or even fatal infections in patients with low immune function. sPLA2 plays different roles in different fungi and is also related to fungal drug resistance. However, the mechanism underlying its drug resistance to azoles has not yet been reported in T. asahii. Therefore, we investigated the drug resistance of T. asahii PLA2 (TaPLA2) by constructing overexpressing mutant strains (TaPLA2OE). TaPLA2OE was generated by homologous recombination of the recombinant vector pEGFP-N1-TaPLA2, induced by the CMV promoter, with Agrobacterium tumefaciens. The structure of the protein was found to be typical of sPLA2, and it belongs to the phospholipase A2_3 superfamily. TaPLA2OE enhanced antifungal drug resistance by upregulating the expression of effector genes and increasing the number of arthrospores to promote biofilm formation. TaPLA2OE was highly sensitive to sodium dodecyl sulfate and Congo red, indicating impaired cell wall integrity due to downregulation of chitin synthesis or degradation genes, which can indirectly affect fungal resistance. In conclusion, TaPLA2 overexpression enhanced the resistance to azoles of T. asahii by enhancing drug efflux and biofilm formation and upregulating HOG-MAPK pathway genes; therefore, it has promising research prospects.

Integrated Transcriptome and Metabolomics to Reveal the Mechanism of Adipose Mesenchymal Stem Cells in Treating Liver Fibrosis.

Liver fibrosis (LF) is a late-stage process observed in various chronic liver diseases with bile and retinol metabolism closely associated with it. Adipose-derived mesenchymal stem cells (ADMSCs) have shown significant therapeutic potential in treating LF. In this study, the transplantation of ADMSCs was applied to a CCl4-induced LF model to investigate its molecular mechanism through a multi-omics joint analysis. The findings reveal that ADMSCs effectively reduced levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), gamma-glutamyltransferase (GGT), Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and α-Smooth muscle actin (α-SMA), thereby mitigating liver lesions, preventing liver parenchymal necrosis, and improving liver collagen deposition. Furthermore, 4751 differentially expressed genes (DEGs) and 270 differentially expressed metabolites (DMs) were detected via transcriptome and metabolomics analysis. Conjoint analysis showed that ADMSCs up-regulated the expression of Cyp7a1, Baat, Cyp27a1, Adh7, Slco1a4, Aldh1a1, and Adh7 genes to promote primary bile acids (TCDCA: Taurochenodeoxycholic acid; GCDCA: Glycochenodeoxycholic acid; GCA: glycocholic acid, TCA: Taurocholic acid) synthesis, secretion and retinol metabolism. This suggests that ADMSCs play a therapeutic role in maintaining bile acid (BA) homeostasis and correcting disturbances in retinol metabolism.

Zinc Oxide Quantum Dots May Provide a Novel Potential Treatment for Antibiotic-Resistant Streptococcus agalactiae in Lama glama.

Streptococcus agalactiae is a significant pathogen that can affect both human beings and animals. The extensive current use of antibiotics has resulted in antibiotic resistance. In our previous research, we found that zinc oxide quantum dots (ZnO QDs) had inhibitory effects on antibiotic-resistant microorganisms. In this study, a strain of Streptococcus agalactiaeWJYT1 with a broad antibiotic-resistant spectrum was isolated and identified from Lama glama at Sichuan Agricultural University Teaching Animal Hospital. The genome for the resistance and virulence genes was analyzed. Additionally, the antibacterial effects and anti-virulence mechanism of ZnO QDs for S. agalactiaeWJYT1 were investigated. The results showed that the genome of S. agalactiaeWJYT1 is 1,943,955 bp, containing 22 resistance genes and 95 virulence genes. ZnO QDs have a good antibacterial effect against S. agalactiaeWJYT1 by reducing bacterial growth and decreasing the expression of virulence genes, including bibA, hylB, sip, and cip, which provides a novel potential treatment for S. agalactiae.

Innate and mild Th17 cutaneous immune responses elicited by subcutaneous infection of immunocompetent mice with Cladosporium cladosporioides.

