Staphylococcus aureus Pneumonia: Preceding Influenza Infection Paves the Way for Low-Virulent Strains

Staphylococcus aureus is a facultative pathogenic bacterium that colonizes the nasopharyngeal area of healthy individuals, but can also induce severe infection, such as pneumonia. Pneumonia caused by mono- or superinfected S. aureus leads to high mortality rates. To establish an infection, S. aureus disposes of a wide variety of virulence factors, which can vary between clinical isolates. Our study aimed to characterize pneumonia isolates for their virulent capacity. For this, we analyzed isolates from colonization, pneumonia due to S. aureus, and pneumonia due to S. aureus/influenza virus co-infection. A total of 70 strains were analyzed for their virulence genes and the host–pathogen interaction was analyzed through functional assays in cell culture systems. Strains from pneumonia due to S. aureus mono-infection showed enhanced invasion and cytotoxicity against professional phagocytes than colonizing and co-infecting strains. This corresponded to the high presence of cytotoxic components in pneumonia strains. By contrast, strains obtained from co-infection did not exhibit these virulence characteristics and resembled strains from colonization, although they caused the highest mortality rate in patients. Taken together, our results underline the requirement of invasion and toxins to cause pneumonia due to S. aureus mono-infection, whereas in co-infection even low-virulent strains can severely aggravate pneumonia.

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Correlation of Twenty Virulence Genes of Staphylococcus aureus with Severity of Atopic Dermatitis in Children as Compared to Healthy Individuals

Journal of Clinical & Experimental Dermatology Research ◽

10.4172/2155-9554.1000174 ◽

2013 ◽

Vol 04 (02) ◽

Author(s):

Anja Jochmann

Keyword(s):

Staphylococcus Aureus ◽

Atopic Dermatitis ◽

Virulence Genes ◽

Healthy Individuals

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SHP2 deficiency promotes Staphylococcus aureus pneumonia following influenza infection

Cell Proliferation ◽

10.1111/cpr.12721 ◽

2019 ◽

Vol 53 (1) ◽

Cited By ~ 3

Author(s):

Wei Ouyang ◽

Chao Liu ◽

Ying Pan ◽

Yu Han ◽

Liping Yang ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Influenza Infection ◽

Staphylococcus Aureus Pneumonia

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Staphylococcus aureus Pneumonia in the Community

Seminars in Respiratory and Critical Care Medicine ◽

10.1055/s-0040-1709992 ◽

2020 ◽

Vol 41 (04) ◽

pp. 470-479

Author(s):

Hangyong He ◽

Richard G. Wunderink

Keyword(s):

Staphylococcus Aureus ◽

Influenza Infection ◽

Community Acquired Pneumonia ◽

Mechanically Ventilated ◽

First Line Therapy ◽

High Incidence ◽

Polymerase Chain ◽

Staphylococcus Aureus Pneumonia ◽

Severe Community Acquired Pneumonia ◽

Panton Valentine Leukocidin

Abstract Staphylococcus aureus is an emergent etiology of community-acquired pneumonia (CAP) over the past 2 decades, with severe community-acquired pneumonia (SCAP) caused by methicillin-resistant S. aureus (MRSA) leading to critical illness and death. S. aureus colonization is associated with a high incidence of pneumonia. Panton-Valentine leukocidin (PVL) is one of the most important virulence factors of S. aureus associated with serious complications. In recent years, community-associated MRSA (CA-MRSA) clones that caused infections in young adults and healthy individuals with no exposure to health care settings and no classical risk factors have emerged. Clinical features at admission including concurrent influenza infection, hemoptysis, multilobar infiltrates, and neutropenia should suggest S. aureus CAP. Sputum Gram stains, cultures (or tracheobronchial aspirates or bronchoalveolar lavage in mechanically ventilated patients), polymerase chain reaction (nasopharyngeal or oropharyngeal or lower respiratory tract specimens), and two sets of blood cultures should be obtained from patients presenting with severe S. aureus CAP. For CAP due to methicillin-susceptible S. aureus, first-line therapy is usually cefazolin, oxacillin, or ceftaroline. For CA-MRSA pneumonia, linezolid is recommended. If vancomycin or teicoplanin are used, combination with clindamycin or rifampicin should be considered in cases of PVL-positive MRSA CAP.

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Faculty Opinions recommendation of Roles of 34 virulence genes in the evolution of hospital‐ and community‐associated strains of methicillin‐resistant Staphylococcus aureus

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.14323.471825 ◽

2006 ◽

Author(s):

David Farrell

Keyword(s):

Staphylococcus Aureus ◽

Virulence Genes ◽

Methicillin Resistant

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Distribution of virulence genes and SCCmec types among methicillin-resistant Staphylococcus aureus of clinical and environmental origin: a study from community of Assam, India

BMC Research Notes ◽

10.1186/s13104-021-05473-3 ◽

2021 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Deepshikha Bhowmik ◽

Shiela Chetri ◽

Bhaskar Jyoti Das ◽

Debadatta Dhar Chanda ◽

Amitabha Bhattacharjee

Keyword(s):

Staphylococcus Aureus ◽

Virulence Genes ◽

Methicillin Resistant Staphylococcus Aureus ◽

Virulence Gene ◽

Type I ◽

Methicillin Resistant ◽

Type Iv ◽

Clinical Community ◽

Type V ◽

Sccmec Types

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.

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Association between a rapid diagnostic test to detect methicillin-resistant Staphylococcus Aureus pneumonia and decreased vancomycin use in a medical intensive care unit over a 30-month period

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.1406 ◽

2021 ◽

pp. 1-3

Author(s):

Chiagozie I. Pickens ◽

Chao Qi ◽

Michael Postelnick ◽

Joseph Paonessa ◽

Helen K. Donnelly ◽

...

Keyword(s):

Intensive Care Unit ◽

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Medical Intensive Care Unit ◽

Pcr Assay ◽

Days Of Therapy ◽

Medical Intensive Care ◽

Staphylococcus Aureus Pneumonia ◽

Few Data ◽

Rule Out

Abstract Vancomycin overuse is common, yet few data are available regarding how to improve stewardship of this antibiotic. We identify an association between use of a PCR assay to rule out MRSA pneumonia and a significant, sustained decrease in average vancomycin days of therapy over a 30-month period.

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Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

BMC Infectious Diseases ◽

10.1186/s12879-019-4547-5 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 8

Author(s):

Xuehan Li ◽

Tao Huang ◽

Kai Xu ◽

Chenglin Li ◽

Yirong Li

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Resistance Genes ◽

Virulence Genes ◽

Mainland China ◽

Geographical Location ◽

Antibiotic Resistance Genes ◽

Virulence Gene ◽

Molecular Characteristics ◽

Staphylococcal Protein A

Abstract Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

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