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Afreen S, Singh N, Kaur M, Chaudhary N, Kumar A, Pahil S, Mohan B, Taneja N. Phenotypic and genomic characterization of a small colony variant of Klebsiella pneumoniae isolated from urine of a prostate cancer case. Indian J Med Microbiol 2024; 51:100664. [PMID: 38977132 DOI: 10.1016/j.ijmmb.2024.100664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 06/12/2024] [Accepted: 07/06/2024] [Indexed: 07/10/2024]
Abstract
Small colony variants (SCVs) in Klebsiella pneumoniae are rare and understudied. We report an SCV of Klebsiella pneumoniae isolated from the urine of a prostate cancer patient undergoing prolonged radiotherapy. The strain was non-lactose fermenting, non-mucoid, slow-growing, multi-drug resistant, and showed atypical biochemical reactions and biofilm formation. On whole genome sequencing, it showed low-level virulence, sequence type 231 and gene CTX-M-15. Three major porins OmpK35, OmpK36 and OmpK37 were found. SCVs pose challenges like difficulties in identification, altered metabolism, and increased biofilm formation, which contribute to persistent infections. Radiotherapy and chemotherapy may have led to the formation of the SCV phenotype.
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Affiliation(s)
- Sana Afreen
- Department of Medical Microbiology, PGIMER, Chandigarh, India.
| | | | | | | | - Ajay Kumar
- Department of Medical Microbiology, PGIMER, Chandigarh, India.
| | - Sapna Pahil
- Department of Medical Microbiology, PGIMER, Chandigarh, India.
| | - Balvinder Mohan
- Department of Medical Microbiology, PGIMER, Chandigarh, India.
| | - Neelam Taneja
- Department of Medical Microbiology, PGIMER, Chandigarh, India.
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Sheykhsaran E, Abbasi A, Memar MY, Ghotaslou R, Baghi HB, Mazraeh FN, Laghousi D, Sadeghi J. The role of Staphylococcus aureus in cystic fibrosis pathogenesis and clinico-microbiological interactions. Diagn Microbiol Infect Dis 2024; 109:116294. [PMID: 38678689 DOI: 10.1016/j.diagmicrobio.2024.116294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 01/05/2024] [Accepted: 03/29/2024] [Indexed: 05/01/2024]
Abstract
Cystic fibrosis (CF) is a progressive and inherited disease that affects approximately 70000 individuals all over the world annually. A mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene serves as its defining feature. Bacterial infections have a significant impact on the occurrence and development of CF. In this manuscript, we discuss the role and virulence factors of Staphylococcus aureus as an important human pathogen with the ability to induce respiratory tract infections. Recent studies have reported S. aureus as the first isolated bacteria in CF patients. Methicillin-resistant Staphylococcus aureus (MRSA) pathogens are approximately resistant to all β-lactams. CF patients are colonized by MRSA expressing various virulence factors including toxins, and Staphylococcal Cassette Chromosome mec (SCCmec) types, and have the potential for biofilm formation. Therefore, variations in clinical outcomes will be manifested. SCCmec type II has been reported in CF patients more than in other SCCmec types from different countries. The small-colony variants (SCVs) as specific morphologic subtypes of S. aureus with slow growth and unusual properties can also contribute to persistent and difficult-to-treat infections in CF patients. The pathophysiology of SCVs is complicated and not fully understood. Patients with cystic fibrosis should be aware of the intrinsic risk factors for complex S. aureus infections, including recurring infections, physiological issues, or coinfection with P. aeruginosa.