Cladosporium cladosporioides is a dematiaceous hyphomycete that is pathogenic in the superficial and deep tissues of both immunodeficient and immunocompetent humans and animals. Our aim was to evaluate the antifungal immune responses elicited by C. cladosporioides in immunocompetent mice. Hence, we subcutaneously injected suspensions of C. cladosporioides spores into immunocompetent mice to investigate the anti-fungal immune responses in the skin. We collected skin tissue samples for histopathological examination, immunofluorescence staining, and quantitative real-time polymerase chain reaction analysis. We observed subcutaneous abscesses in mice after subcutaneous injection of C. cladosporioides. A large number of inflammatory cells, including dendritic cells, macrophages, and neutrophils, infiltrated the focal abscess, with comparatively few infiltrating inflammatory cells in the epidermal and dermal layers of the skin. We detected the expression of CD54 in the abscesses and the skin. Gene expression of the pattern recognition receptors Dectin-1 and TLR-2 was higher in infected mice than in controls. Gene expression of the cytokines IL-6, IL-1ß, and IL-17A also increased after infection, suggesting that the Th17 signaling pathway may be involved in the anti-fungal response. Although the pathogenicity of C. cladosporioides in healthy mice was weak after subcutaneous infection, resulting in few serious pathological phenomena, it appears that innate and Th17 immune responses play important roles in the cutaneous host response to C. cladosporioides. These findings lay a foundation for further study of the pathogenic mechanism and treatment of C. cladosporioides infection.

Nanocarriers for combating biofilms: Advantages and challenges.

Bacterial biofilms are highly resistant to antibiotics and pose a great threat to human and animal health. The control and removal of bacterial biofilms have become an important topic in the field of bacterial infectious diseases. Nanocarriers show great anti-biofilm potential because of their small particle size and strong permeability. In this review, the advantages of nanocarriers for combating biofilms are analysed. Nanocarriers can act on all stages of bacterial biofilm formation and diffusion. They can improve the scavenging effect of biofilm by targeting biofilm, destroying extracellular polymeric substances and enhancing the biofilm permeability of antimicrobial substances. Nanocarriers can also improve the antibacterial ability of antimicrobial drugs against bacteria in biofilm by protecting the loaded drugs and controlling the release of antimicrobial substances. Additionally, we emphasize the challenges faced in using nanocarrier formulations and translating them from a preclinical level to a clinical setting.

Role of Hfq in glucose utilization, biofilm formation and quorum sensing system in Bacillus subtilis.

Hfq is an RNA-binding protein, its main function is to participate in post-transcriptional regulation of bacteria and regulate small regulatory RNA (sRNA) and messenger RNA (mRNA) stability, but the Hfq function of Bacillus subtilis (B. subtilis) has not been fully explained. In this study, we used the strains of B. subtilis168 (BS168), BS168Δhfq and BS168Δhfq-C to explore the effects of Hfq on the glucose utilization, biofilm formation and quorum sensing (QS) system of B. subtilis. The results showed that the knockout of hfq resulted in growth defects when bacteria were cultured in the Luria-Bertani (LB) medium, but we did not observe the same effects in Nitrogen medium (NM) and Inorganic Salt-free medium (ISM). We further found that the growth of strains under different glucose concentrations was also different, which was related to the expression of CcpA. Interestingly, the hfq mutant showed increased resistance to a high-glucose environment. Furthermore, the biofilm and extracellular poly saccharides (EPS) formation of BS168Δhfq decreased significantly. At the same time, changes were observed in the morphology of the biofilm, such as larger intercellular space of the biofilm and thinner edge. The qRT-PCR results confirmed that the hfq knockout caused significant up-regulation or down-regulation of gene expression in QS system, and down-regulated genes were involved in the positive regulation of biofilm formation. Taken together, we demonstrated that Hfq plays a vital role in glucose utilization, biofilm formation and QS of B. subtilis, which provides a new perspective for subsequent related research.

Microsporum gypseum Isolated from Ailuropoda melanoleuca Provokes Inflammation and Triggers Th17 Adaptive Immunity Response.

