Characterization of Extended-Spectrum ß-Lactamase-Producing Escherichia coli in Animal Farms in Hunan Province, China.

Multi-drug resistance of bacteria producing extended-spectrum ß-lactamase (ESBL) is a public health challenge. Thus, this study aimed to investigate the antimicrobial susceptibility of ESBL-producing Escherichia coli (ESBL-EC) in Hunan Province, China. A total of 1366 fecal samples were collected from pig, chicken, and cattle farms over a six-year period, which were assessed using strain isolation, 16S rRNA identification, polymerase chain reaction, drug sensitivity testing, whole-genome sequencing, and bioinformatics analysis. The results showed an overall prevalence of 6.66% for ESBL-EC strains, with ESBL positivity extents for pigs, chickens, and cattle isolates at 6.77%, 6.54%, and 12.5%, respectively. Most ESBL-EC isolates were resistant to cefotaxime, tetracycline, and trimethoprim-sulfamethoxazole; however, all the isolates were susceptible to meropenem, with relatively low resistance to amikacin and tigecycline. Various multi-locus sequence types with different origins and similar affinities were identified, with ST155 (n = 16) being the most common subtype. Several types of resistance genes were identified among the 91 positive strains, with beta-lactamase blaCTX-M-55 being the most common ESBL genotype. IncFIB was the predominant plasmid type. Widespread use of antibiotics in animal farming may increase antibiotic resistance, posing a serious threat to the health of farmed animals and, thus, to human food security and health.

Serotyping and Antimicrobial Resistance Profiling of Multidrug-Resistant Non-Typhoidal Salmonella from Farm Animals in Hunan, China.

Non-typhoidal Salmonella (NTS) is a foodborne pathogen and a prevalent causative agent for disease outbreaks globally. The Salmonella enterica serovar 4,[5],12:i:- (S.4,[5],12:i:-) belongs to the monophasic variant of Salmonella typhimurium, which is of current global concern. In this study, the epidemiology and genomic characterization of S. 4,[5],12:i:- isolates from 17 livestock farms in Hunan Province between 2019 and 2020, as well as their susceptibility to 14 antimicrobial agents, were profiled. Twelve Salmonella serotypes were identified using the White-Kauffmann-Le Minor scheme, and whole-genome sequencing analyses were conducted based on these isolates. Overall, 107 Salmonella strains were isolated, of which 73% (78/107) were multidrug resistant. Resistance to tetracycline (85.05%) was found to be the most prevalent, followed by the oqxAB and aac(6')-Ib-cr genes. S. typhimurium (monophasic) 4,[5],12:i:- was the most common serotype, followed by S. typhimurium and S. derby. Most antimicrobial-resistant strains were isolated from pigs, indicating that they could be important reservoirs of resistant non-typhoidal Salmonella strains. The presence of similar genetic environments in S. 4,[5],12:i:- indicates both vertical and horizontal transmission of resistance plasmids, which may promote the spread of drug resistance genes. Appropriate measures should be taken to curb the prevalence of S. 4,[5],12:i:-.

Characteristics of tet(X4)-Producing Escherichia coli in Chicken and Pig Farms in Hunan Province, China.

BACKGROUND: The plasmid-mediated tigecycline resistance gene tet(X4) confers a high level of resistance to tigecycline. The experiment aims to investigate the prevalence and characterization of tet(X4) in Escherichia coli isolates from chicken and pig farms in Hunan province, China. METHODS: A total of six tet(X4) positive strains were identified in 257 E. coli derived from chicken samples in Xiangtan city (n = 2), pig samples in Xiangxiang city (n = 1), Chenzhou city (n = 2), and Zhuzhou city (n = 1). The presence of tet(X4) was directly detected by PCR assay, and then the broth dilution method determined the antimicrobial susceptibility profile of the tet(X4)-positive isolates. Genomic locations were identified by whole-genome sequencing (WGS) and bioinformatics. RESULTS: Almost all tet(X4)-positive strains showed high resistance to multidrug, including tigecycline. Resistome analysis revealed many antibiotic resistance genes, including those with resistance to tetracyclines, ß-lactams, phenicols, quinolones, lincosamides chloramphenicol, aminoglycosides and sulfamids. These tet(X4)-bearing strains exhibited six distract STs, such as ST10, 202, ST218, ST362, ST2077, ST7068. The plasmid replicon types carrying tet(X4) were the hybrid plasmid IncFIA(HI1)/IncHIA/IncHIB(R27) (5/6) and IncX1 (1/6). CONCLUSIONS: The presence of similar genetic environments in E. coli from different cities suggests there may be horizontal transmission pathways promoting the broad spread of drug-resistant genes in Hunan Province, putting great pressure on multidrug resistance monitoring.

