Multicenter Investigation of Drug-Resistance in Burkholderia Cepacia Bloodstream Infections in Hebei Province, China, from 2016 to 2021.

Objective: To compare the epidemiological characteristics and drug resistance of Burkholderia cepacia isolated from blood cultures, and to provide data support and a scientific basis for the clinical treatment and detection of hospital infections. Methods: The Hebei Province Antimicrobial Surveillance Network received 349 B. cepacia strains isolated from blood cultures reported by 83 hospitals, from 2016 to 2021. These strains were identified by MALDI-TOF MS and, the antibiotic sensitivity tests were carried out using the VITEK 2 COMPACT system. The 2023 Institute of Clinical and Laboratory Standardization drug-susceptibility breakpoints were used for drug susceptibility testing and the data were analyzed using WHONET5.6 software. Results: A total of 349 B. cepacia strains were isolated from 2016 to 2021, including 68 strains from secondary hospitals and 281 strains from tertiary hospitals. The ratios of male: female patients with B. cepacia bloodstream infections in all hospitals, secondary hospitals, and tertiary hospitals were 1.49:1 (209/140), 2.09:1 (46/22), and 1.38:1 (163/118), respectively. Most B. cepacia strains were isolated in intensive care units (ICUs), followed by internal medicine departments, accounting for 49.57% (173/349) and 22.92% (80/349), respectively. Regarding the age distribution, most patients were elderly (>65 years, 57.59%, 201/349), with numbers of patients gradually declining with decreasing of age. The resistance rates for levofloxacin, ceftazidime, and sulfamethoxazole decreased over the 6-year period (P<0.05), while there were no significant changes in the resistance rates for meropenem, chloramphenicol, and minocycline (P>0.05). There was no significant difference in drug-resistance rates between secondary and tertiary hospitals (P>0.05). Conclusion: Attention should be paid to bloodstream infections caused by B. cepacia, especially elderly patients and patients admitted to the ICU. The difficult treatment characteristics of B. cepacia bloodstream infections mean that laboratories and clinicians should pay careful attention to drug resistance to provide a basis for their prevention and empirical treatment.

Novel target and PCR assay for identification of hypervirulent ST1 (BI/NAP1/027) Clostridioides difficile and detection of toxigenic C. Difficile.

BACKGROUND AND AIMS: The incidence of Clostridioides difficile infection and the prevalence of hypervirulent ST1 (BI/NAP1/027)strain are increasing, especially in developing countries. We aimed to develop a new PCR assay for the identification of hypervirulent ST1 strains and toxigenic C. difficile in stool samples. MATERIALS AND METHODS: We established a quadruplex TaqMan real-time PCR (pilW_4-plex PCR) assay targeting the pilW, a ST1-specific type Ⅳ minor pilin gene, and three C. difficile genes including cdtB, tcdB, and hsp. The sensitivity and specificity of the assay was tested using 403C. difficile isolates and 180 unformed stool sample. The results were compared with anaerobic culture-based conventional PCR method and MLST. RESULTS: The pilW_4-plex PCR identified toxigenic C. difficile in 333 (82.6%, 333/403) isolates with 100% sensitivity and specificity, and in 78 (43.3%, 78/180) stool samples with the sensitivity and specificity of 94.7% and 93.3%, respectively. Hypervirulent ST1 were detected in 21 strains and nine stool samples by the pilW_4-plex PCR. The pilW_4-plex PCR assay has no cross-reaction with non-toxigenic C. difficile or other bacteria. CONCLUSION: The pilW_4-plex PCR assay is an accurate and rapid method with high sensitivity and specificity for identification of ST1 and detection of toxigenic C. difficile in stool.

Clostridioides difficile infection in infants: a case report and literature review.

BACKGROUND: Clostridioides difficile (C. difficile) is the major pathogen causing antibiotic-associated diarrhea. There are a variety of symptoms associated with C. difficile infection (CDI) in adults, including self-limiting diarrhea, pseudomembranous colitis, toxic megacolon, septic shock, and even death from the infection. However, the infant's intestine appears to be completely resistant to the effects of C. difficile toxins A and B with rare development of clinical symptoms. CASE PRESENTATION: In this study, we reported a 1-month-old girl with CDI who was born with neonatal hypoglycemia and necrotizing enterocolitis. Her symptom of diarrhea occurred after extensive use of broad-spectrum antibiotics during hospitalization and was accompanied by elevated white blood cell, platelet, and C-reactive protein levels, and repeated routine stool examinations were abnormal. She was recovered by norvancomycin (an analogue of vancomycin) and probiotic treatment. The results of 16 S rRNA gene sequencing also demonstrated the recovery of intestinal microbiota with the enrichment of Firmicutes and Lactobacillus. CONCLUSIONS: Based on the literature review and this case report, clinicians should also pay attention to diarrhea caused by C. difficile in infants and young children. More strong evidence is needed to explain the true prevalence of CDI in this population and to better understand the C. difficile-associated diarrhea in infants.

