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.

Retrospective Analysis of Sensitivity Characteristics of Enterobacteriaceae: A Study Based on Specimen Types, Sex, and Age Bracket of Patients.

Objective: Enterobacteriaceae have displayed widespread trends of antimicrobial resistance in recent years. Therefore, we aimed to analyse the antimicrobial susceptibility of common bacteria and explore the significance in treatment and research of infections induced by Enterobacteriaceae. Methods: We retrospectively analysed 10,775 antimicrobial susceptibility test results acquired over a 6-year period in the affiliated hospital of Chengde Medical University. We divided the data based on specimen type (blood, sputum, pus, or urine), and population characteristics (age bracket and sex) for analysis. We mainly analysed the antimicrobial susceptibility of Escherichia coli (Eco), Klebsiella pneumoniae (Kpn), and Enterobacter cloacae (Ecl). Results: In our study, it was found that the resistance rates of Eco, Kpn, and Ecl to most antimicrobial agents were significantly different (P < 0.05) on specimen type and age bracket. The Eco from sputum had the highest resistance rates except ciprofloxacin (CIP), levofloxacin (LVX), and gentamicin (GEN); the Kpn from urine had the highest resistance rates to all antimicrobial agents; the Ecl from urine had the highest resistance rates to most antimicrobial agents. The Eco from geriatric patients had the highest resistance rates except GEN and SXT; the Kpn from adult patients had the lowest resistance rates to most antimicrobial agents except LVX. The Eco isolated from males had higher resistance rates to most antimicrobial agents except CIP, LVX, and NIT than those isolated from females; the Kpn showed significant differences in antimicrobial susceptibility to only 5 out of 22 antimicrobial agents (P < 0.05); the Ecl showed significant differences in susceptibility only to two antimicrobial agents, LVX and TOB (P < 0.01). Conclusion: The antimicrobial susceptibility of Enterobacteriaceae was significantly different among specimen type, age bracket and sex of patients, which is of great significance for the treatment and research of infection.

Bacteria can drill holes: Salmonella enterica serovar London infection of the leg and heel with colonization of the gut.

Salmonella enterica serovar London is known to colonize the human digestive tract and can cause gastroenteritis and diarrhea. The excretion of S. London in the stool can spread into the environment. However, S. London colonization of the gut is not known to cause infection of the soft tissues. Here, we report a case of S. London infection of the skin and soft tissue of the leg and heel.

A case of Aspergillus salwaensis-induced spinal infection / 中国热带医学

@#Abstract: To report a case of Aspergillus salwaensis-induced spinal infection and its laboratory detection. The inflammatory granulation and necrotic tissue samples of a patient with spinal infection were collected from, the Affiliated Hospital of Chengde Medical College on June 17, 2020 for direct smear microscopy and culture, and the isolated strain was identified by microscopy by smear staining, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), molecular identification and in vitro antifungal susceptibility test. The patient was 62 years old female and presented with recurrent chest and back pain with no obvious cause. The initial diagnosis was spinal infection, after 7 days of treatment with levofloxacin, the effect was not good. Surgery was then performed remove the lesion via posterior thoracic debridement, and fungal hypha was observed under microscope in tissue specimens. The isolated strains had no typical structure, MALDI-TOF-MS was used for identification for many times, but there was no identification result. After 7 days of fluconazole treatment, the patient's condition improved, and her chest and back pain were alleviated compared to before surgery. The patient was discharged and followed up in the outpatient department, the fungus was later identified as Aspergillus salwaensis by sequence analysis of the internal transcribed spacer (ITS) gene sequencing, and the patient's antifungal medication was changed to voriconazole after with the attending physician. The patient consciously recovered well with no pain in the operative area and normal spinal activity at 1 year follow-up. The possibility of spinal fungal infection should be considered in patients with back pain without a clear cause and poor response to routine antibiotic treatment. Direct smear report of microscopic results are very important for guiding clinical antibiotic selection for rare filament fungi with atypical colony and microscopic morphology and unsuccessful MALDI-TOF-MS identification, molecular biological methods such as ITS sequence analysis can be helpful for early identification of the fungal species, improving identification speed.