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Affiliation(s)
- Elham Sheykhsaran
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amin Abbasi
- Department of Food Science and Technology, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Ghotaslou
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Bannazadeh Baghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fariba Naeimi Mazraeh
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Delara Laghousi
- Social Determinants of Health Research Center, Health Management and Safety Promotion Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Javid Sadeghi
- Immunology Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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Xu X, Zhang X, Zhang G, Abbasi Tadi D. Prevalence of antibiotic resistance of Staphylococcus aureus in cystic fibrosis infection: a systematic review and meta-analysis. J Glob Antimicrob Resist 2024; 36:419-425. [PMID: 37211214 DOI: 10.1016/j.jgar.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/23/2023] Open
Abstract
OBJECTIVES Cystic fibrosis (CF) is a hereditary recessive disease that affects the mucous clearance of the lungs and allows bacteria such as Staphylococcus aureus to settle in the lung and cause infection. This study examined the prevalence of antibiotic resistance of S. aureus in cystic fibrosis infection using a systematic review and meta-analysis. METHODS A comprehensive and systematic search of related articles was conducted through the PubMed, Scopus, and Web of Science databases until March 2022. The weighted pooled resistance rate of antibiotics was analysed with Freeman-Tukey double arcsine transformation in the Stata software version 17.1 using the Metaprop command. RESULTS In this meta-analysis, 25 studies were used based on criteria to evaluate the pattern of S. aureus resistance in CF. Vancomycin and teicoplanin were the most effective options for treatment of CF patients; the highest level of antibiotic resistance observed was to erythromycin and clindamycin. CONCLUSION High levels of resistance to most of the antibiotics studied was observed. The high levels of antibiotic resistance observed are worrisome and indicate the need to monitor antibiotic use.
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Affiliation(s)
- Xuemei Xu
- Pharmacy department, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine
| | - Xiang Zhang
- Laboratory Department, The Fifth Hospital of Rui'an, Rui'an, China
| | - Guoying Zhang
- Rui'an People's Hospital and the Third Hospital Affiliated to Wenzhou Medical University, Rui'an, China
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Ryan H, Ballard E, Stockwell RE, Duplancic C, Thomson RM, Smith K, Bell SC. A systematic review of the clinical impact of small colony variants in patients with cystic fibrosis. BMC Pulm Med 2023; 23:323. [PMID: 37658311 PMCID: PMC10474644 DOI: 10.1186/s12890-023-02611-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Cystic fibrosis (CF) is a life-limiting disorder that is characterised by respiratory tract inflammation that is mediated by a range of microbial pathogens. Small colony variants (SCVs) of common respiratory pathogens are being increasingly recognised in CF. The aim of this systematic review is to investigate the prevalence of SCVs, clinical characteristics and health outcomes for patients with CF, and laboratory diagnostic features of SCVs compared to non-small colony variants (NCVs) for a range of Gram-positive and Gram-negative respiratory pathogens. METHODS A literature search was conducted (PubMed, Web of Science, Embase and Scopus) in April 2020 to identify articles of interest. Data pertaining to demographic characteristics of participants, diagnostic criteria of SCVs, SCV prevalence and impact on lung function were extracted from included studies for analysis. RESULTS Twenty-five of 673 studies were included in the systematic review. Individuals infected with SCVs of Staphylococcus aureus (S. aureus) were more likely to have had prior use of the broad-spectrum antibiotic trimethoprim sulfamethoxazole (p < 0.001), and the prevalence of SCVs in patients infected with S. aureus was estimated to be 19.3% (95% CI: 13.5% to 25.9%). Additionally, patients infected with SCVs of Gram-negative and Gram-positive pathogens were identified to have a lower forced expiratory volume in one second percentage predicted (-16.8, 95% CI: -23.2 to -10.4) than those infected by NCVs. Gram-positive SCVs were commonly described as small and non-haemolytic, grown on Mannitol salt or blood agar for 24 h at 35°C and confirmed using tube coagulase testing. CONCLUSION The findings of this systematic review demonstrate that SCVs of S. aureus have a high prevalence in the CF community, and that the occurrence of SCVs in Gram-positive and Gram-negative pathogens is linked to poorer respiratory function. Further investigation is necessary to determine the effect of infection by SCVs on the CF population.
