Three Cases of Non-Tuberculosis Mycobacterium Skin Infection Outbreak in Beauty Institutions.

BACKGROUND: From June 2021 to July 2021, our hospital confirmed 3 cases of Mycobacterium infection in skin abscesses. All 3 patients underwent thread embedding and weight loss surgery at the same informal beauty institution, with a history of silk protein injection. None of the patients had any other underlying diseases or surgical history. Symptoms and signs show that the disease is acute and the course of the disease is short. All patients have found subcutaneous masses in different parts of the body. In most cases, the masses show redness and swelling, and some of the masses are accompanied by tenderness, wave sensation, and rupture. After some of the masses rupture, purulent secretions can be seen. METHODS: The pus secreted by the skin lesions of the three patients were cultured to a single bacterium, which was identified by MALDI-TOF MS. Multiple locus sequence typing (MLST) was performed using three specific genes (hsp65, rpoB, and secA1) and seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH). The results were queried through the MLST database of Mycobacterium abscess. RESULTS: All three strains of bacteria were Mycobacterium abscess type ST279 massiliense subtype. Three antibacterial drugs including cefmetazole, amikacin, and clarithromycin were administered in combination with 5-aminolevulinic acid photodynamic therapy (ALA-PDT). After 3 - 6 months, there was no obvious redness or swelling in the surrounding tissues of the wound, and no obvious purulent secretions were observed. All patients were cured and discharged from the hospital. After a follow-up of six months, there was no recurrence of the lesions. CONCLUSIONS: Medical institutions must strictly follow infection control guidelines and take preventive measures to prevent such incidents from happening again. ALA-PDT as a combination therapy for nontuberculous Mycobacterium (NTM) skin infections can improve treatment efficacy and shorten antibiotic usage time.

Lumbar Spine Infected by Mycobacterium tuberculosis and Cryptococcus neoformans: a Rare Case Report.

BACKGROUND: In July 2023, our hospital confirmed one case of lumbar spine infected complicated by Mycobacterium tuberculosis and Cryptococcus neoformans. The patient was admitted due to lower back pain for 1 year and a hard lump for 3 months. Symptoms and signs: Dressing can be seen fixed on the lower back, with severe bleeding. When the dressing is removed, a hard and protruding lump with a size of 6 cm x 8 cm, a sinus tract can be seen near the mass, with a slightly red wound and a sinus depth of about 3 cm. Light red fluid can be seen flowing out. There are no symptoms such as redness, swelling, or heat in the rest of the lower back, and the patient has no other underlying diseases or surgical history. METHODS: Lumbar magnetic resonance imaging and lumbar CT examination; Percutaneous puncture lumbar vertebral biopsy was performed, and the biopsy tissue was subjected to pathological examination, mNGS (metagenomic next-generation sequencing), and acid-fast staining; Extract pus from the lump for fungal culture and ink staining, and identify the fungi through MALDI-TOF MS. RESULTS: Bone destruction and bone marrow edema in the L5 vertebral body, compression of the spinal canal at the L5 vertebral body level; The pathological results of the biopsy tissue indicate granulomatous lesions. The acid-fast staining of the tissue is positive, and the mNGS of the tissue indicates infection with Mycobacterium tuberculosis. A single fungus was cultured from pus and identified by MALDI-TOF MS as Cryptococcus neoformans. Clinically, isoniazid 0.3 g ivgtt + rifampicin 0.45 g qd po + ethambutol 0.25 g qd po + pyrazinamide 0.75 g qd po + fluconazole 0.3 g qd po was administered for treatment. After 11 days, there was slight pain at the incision site, and the original symptoms were significantly relieved. The wound dressing was fixed in place, dry and without obvious exudation. Improved and discharged, followed up for 3 months with no recurrence of the lesion. CONCLUSIONS: mNGS is an effective identification technique that can be used to accurately diagnose suspected infection cases. MALDI-TOF MS has significant advantages over traditional detection methods in shortening detection time. This case achieved satisfactory treatment results for patients through a reasonable treatment plan, which is of great significance for exploring the diagnosis and treatment of similar disease infections.

Outbreak of Cosmetology-Acquired Mycobacterium abscessus Skin Infection.

This case report describes numerous warm, red, edematous, tender, fluctuant, and purulent draining nodules on the abdomen following a catgut implant procedure.

Epidemiology and resistance mechanisms of tigecycline- and carbapenem-resistant Enterobacter cloacae in Southwest China: a 5-year retrospective study.

