Multi-drug-resistant Klebsiella pneumoniae (MDR K. pneumonia) is increasingly being reported with corresponding increase in morbidity and mortality all over the world. However, limited information is available concerning MDR K. pneumonia in giant pandas. The objective of this study was to grasp the drug resistance profile of MDR K. pneumonia isolated from giant pandas. A total of 182 K. pneumoniae isolates were collected from fresh feces of 94 captive giant pandas of different ages and sex and separated by season. We performed a standard disk diffusion antimicrobial susceptibility test with the isolates and further evaluated the antibiotic resistance genes (ARGs) of multi-drug-resistant strains by high-throughput quantitative PCR. In addition, we then analyzed mobile genetic elements (MGEs), integron gene cassettes, and the multi-locus sequence typing of multi-drug-resistant strains by PCR. Antimicrobial susceptibility testing results demonstrated that a total of 30 (16.5%) K. pneumoniae isolates showed multiple drug resistances. The thirty MDR K. pneumonia isolates were mainly resistant to amoxicillin (100.0%), doxycycline (86.7%), chloramphenicol (60.0%), compound trimethoprim (60.0%) and trimethoprim (56.7%). Fifty different types of antibiotic resistance genes were found, which included a total of 671 antibiotic resistance genes, in the 30 multi-drug-resistant isolates. The top ten resistance genes were: vanTC-02, aacC, blaCTX-M-04, blaSHV-01, blaSHV-02, ampC-04, blaOXY, tetD, blaTEM and tetA-02. Thirteen mobile genetic elements were detected, of which IS26 (96.67%) and intI1 (96.67%) had the highest frequency. The thirty MDR K. pneumonia isolates were negative for the traA, traF, tnsA, IS1133, ISpa7, ISkpn6, intI2 and intI3 genes. Moreover, a further investigation of integrons revealed that two types of specific gene cassettes (dfrA12 + orfF + aadA2 and dfrA12 + orfF) were identified in class 1 integrons. Multi-locus sequence typing results showed that 22 STs in the thirty MDR K. pneumonia isolates were identified, the main type was ST37 (5/30). Our results illustrate that effective surveillance and strict biosecurity strategies should be taken to prevent the spread of multi-drug-resistant bacteria, and monitor the emergence of mobile genetic elements and integrons.

Bacterial infection and imbalance of bacterial community in the genitourinary system of giant panda could affect the reproductive health. In severe cases, it can also lead to abortion. In this study, 13 of vaginal secretions in the estrue (E) group and seven of vaginal secretions in the non-estrue (NE) group were used to study the composition and diversity of vaginal bacterial communities between estrus and non-estrus by 16S rRNA gene sequencing analysis. The results showed that the vaginal microbiome in giant pandas shared the same top five abundant species between estrus and non-estrus at the phylum level. However, the vaginal microbiome changed significantly during estrus at the genus level. In top 10 genera, the abundance of Escherichia, Streptococcus, and Bacteroides in the E group was significantly higher than that in the NE group (p<0.05); Azomonas, Porphyromonas, Prevotella, Campylobacter, and Peptoniphilus in the NE group was significantly higher than that in the E group (p<0.05). The richness and diversity of vaginal microbiome in giant panda on estrus were significantly lower than those on non-estrus (p<0.05). It is noteworthy that the abundance of Streptococcus, Escherichia, and Bacteroides of vagina in giant pandas maintained low abundance in the daily. Whereas, they increased significantly during estrus period, which may play an important role in female giant pandas during estrus period. It was hypothesized that hormones may be responsible for the changes in the vaginal microbiome of giant pandas between estrus and no-estrus stages.