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Affiliation(s)
- Harrigan Ryan
- Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia
| | - Emma Ballard
- Statistics Unit, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Rebecca E Stockwell
- Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, QLD, Australia
| | - Christine Duplancic
- Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia
| | - Rachel M Thomson
- Respiratory Research Group, Gallipoli Medical Research Foundation, Greenslopes, QLD, Australia
| | - Kimberley Smith
- Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia
| | - Scott C Bell
- Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia.
- Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, QLD, Australia.
- Translational Research Institute, Woolloongabba, QLD, Australia.
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Keim KC, George IK, Reynolds L, Smith AC. The Clinical Significance of Staphylococcus aureus Small Colony Variants. Lab Med 2022; 54:227-234. [PMID: 36226897 DOI: 10.1093/labmed/lmac101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Abstract
A burdensome, atypical phenotype of Staphylococcus aureus (SA) called S aureus small colony variant (SA-SCV) has been identified, which is induced as a result of a combination of environmental stressors, including polymicrobial interactions. The SA-SCVs exhibit altered phenotypes as a result of metabolic dormancy caused by electron transport deficiency, leading to increased biofilm production and alterations to antimicrobial susceptibility. The SA-SCVs typically exhibit altered colony morphology and biochemical reactions compared with wild-type SA, making them difficult to detect via routine diagnostics. The SA-SCVs have been found to contribute to chronic or recurrent infections, including skin and soft-tissue infections, foreign-body associated infection, cystic fibrosis, and sepsis. There is evidence that SA-SCVs contribute to patient morbidity and mortality as a result of diagnostic difficulties and limited treatment options. New detection methods may need to be developed that can be incorporated into routine diagnostics, which would allow for better assessment of specimens and introduce new considerations for treatment.
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Affiliation(s)
- Klara C Keim
- Department of Immunology and Microbiology, School of Medicine, Anschutz Medical Campus, University of Colorado , Aurora, CO , USA
| | - Isaiah K George
- Department of Honors Studies, Texas Tech University , Lubbock, TX , USA
| | - Landrye Reynolds
- Department of Honors Studies, Texas Tech University , Lubbock, TX , USA
| | - Allie C Smith
- Department of Honors Studies, Texas Tech University , Lubbock, TX , USA
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Zhou S, Rao Y, Li J, Huang Q, Rao X. Staphylococcus aureus small-colony variants: Formation, infection, and treatment. Microbiol Res 2022; 260:127040. [DOI: 10.1016/j.micres.2022.127040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 04/10/2022] [Accepted: 04/11/2022] [Indexed: 10/18/2022]
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Zulkefli NJ, Teh CSJ, Mariappan V, Ngoi ST, Vadivelu J, Ponnampalavanar S, Chai LC, Chong CW, Yap IKS, Vellasamy KM. Genomic comparison and phenotypic profiling of small colony variants of Burkholderia pseudomallei. PLoS One 2021; 16:e0261382. [PMID: 34910764 PMCID: PMC8673655 DOI: 10.1371/journal.pone.0261382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/30/2021] [Indexed: 11/18/2022] Open
Abstract
Burkholderia pseudomallei (B. pseudomallei) is an intracellular pathogen that causes melioidosis, a life-threatening infection in humans. The bacterium is able to form small colony variants (SCVs) as part of the adaptive features in response to environmental stress. In this study, we characterize the genomic characteristics, antimicrobial resistance (AMR), and metabolic phenotypes of B. pseudomallei SCV and wild type (WT) strains. Whole-genome sequence analysis was performed to characterize the genomic features of two SCVs (CS and OS) and their respective parental WT strains (CB and OB). Phylogenetic relationship between the four draft genomes in this study and 19 publicly available genomes from various countries was determined. The four draft genomes showed a close phylogenetic relationship with other genomes from Southeast Asia. Broth microdilution and phenotype microarray were conducted to determine the AMR profiles and metabolic features (carbon utilization, osmolytes sensitivity, and pH conditions) of all strains. The SCV strains exhibited identical AMR phenotype with their parental WT strains. A limited number of AMR-conferring genes were identified in the B. pseudomallei genomes. The SCVs and their respective parental WT strains generally shared similar carbon-utilization profiles, except for D,L-carnitine (CS), g-hydroxybutyric acid (OS), and succinamic acid (OS) which were utilized by the SCVs only. No difference was observed in the osmolytes sensitivity of all strains. In comparison, WT strains were more resistant to alkaline condition, while SCVs showed variable growth responses at higher acidity. Overall, the genomes of the colony morphology variants of B. pseudomallei were largely identical, and the phenotypic variations observed among the different morphotypes were strain-specific.
