Novel Providencia xianensis sp. nov.: A multidrug-resistant species identified in clinical infections.

Providencia genus is known to harbor certain opportunistic pathogens capable of causing human infections. Here, we report two strains of multidrug-resistant bacteria initially identified as Providencia rettgeri by mass spectrometry, but genome analysis revealed their ANI (79.84-84.20%) and dDDH (21.1-25.6%) values to fall below the accepted species threshold for known Providencia species. We therefore propose that these isolates be recognized as a novel species, Providencia xianensis sp. nov. Alarmingly, both strains, isolated from locations far apart, exhibited resistance to last-resort antibiotics, indicating their possible wide distribution, underscoring the urgency for immediate attention and enhanced surveillance for this emerging multidrug-resistant pathogen.

Early predictors of severe COVID-19 among hospitalized patients.

BACKGROUND: Limited research has been conducted on early laboratory biomarkers to identify patients with severe coronavirus disease (COVID-19). This study fills this gap to ensure appropriate treatment delivery and optimal resource utilization. METHODS: In this retrospective, multicentre, cohort study, 52 and 64 participants with severe and mild cases of COVID-19, respectively, were enrolled during January-March 2020. Least absolute shrinkage and selection operator and binary forward stepwise logistic regression were used to construct a predictive risk score. A prediction model was then developed and verified using data from four hospitals. RESULTS: Of the 50 variables assessed, eight were independent predictors of COVID-19 and used to calculate risk scores for severe COVID-19: age (odds ratio (OR = 14.01, 95% confidence interval (CI) 2.1-22.7), number of comorbidities (OR = 7.8, 95% CI 1.4-15.5), abnormal bilateral chest computed tomography images (OR = 8.5, 95% CI 4.5-10), neutrophil count (OR = 10.1, 95% CI 1.88-21.1), lactate dehydrogenase (OR = 4.6, 95% CI 1.2-19.2), C-reactive protein OR = 16.7, 95% CI 2.9-18.9), haemoglobin (OR = 16.8, 95% CI 2.4-19.1) and D-dimer levels (OR = 5.2, 95% CI 1.2-23.1). The model was effective, with an area under the receiver-operating characteristic curve of 0.944 (95% CI 0.89-0.99, p < 0.001) in the derived cohort and 0.8152 (95% CI 0.803-0.97; p < 0.001) in the validation cohort. CONCLUSION: Predictors based on the characteristics of patients with COVID-19 at hospital admission may help predict the risk of subsequent critical illness.

Structural insight into the role of the PAS domainfor signal transduction in sensor-kinase BvgS.

The two-component system BvgAS controls the virulence regulon in Bordetella pertussis BvgS is the prototype of a family of sensor histidine-kinases harboring periplasmic Venus flytrap (VFT) domains. The VFT domains are connected to the cytoplasmic kinase moiety by helical linkers separated by a Per-ARNT-Sim (PAS) domain. Antagonism between the two linkers, as one forms a coiled coil when the other is dynamic and vice versa, regulates BvgS activity. Here we solved the structure of the intervening PAS domain by X-ray crystallography. Two forms were obtained that notably differ by the connections between the PAS core domain and the flanking helical linkers. Structure-guided mutagenesis indicated that those connections participate in the regulation of BvgS activity. The PAS domain thus appears to function as a switch-facilitator module whose conformation determines the output of the system. As many BvgS homologs have similar architectures, the mechanisms unveiled here are likely to generally apply to the regulation of sensor-histidine kinases of that family.IMPORTANCEThe whooping cough agent Bordetella pertussis colonizes the human respiratory tract using virulence factors co-regulated by the sensory transduction system BvgAS. BvgS is a model for a family of sensor-kinase proteins, some of which are found in important bacterial pathogens. BvgS functions as a kinase or a phosphatase depending on external signals, which determines if B. pertussis is virulent or avirulent. Deciphering its mode of action might thus lead to new ways of fighting infections. Here we used X-ray crystallography to solve the three-dimensional structure of the domain that precedes the enzymatic moiety and identified features that regulate BvgS activity. As many sensor-kinases of the BvgS family harbor homologous domains, the mechanism unveiled here might be of general relevance.

Evaluation of the Autof MS1000 mass spectrometer in the identification of clinical isolates.

