Unveiling the genetic architecture and transmission dynamics of a novel multidrug-resistant plasmid harboring blaNDM-5 in E. Coli ST167: implications for antibiotic resistance management.

BACKGROUND: The emergence of multidrug-resistant (MDR) Escherichia coli strains poses significant challenges in clinical settings, particularly when these strains harbor New Delhi metallo-ß-lactamase (NDM) gene, which confer resistance to carbapenems, a critical class of last-resort antibiotics. This study investigates the genetic characteristics and implications of a novel blaNDM-5-carrying plasmid pNDM-5-0083 isolated from an E. coli strain GZ04-0083 from clinical specimen in Zhongshan, China. RESULTS: Phenotypic and genotypic evaluations confirmed that the E. coli ST167 strain GZ04-0083 is a multidrug-resistant organism, showing resistance to diverse classes of antibiotics including ß-lactams, carbapenems, fluoroquinolones, aminoglycosides, and sulfonamides, while maintaining susceptibility to monobactams. Investigations involving S1 pulsed-field gel electrophoresis, Southern blot analysis, and conjugation experiments, alongside genomic sequencing, confirmed the presence of the blaNDM-5 gene within a 146-kb IncFIB plasmid pNDM-5-0083. This evidence underscores a significant risk for the horizontal transfer of resistance genes among bacterial populations. Detailed annotations of genetic elements-such as resistance genes, transposons, and insertion sequences-and comparative BLAST analyses with other blaNDM-5-carrying plasmids, revealed a unique architectural configuration in the pNDM-5-0083. The MDR region of this plasmid shares a conserved gene arrangement (repA-IS15DIV-blaNDM-5-bleMBL-IS91-suI2-aadA2-dfrA12) with three previously reported plasmids, indicating a potential for dynamic genetic recombination and evolution within the MDR region. Additionally, the integration of virulence factors, including the iro and sit gene clusters and enolase, into its genetic architecture poses further therapeutic challenges by enhancing the strain's pathogenicity through improved host tissue colonization, immune evasion, and increased infection severity. CONCLUSIONS: The detailed identification and characterization of pNDM-5-0083 enhance our understanding of the mechanisms facilitating the spread of carbapenem resistance. This study illuminates the intricate interplay among various genetic elements within the novel blaNDM-5-carrying plasmid, which are crucial for the stability and mobility of resistance genes across bacterial populations. These insights highlight the urgent need for ongoing surveillance and the development of effective strategies to curb the proliferation of antibiotic resistance.

Streptococcus dysgalactiae subsp. dysgalactiae presents with progressive weakness in limbs: a case report and literature review.

BACKGROUND: Streptococcus dysgalactiae subsp. dysgalactiae has been identified as an animal pathogen that is thought to occur only in animal populations. Between 2009 and 2022, humans infected with SDSD were reported rarely. There is a lack of details on the natural history, clinical features, and management of disease caused by this pathogen. This case outlines a human SDSD with muscle aches and progressive loss of muscle strength leading to immobility and multi-organ dysfunction syndrome. CASE PRESENTATION: She presented with muscle pain and weakness, and later developed a sore throat, headache and fever with a maximum temperature of 40.5 °C. The muscle strength of the extremities gradually decreased to grade 1 and the patient was unable to move on his own. Next-generation blood sequencing and multi-culture confirmed the presence of Streptococcus dysgalactiae and Streptococcus dysgalactiae subsp. Dysgalactiae, respectively. A Sequential Organ Failure Assessment score of 6 indicated septicemia, and therapeutic antibiotics were prescribed empirically. After 19 days of inpatient treatment, the patient's condition greatly improved and completely recovered within a month. CONCLUSION: Symptoms of Streptococcus dysgalactiae subsp. dysgalactiae presenting with progressive limb weakness resemble polymyositis, so a precise differential diagnosis is essential. Multidisciplinary consultation is helpful when polymyositis cannot be ruled out and facilitates the choice of an optimal treatment protocol. In the context of this case, penicillin is an effective antibiotic for Streptococcus dysgalactiae subsp. dysgalactiae infection.

Leptospira infection complicated by demyelinating disease: A case report.