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Affiliation(s)
- Noorfatin Jihan Zulkefli
- Faculty of Medicine, Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- Faculty of Medicine, Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
- * E-mail: (CSJT); (KMV)
| | - Vanitha Mariappan
- Faculty of Health Sciences, Centre of Toxicology and Health Risk Studies (CORE), Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Soo Tein Ngoi
- Faculty of Medicine, Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Jamuna Vadivelu
- Faculty of Medicine, Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
| | | | - Lay Ching Chai
- Faculty of Science, Institute of Biological Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chun Wie Chong
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
- Institute for Research, Development & Innovation, International Medical University, Kuala Lumpur, Malaysia
| | - Ivan Kok Seng Yap
- Sarawak Research and Development Council, Kuching, Sarawak, Malaysia
| | - Kumutha Malar Vellasamy
- Faculty of Medicine, Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
- * E-mail: (CSJT); (KMV)
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Varela MC, Roch M, Taglialegna A, Long SW, Saavedra MO, Rose WE, Davis JJ, Hoffman LR, Hernandez RE, Rosato RR, Rosato AE. Carbapenems drive the collateral resistance to ceftaroline in cystic fibrosis patients with MRSA. Commun Biol 2020; 3:599. [PMID: 33093601 PMCID: PMC7582194 DOI: 10.1038/s42003-020-01313-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/30/2020] [Indexed: 01/14/2023] Open
Abstract
Chronic airways infection with methicillin-resistant Staphylococcus aureus (MRSA) is associated with worse respiratory disease cystic fibrosis (CF) patients. Ceftaroline is a cephalosporin that inhibits the penicillin-binding protein (PBP2a) uniquely produced by MRSA. We analyzed 335 S. aureus isolates from CF sputum samples collected at three US centers between 2015-2018. Molecular relationships demonstrated that high-level resistance of preceding isolates to carbapenems were associated with subsequent isolation of ceftaroline resistant CF MRSA. In vitro evolution experiments showed that pre-exposure of CF MRSA to meropenem with further selection with ceftaroline implied mutations in mecA and additional mutations in pbp1 and pbp2, targets of carbapenems; no effects were achieved by other β-lactams. An in vivo pneumonia mouse model showed the potential therapeutic efficacy of ceftaroline/meropenem combination against ceftaroline-resistant CF MRSA infections. Thus, the present findings highlight risk factors and potential therapeutic strategies offering an opportunity to both prevent and address antibiotic resistance in this patient population.
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Affiliation(s)
- Maria Celeste Varela
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Melanie Roch
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Agustina Taglialegna
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Scott W Long
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Matthew Ojeda Saavedra
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Warren E Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - James J Davis
- Argonne National Laboratory (DOE), Lemont, IL, USA
- Computation Institute, University of Chicago, Chicago, IL, USA
| | - Lucas R Hoffman
- Department of Pediatrics and Department of Microbiology, University of Washington, Seattle, WA, USA
- Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Rafael E Hernandez
- Department of Pediatrics and Department of Microbiology, University of Washington, Seattle, WA, USA
- Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Roberto R Rosato
- Houston Methodist Cancer Center, Houston Methodist Hospital, Houston, USA
| | - Adriana E Rosato
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA.