BACKGROUND: To evaluate the accuracy and performance of the Autof MS1000 mass spectrometer in bacteria and yeast identification, 2342 isolates were obtained from microbial cultures of clinical specimens (e.g. blood, cerebrospinal fluid, respiratory tract samples, lumbar puncture fluid, wound samples, stool, and urine) collected in 2019 in Henan Provincial People's Hospital. Repetitive strains from the same patient were excluded. We tested the Autof MS1000 and Bruker Biotyper mass spectrometry systems and the classical biochemical identification system VITEK 2/API 20C AUX. Inconsistencies in strain identification among the three systems were identified by 16S rDNA and gene sequencing. RESULTS: At the species level, the Autof MS1000 and Bruker Biotyper systems had isolate identification accuracies of 98.9 and 98.5%, respectively. At the genus level, the Autof MS1000 and Bruker Biotyper systems were 99.7 and 99.4% accurate, respectively. The instruments did not significantly differ in identification accuracy at either taxonomic level. The frequencies of unreliable identification were 1.1% (26/2342) for the Autof MS1000 and 1.5% (34/2342) for the Bruker Biotyper. In vitro experiments demonstrated that the coincidence rate of the Autof MS1000 mass spectrometer in the identification of five types of bacteria was > 93%, the identification error rate was < 3%, and the no identification rate was 0. This indicates that the Autof MS1000 system is acceptable for identification. CONCLUSIONS: The Autof MS1000 mass spectrometer can be utilised to identify clinical isolates. However, an upgradation of the database is recommended to correctly identify rare strains.

First case of infective endocarditis caused by Methylobacterium radiotolerans.

Methylobacterium radiotolerans has only been identified in blood samples from end-stage renal failure or leukaemia patients in clinic. Here, we report a case of infective endocarditis (IE) caused by M. radiotolerans. 16S rRNA sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to identify the bacteria isolated from cardiac vegetation. A drug sensitivity test was conducted by disk diffusion on blood Mueller-Hinton agar. This isolate was identified as M. radiotolerans, which was susceptible to aminoglycosides and ciprofloxacin. Our findings also suggest that M. radiotolerans can cause infection in a patient with normal immune function.

Evaluation of an optimized method to directly identify bacteria from positive blood cultures using MALDI-TOF mass spectrometry.

BACKGROUND: Although various methods have been developed to directly identify bacteria from positive blood cultures by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), the necessity of using commercial kits still leads to a high cost and long assay time. Moreover, few evaluations of these methods have been conducted. This study aimed to evaluate the feasibility of an optimized MALDI-TOF MS method for direct identification of bacteria in positive blood cultures. METHODS: A total of 829 non-repeated positive cultures were collected from July 2018 to August 2019, and direct identification was performed by an optimized MALDI-TOF MS method. The same positive blood cultures were sub-cultivated to obtain a single bacterial colony and identified by classical biochemical BD testing, which is the gold standard to compare the accuracy of direct identification of positive blood cultures by MALDI-TOF MS. RESULTS: After excluding 7 false-positive samples from the 829 positive blood cultures, the most accurate rate of direct identification by this optimized MALDI-TOF MS method was for gram-negative bacteria (91.5%), followed by gram-positive bacteria (88.3%), fungi (84.8%), anaerobic bacteria (80%), and other rare bacteria (66.67%). CONCLUSION: Common bacteria in positive blood cultures can be identified directly within 1 hour by MALDI-TOF MS, and thus, this optimized method can be used as a primary identification method by clinicians. Routine implementation of this method may significantly increase the optimal utilization rate of antibiotics and decrease mortality in bacteremia patients.

Microbiological Analysis and Mortality Risk Factors in Patients with Polymicrobial Bloodstream Infections.