Prevalence and molecular characterization of Clostridioides difficile infection in China over the past 5 years: a systematic review and meta-analysis.

OBJECTIVES: The aim of this study was to provide an overview of the prevalence and molecular characteristics of Clostridioides difficile infection (CDI) in China in the past 5 years. METHODS: A systematic literature review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines. Nine databases were searched for relevant studies published between January 2017 and February 2022. The Joanna Briggs Institute critical appraisal tool was used to assess the quality of included studies, and R software version 4.1.3 was used for data analysis. Funnel plots and Egger regression tests were also performed to assess publication bias. RESULTS: A total of 50 studies were included in the analysis. The pooled prevalence of CDI in China was 11.4% (2696/26,852). The main circulating C. difficile strains in southern China were ST54, ST3, and ST37, consistent with the overall situation in China. However, the most prevalent genotype in northern China was ST2, which was previously underappreciated. CONCLUSION: Based on our findings, increased awareness and management of CDI is necessary to reduce the prevalence of CDI in China.

Antimicrobial Activity of Tannic Acid In Vitro and Its Protective Effect on Mice against Clostridioides difficile.

Clostridioides difficile infection (CDI), recurrently reported as an urgent threat owing to its increased prevalence and mortality, has attracted significant attention. As the use of antibiotics to treat CDI has many limitations, such as high recurrence rate, the need to actively seek and develop other drugs that can effectively treat CDI with fewer side effects has become a key issue in CDI prevention and treatment. This study aimed to evaluate the inhibitory effect of Galla chinensis (GC) and its main component, tannic acid (TA), against C. difficile in vitro and its therapeutic effect on CDI in vivo. When GC and TA concentrations were 250 and 64 mg/L, respectively, the cumulative antibacterial rate against C. difficile reached 100%. The sub-MIC of TA significantly inhibited C. difficile sporulation, toxin production, and biofilm formation in vitro. Compared with the CDI control group, TA-treated mice lost less weight and presented a significantly improved survival rate. TA significantly reduced the number of spores in feces, decreased serum TcdA level, and increased serum interleukin 10 (IL-10). Based on the inhibitory effect of TA on C. difficile in vitro and its therapeutic effect on the CDI mouse model, we consider TA as a potentially effective drug for treating CDI. IMPORTANCE Clostridioides difficile is one of the major pathogens to cause antibiotic-associated diarrhea. Although antibiotic treatment is still the most commonly used and effective treatment for CDI, the destruction of indigenous intestinal microbiota by antibiotics is the main reason for the high CDI recurrence rate of about 20%, which is increasing every year. Moreover, the growing problem of drug resistance has also become a major hidden danger in antibiotic treatment. GC has been used to treat diarrhea in traditional Chinese medicine. In the present study, we evaluated the inhibitory effect of TA, the main component of GC, on dissemination and pathogenic physiological functions of C. difficile in vitro, as well as its therapeutic efficacy in a CDI model. Overall, TA is considered to be a potentially effective drug for CDI treatment.

Effects of a fully enclosed hollow-fiber centrifugal ultrafiltration technique for laboratory biosafety improvement.

Laboratory biosafety has become a core focus in biological analysis, owing to the frequent occurrence of laboratory-acquired infections caused by the leakage of pathogenic microorganisms. For this purpose, the authors developed a safe pretreatment device combining a sealing technique with a direct injection technique. In this study, several bacteria and viruses were used to validate the filtration effect of the invention. Data show that the new device can completely filter bacteria and that the filtration rates for hepatitis B virus and hepatitis C virus reached 94% and 96%, respectively. The results show that the new preparation device can effectively block these pathogens and can improve biological safety and provide powerful protection for technicians.

Carriage of Clostridioides difficile in healthy infants in the community of Handan, China: A 1-year follow-up study.

OBJECTIVE: Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions. A 1-year follow-up study was performed to determine the incidence, kinetics and influencing factors of C. difficile intestinal colonization. METHODS: Twenty-nine healthy infants (14 girls and 15 boys) living at home with their parents in Handan City were followed by survey from birth to 1 year of age, specifically from October 2014 through December 2015. C. difficile isolates were typed by PCR ribotyping and analyzed for the presence of toxin genes. RESULTS: During the follow-up study period in the first year of life, 20 of the 29 total enrolled infants acquired C. difficile. A total of 437 fecal samples were obtained, and 111 (25.4%) samples contained C. difficile, including 79 (71.2%) toxigenic strains. The toxigenic isolates comprised six PCR ribotypes, and two PCR ribotypes were identified as nontoxigenic strains. CONCLUSION: Our study showed that C. difficile colonization increase with age during the 12-month period, and the dominant toxigenic types of C. difficile isolates in infants were those involved in long-term colonization. Feeding patterns may affect the dynamic progress of C. difficile colonization.

Epidemiological investigation of Clostridioides difficile colonization in Chinese community infants.

