Escherichia coli tetracycline efflux determinants in relation to tetracycline residues in chicken

ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tc^r) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tc^r E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment.     

Correlation of PD-L1 Expression with Tumor Mutation Burden and Gene Signatures for Prognosis in Early-Stage Squamous Cell Lung Carcinoma

Objectives

Anti–programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) immunotherapy has demonstrated success in the treatment of advanced NSCLC. Recently, PD-1/PD-L1 blockade also has demonstrated interesting results in small trials of neoadjuvant treatment in stage IB to IIIA NSCLC. In addition, several clinical trials using anti–PD-1/PD-L1 immunotherapy as an adjuvant or neoadjuvant treatment in patients with resectable stage NSCLC are ongoing. However, few analyses of anti–PD-1/PD-L1 immunotherapy–related biomarkers in early-stage squamous cell lung carcinoma (SqCLC) have been reported. In this study, we evaluated PD-L1 protein expression, tumor mutation burden, and expression of an immune gene signature in early-stage SqCLC, providing data for identifying the potential role for patients with anti–PD-1/PD-L1 treatment in early-stage SqCLC.

Carotid sheath lipoma: first case report in the English literature

Lipomas are the most commonly encountered benign mesenchymal tumour, arising in any location where fat is normally present. Lipomas in the head and neck are rare in all age groups. Cases of vascular sheath lipomas in the femoral region have only been reported in adults. In children, vascular sheath lipomas have not been described to date. We report the first case of a carotid sheath lipoma in a seven-year-old boy. He had a non-tender soft mass with ill defined borders occupying the left upper part of the neck. Magnetic resonance imaging showed a mass at the bifurcation of the left common carotid artery without involving the same. The mass was hyperintense on T1 and T2 weighted sequences, suggestive of a lipoma. The lipoma was enucleated after incising the carotid sheath, safeguarding its contents. Histopathology confirmed it as a lipoma.     

Atypical Presentation of Cavernous Sinus Infection with Intracavernous ICA Aneurysm

In a typical presentation of intracavernous internal carotid artery aneurysm and cavernous sinus infection there is involvement of 3rd, 4th and 6th cranial nerves along with 2nd and 5th cranial nerve. Here we present a case of a 32 years old male with unilateral mycotic intracavernous internal carotid artery aneurysm with a history of head injury. Atypical features in this case was involvement of distantly situated multiple cranial nerves and sparing the 5th cranial nerve and optic nerve which are more near and commonly involved. Besides this patient has marked sphenoid sinusitis on left side but having no sign and symptoms.