- Riverside University Health System-Medical Center, 26520 Cactus Avenue, Moreno Valley, CA, 92555, USA.
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de Souza DC, Cogo LL, Palmeiro JK, Dalla-Costa LM, de Oliveira Tomaz AP, Riedi CA, Rosario Filho NA. Thymidine-auxotrophic Staphylococcus aureus small-colony variant bacteremia in a patient with cystic fibrosis. Pediatr Pulmonol 2020; 55:1388-1393. [PMID: 32176841 DOI: 10.1002/ppul.24730] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Small-colony variants (SCVs) are a morphologic subtype of Staphylococcus aureus that may occur through several mechanisms including auxotrophism for thymidine, hemin, or menadione. Auxotrophic SCV for thymidine fail to synthesize DNA specifically because of mutations in the thymidylate synthase gene. We isolated S. aureus thymidine-dependent SCVs (TD-SCV) from blood and respiratory samples of a pediatric patient with cystic fibrosis and pulmonary exacerbation. METHODS Nutritional dependence of SCVs on hemin, menadione, and thymidine was evaluated. Antimicrobial susceptibility testing was performed through broth microdilution. Polymerase chain reaction was carried out for mecA, ermA, ermB, ermC, msrA, and msrB resistance genes. DNA sequencing was used to determine mutations in thyA and the multilocus sequence typing to identify genetic relatedness. RESULTS Methicillin-sensitive S. aureus with normal and TD-SCV phenotypes were isolated from respiratory samples and a TD-SCV phenotype was isolated from blood culture. Macrolides resistance was attributed to ermC and msrB genes. All isolates belonged to ST398. The thyA gene in S. aureus is 957 nucleotides in length and encodes a protein of 318 amino acids. The TD-SCV isolates carried a -2 nt frameshift mutation (delta 667GC668) in thyA, creating a stop codon at residue 222 close to the predicted binding site for deoxyuridine monophosphate. CONCLUSIONS The pathogenesis of SCVs is complex and not fully elucidated. Factors inherent to the patient such as physiological conditions, recurrent infections, or coinfection should be considered. Although SCVs are considered less virulent, they showed the ability to invade and cause bacteremia in the patient.
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Affiliation(s)
- Dilair C de Souza
- Laboratório de Bacteriologia, Complexo Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
| | - Laura L Cogo
- Laboratório de Bacteriologia, Complexo Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
| | - Jussara K Palmeiro
- Programa de Pós-graduação em Biotecnologia e saúde da Criança e do Adolescente, Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil.,Departamento de Análises Clínicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Libera M Dalla-Costa
- Programa de Pós-graduação em Biotecnologia e saúde da Criança e do Adolescente, Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Ana P de Oliveira Tomaz
- Laboratório de Bacteriologia, Complexo Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil.,Programa de Pós-graduação em Biotecnologia e saúde da Criança e do Adolescente, Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Brazil
| | - Carlos A Riedi
- Departamento de Pediatria, Complexo Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
| | - Nelson A Rosario Filho
- Departamento de Pediatria, Complexo Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Brazil
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Langlois JP, Millette G, Guay I, Dubé-Duquette A, Chamberland S, Jacques PÉ, Rodrigue S, Bouarab K, Marsault É, Malouin F. Bactericidal Activity of the Bacterial ATP Synthase Inhibitor Tomatidine and the Combination of Tomatidine and Aminoglycoside Against Persistent and Virulent Forms of Staphylococcus aureus. Front Microbiol 2020; 11:805. [PMID: 32431678 PMCID: PMC7216300 DOI: 10.3389/fmicb.2020.00805] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/03/2020] [Indexed: 12/15/2022] Open
Abstract
Tomatidine (TO), a steroid alkaloid, exerts a strong bactericidal activity on the infection-persistent phenotype of Staphylococcus aureus, the small-colony variant (SCV), with a minimal inhibitory concentration (MIC) of 0.06 μg/ml. Also, the combination of TO to an aminoglycoside (AMG) shows a strong synergistic effect against prototypical (WT) S. aureus (MIC 0.06 μg/ml), which is otherwise unaffected by TO alone (MIC > 128 μg/ml). We have recently established that the ATP synthase (subunit AtpE) was the molecular target of TO and that TO reduces the production of ATP in S. aureus. The purpose of this study was to understand how TO and the TO-AMG combination exert bactericidal activities against S. aureus SCV and WT strains, respectively. The impact of TO and of the TO-gentamicin (GEN) combination on the membrane potential