Purpose: To study the etiological characteristics and risk factors affecting the prognosis of patients with polymicrobial bloodstream infections. Patients and Methods: Overall, 141 patients with polymicrobial bloodstream infections in Henan Provincial People's Hospital during 2021 were included. Laboratory test indexes, department of admission, sex, age, intensive care unit (ICU) admission, surgical history, and central venous catheter placement were collected. Patients were divided into surviving and deceased groups based on outcomes at discharge. Mortality risk factors were identified by univariate and multivariable analyses. Results: Seventy-two of 141 patients survived. Patients were mainly from the ICU and the Departments of Hepatobiliary Surgery and Hematology. Overall, 312 microbial strains were detected: 119 gram-positive, 152 gram-negative, and 13 anaerobic bacteria and 28 fungi. Among the gram-positive bacteria, coagulase-negative staphylococci were most frequent (44/119, 37%), followed by enterococci (35/119, 29.4%). Among coagulase-negative staphylococci, methicillin-resistant coagulase-negative staphylococci incidence was 75% (33/44). Among gram-negative bacteria, Klebsiella pneumoniae was most common (45/152, 29.6%), followed by Escherichia coli (25/152, 16.4%) and Pseudomonas aeruginosa (13/152, 8.6%). Among K. pneumoniae, the incidence of carbapenem-resistant (CR) K. pneumoniae was 45.7% (21/45). On univariate analysis, mortality risk factors included increased white blood cells and C-reactive protein, decreased total protein and albumin, CR strains, ICU admission, central venous catheter, multiple organ failure, sepsis, shock, pulmonary diseases, respiratory failure, central nervous system diseases, cardiovascular diseases, hypoproteinemia, and electrolyte disturbances (P < 0.05). Multivariable analysis showed that ICU admission, shock, electrolyte disorders, and central nervous system diseases were independent mortality risk factors. The survival curve shows that the survival rate of patients with polymicrobial CR bloodstream infections was lower than that of patients with polymicrobial non-CR bloodstream infections (P=0.029). Conclusion: Patients with polymicrobial bloodstream infections are typically critically ill and harbor multidrug-resistant bacteria. Thus, to minimize mortality rate in critically ill patients, changes in infectious flora should be monitored, antibiotics selected reasonably, and invasive procedures reduced.

Polynucleotide Phosphorylase Mediates a New Mechanism of Persister Formation in Escherichia coli.

Despite the identification of many genes and pathways involved in the persistence phenomenon in bacteria, the mechanisms of persistence are not well understood. Here, using Escherichia coli, we identified polynucleotide phosphorylase (PNPase) as a key regulator of persister formation. We constructed the pnp knockout strain (Δpnp) and its complemented strain and exposed them to antibiotics and stress conditions. The results showed that, compared with the wild-type strain W3110, the Δpnp strain had significant defects in persistence to antibiotics and stresses, and the persistence phenotype was restored upon complementation with the pnp gene. Transcriptome sequencing (RNA-seq) analysis revealed that 242 (166 upregulated and 76 downregulated) genes were differentially expressed in the Δpnp strain compared with the W3110 strain. KEGG analysis of the upregulated genes showed that these genes were mostly mapped to metabolism and virulence pathways, of which most are positively regulated by the global regulator cyclic AMP receptor protein (CRP). Correspondingly, the transcription level of the crp gene in the Δpnp strain increased 3.22-fold in the early stationary phase. We further explored the indicators of cellular metabolism of the Δpnp strain, the phenotype of the pnp and crp double-deletion mutant, and the transcriptional activity of the crp gene. Our results indicate that PNPase controls cellular metabolism by negatively regulating the crp operon via targeting the 5'-untranslated region of the crp transcript. This study reveals a persister mechanism and provides novel targets for the development of drugs against persisters for more effective treatment. IMPORTANCE Persisters pose significant challenges for a more effective treatment of persistent infections. An improved understanding of mechanisms of persistence will provide therapeutic targets important for the development of better treatments. Since recent studies with the key tuberculosis persister drug pyrazinamide have implicated polynucleotide phosphorylase (PNPase) as a drug target, in this study, we addressed the possibility that PNPase might be involved in persistence in Escherichia coli. Our study demonstrates PNPase indeed being involved in persistence, provides a mechanism by which PNPase controls persister formation, and suggests a new therapeutic target for treating persistent bacterial infections.

Validation of a predictive model for coronary artery disease in patients with diabetes.

BACKGROUND: No reliable model can currently be used for predicting coronary artery disease (CAD) occurrence in patients with diabetes. We developed and validated a model predicting the occurrence of CAD in these patients. METHODS: We retrospectively enrolled patients with diabetes at Henan Provincial People's Hospital between 1 January 2020 and 10 June 2020, and collected data including demographics, physical examination results, laboratory test results, and diagnostic information from their medical records. The training set included patients ( n  = 1152) enrolled before 15 May 2020, and the validation set included the remaining patients ( n  = 238). Univariate and multivariate logistic regression analyses were performed in the training set to develop a predictive model, which were visualized using a nomogram. The model's performance was assessed by area under the receiver-operating characteristic curve (AUC) and Brier scores for both data sets. RESULTS: Sex, diabetes duration, low-density lipoprotein, creatinine, high-density lipoprotein, hypertension, and heart rate were CAD predictors in diabetes patients. The model's AUC and Brier score were 0.753 [95% confidence interval (CI) 0.727-0.778] and 0.152, respectively, and 0.738 (95% CI 0.678-0.793) and 0.172, respectively, in the training and validation sets, respectively. CONCLUSIONS: Our model demonstrated favourable performance; thus, it can effectively predict CAD occurrence in diabetes patients.

