[Moraxella catarrhalis: an emerging respiratory pathogen]

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...

Human respiratory syncytial virus (RSV) is a widespread pathogen that primarily targets infants and young children but also poses a serious health risk to elderly and immunocompromised individuals. Belonging to the Pneumoviridae family, RSV is a negative-sense, single-stranded RNA virus within the Pneumovirus genus. Its global health burden is significant, with millions of cases annually resulting in hospitalizations and mortality, particularly in resource-limited settings. Although most...