and generation of reactive oxygen species (ROS) were determined using florescent probes. GEN uptake in WT was assessed in the presence of TO. Virulence of SCV and WT strains as well as of in vitro-selected mutants showing resistance to TO or the TO-GEN combination was evaluated in a murine thigh infection model. TO causes a reduction in membrane potential in both WT and SCV, but significant amounts of ROS are only produced in SCVs. Besides, the presence of TO improves the uptake of GEN by the WT strain and the combination TO-GEN generated 2.5-folds more ROS in WT, compared to that induced by GEN alone. Under anaerobic conditions, WT adopts a fermentative slow-growth phenotype and becomes susceptible to TO even if used alone. In vivo, TO- or TO-GEN-resistant strains were significantly altered in their ability to colonize tissues. These results shed light on the mechanism of action of TO and its synergy with AMGs against S. aureus WT. TO bactericidal activity against SCVs is attributable to both a critical drop in the membrane potential accompanied by a substantial ROS production. In the WT, TO helps GEN uptake and ROS is also important for the synergy. Acquiring resistance to TO significantly impairs virulence. The residual ATP synthase activity of SCVs might represent the Achilles’ heel of persistent S. aureus.
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Affiliation(s)
- Jean-Philippe Langlois
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Guillaume Millette
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Isabelle Guay
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alexis Dubé-Duquette
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Suzanne Chamberland
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Pierre-Étienne Jacques
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Sébastien Rodrigue
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Kamal Bouarab
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Éric Marsault
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - François Malouin
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
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11
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Normandin C, Malouin F, Marsault E. Gram-Scale Synthesis of Tomatidine, a Steroid Alkaloid with Antibiotic Properties Against Persistent Forms of Staphylococcus aureus. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Chad Normandin
- Institut de Pharmacologie de Sherbrooke; Université de Sherbrooke; 3001, 12th Avenue N J1H 5N4 Sherbrooke Quebec Canada
| | - François Malouin
- Département de Biologie; Université de Sherbrooke; 2500 Boul. de l'Université J1K 2X9 Sherbrooke Québec Canada
| | - Eric Marsault
- Institut de Pharmacologie de Sherbrooke; Université de Sherbrooke; 3001, 12th Avenue N J1H 5N4 Sherbrooke Quebec Canada
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A Mutant RNA Polymerase Activates the General Stress Response, Enabling Escherichia coli Adaptation to Late Prolonged Stationary Phase. mSphere 2020; 5:5/2/e00092-20. [PMID: 32295870 PMCID: PMC7160681 DOI: 10.1128/msphere.00092-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
An important general mechanism of a bacterium’s adaptation to its environment involves adjusting the balance between growing fast and tolerating stresses. One paradigm where this plays out is in prolonged stationary phase: early studies showed that attenuation, but not complete elimination, of the general stress response enables early adaptation of the bacterium E. coli to the conditions established about 10 days into stationary phase. We show here that this balance is not static and that it is tilted back in favor of the general stress response about 2 weeks later. This can be established by direct mutations in the master regulator of the general stress response or by mutations in the core RNA polymerase enzyme itself. These conditions can support the development of antibiotic tolerance although the bacterium is not exposed to the antibiotic. Further exploration of the growth-stress balance over the course of stationary phase will necessarily require a deeper understanding of the events in the extracellular milieu. Escherichia coli populations undergo repeated replacement of parental genotypes with fitter variants deep in stationary phase. We isolated one such variant, which emerged after 3 weeks of maintaining an E. coli K-12 population in stationary phase. This variant displayed a small colony phenotype and slow growth and was able to outcompete its ancestor over a narrow time window in stationary phase. The variant also shows tolerance to beta-lactam antibiotics, though not previously exposed to the antibiotic. We show that an RpoC(A494V) mutation confers the slow growth and