Microsporum gypseum causes dermatomycoses in giant pandas (Ailuropoda melanoleuca). This study aimed to investigate the immune response of M. gypseum following deep infection. The degree of damage to the heart, liver, spleen, lungs, and kidneys was evaluated using tissue fungal load, organ index, and histopathological methods. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) detected the mRNA expression of receptors and cytokines in the lung, and immunofluorescence staining and flow cytometry, were used to assess immune cells in the lung. The results indicated that conidia mainly colonized the lungs and caused serious injury with M. gypseum infection. Furthermore, dectin-1, TLR-2, and TLR-4 played a role in recognizing M. gypseum cells. Numerous inflammatory cells, mainly macrophages, dendritic cells, polymorphonuclear neutrophils, and inflammatory cytokines (TGF-ß, TNF-α, IL-1ß, IL-6, IL-10, IL-12, and IL-23), were activated in the early stages of infection. With the high expression of IL-22, IL-17A, and IL-17F, the Th17 pathway exerted an adaptive immune response to M. gypseum infection. These results can potentially aid in the diagnosis and treatment of diseases caused by M. gypseum in giant pandas.

RNA-binding protein Hfq plays a vital role in cellulose decomposition throughout affecting cellulase gene expression.

OBJECTIVE: To study the function of the RNA-binding protein Hfq in Bacillus subtilis cellulose decomposition. RESULTS: In the medium with sodium carboxymethylcellulose (Na-CMC) as the sole carbon source, the knockout of Hfq resulted in a 38.0% ± 2.1% and 76.6% ± 7.1% decrease in cellulose hydrolysis ability and cellulase activity, respectively. The results of real-time quantitative PCR revealed that several cellulase genes (eglS, bglA, and bglC) were significantly downregulated in the Hfq knockout strain. The isogenic Δhfq complemented strain recovered the cellulose hydrolysis ability, cellulase activity, and expression level of cellulase genes. In addition, the survival of Hfq mutant in stationary phase was significantly affected. CONCLUSION: RNA-binding protein Hfq is involved in the regulation of cellulose hydrolysis ability, cellulase activity, cellulase gene expression, and stationary phase survival.

First identification and genotyping of Enterocytozoon bieneusi and Encephalitozoon spp. in pet rabbits in China.

BACKGROUND: Microsporidia are common opportunistic parasites in humans and animals, including rabbits. However, only limited epidemiology data concern about the prevalence and molecular characterization of Enterocytozoon bieneusi and Encephalitozoon spp. in rabbits. This study is the first detection and genotyping of Microsporidia in pet rabbits in China. RESULTS: A total of 584 faecal specimens were collected from rabbits in pet shops from four cities in Sichuan province, China. The overall prevalence of microsporidia infection was 24.8% by nested PCR targeting the internal transcribed spacer (ITS) region of E. bieneusi and Encephalitozoon spp. respectively. E. bieneusi was the most common species (n = 90, 15.4%), followed by Encephalitozoon cuniculi (n = 34, 5.8%) and Encephalitozoon intestinalis (n = 16, 2.7%). Mixed infections (E. bieneusi and E. cuniculi) were detected in five another rabbits (0.9%). Statistically significant differences in the prevalence of microsporidia were observed among different cities (χ2 = 38.376, df = 3, P < 0.01) and the rabbits older than 1 year were more likely to harbour microsporidia infections (χ2 = 9.018, df = 2, P < 0.05). Eleven distinct genotypes of E. bieneusi were obtained, including five known (SC02, I, N, J, CHY1) and six novel genotypes (SCR01, SCR02, SCR04 to SCR07). SC02 was the most prevalent genotype in all tested cities (43.3%, 39/90). Phylogenetic analysis showed that these genotypes were clustered into group 1-3 and group 10. Meanwhile, two genotypes (I and II) were identified by sequence analysis of the ITS region of E. cuniculi. CONCLUSION: To the best of our knowledge, this is the first report of microsporidia infection in pet rabbits in China. Genotype SC02 and four novel genotypes were classified into potential zoonotic group 1, suggesting that pet rabbits may cause microsporidiosis in humans through zoonotic transmissions. These findings provide preliminary reference data for monitoring microsporidia infections in pet rabbits and humans.

Relationships between placental adiponectin, leptin, visfatin and resistin and birthweight in cattle.