Risk Factors and Outcomes for Isolation with Polymyxin B-Resistant Enterobacterales from 2018-2022: A Case-Control Study.

Purpose: To analyze the risk factors and clinical outcomes of patients isolated with polymyxin B-resistant (PR) Enterobacterales from various clinical specimens to prevent and control the spread of these strains. Methods: This retrospective case-control study included 72 PR Enterobacterales-positive cases and 144 polymyxin B-susceptible (PS) Enterobacterales controls from 2018 to 2022. Patients with PR Enterobacterales isolated in various clinical cultures were defined as cases. Patients with PS Enterobacterales cultures at similar anatomic sites during the same period were randomly selected as controls. Data were collected from clinical and laboratory test records. Bivariable logistic regression and Pearson's chi-square tests were used to assess risk factors. Results: PR strains were predominantly Klebsiella pneumoniae (72.2%) and Salmonella enteritidis (8.3%). Of the patients, 66.04% were admitted to an intensive care unit (ICU). Risk factors for isolation with PR strains included chronic heart disease (P = 0.012; odds ratio [OR] 1.15; 95% confidence interval [CI] 1.03-1.28), immunosuppressant use (P = 0.016; OR 1.04 [1.0-1.07), drainage tube [head] (P = 0.006; OR 1.1 [1.0-1.1]), and polymyxin B exposure (P = 0.007; OR 1.03 [1.0-1.06]. With respect to outcomes, admission to an ICU (P = 0.003; OR 7.1 [1.9-25.4]), hypertension (P = 0.035; OR 1.4 [1.02-1.83]), and drainage tube [head] (P = 0.044; OR 1.1 [1.0-1.15]) were associated with treatment failure. Additionally, treatment failure was more frequent in patients (45.83%) than in controls (14.58%). Conclusion: The major risk factors for isolation with PR strains were chronic heart disease, exposure to immunosuppressants, use of drainage tubes, and polymyxin B exposure. The isolation of PR strains in patients was a predictor of unfavorable outcomes. These findings provide a basis for monitoring the spread of PR Enterobacterales.

Characteristics of humoral and cellular responses to coronavirus disease 2019 (COVID-19) inactivated vaccine in central China: A prospective, multicenter, longitudinal study.

Introduction: In China, the long-term immunogenicity and adverse effects of inactivated vaccines produced by different or the same manufacturer remain unclear. Therefore, the objective of this study was to evaluate the cellular immune responses and neutralizing antibody kinetics of homologous and heterologous administrations of an inactivated coronavirus disease 2019 (COVID-19) vaccine 240 days after the second vaccination. Methods: This prospective, multicenter, observational, longitudinal study involved 595 participants with a negative SARS-CoV-2 polymerase chain reaction result who were serologically tested and followed for 8 months after vaccination. Neutralizing antibodies, interferon-gamma (IFN-γ), interleukin (IL)-6, CD4+ T-lymphocyte, and B-lymphocyte counts were evaluated in serum samples after stimulation with 2 µg/mL SARS-CoV-2 spike protein for 16 h at follow-up intervals of 2 months. Results: Most participants [582/595; 146 male participants, 449 female participants; mean age 35 (26-50 years)] rapidly developed neutralizing antibodies after two doses of the vaccine administered 3-weeks apart. The positive rate of neutralizing antibodies peaked at 97.7% at 60-90 days, decreased, and stabilized at 82.9% at 181-240 days post-vaccination. Lower antibody concentrations were correlated with older age, longer duration after vaccination, non-health care workers, mixed-manufacturer vaccinations, and intervals of less than 40 days between two doses of vaccination, whereas lower IFN-γ levels and B-lymphocyte counts were associated with older age, blood type A, and non-health care workers. A higher IL-6 level was associated with older age, mixed-manufacturer vaccinations, intervals of less than 40 days between two doses of vaccination, and medical staff. Adverse reactions were mild or moderate and self-limited, with no serious events reported. Discussion: Two doses of the Chinese inactivated vaccine induced robust and rapid antibody expression and cellular immune responses. Boosting vaccination is considered important, as antibodies and cellular immune responses were reduced in susceptible populations.

