Nasopharyngeal Carriage of Penicillin-resistant Streptococcus pneumoniae in Children With Sickle Cell Disease

Nasopharyngeal carriage of Streptococcus pneumoniae was studied in children with sickle cell disease. The incidence of nasopharyngeal isolation was 17.8%. Groups 23 and 6 and type 14 predominated.

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Nasopharyngeal Carriage of Methicillin-Resistant Staphylococcus aureus (MRSA) among Sickle Cell Disease (SCD) Children in the Pneumococcal Conjugate Vaccine Era

Infectious Disease Reports ◽

10.3390/idr13010022 ◽

2021 ◽

Vol 13 (1) ◽

pp. 191-204

Author(s):

Nicholas T. K. D. Dayie ◽

Deborah N. K. Sekoh ◽

Fleischer C. N. Kotey ◽

Beverly Egyir ◽

Patience B. Tetteh-Quarcoo ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Sickle Cell Disease ◽

Conjugate Vaccine ◽

Sickle Cell ◽

Pneumococcal Conjugate Vaccine ◽

Diffusion Method ◽

Nasopharyngeal Carriage ◽

Cell Disease ◽

Coagulase Negative Staphylococci ◽

Methicillin Resistant

The aim of this cross-sectional study was to investigate Staphylococcus aureus nasopharyngeal carriage epidemiology in relation to other nasopharyngeal bacterial colonizers among sickle cell disease (SCD) children about five years into pneumococcal conjugate vaccine 13 (PCV-13) introduction in Ghana. The study involved bacteriological culture of nasopharyngeal swabs obtained from 202 SCD children recruited from the Princess Marie Louise Children’s Hospital. S. aureus isolates were identified using standard methods and subjected to antimicrobial susceptibility testing using the Kirby-Bauer disc diffusion method. Cefoxitin-resistant S. aureus isolates were screened for carriage of the mecA, pvl, and tsst-1 genes using multiplex polymerase chain reaction. The carriage prevalence of S. aureus was 57.9% (n = 117), and that of methicillin-resistant S. aureus (MRSA) was 3.5% (n = 7). Carriage of the mecA, pvl, and tsst-1 genes were respectively demonstrated in 20.0% (n = 7), 85.7% (n = 30), and 11.4% (n = 4) of the cefoxitin-resistant S. aureus isolates. PCV-13 vaccination (OR = 0.356, p = 0.004) and colonization with coagulase-negative staphylococci (CoNS) (OR = 0.044, p < 0.0001) each protected against S. aureus carriage. However, none of these and other features of the participants emerged as a determinant of MRSA carriage. The following antimicrobial resistance rates were observed in MRSA compared to methicillin-sensitive S. aureus: clindamycin (28.6% vs. 4.3%), erythromycin (42.9% vs. 19.1%), tetracycline (100% vs. 42.6%), teicoplanin (14.3% vs. 2.6%), penicillin (100% vs. 99.1%), amoxiclav (28.6% vs. 3.5%), linezolid (14.3% vs. 0.0%), ciprofloxacin (42.9% vs. 13.9%), and gentamicin (42.9% vs. 13.0%). The proportion of S. aureus isolates that were multidrug resistant was 37.7% (n = 46). It is concluded that S. aureus was the predominant colonizer of the nasopharynx of the SCD children, warranting the continuous monitoring of this risk group for invasive S. aureus infections.

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Streptococcus pneumoniae and Its Virulence Factors H2O2 and Pneumolysin Are Potent Mediators of the Acute Chest Syndrome in Sickle Cell Disease

Toxins ◽

10.3390/toxins13020157 ◽

2021 ◽

Vol 13 (2) ◽

pp. 157

Author(s):

Joyce Gonzales ◽

Trinad Chakraborty ◽

Maritza Romero ◽

Mobarak Abu Mraheil ◽

Abdullah Kutlar ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Sickle Cell Disease ◽

Virulence Factors ◽

Sickle Cell ◽

Biological Activities ◽

Acute Chest Syndrome ◽

Antibiotics Resistance ◽

Cell Disease ◽

Antibiotic Drug ◽

Tract Infections

Sickle cell disease (SCD) is one of the most common autosomal recessive disorders in the world. Due to functional asplenia, a dysfunctional antibody response, antibiotic drug resistance and poor response to immunization, SCD patients have impaired immunity. A leading cause of hospitalization and death in SCD patients is the acute chest syndrome (ACS). This complication is especially manifested upon infection of SCD patients with Streptococcus pneumoniae (Spn)—a facultative anaerobic Gram-positive bacterium that causes lower respiratory tract infections. Spn has developed increased rates of antibiotics resistance and is particularly virulent in SCD patients. The primary defense against Spn is the generation of reactive oxygen species (ROS) during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn itself produces high levels of the ROS hydrogen peroxide (H2O2) as a virulence strategy. Apart from H2O2, Spn also secretes another virulence factor, i.e., the pore-forming exotoxin pneumolysin (PLY), a potent mediator of lung injury in patients with pneumonia in general and particularly in those with SCD. PLY is released early on in infection either by autolysis or bacterial lysis following the treatment with antibiotics and has a broad range of biological activities. This review will discuss recent findings on the role of pneumococci in ACS pathogenesis and on strategies to counteract the devastating effects of its virulence factors on the lungs in SCD patients.

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