Adipokines can affect intrauterine development while calf birthweight (CBW) is a breeding standard of calves, which reflects the status of fetal intrauterine development. To explore the correlation between placental adipokines and CBW, 54 healthy Chinese Holstein cows were used in the present study. The cows were grouped according to the CBW of their calves. Placentas were collected immediately after delivery and enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction were used to detect the placental expression levels of adiponectin, leptin, visfatin and resistin. Our results show that the mRNA transcription and blood placental content of adiponectin, leptin, visfatin and resistin increased with increasing CBW. The analysis showed that the mRNA transcription levels of placental adiponectin, leptin and resistin were positively correlated with CBW. The mRNA and protein expression levels of adiponectin, leptin and visfatin between the three groups were significantly correlated. Placental resistin mRNA levels correlated positively with adiponectin mRNA, but not leptin or visfatin. The protein expression levels of resistin were significantly positively correlated with those of adiponectin, leptin and visfatin. These results suggest that placental adipokines play important roles in regulating calf intrauterine growth.

High prevalence of multi-drug resistances and diversity of mobile genetic elements in Escherichia coli isolates from captive giant pandas.

The purpose of this study was to characterize the antimicrobial resistance produced by mobile genetic elements and integron gene cassettes in Escherichia coli isolated from the feces of captive giant pandas. We performed a standard disk diffusion antimicrobial susceptibility test with 84 E. coli isolates and further evaluated the mobile genetic elements and integron gene cassettes. The antimicrobial susceptibility test demonstrated that 43.37% (36/84) of the isolates showed multiple drug resistances. The E. coli isolates mainly showed resistance to aztreonam (86.90%, 73/84) and amoxicillin/clavulanic acid (80.95%, 68/84). The most frequently observed resistance patterns were ampicillin/amoxicillin-clavulanic acid (13.10%, n = 11), and doxycycline/amoxicillin-clavulanic acid (4.76%, n = 4). Further analyses detected 11 mobile genetic elements, of which merA (54/84, 64.30%) had the highest frequency. All isolates were negative for intI3, traA, tnpU, traF, tnp513, tnsA, ISkpn7, ISpa7, ISkpn6, and ISCR1. We further analyzed antimicrobial resistance-related integrons among 30 E. coli isolates (the 27 intI1-positive isolates and the 3 intI2-positive isolates); six gene cassette profiles (dfrA17+aadA5, aadA2, dfrA12+aadA2, dfrA1+aadA1, dfrA1, and aadA1) were identified in the 27 intI1-positive isolates, but not in the three intI2-positive ones. Our study sheds light on the prevalence of multiple drug resistances and the diversity of mobile genetic elements in E. coli isolates, and highlights the necessity to monitor antibiotic resistance in more E. coli strains from captive giant pandas.

Identification, genotyping, and pathogenicity of Trichosporon spp. Isolated from Giant pandas (Ailuropoda melanoleuca).

BACKGROUND: Trichosporon is the dominant genus of epidermal fungi in giant pandas (Ailuropoda melanoleuca) and causes local and deep infections. To provide the information needed for the diagnosis and treatment of trichosporosis in giant pandas, the sequence of ITS, D1/D2, and IGS1 loci in 29 isolates of Trichosporon spp. which were isolated from the body surface of giant pandas were combination to investigate interspecies identification and genotype. Morphological development was examined via slide culture. Additionally, mice were infected by skin inunction, intraperitoneal injection, and subcutaneous injection for evaluation of pathogenicity. RESULTS: The twenty-nine isolates of Trichosporon spp. were identified as 11 species, and Trichosporon jirovecii and T. asteroides were the commonest species. Four strains of T. laibachii and one strain of T. moniliiforme were found to be of novel genotypes, and T. jirovecii was identified to be genotype 1. T. asteroides had the same genotype which involved in disseminated trichosporosis. The morphological development processes of the Trichosporon spp. were clearly different, especially in the processes of single-spore development. Pathogenicity studies showed that 7 species damaged the liver and skin in mice, and their pathogenicity was stronger than other 4 species. T. asteroides had the strongest pathogenicity and might provoke invasive infection. The pathological characteristics of liver and skin infections caused by different Trichosporon spp. were similar. CONCLUSIONS: Multiple species of Trichosporon were identified on the skin surface of giant panda, which varied in morphological development and pathogenicity. Combination of ITS, D1/D2, and IGS1 loci analysis, and morphological development process can effectively identify the genotype of Trichosporon spp.

Molecular characterization and new genotypes of Enterocytozoon bieneusi in pet chipmunks (Eutamias asiaticus) in Sichuan province, China.