Evaluation of Commercial Products for Colistin and Polymyxin B Susceptibility Testing for mcr-Positive and Negative Escherichia coli and Klebsiella pneumoniae in China.

Purpose: To evaluate the performance of five widespread commercial products for colistin and polymyxin B susceptibility testing in China for mcr-positive and -negative Escherichia coli and Klebsiella pneumoniae. Methods: A total of 132 E. coli and 83 K. pneumoniae strains (including 68 mcr-1-positive E. coli and 28 mcr-8-positive K. pneumoniae) were collected. We analysed the performance of colistin susceptibility (with Vitek 2 and Phoenix M50) and the performance of polymyxin B susceptibility (with DL-96II, MA120, and a Polymyxin B Susceptibility Test strip; POL E-strip). Broth microdilution was used as the gold standard. Categorical agreement (CA), essential agreement (EA), major error (ME), and very major error (VME) were calculated for comparisons. Results: For E. coli, the total CA, EA, ME, and VME to colistin were as follows: Vitek 2, 98.5%/98.5%/0%/2.9%; and Phoenix M50, 98.5%/97.7%/0%/2.9%. The total CA, EA, ME, and VME to polymyxin B were as follows: POL E-strip, 99.2%/63.6%/1.6%/0%; MA120, 70.0%/-/0%/58.8%; and DL-96II, 80.2%/-/1.6%/36.8%. Only Vitek 2 and Phoenix M50 presented satisfactory performances for mcr-1-positive E. coli. For K. pneumoniae, the total CA, EA, ME, and VME to colistin were as follows: Vitek 2, 73.2%/72.0%/0%/61.6%; and Phoenix M50, 74.7%/74.7%/0%/58.3%. The total CA, EA, ME, and VME to polymyxin B were as follows: POL E-strip, 91.6%/74.7%/2.1%/16.7%; MA120, 92.8%/-/2.1%/13.9%; and DL-96II, 92.2%/-/2.1%/8.3%. All systems were unsatisfactory for mcr-8-positive K. pneumoniae. When the susceptibility of mcr-negative strains was tested, all systems presented excellent performance. Conclusion: Vitek 2 and Phoenix M50 with colistin for E. coli showed acceptable performance regardless of mcr-1 expression, while DL-96II, MA120, and the POL E-strip performed worse for mcr-1-positive strains. Furthermore, mcr-8 greatly affected the performance of all systems with both colistin and polymyxin B for K. pneumoniae isolates.

Epidemiology and genotypic characteristics of carbapenem resistant Enterobacterales in Henan, China: a multicentre study.

OBJECTIVES: To identify the carbapenemase and colistin resistance genes and epidemiological status of carbapenem-resistant Enterobacterales (CRE) among 7 secondary and 11 tertiary hospitals in Henan province, China. METHODS: CRE isolates and clinical data of infected patients were collected from 7 secondary and 11 tertiary hospitals in Henan from July to September 2019 and analysed retrospectively. Polymerase chain reaction (PCR) and gene sequencing were performed to detect carbapenemase and colistin resistance genes; multilocus sequence typing was also performed. RESULTS: In total, 238 nonduplicate CRE isolates were collected mainly from the respiratory tract (54.20%) and blood (18.91%) of CRE-infected patients, half of them aged >65 years (45.80%). Carbapenem-resistant Klebsiella pneumoniae (CRKP) was the most common CRE (184 isolates, 77.31%) with constituent ratios of 84.38% and 72.54% in secondary and tertiary hospitals, respectively. In 184 CRKP isolates, blaKPC-2 (89.13%) was the dominant carbapenemase gene, and ST11 (71.74%) was the most prevalent sequence type (ST), with constituent ratios of 83.95% and 62.14% in secondary and tertiary hospitals, respectively. In 29 carbapenem-resistant Escherichia coli (CREC) isolates, blaNDM-5 (58.62%) and ST2 (31.03%) were prevalent. Four CRKP isolates and one CREC isolate were colistin-resistant and carried the plasmid-mediated mcr-1 gene. CONCLUSION: Our results showed a wide spread of CRKP-ST11 with KPC-2 carbapenemase in the analysed 18 hospitals. The CRKP constituent ratio, CRKP-STs, and CREC carbapenemase genes between secondary and tertiary hospitals showed significant differences. The emergence of a colistin-resistant CRKP with plasmid-mediated resistance gene mcr-1 is of serious concern due to the limited treatment options.