Clostridioides difficile is a colonizer of the human gut; asymptomatic colonization has been reported to be more common in infants and is highly variable across regions even with no symptoms of diarrhea or death. Antibiotic treatment strategies might increase the antibiotic resistance of C. difficile. We performed a one-point study involving 1098 healthy infants (0-36 months) to address the deficiency of reports on C. difficile colonization in Chinese community infants. The C. difficile colonization rate was 22.8% (250/1098), and more than half of the strains (55.2%) were toxigenic isolates. Among the 138 toxigenic isolates, 111 were of the A+B+CDT- genotype, 26 strains were A-B+CDT-, and one strain was A+B+CDT+. Fifteen different PCR ribotypes were found among the 250 isolates, and PCR-ribotype HB03 appeared to be dominant type, accounting for 19.6% (49/250). High levels of resistance to antimicrobial agents were observed. Our study showed that age and hospitalization before stool collection were positively correlated with the C. difficile colonization rate, whereas the delivery term was negatively related to the colonization rate. Particular attention should be paid to the increasing resistance of C. difficile to rifamycin.

Comparison of a newly developed binary typing with ribotyping and multilocus sequence typing methods for Clostridium difficile.

Clostridium difficile is the causative pathogen for antibiotic-related nosocomial diarrhea. For epidemiological study and identification of virulent clones, a new binary typing method was developed for C. difficile in this study. The usefulness of this newly developed optimized 10-loci binary typing method was compared with two widely used methods ribotyping and multilocus sequence typing (MLST) in 189 C. difficile samples. The binary typing, ribotyping and MLST typed the samples into 53 binary types (BTs), 26 ribotypes (RTs), and 33 MLST sequence types (STs), respectively. The typing ability of the binary method was better than that of either ribotyping or MLST expressed in Simpson Index (SI) at 0.937, 0.892 and 0.859, respectively. The ease of testing, portability and cost-effectiveness of the new binary typing would make it a useful typing alternative for outbreak investigations within healthcare facilities and epidemiological research.

Identification and Characterization of Clostridium difficile Sequence Type 37 Genotype by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Clostridium difficile multilocus sequence type 37 (ST37), which mainly corresponds to ribotype 017, has been a dominant genotype circulating in China. In this study, we report the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to analyze and characterize 204 C. difficile clinical isolates, including 49 ST37 and 155 non-ST37 isolates collected in China and other countries. The distributions of two major protein peaks (m/z 3,242 and 3,286) were significantly different between ST37 and non-ST37 prototype strains and clinical isolates. This difference was reproducible when analysis was performed on different colonies in different runs. This finding was repeated and confirmed by both bioMérieux Vitek MS and Bruker Microflex LT systems on isolates recovered from a variety of geographic regions worldwide. The combination of the two peaks was present in 47 of 49 ST37 isolates, resulting in a sensitivity of 95.9%. In contrast, the peak combination was absent in 153 of 155 non-ST37 isolates, resulting in a specificity of 98.7%. Our results suggest that MALDI-TOF MS is a rapid and reliable tool to identify C. difficile genotype ST37. Work is in progress to characterize the two molecules having peaks at m/z 3,242 and 3,286, which appear to be specific to C. difficile genotype ST37.

Molecular Characterization of Clostridium difficile Isolates from Human Subjects and the Environment.

Clostridium difficile is a spore-forming, gram-positive, anaerobic bacillus that can cause C. difficile infection (CDI). However, only a few studies on the prevalence and antibiotic resistance of C. difficile in healthy individuals in China have been reported. We employed a spore enrichment culture to screen for C. difficile in the stool samples of 3699 healthy Chinese individuals who were divided into 4 groups: infants younger than 2 years of age and living at home with their parents; children aged 1 to 8 years of age and attending three different kindergarten schools; community-dwelling healthy adult aged 23-60 years old; and healthcare workers aged 28-80 years old. The C. difficile isolates were analyzed for the presence of toxin genes and typed by PCR ribotyping and multilocus sequence typing (MLST). The minimum inhibitory concentration of 8 antimicrobial agents was determined for all of the isolates using the agar dilution method. The intestinal carriage rate in the healthy children was 13.6% and ranged from 0% to 21% depending on age. The carriage rates in the 1654 community-dwelling healthy adults and 348 healthcare workers were 5.5% and 6.3%, respectively. Among the isolates, 226 were toxigenic (225 tcdA+/tcdB+ and 1 tcdA+/tcdB+ ctdA+/ctdB+). Twenty-four ribotypes were found, with the dominant type accounting for 29.7% of the isolates. The toxigenic isolates were typed into 27 MLST genotypes. All of the strains were susceptible to vancomycin, metronidazole, fidaxomicin, and rifaximin. High resistance to levofloxacin and ciprofloxacin at rates of 39.8% and 98.3%, respectively, were observed. ST37 isolates were more resistant to levofloxacin than the other STs. The PCR ribotypes and sequence types from the healthy populations were similar to those from the adult patients.