small colony phenotype on this variant. The ability of this mutation to confer a growth advantage in stationary phase depends on the availability of the stationary-phase sigma factor σS. The RpoC(A494V) mutation upregulates the σS regulon. As shown over 20 years ago, early in prolonged stationary phase, σS attenuation, but not complete loss of activity, confers a fitness advantage. Our study shows that later mutations enhance σS activity, either by mutating the gene for σS directly or via mutations such as RpoC(A494V). The balance between the activities of the housekeeping major sigma factor and σS sets up a trade-off between growth and stress tolerance, which is tuned repeatedly during prolonged stationary phase. IMPORTANCE An important general mechanism of a bacterium’s adaptation to its environment involves adjusting the balance between growing fast and tolerating stresses. One paradigm where this plays out is in prolonged stationary phase: early studies showed that attenuation, but not complete elimination, of the general stress response enables early adaptation of the bacterium E. coli to the conditions established about 10 days into stationary phase. We show here that this balance is not static and that it is tilted back in favor of the general stress response about 2 weeks later. This can be established by direct mutations in the master regulator of the general stress response or by mutations in the core RNA polymerase enzyme itself. These conditions can support the development of antibiotic tolerance although the bacterium is not exposed to the antibiotic. Further exploration of the growth-stress balance over the course of stationary phase will necessarily require a deeper understanding of the events in the extracellular milieu.
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Chalmers SJ, Wylam ME. Methicillin-Resistant Staphylococcus aureus Infection and Treatment Options. Methods Mol Biol 2020; 2069:229-251. [PMID: 31523777 DOI: 10.1007/978-1-4939-9849-4_16] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infection worldwide, including a wide array of both hospital- and community-acquired infections-most commonly bacteremia, upper and lower respiratory tract infection, skin and soft-tissue infection, osteomyelitis, and septic arthritis. This chapter describes the epidemiology of MRSA infection, its ability to confer antibiotic resistance and produce a wide array of virulence factors, and its pivotal role in human infection, especially cystic fibrosis. It also provides an introduction to the strategies for treatment of both chronic and acute MRSA infections.
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Affiliation(s)
- Sarah J Chalmers
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Mark E Wylam
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.
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Esposito S, Pennoni G, Mencarini V, Palladino N, Peccini L, Principi N. Antimicrobial Treatment of Staphylococcus aureus in Patients With Cystic Fibrosis. Front Pharmacol 2019; 10:849. [PMID: 31447669 PMCID: PMC6692479 DOI: 10.3389/fphar.2019.00849] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/03/2019] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus is a ubiquitous human commensal pathogen. It is commonly isolated in cystic fibrosis (CF) patients and is considered one of the main causes of the recurrent acute pulmonary infections and progressive decline in lung function that characterize this inherited life-threatening multisystem disorder. However, the true role of S. aureus in CF patients is not completely understood. The main aim of this narrative review is to discuss the present knowledge of the role of S. aureus in CF patients. Literature review showed that despite the fact that the availability and use of drugs effective against S. aureus have coincided with a significant improvement in the prognosis of lung disease in CF patients, clearly evidencing the importance of S. aureus therapy, how to use old and new drugs to obtain the maximal effectiveness has not been precisely defined. The most important problem remains that the high frequency with which S. aureus is carried in healthy subjects prevents the differentiation of simple colonization from infection. Moreover, although experts recommend antibiotic administration in CF patients with symptoms and in those with persistent detection of S. aureus, the best antibiotic approach has not been defined. All these problems are complicated by the evidence that the most effective antibiotic against methicillin-resistant S. aureus (MRSA) cannot be used in patients with CF with the same schedules used in patients without CF. Further studies are needed to solve these problems and to assure CF patients the highest level of care.