The Prevalence and Genotype Distribution of Human Papillomaviruses Among Men in Henan Province of China.

Background: This paper aimed to assess the prevalence of human papillomavirus (HPV) infection and the associations of sociodemographic and behavioral characteristics with HPV in unvaccinated men in Henan Province before the mass administration of the HPV vaccine through a baseline survey. Methods: Between June 2015 to June 2020, 3,690 men were tested for the HPV genotype at the Henan Provincial People's Hospital. The HPV genotype was detected by a polymerase chain reaction (PCR)-based hybridization gene chip assay. Results: The overall HPV infection rate was 29.97%; The most prevalent genotypes were HPV 6 (21.76%), 11 (12.68%), 16 (8.94%), 58 (5.37%), 18 (3.41%), 84 (3.25%), 61 (3.09%), and 81 (3.09%). Low-risk HPV (LR-HPV) infection (24.91%) and single infection (17.78%) were the most prevalent forms. Age-specific HPV distribution was presented as a bimodal curve; the youngest age group (≤ 25 years) had the highest HPV infection rate (36.03%), followed by the 36-40-year-old group (33.68%). Men with Junior high school or above were more likely to have Pure-LR HPV infection. Unmarried status and smoking increased single and LR-HPV infection. Multiple lifetime sex partners and not using a condom were more likely to cause LR-HPV infection. Conclusions: The data on the prevalence and HPV infection type distribution in men in Henan Province could serve as a valuable reference to guide nationwide screening. We provide a time-based estimate of the maximum impact of the HPV vaccine and critical reference measurements important for assessing the clinical benefits of HPV vaccination and the increase in non-vaccine HPV types.

Transcriptomic Analysis of Mycobacterium leprae-Stimulated Response in Peripheral Blood Mononuclear Cells Reveal Potential Biomarkers for Early Diagnosis of Leprosy.

We aimed to identify an unique host transcriptional signature in peripheral blood mononuclear cells (PBMCs) in response to Mycobacterium leprae antigens to distinguish between patients with leprosy and non-leprosy controls for early diagnosis of the disease. Sixteen individuals were enrolled in the discovery cohort [eight patients with leprosy, comprising four multibacillary (MB) and four paucibacillary (PB); and eight non-leprosy controls, comprising four healthy house contacts (HHCs) and four endemic controls (ECs)]. The differences in the transcriptome response of PBMCs to M. leprae sonicate antigen were evaluated between leprosy patients and non-leprosy controls, and 12 differentially expressed genes (CCL2/MCP-1, IL-8, JAKM, ATP, ND1, SERP, FLJ10489, LINC00659, LOC34487, LOC101928143, MIR22, and NCF1C) were identified. The accuracy of the 12 differentially expressed genes was further validated for the diagnosis of leprosy using real-time quantitative PCR in 82 individuals (13 MB, 10 PB, 37 HHCs, and 22 ECs) in the validation cohort. We found that a 5 gene signature set IL-8, CCL2/MCP-1, SERP, LINC00659 and FLJ10489 had a suitable performance in discriminating leprosy from ECs. In addition, elevated expression of IL-8, CCL2/MCP-1, SERP and LINC00659 was associated with MB diagnosis compared with ECs, whereas increased expression of IL-8, CCL2/MCP-1, SERP and FLJ10489 was found to be useful biomarkers for PB diagnosis from ECs. Moreover, we found decreased expression of NCF1C among leprosy patients could distinguish leprosy from HHCs, whereas higher expression of CCL2 among MB than PB could distinguish different leprosy patients. In conclusion, among the 12 candidate host genes identified, a three gene signature IL-8, CCL2/MCP-1, and SERP showed the best performance in distinguishing leprosy patients from healthy controls. These findings may have implications for developing a rapid blood-based test for early diagnosis of leprosy.

Severe Acute Respiratory Syndrome Coronavirus 2 Viral RNA Load Status and Antibody Distribution Among Patients and Asymptomatic Carriers in Central China.