Characteristics of the plasmid-mediated colistin-resistance gene mcr-1 in Escherichia coli isolated from a veterinary hospital in Shanghai.

The mobile colistin-resistance (mcr)-1 gene is primarily detected in Enterobacteriaceae species, such as Escherichia coli and Salmonella enterica, and represents a significant public health threat. Herein, we investigated the prevalence and characteristics of mcr-1-positive E. coli (MCRPEC) in hospitalized companion animals in a pet hospital in Shanghai, China, from May 2021 to July 2021. Seventy-nine non-duplicate samples were collected from the feces (n = 52) and wounds (n = 20) of cats and dogs and the surrounding hospital environment (n = 7). Seven MCRPEC strains, identified using screening assays and polymerase chain reaction, exhibited multidrug-resistant phenotypes in broth-microdilution and agar-dilution assays. Based in whole-genome sequencing and bioinformatics analyses, all seven isolates were determined to belong to sequence type (ST) 117. Moreover, the Incl2 plasmid was prevalent in these MCRPEC isolates, and the genetic environment of the seven E. coli strains was highly similar to that of E. coli SZ02 isolated from human blood. The isolates also harbored the ß-lactamase gene bla CTX-M-65, and florfenicol resistance gene floR, among other resistance genes. Given that horizontal transfer occurred in all seven strains, E. coli plasmid transferability may accelerate the emergence of multidrug-resistant bacteria and may be transmitted from companion animals to humans. Therefore, the surveillance of MCRPEC isolates among companion animals should be strengthened.

Occurrence of blaNDM-1-Positive Providencia spp. in a Pig Farm of China.

Antibiotics have been extensively used to ensure the productivity of animals on intensive livestock farms. Accordingly, antimicrobial-resistant organisms, which can be transmitted to humans via the food chain, pose a threat to public health. The Enterobacterium antimicrobial resistance gene, blaNDM-1, is a transmissible gene that has attracted widespread attention. Here, we aimed to investigate the prevalence of Enterobacteriaceae carrying blaNDM-1 on an intensive pig farm. A total of 190 samples were collected from a pig farm in Hunan Province, China. Resistant isolates were selected using MacConkey agar with meropenem and PCR to screen for blaNDM-1-positive isolates. Positive strains were tested for conjugation, antimicrobial susceptibility, and whole-genome sequencing. Four blaNDM-1-positive Providencia strains were obtained, and multidrug resistance was observed in these strains. The structure carrying blaNDM-1 did not conjugate to E. coli J53 after three repeated conjugation assays. This suggests that, in intensive farming, attention should be focused on animal health and welfare to reduce the frequency of antibiotic usage. Carbapenem-resistant Enterobacteriaceae in the breeding industry should be included in systematic monitoring programs, including animal, human, and environmental monitoring programs.

Structure and function encoding of a bidirectional activatable synergetic DNA machine for speeded and ultrasensitive determination of microRNAs.

This work describes the unique design of a bidirectional activatable synergetic DNA machine (BAS-DNA machine) for speeded and ultrasensitive determination of microRNA-21 (miR-21), a well-known biomarker for biomedical research and early diagnosis of lung cancer. The BAS-DNA machine is composed by a pair of track strands (Track 1 and Track 2) encoding with two regions in the opposite direction for miR-21 recognition. Introduction of miR-21 can hybridize either with Track 1 or with Track 2 to activate the BAS-DNA machine with a synergistic effect for speeded amplifying the fluorescence signal. Moreover, compared with common DNA machine with only one switch for exogenous target recognition, the BAS-DNA machine with two switches for miR-21 binding allows the speeded and strong operation of the autonomous strand scission, replication, and displacement on Track 1 and Track 2 simultaneously. This behavior makes the BAS-DNA machine powerful for ultrasensitive, specific, and fast screening of miR-21 even from real biological samples, and the fluorescence signal was found to be linear from 1 pM to 10 nM with a detection limit of 703.6 fM. We envision this BAS-DNA machine with its superior assay performance will provide a new avenue for simple, sensitive, and affordable biomedical assays.

TTN/TP53 mutation might act as the predictor for chemotherapy response in lung adenocarcinoma and lung squamous carcinoma patients.