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Affiliation(s)
- Susanna Esposito
- Pediatric Clinic, Cystic Fibrosis Center of Umbria Region, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Perugia, Italy
| | - Guido Pennoni
- Pediatric Unit, Cystic Fibrosis Center of Umbria Region, Branca Hospital, Branca, Italy
| | - Valeria Mencarini
- Pediatric Unit, Cystic Fibrosis Center of Umbria Region, Branca Hospital, Branca, Italy
| | - Nicola Palladino
- Pediatric Unit, Cystic Fibrosis Center of Umbria Region, Branca Hospital, Branca, Italy
| | - Laura Peccini
- Pediatric Clinic, Cystic Fibrosis Center of Umbria Region, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Perugia, Italy
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Savant AP, McColley SA. Cystic fibrosis year in review 2018, part 1. Pediatr Pulmonol 2019; 54:1117-1128. [PMID: 31106528 DOI: 10.1002/ppul.24361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/28/2019] [Accepted: 04/29/2019] [Indexed: 12/14/2022]
Abstract
Cystic fibrosis research and case reports were robust in the year 2018. This report summarizes research and cases related to Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulator therapies, inflammation and infection, epidemiology and the physiologic, and imaging assessment of disease.
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Affiliation(s)
- Adrienne P Savant
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Stanley Manne Children's Research Institute, Chicago, Illinois.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Susanna A McColley
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois.,Stanley Manne Children's Research Institute, Chicago, Illinois.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
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Salmonella enterica persister cells form unstable small colony variants after in vitro exposure to ciprofloxacin. Sci Rep 2019; 9:7232. [PMID: 31076596 PMCID: PMC6510897 DOI: 10.1038/s41598-019-43631-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/27/2019] [Indexed: 01/12/2023] Open
Abstract
Persistence phenotype and small colony variants (SCVs) can be part of a bacterial bet-hedging strategy for survival under environmental stresses, such as antimicrobial exposure. These phenotypes are of particular concern in persistent and relapsing infections, since cells resume to normal growth after cessation of the stressful condition. In this context, we found persisters and unstable SCVs as phenotypic variants of Salmonella enterica that were able to survive ciprofloxacin exposure. A high heterogeneity in persister levels was observed among S. enterica isolates grown under planktonic and biofilm conditions and exposed to ciprofloxacin or ceftazidime, which may indicate persistence as a non-multidrug-tolerant phenotype. Nevertheless, a comparable variability was not found in the formation of SCVs among the isolates. Indeed, similar proportions of SCV in relation to normal colony phenotype (NCP) were maintained even after three successive cycles of ciprofloxacin exposure testing colonies from both origins (SCV or NCP). Additionally, we found filamentous and dividing cells in the same scanning electron microscopy images from both SCV and NCP. These findings lead us to hypothesize that besides variability among isolates, a single isolate may generate distinct populations of persisters, where cells growing under distinct conditions may adopt different and perhaps complementary survival strategies.
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Dezube R, Jennings MT, Rykiel M, Diener-West M, Boyle MP, Chmiel JF, Dasenbrook EC. Eradication of persistent methicillin-resistant Staphylococcus aureus infection in cystic fibrosis. J Cyst Fibros 2019; 18:357-363. [DOI: 10.1016/j.jcf.2018.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/20/2018] [Accepted: 07/20/2018] [Indexed: 01/09/2023]
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