OBJECTIVES: The prevalence and molecular epidemiology of tigecycline resistance in carbapenem-resistant Enterobacter cloacae (CREC) in mainland China is unknown. We aimed to investigate the molecular characteristics and mechanisms of tigecycline-resistant CREC (TCREC) in Southwest China. METHODS: We conducted a 5-year retrospective study. TCREC isolates underwent antimicrobial susceptibility testing, PFGE and MLST. We determined the presence of genes, deficiency of outer membrane proteins (OMPs) and expression of efflux pumps using PCR, reverse transcription PCR and SDS-PAGE. RESULTS: A large proportion of CREC isolates (21.7%; 36/166) were TCREC. All isolates were resistant to ertapenem, whereas 67% remained susceptible to imipenem and meropenem. ST88 (10/36; 27.8%) was predominant and was associated with moderate resistance to tigecycline and high resistance to carbapenems, followed by ST256 (3/36; 8.3%), ST78 (2/36; 5.6%), ST557 (2/36; 5.6%) and ST102 (2/36; 5.6%). blaNDM-1 (6/36; 16.7%) was the most common carbapenemase gene, and ST88 (5/6; 83.3%) was the most common type, followed by blaIMP-8 (3/36; 8.3%). Coexistence of extended-spectrum ß-lactamase (ESBL) genes and OmpF and/or OmpC loss was found in 27/36 isolates; additionally, increased co-expression of efflux pump genes acrB and oqxA was identified in 25/36 isolates, which may together contribute to co-resistance to carbapenems and tigecycline. CONCLUSION: Most ST88 strains carried carbapenemases, especially NDM-1. Overexpression of efflux pumps contributed to tigecycline resistance. The presence of carbapenemase and/or ESBL genes and lack of OMPs, but not efflux pump overexpression, may confer carbapenem resistance. Reasonable supervision and management of the epidemic of TCREC will help to stem the transmission of isolates.

Duplex Reverse Transcription Multienzyme Isothermal Rapid Amplification Assays for Detecting SARS-CoV-2.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that brings a significant public health challenge. A rapid and simple method is necessary for testing suspected samples and screening the population. METHODS: To better monitor sample effectiveness, this study described a method to detect nucleocapsid protein gene (N gene) of SARS-CoV-2 and human ACTB gene employing real-time duplex reverse transcription multienzyme isothermal rapid amplification (RT-MIRA) assays. RESULTS: The established real-time duplex RT-MIRA assays showed that no cross-reactions were observed to other pathogens and the detection limit was 100 copies/reaction. Using simulated clinical samples to test established assays further and the amplification process took no more than 20 minutes at 42°C. CONCLUSIONS: RT-MIRA assays are faster and easier than reverse transcription real-time polymerase chain reaction (RT-PCR). It is expected to be further optimized and evaluated in the detection of SARS-CoV-2 confirmed cases.

Preliminary Evaluation of Rapid Visual Identification of Burkholderia pseudomallei Using a Newly Developed Lateral Flow Strip-Based Recombinase Polymerase Amplification (LF-RPA) System.

Burkholderia pseudomallei is an important infectious disease pathogen that can cause melioidosis. Melioidosis is mainly prevalent in Thailand, northern Australia and southern China and has become a global public health problem. Early identification of B. pseudomallei is of great significance for the diagnosis and prognosis of melioidosis. In this study, a simple and visual device combined with lateral flow strip-based recombinase polymerase amplification (LF-RPA) was developed, and the utility of the LF-RPA assay for identifying B. pseudomallei was evaluated. In order to screen out the optimal primer probe, a total of 16 pairs of specific primers targeting the orf2 gene of B. pseudomallei type III secretion system (T3SS) cluster genes were designed for screening, and F1/R3 was selected as an optimal set of primers for the identification of B. pseudomallei, and parameters for LF-RPA were optimized. The LF-RPA can be amplified at 30-45°C and complete the entire reaction in 5-30 min. This reaction does not cross-amplify the DNA of other non-B. pseudomallei species. The limit of detection (LOD) of this assay for B. pseudomallei genomic DNA was as low as 30 femtograms (fg), which was comparable to the results of real-time PCR. Moreover, 21 clinical B. pseudomallei isolates identified by 16S rRNA gene sequencing were retrospectively confirmed by the newly developed LF-RPA system. Our results showed that the newly developed LF-RPA system has a simple and short time of operation and has good application prospect in the identification of B. pseudomallei.

Risk factors with the development of infection with tigecycline- and carbapenem-resistant Enterobacter cloacae.

BACKGROUND: Tigecycline is regarded as a last resort treatment for carbapenem-resistant Enterobacter cloacae (CREC) infections, and increasing numbers of tigecycline- and carbapenem-resistant E. cloacae (TCREC) isolates have been reported in recent years. However, risk factors and clinical impacts of these isolates are poorly characterized. PATIENTS AND METHODS: We conducted a retrospective case-case-control study of hospitalized patients with TCREC infection during the period 2012-2016 in Chongqing, China. Case patients with TCREC and those with CREC were compared to a control group with no E. cloacae infection. Multivariate logistic regression models were used to identify independent risk factors for acquiring TCREC and CREC. RESULTS: A total of 36 TCREC cases, 36 CREC cases, and 100 controls were enrolled in our study. Multivariable analysis indicated that nasal catheter (OR: 8.9; 95% CI: 1.1-75.2), exposure to penicillin (OR: 95.9; 95% CI: 8.9-1038.3), aminoglycosides (OR: 42.1; 95% CI: 2.1-830.6), and fluoroquinolones (OR: 18.6; 95% CI: 1.9-185.6) were independent predictors for acquiring TCREC. In addition, venous catheterization (OR: 12.2; 95% CI: 2.5-58.5), penicillin (OR: 30.8; 95% CI: 7.9-120.0), and broad-spectrum cephalosporin (OR: 5.0; 95% CI: 1.5-17.3) were independently associated with CREC acquisition. CONCLUSION: Reasonable antibiotic stewardship programs and surveillance are necessary to control the tigecycline resistance among high-risk patients.