A Case of Meningitis in an Infant Due to Hypervirulent Klebsiella pneumoniae Transmission Within a Family.

Hypervirulent Klebsiella pneumoniae (hvKP), an emerging pathotype derived from K. pneumoniae, frequently causes invasive infections of multiple organs and is associated with both high disability and fatality rates. In this study, a case of meningitis in a young infant caused by hvKP is presented. Cytological and biochemical examinations of the cerebrospinal fluid (CSF) revealed purulent meningitis, a diagnosis that was confirmed by a positive CSF culture result. The pathogen was identified as hvKP through analysis of positive virulence-associated genes. Meanwhile, hvKP was also isolated from stool samples of both the infant and her father. Antimicrobial susceptibility, capsular typing, and multilocus sequence typing (MLST) of three isolates from the infant's CSF and stool and her father's stool samples were analyzed. The three K. pneumoniae isolates were susceptible to all antibiotics except ampicillin and were identified as capsular serotype K2 and sequence type 86. These genetic relatedness analyses indicated that the strain isolated from the infant's CSF might have originated from her father's stool via familial transmission. This case is the first report of meningitis in an infant due to hvKP transmitted within a family.

Effects of Blood Culture Aerobic/Anaerobic Bottle Collection Patterns from Both Sides of the Body on Positive Blood Culture Rate and Time-to-Positivity.

Background: Although the principles for blood cultures (BCs) guidelines provide a recommendation for collection patterns, the complexity of clinical practice occasionally prompts clinicians to adopt non-standard collection patterns. Here, we investigate the influences of different BC collection patterns on detection of pathogens. Methods: The BC collection patterns of 96 hospitals were surveyed online. And a retrospective study of BC data from a tertiary hospital was conducted. Results: The results showed that 53.1% of hospitals adopted the recommended patterns. Among the 1439 episodes of true-positive BCs, 67.4% were found in both the left- and right-sided bottles; 58.2% were found in both aerobic and anaerobic bottles. Conclusion: The present study suggested that the rate of standard collection patterns of blood culture was low and the non-standard collection patterns were associated with decreased detection of pathogens. Simultaneous collection of blood on the left and right sides was recommended as an effective pattern of BC collection.

Direct Identification, Antimicrobial Susceptibility Testing, and Extended-Spectrum ß-Lactamase and Carbapenemase Detection in Gram-Negative Bacteria Isolated from Blood Cultures.

Purpose: To shorten the turnaround time for blood culture (BC) analyses, a rapid method was developed for the direct identification, antimicrobial susceptibility testing (AST), and multidrug resistance testing of bacteria-positive BCs. Materials and Methods: The mixtures in BC bottles were treated with the multistep centrifugation method developed here and the conventional culture-based method. The bacterial sediment obtained after centrifugation was analyzed directly with MALDI-TOF MS and Vitek 2 Compact, and AST was performed directly with the Kirby-Bauer (K-B) disk diffusion, VITEK 2 Compact, and E-test methods. Extended spectrum lactamases (ESBLs) were detected with discs containing cefotaxime, cefotaxime/clavulanate, ceftazidime, and ceftazidime/clavulanate, and carbapenemase was detected with the modified carbapenem inactivation method (mCIM) and EDTA-mCIM (eCIM). Results: All the results of direct testing were compared to those of the conventional methods, to evaluate the accuracy of the direct methods. The accuracies of the direct Vitek 2 Compact and MALDI-TOF MS methods were 95.5% (214/224) and 90.2% (202/224), respectively. Direct AST with K-B, Vitek 2, and E-test showed category agreement of 96.0% (2611/2721), 96.1% (2614/2721), and 97.4% (2650/2721), respectively, and the major errors and very major errors were < 2% for all three methods. In the direct determination of ESBLs, the results for cefotaxime combined with cefotaxime/clavulanate were completely consistent with those after the standard isolation method. The carbapenemase detection rate with direct mCIM and eCIM was exactly the same as that with the standard method. Conclusion: These direct procedures based on multistep centrifugation are not only highly accurate but are appropriate for clinical laboratory use because the turnaround time is shorter.