BACKGROUND: Chemotherapy is the preferred treatment in many types of cancer including lung cancer. However, most of patients resist chemotherapy resulting in disease progressive and recurrence. Titin (TTN) mutation is proved as a beneficial role in lung squamous carcinoma (LUSC), but the predictive role on chemotherapy resistance of lung cancer is still limited and discussable. METHODS: Clinical information and related somatic mutation profiles were obtained from The Cancer Genome Atlas (TCGA) database and analyzed by R-Studio using R-package. Overall survival (OS) curve and the association between gene mutation and clinical features were determined by GraphPad 6.0 software. RESULTS: Available data including 563 lung adenocarcinoma (LUAD) and 505 LUSC subjects were included in this study. Among all patients, 205 out of 563 LUAD and 326 out of 505 LUSC patients displayed TTN gene mutation. When comparing the clinical features in TTN-mutated patients to patients without TTN mutation who received chemotherapy, the tumors were always located in the upper lung in LUAD patients with TTN mutation and most of TTN-mutated subjects were at low pathological stage, which was not observed in LUSC patients. However, patients with TTN-mutation, particularly missense mutation, had a higher chemosensitivity and longer OS period than that patients without TTN mutation in both LUAD and LUSC. Of note, LUAD and LUSC patients possessed favorable OS and better chemotherapy response benefiting from TTN/tumor protein 53 (TP53) double mutation compared to TTN and TP53 mutation alone, respectively. Additionally, TTN/TP53 double mutation-initiated high rate of chemotherapy response were largely concentrated within LUAD and LUSC patients whose anatomic neoplasm subdivision were located in the upper lung. CONCLUSIONS: Collectively, TTN/TP53 co-mutation is possibly served as an effective predictor for OS and chemotherapy response in lung cancer.

Clinical characteristics of 78 cases of patients infected with coronavirus disease 2019 in Wuhan, China.

Coronavirus disease 2019 (COVID-19) emerged in Wuhan and rapidly spread throughout the world in December 2019. The present study aimed to describe the clinical characteristics and laboratory findings of 78 patients with COVID-19 in order to enhance the understanding of the disease. Medical records and data of 78 patients with COVID-19, including demographics, clinical features, laboratory findings and radiological characteristics, were collected and analyzed. Of the 78 hospitalized patients with COVID-19, the median age was 66.5 years and 48.7% of patients were male. Hypertension and diabetes were the most common chronic underlying diseases, and the most common symptoms were a cough and a fever. Furthermore, the most common findings on the chest CT were extensive ground-glass opacity and bilateral shadowing. Anemia and lymphocytopenia were the most common abnormalities identified during routine blood tests. COVID-19 caused early liver renal damage, with 52.9% of patients displaying elevated D-dimer levels, 98.7% of patients displaying elevated IL-6 levels and 80.8% of patients displaying a reduced level of low-density lipoprotein cholesterol (LDL-C). In the present single-center case study of 78 patients with COVID-19 in Wuhan, China, the patients displayed abnormal routine blood tests, liver function, renal function and levels of D-dimer, LDL-C and IL-6. Therefore, the development of drugs and vaccines that can be used to prevent and treat infections of COVID-19 is urgently required.

miR-218 expression in osteosarcoma tissues and its effect on cell growth in osteosarcoma cells.

OBJECTIVE: To investigate the expression of miR-218 and its clinical significance in osteosarcoma tissues and explore its effect on proliferation and apoptosis in osteosarcoma cells. METHODS: miR-218 expression was detected in 76 samples of surgically resected osteosarcoma and matched normal tumor-adjacent tissues using quantitative reverse transcription polymerase chain reaction (qRT-PCR). MiR-218 was over-expressed by exogenous miR-218 plasmids in Saos-2 cells, and then BrdU cell proliferation assay and flow cytometry were used to determine cell proliferation and apoptosis. RESULTS: The expression of miR-218 in osteosarcoma tissues was significantly lower than those in normal tumor-adjacent tissues (t=8.735, P<0.001). MiR-218 expression in tumor tissues was significantly correlated with tumor size (χ(2)=5.380, P=0.020), clinical stage (χ(2)=6.692, P=0.010) and distant metastasis (χ(2)=4.180, P=0.041). MiR-218 was obviously over-expressed by exogenous miR-218 plasmids (t=19.42, P<0.001), and miR-218 overexpression significantly reduced cell proliferation (t=9.045, P<0.001) and induced apoptosis (t=12.38, P<0.001) in Saos-2 cells. CONCLUSIONS: The low-expression of miR-218 is correlated with the poor clinicopathological features in osteosarcoma. Moreover, miR-218 overexpression reduces cancer cell proliferation and induces apoptosis in Saos-2 cells, suggesting that miR-218 may play a key role in the progression of human osteosarcoma.