Leptospirosis is a zoonotic disease, found worldwide, that is caused by bacteria of the genus Leptospira. People can be infected with Leptospira if they come in direct contact with the urine of an infected animal. Leptospirosis may be associated with demyelinating lesions of the central nervous system. This case report describes a 66-year-old female patient who presented with fever and generalized aches and progressed to unconsciousness within a few hours of admission. Laboratory tests showed Leptospira infection, and brain magnetic resonance imaging revealed acute demyelinating lesions. The patient responded well to penicillin and intravenous methylprednisolone therapy. Leptospirosis presenting with acute disseminated encephalomyelitis is rare. In this patient, an interdisciplinary collaboration involving the neurologist, radiologist, and pathologist was crucial for diagnosis and management. Further studies are warranted to investigate whether there is a correlation between demyelinating lesions and leptospiral infection.

Study on the Association of Homocysteine and C-Reactive Protein with Neurofunctional Changes in Patients with Acute Ischemic Stroke After Endovascular Stent Treatment.

Objective: To examine the association of homocysteine (HCY) and C-reactive protein (CRP) with neurofunctional changes in patients with acute ischemic stroke (AIS) after stent treatment. Methods: A total of 110 patients with AIS treated with stents were divided into a high HCY group (n = 59) and a normal HCY group (n = 51) based on the HCY level. Pearson correlation analysis and logistic linear regression analysis were used to analyze the related factors that affect the National Institutes of Health Stroke Scale (NIHSS) score changes after stent treatment. Results: (1) The area under the receiver operating characteristic (ROC) curve for HCY was 0.995 (95% confidence interval [CI]: 0.984-1.005, P = 0.000), and the best predictive value was 12.75 µmol/L (sensitivity 89.9%, specificity 98.0%). The area under the ROC curve for CRP was 0.665 (95% CI: 0.564-0.767, P = 0.003), and the best predictive value was 9.7 mg/L; (2) comparison between the high HCY group and the normal HCY group showed statistical differences (P < 0.05) in HCY, CRP, and the NIHSS score at admission, the NIHSS score after treatment, gender, history of diabetes, and history of atrial fibrillation; (3) both HCY and CRP were proven to be correlated with the NIHSS score after treatment (0.188, P = 0.050) and (0.194, P = 0.042), respectively, using Pearson correlation analysis; (4) HCY, low-density lipoprotein, CRP, cystatin C, glucose, history of atrial fibrillation, history of diabetes, and the NIHSS score at admission as the risk factors. Conclusion: High HCY and CRP levels are related to the neurofunctional changes in patients with AIS treated with stents and can be used as indicators to assess the risk of treating AIS with stents and as serum markers to predict prognoses.

Impact of Glycosylated Hemoglobin on the Prognosis of Patients with Acute Ischemic Stroke Treated with Arterial Thrombolysis.

BACKGROUND: To investigate the impact of glycosylated hemoglobin (HbA1c) on the prognosis of patients with acute ischemic stroke (AIS) treated with intra-arterial thrombolysis (IAT). METHODS: The clinical data of 136 patients with AIS treated with IAT at the Zhongshan City People's Hospital were retrospectively analyzed. The patients were divided into a high HbA1c group (HHbA1c) (≥6.5%) and a normal HbA1c group (NHbA1c) (<6.5%). According to National Institutes of Health Stroke Scale (NIHSS) score after thrombolysis, patients were divided into a good prognosis group (GP) (≥4 or <4 points reduction) and a poor prognosis group (PP) (≤4 or >4 points reduction). RESULTS: There were significant differences in the HbA1c and glucose levels, NIHSS scores at admission and at discharge, complication rates, and mortality rates between groups HHbA1c and NHbA1c (P < .05) and between groups GP and PP (P < .05). The multivariate logistic regression analysis showed that HbA1c level (odds ratio [OR] 0.717; 95% confidence interval [CI] 0.545 to 0.889) and NIHSS score at admission (OR 0.894; 95% CI 0.814 to 0.982) were risk factors for neurological improvement in IAT-treated patients with AIS. CONCLUSIONS: HbA1c level is associated with neurological function improvement in IAT-treated patients with AIS and can be used as a serological indicator of poor prognosis.