Background: Parasitic infections are among the important causes of death of giant pandas (Ailuropoda melanoleuca) that hamper their survival in the wild. There are about 35 species of parasites which have been identified in giant pandas, but no information is currently available regarding the infection of Babesia in giant pandas. Babesia spp. are common intraerythrocytic parasite in wildlife, transmitted by ixodid ticks, which cause babesiosis. Clinical signs of babesiosis include fever, hemolysis, anemia, jaundice and death. Methods: A species of Babesia was detected in the blood of a giant panda based on morphology and PCR amplification of the 18S rRNA gene. The phylogenetic relationship of Babesia sp. infecting giant panda was assessed by gene sequence alignment and phylogenetic analysis. Results: Our analysis revealed that the Babesia isolate detected was most similar to an unidentified species of Babesia identified in black bears (Ursus thibetanus japonicus) from Japan (Babesia sp. Iwate, AB586027.1) with a 99.56% sequence similarity, followed by Babesia sp. EBB (AB566229.1, 99.50%) and Babesia sp. Akita (AB566229.1, 99.07%). Conclusions: To our knowledge, this is the first report of Babesia detected in the giant panda. The results indicate that this Babesia sp. may be a novel species, currently named Babesia sp. strain EBP01.

Introduction: The giant panda (Ailuropoda melanoleuca) reproduction is of worldwide attention, and the vaginal microbiome is one of the most important factors affecting the reproductive rate of giant pandas. The aim of this study is to investigate the diversity of vaginal mycobiota structure, and potential pathogenic fungi in female giant pandas during estrus and non-estrus.Methods: This study combined with high-throughput sequencing and laboratory testing to compare the diversity of the vaginal mycobiota in giant pandas during estrus and non-estrus, and to investigate the presence of potentially pathogenic fungi. Potentially pathogenic fungi were studied in mice to explore their pathogenicity.Results and discussion: The results revealed that during estrus, the vaginal secretions of giant pandas play a crucial role in fungal colonization. Moreover, the diversity of the vaginal mycobiota is reduced and specificity is enhanced. The abundance of Trichosporon and Cutaneotrichosporon in the vaginal mycobiota of giant pandas during estrus was significantly higher than that during non-estrus periods. Apiotrichum and Cutaneotrichosporon were considered the most important genera, and they primarily originate from the environment owing to marking behavior exhibited during the estrous period of giant pandas. Trichosporon is considered a resident mycobiota of the vagina and is an important pathogen that causes infection when immune system is suppressed. Potentially pathogenic fungi were further isolated and identified from the vaginal secretions of giant pandas during estrus, and seven strains of Apiotrichum (A. brassicae), one strain of Cutaneotrichosporon (C. moniliiforme), and nine strains of Trichosporon (two strains of T. asteroides, one strain of T. inkin, one strain of T. insectorum, and five strains of T. japonicum) were identified. Pathogenicity results showed that T. asteroides was the most pathogenic strain, as it is associated with extensive connective tissue replacement and inflammatory cell infiltration in both liver and kidney tissues. The results of this study improve our understanding of the diversity of the vaginal fungi present in giant pandas and will significantly contribute to improving the reproductive health of giant pandas in the future.

Background: Extended-spectrum β-lactamases (ESBL)-producing strains of Klebsiella pneumoniae remain a worldwide, critical clinical concern. However, limited information was available concerning ESBL-producing Klebsiella pneumoniae in giant pandas. The objective of this study was to characterize ESBL-producing Klebsiella pneumoniae isolates from captive giant pandas. A total of 211 Klebsiella pneumoniae isolates were collected from 108 giant pandas housed at the Chengdu Research Base of Giant Panda Breeding (CRBGP), China. Samples were screened for the ESBL-producing phenotype via the double-disk synergy test. Result: A total of three (1.42%, n = 3/211) ESBL-producing Klebsiella pneumoniae strains were identified, and characterization of ESBL-producing Klebsiella pneumoniae isolates were studied by the detection of ESBL genes and mobile genetic elements (MGEs), evaluation of antimicrobial susceptibility and detection of associated resistance genes. Clonal analysis was performed by multi-locus sequencing type (MLST). Among the three ESBL-producing isolates, different ESBL-encoding genes, including bla_CTX-M, and bla_TEM, were detected. These three isolates were found to carry MGEs genes (i.e., IS903 and tnpU) and antimicrobial resistance genes (i.e., aac(6')-Ib, aac(6')-I, qnrA, and qnrB). Furthermore, it was found that the three isolates were not hypermucoviscosity, resistant to at least 13 antibiotics and belonged to different ST types (ST37, ST290, and ST2640). Conclusion: Effective surveillance and strict infection control strategies should be implemented to prevent outbreaks of ESBL-producing Klebsiella pneumoniae in giant pandas.