BACKGROUND: Enterocytozoon bieneusi, the most commonly identified microsporidian species in humans, is also identified in livestock, birds, rodents, reptiles, companion animals, even wastewater. However, there is no information available on occurrence of E. bieneusi in pet chipmunks. The aim of the present study was to determine the genotypes, molecular characterization of E. bieneusi in pet chipmunks, and assess the zoonotic potential. RESULTS: A total of 279 fecal specimens were collected from chipmunks from seven pet shops and one breeding facility in Sichuan province, China. The prevalence for E. bieneusi was 17.6% (49/279) based on nested PCR targeting the internal transcribed spacer (ITS) region. The prevalence of E. bieneusi in chipmunks < 90 days of age was significantly higher than that in older chipmunks; however, differences among different sources and between genders were not significant. Eight genotypes of E. bieneusi were identified, including four known genotypes (D, Nig7, CHG9, and CHY1) and four novel genotypes (SCC-1 to 4). Phylogenetic analysis classified these genotypes into four distinct groups as follows: genotypes D and CHG9 clustered into group 1 of zoonotic potential; genotypes Nig7 and CHY1 clustered into group 6 and a new group, respectively; the four novel genotypes (SCC-1 to 4) formed a separate group named group 10. CONCLUSIONS: To the best of our knowledge, this is the first study reporting the prevalence and genotypes of E. bieneusi in pet chipmunks in China. Genotypes D and Nig7, found in chipmunks in this study, have also been previously identified in humans, which suggests that chipmunks might play a role in the transmission of this pathogen to humans.

Characterization of the Gut Microbiota in Six Geographical Populations of Chinese Rhesus Macaques (Macaca mulatta), Implying an Adaptation to High-Altitude Environment.

Knowledge about the impact of different geographical environments on rhesus macaque gut microbiota is limited. In this study, we compared the characteristics of gut microbiota in six different Chinese rhesus macaque populations, including Hainan, Nanning, Guizhou, Xichang, Jianchuan and Tibet. Through the composition analysis of operational taxonomic units (OTUs), we found that there were significant differences in the abundance of core overlapping OTUs in the six Chinese groups. Specifically, the Tibet population exhibited the highest gut microbial diversity and the most unique OTUs. Statistically significant differences in the composition of gut microbiota among the six groups at phylum and family level were evident. Specifically, Tibet had higher abundances of Firmicutes and lower abundances of Bacteroidetes than the other geographical groups, and the higher abundance of Firmicutes in the Tibetan group was mainly caused by a significant increase in the family Ruminococcaceae and Christensenellaceae. Phylogenetic investigation of communities by reconstruction of unobserved state analysis showed that the enrichment ratio for environmental information processing and organismal systems was the highest in the Tibet population. Additionally, our results suggested that in the adaptation process of rhesus macaques to different geographical environments, the abundance of the core common flora of the intestinal microbes had undergone varying degree of change and produced new and unique flora, both of which helped to reshape the gut microbiota of rhesus macaques. In particular, this change was more obvious for animals in the high-altitude environments.

Occurrence and Genetic Characteristics of Cryptosporidium hominis and Cryptosporidium andersoni in Horses from Southwestern China.

A total of 333 fecal specimens from horses in southwestern China were genotyped based on analysis of the small subunit rRNA (SSU rRNA) gene. Cryptosporidium hominis and Cryptosporidium andersoni were identified in 2 and 4 stool specimens, respectively. The identification of C. hominis was confirmed by sequence analysis of the 70-kDa heat shock protein (HSP70) and oocyst wall protein (COWP) genes. Subtyping analysis of the 60-kDa glycoprotein (GP60) gene sequence of C. hominis revealed a new rare subtype Id, named IdA15; only three Id isolates have been reported in humans to date. Multilocus sequence typing (MLST) analysis indicated that the C. andersoni subtype was A6, A5, A2, and A1 at the four minisatellite loci (MS1, MS2, MS3, and MS16, respectively). This is the first report to identify the presence of C. andersoni and C. hominis in horses in southwestern China and the first to identify a rare zoonotic subtype Id of C. hominis in horses. These findings suggest that infected horses may act as potential reservoirs of Cryptosporidium to transmit infections to humans.