This study aimed to monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral loads and specific serum-antibodies (immunoglobulin [Ig] G and M) among confirmed patients and asymptomatic carriers from returning healthy travelers. The throat swabs, sputum, and stool samples from 57 hospitalized coronavirus disease (COVID-19) patients and 8 asymptomatic carriers, among 170 returning healthy travelers were tested using reverse-transcription real-time polymerase chain reaction. SARS-CoV-2 IgM/IgG antibodies were detected via serum chemiluminescence assay. Sequential results showed higher viral RNA loads in the throat, sputum, and stool samples at 3-12 and 6-21 days after symptom onset among severely ill COVID-19 patients. Shorter viral habitation time (1-8 days) was observed in the oropharyngeal site and intestinal tract of asymptomatic carriers. The IgG and IgM response rates were 19/37 (51.4%) and 23/37 (62.6%) among the 29 confirmed patients and 8 asymptomatic carriers, respectively, within 66 days from symptom or detection onset. The median duration between symptom onset and positive IgG and IgM results was 30 (n=23; interquartile range [IQR]=20-66) and 23 (n=19; IQR=12-28) days, respectively. Of 170 returning healthy-travelers to China, 4.7% were asymptomatic carriers (8/170) within 2 weeks, and the IgG and IgM positivity rate was 12.8% (12/94). IgM/IgG-positivity confirmed 3 suspected SARS-CoV-2 cases, despite negative results for SARS-CoV-2 RNA. Compared with other respiratory viral infectious diseases, COVID-19 has fewer asymptomatic carriers, lower antibody response rates, and a longer antibody production duration in recovered patients and the contacted healthy population. This is an indication of the complexity of COVID-19 transmission.

Molecular Mechanism of Polymyxin Resistance in Multidrug-Resistant Klebsiella pneumoniae and Escherichia coli Isolates from Henan Province, China: A Multicenter Study.

PURPOSE: To evaluate polymyxin-resistant Klebsiella pneumoniae and Escherichia coli prevalence and characteristics in the Henan province, China. MATERIALS AND METHODS: A total of 2301 bacterial isolates collected at six hospitals were assessed. Their response to polymyxin was evaluated by minimum inhibitory concentration (MIC) analysis, and the mobilized colistin resistance (mcr) and carbapenemase gene were explored. Mutations on mgrB, phoPQ, pmrAB, and crrAB in polymyxin-resistant K. pneumoniae were detected by PCR. phoP, phoQ, pmrK, pmrA, pmrB, and pmrC transcriptional levels were quantified by RT-qPCR. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing were performed to determine the phylogenetic relationship between the polymyxin-resistant isolates. RESULTS: Of the E. coli and K. pneumoniae isolates identified, 0.3% and 1.4% were polymyxin-resistant, respectively, with MICs of 4-64 µg/mL. All polymyxin-resistant isolates were susceptible to tigecycline. Four E. coli isolates were mcr-1-positive and one was carbapenem-resistant, carrying bla NDM-5 and mcr-1. One K. pneumoniae isolate was mcr-1-positive and nine were carbapenem-resistant (PRCRKP), carrying bla KPC-2 but not mcr-1. The five E. coli isolates belonged to four sequence types (ST2, ST132, ST632, and ST983). All PRCRKP isolates belonged to ST11. However, all 16 isolates belonged to different PFGE types with <95% genetic similarity. Insertion sequences in mgrB were detected in nine (81.8%) polymyxin-resistant K. pneumoniae samples. Colistin resistance was linked with pmrHFIJKLM operon upregulation, with phoP, phoQ, and pmrK being overexpressed in all but one of the polymyxin-resistant K. pneumoniae samples. Furthermore, 33.3% of patients carrying polymyxin-resistant isolates had previously used polymyxin, and 66.7% patients displayed good clinical outcomes. CONCLUSION: The K. pneumoniae polymyxin resistance rate was slightly higher than that of E. coli and mcr-1 was more common in E. coli than in K. pneumoniae. Moreover, the insertion of ISkpn14 into mgrB may be the main contributor to polymyxin-resistance in K. pneumoniae in Henan.

Non-tuberculous Mycobacterial Infection of the Musculoskeletal System Detected at Two Tertiary Medical Centres in Henan, China, 2016-2020.

