Infections by multidrug-resistant Gram-negative Bacteria: What's new in our arsenal and what's in the pipeline?

The spread of multidrug-resistant bacteria is an ever-growing concern, particularly among Gram-negative bacteria because of their intrinsic resistance and how quickly they acquire and spread new resistance mechanisms. Treating infections caused by Gram-negative bacteria is a challenge for medical practitioners and increases patient mortality and cost of care globally. This vulnerability, along with strategies to tackle antimicrobial resistance development, prompts the development of new antibiotic agents and exploration of alternative treatment options. This article summarises the new antibiotics that have recently been approved for Gram-negative bacterial infections, looks down the pipeline at promising agents currently in phase I, II, or III clinical trials, and introduces new alternative avenues that show potential in combating multidrug-resistant Gram-negative bacteria.     

Obstructive ureteric calculus with superimposed infections causing reversible posterior leukoencephalopathy syndrome: A case report

Rationale:Reversible posterior leukoencephalopathy syndrome (RPLS) is a clinicoradiological phenomenon first observed 2 decades ago. Reversibility is the hallmark of this rare clinical phenomenon once the triggering pathology is aptly and adequately treated. Tinnitus preceding bilateral hearing loss as a symptomatology of RPLS has not been reported in the literature. Furthermore, chronic obstructive ureteric calculus with superimposed infections as a cause of RPLS has not been reported in the literature.Patient concerns:A 57-year-old female was admitted at our facility because of 2 days history of hearing loss in both ears. She experienced tinnitus in both ears 2 weeks prior to the hearing loss. She is a known hypertensive. She has also undergone multiple surgical treatments for urinary calculi.Diagnosis:Computed tomography (CT) scan of the urinary system revealed a calculus at the right ureter. Magnetic resonance imaging (MRI) showed abnormal signals at both temporo-parieto-occipital (TPO) cortices, the subcortical area, as well as the left hippocampus which was consistent with the diagnosis of RPLS.Interventions:While on antibiotics for treatment of infections, the patient went into hypertensive encephalopathy and pneumonia was also established necessitating intensive care.Outcomes:We observed a resolution of the patient''s temperature and hypertension when the right ureteric stone finally descended into the bladder. Also, we observed disappearance of the abnormal signals at both TPO cortices, the subcortical area, as well as the left hippocampus. Two years follow-up revealed no recurrence of her symptomatology.Lesions:Patients who present with hypertensive encephalopathy maybe more prone to developing RPLS. Renal insufficiency alone or hypertension alone may not be single predisposing entities to RPLS but rather multiple predisposing factors.     

Radiation induced glioma in a sexagenarian: A case report

Introduction:Radiation induced gliomas often occurs after radiation therapy for other brain tumors. Medulloblastoma often occurs in children and its associated radiation-induced glioblastoma multiforme''s (GBM) after radiotherapy often has a long latency period. Our case is very unique because the medulloblastoma was detected at an advance age and the latency period of radiation-induced GBM was relatively shorter.Patients Concerns:A 64-year-old male was first admitted at our hospital in March 2018 with dizziness, vomiting, and blurred vision.Diagnosis:Magnetic resonance imaging of brain revealed a lesion with local mixed density and mass enhancement in left cerebellar region. Histopathology established medulloblastoma (World Health Organization) grade 4 and a classic histological subtype after surgery.Intervention:Surgical resection followed by radiation therapy were the initial therapeutic modalities.Outcomes:In April 2019, the patient was readmitted with dizziness and blurred vision. Magnetic resonance imaging showed the left cerebellar hemisphere bulky enhancement lesion. Again, a multimodal therapy comprising surgical resection, radiation therapy as well as chemotherapy was adapted after histopathology established GBM.Lesion:Radiotherapy for medulloblastoma patients at advance ages is a critical predisposing factor for the development of radiation-induced GBM in a very short period of time. We suggest that, radiotherapy as adjuvant therapy for medulloblastoma patients at advance ages should be chosen with extreme caution.     

Hemangioblastoma masquerading as a ring enhancing lesion in the cerebellum: A case report

Rationale:Hemangioblastomas (HGBMs) are very rare, and the cerebellum is usually the most common site of occurrence. HGBMs with ring-enhanced walls are often misdiagnosed as metastases, abscesses, glioblastomas, tuberculomas, and demyelinating diseases. Thus, we present a rare case of HGBM masquerading as a ring-enhancing lesion in the cerebellum.Patient concerns:We present a 33-year-old female who was admitted to our department because of headaches, unstable walking, and visual loss in both eyes. Cranial nerve examination revealed deficits in cranial nerve II.Diagnosis:Magnetic resonance imaging revealed 2 cystic lesions in the cerebellum, with irregular ring-enhanced cyst walls composed of smaller nodular parts. Immunohistochemical staining of resected specimens established HGBM.Interventions:The lesions were completely resected using a right retrosigmoid approach.Outcomes:Two years of follow-up revealed no recurrence of her symptoms or tumor. She is currently well and performs her daily duties.Lessons:HGBMs with enhanced cysts are often misdiagnosed by radiology because of their ring-enhanced nature. Computed tomography angiography may be the best modality for differentiating cerebellar HGBM from other ring-enhancing lesions. Surgery is the gold standard of treatment for these lesions.     

Hybrid operation for arteriovenous malformations with associated multiple intracranial aneurysms and subarachnoid hemorrhage: Case report

Rationale:The hybrid surgical concept for the treatment of brain arteriovenous malformations (AVMs) with associated intracranial aneurysms (IAs) is still not widely practiced. Concomitant occurrence of AVMs with IAs is common. Subarachnoid hemorrhage (SAH) as a result of AVM or IA rupture is often associated with these dual pathological phenomena. We present a case of concomitant occurrence of AVMs and IAs that was successfully treated using the hybrid operation concept.Patient concerns:A 62-year-old man presented with sudden onset of severe headache, dizziness, nausea, and vomiting for 4 hours.Diagnosis:Computed tomography revealed SAH and a hematoma in the right frontal lobe. A computed tomographic angiogram also revealed a right frontal AVM with 3 IAs.Interventions:We used a hybrid operating room to successfully treat both AVMs and IAs.Outcomes:Two years of follow-up showed that the patients were well and performed their daily duties.Lessons:The hybrid operating room is an innovative, safe, and effective method for the treatment of AVMs with associated IAs, particularly high-grade AVMs and IAs with hemorrhage or SAH. Patients with concomitant AVMs and IAs have the highest chance of hemorrhage compared with those with AVM or IAs alone.     

Pregnane glycosides from Caralluma russeliana

The aerial parts of Caralluma russeliana yielded four new pregnane glycosides, russeliosides A-D (1-4), in addition to a known flavone glycoside, luteolin 4'-O-beta-D-neohesperidoside. The structures of compounds 1-4 were elucidated using a combination of spectroscopic methods.