Non-tuberculous mycobacterial (NTM) infection of the musculoskeletal system is rare but poses a grave threat to public health. These infections yield non-specific symptoms that remain undetected until the development of the later stages of the disease. In this study, we performed a retrospective review of 25 cases of musculoskeletal NTM infection at two tertiary medical centres over a 5-year period to determine the clinical features and improve the current clinical diagnosis and treatment. The most common mycobacterial species detected were Mycobacterium fortuitum in eleven patients, Mycobacterium abscessus in eight patients, Mycobacterium houstonense in three patients, Mycobacterium avium in two patients, and Mycobacterium smegmatis in one patient. The sites of infection included the limbs and joints, most commonly the knee (ten patients) and foot (six patients). The median duration from the onset of symptoms to diagnosis was 2.5 months (0.8-13.5 months). Deep sinus tracts extending to the surgical site were observed in 60% of the patients (15/25), and granulomatous inflammation and granulomatous inflammation with necrosis occurred in 60% of the patients (15/25). All patients underwent surgical treatment for infection control, and all patients, except one, received antimycobacterial therapy based on drug sensitivity assays. The median duration of the antimicrobial chemotherapy was 5 months (range: 3-20 months). At the final follow-up, 24 patients presented with absence of recurrence and one patient succumbed owing to heart failure after debridement. Our findings highlight the importance of vigilance and improvements in the diagnostic methods for musculoskeletal NTM infection. Aggressive surgical treatment and antimycobacterial drug treatment can help achieve satisfactory results.

Prevalence and Genetic Diversity of Clostridium perfringens Isolates in Hospitalized Diarrheal Patients from Central China.

OBJECTIVE: This study aimed to investigate the prevalence, genetic diversity and clinical characteristics of Clostridium perfringens isolates from hospitalized clinical diarrheal patients. METHODS: A prospective study was conducted on 1108 patients with diarrhea during hospitalization. Stool samples were cultured for C. perfringens, and the toxin genes were detected by PCR. The available clinical data of 112 patients were analyzed to study the clinical features of various isolates. Multi-locus sequence typing (MLST) was performed to assess phylogenetic relationship between different isolates. RESULTS: A total of 153 (13.8%) isolates were obtained from patients' stools. C. perfringens type F (49.0%) was the major toxin type in the isolates, followed by type A (n = 59, 38.6%) and type C (n = 14, 9.2%). Patients older than 50 years and those with underlying diseases of cancer, hepatobiliary system, and ulcerative colitis (UC) were more predisposed to C. perfringens type F and type A infection than to type C. The patients infected with type C experienced more severe clinical symptoms compared to those with type A infection. There was a significant association between type FC and foodborne gastrointestinal (GI) diseases (p = 0.018), between type FP and antibiotic-associated diarrhea (AAD) (p < 0.001), and between type A and sporadic diarrhea (SD) (p < 0.001). Phylogenetic analysis indicated that type F isolates carrying a chromosomal cpe gene mainly belonged to ST77 (6/15 isolates). Type F isolates with cpe gene on a plasmid exhibited high genetic diversity. CONCLUSION: High prevalence and considerable genetic diversity of C. perfringens type F were found in clinical diarrheal patients. Elderly people and patients with cancer, hepatobiliary diseases or UC, or suspected of having food poisoning (FP) may be targeted for routine testing of C. perfringens toxin genes and may benefit from early detection of C. perfringens type C isolates that cause more severe clinical symptoms.

Risk Factors for Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections and Outcomes.

PURPOSE: The incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections (BSIs) is increasing globally; however, little has been reported on the risk factors and outcomes of CRKP BSIs in central China. This study aimed to determine the clinical risk factors for CRKP BSIs and the outcomes of CRKP BSIs. PATIENTS AND METHODS: We performed a case-control study of 239 patients with K. pneumoniae BSIs who were treated at Henan Provincial People's Hospital between July 2017 and July 2018. The cases (n=98, 41%) had CRKP BSIs, and the controls (n=141, 59%) had non-carbapenem-resistant K. pneumoniae (non-CRKP) BSIs. Antimicrobial sensitivity was determined using automated broth microdilution and an agar disk diffusion method. Data were obtained from clinical and laboratory records. Multivariate logistic regression and Pearson chi-square tests were used to identify clinical factors and outcomes associated with carbapenem resistance. RESULTS: Risk factors for carbapenem resistance included recent carbapenem use (odds ratio [OR]: 9.98, 95% confidence interval [CI]: 5.2-17.1, P<0.001), invasive procedures (OR: 11.1, 95% CI: 3.3-37.7, P<0.001), and pre-existing diseases of the digestive system (OR: 8.22, 95% CI: 1.73-39.2, P=0.008). Treatment failure was more frequent in the cases (84.7%) than in the controls (32.6%). CONCLUSION: Exposure to antibiotics, especially carbapenems, and invasive procedures were the major risk factors for carbapenem resistance among patients with K. pneumoniae BSIs. Strict control measures should be implemented to prevent the emergence and spread of CRKP.