Small-colony Variants (SCVs) of Staphylococci: A Role in Foreign Body-associated Infections

2007 ◽  
Vol 30 (9) ◽  
pp. 778-785 ◽  
Author(s):  
C. Von Eiff ◽  
K. Becker
Keyword(s):  
Foreign Body ◽  
Defense Mechanisms ◽  
Susceptibility Testing ◽  
Slow Growth ◽  
Clinical Laboratory ◽  
Coagulase Negative Staphylococci ◽  
Small Colony Variants ◽  
The Past ◽  
Small Colony ◽  
Antibacterial Chemotherapy

Staphylococci have various strategies for resisting therapy that extend beyond classic mechanisms. Clinical experience with device-associated infections as well as with infections due to small-colony variants (SCVs) clearly shows that both antibacterial chemotherapy and host defense mechanisms are often unable to eliminate the pathogens and cure these infections. Of particular interest is the fact that in the past few years an increasing number of various foreign body-related infections due to staphylococcal SCVs have been reported. In this overview, the characteristics of SCVs recovered from clinical specimens and of defined mutants displaying the SCV phenotype are described. Their slow growth and changing biochemical and physiological features represent a challenge to clinical laboratory personnel, because recovery, identification, as well as susceptibility testing of these variants need particular efforts. In addition, the reduced susceptibility to aminoglycosides and the ability of SCVs to persist intracellularly require specific attention for the treatment of these infections. Thus, special efforts to search for these variants formed by Staphylococcus aureus or by coagulase-negative staphylococci should be considered when an infection is particularly resistant to therapy, persists for a long period or fails to respond to apparently adequate therapy with antimicrobial compounds.

Characterization of Staphylococcus epidermidis and Staphyloccocus warneri small-colony variants associated with prosthetic-joint infections

2014 ◽  
Vol 63 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Agnieszka Bogut ◽  
Justyna Niedźwiadek ◽  
Maria Kozioł-Montewka ◽  
Dagmara Strzelec-Nowak ◽  
Jan Blacha ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Staphylococcus Epidermidis ◽  
Hip Prosthesis ◽  
Joint Infection ◽  
Coagulase Negative Staphylococci ◽  
Sensitivity Testing ◽  
Small Colony Variants ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections ◽  
Small Colony

We determined the frequency of isolation of staphylococcal small-colony variants (SCVs) from 31 culture-positive patients undergoing revision of total hip prosthesis for aseptic loosening or presumed prosthetic-joint infection (PJI). We analysed auxotrophy of cultured SCVs, their antimicrobial susceptibility profiles and their biofilm-forming capacity. Eight SCV strains were cultivated from six (19 %) patients. All SCVs were coagulase-negative staphylococci (CNS) with Staphylococcus epidermidis as the predominant species; there was also one Staphylococcus warneri SCV. The SCVs were auxotrophic for haemin, with one strain additionally auxotrophic for menadione. We noted the presence of two phenotypically (differences concerning antimicrobial susceptibility) and genetically distinct SCV strains in one patient, as well as the growth of two genetically related SCVs that differed in terms of their morphology and the type of auxotrophy in another. Seven out of eight SCVs were resistant to meticillin and gentamicin. In addition, antibiotic sensitivity testing revealed three multidrug-resistant SCV–normal-morphology isolate pairs. One S. epidermidis SCV harboured icaADBC genes and was found to be a proficient biofilm producer. This paper highlights the involvement of CNS SCVs in the aetiology of PJIs, including what is believed to be the first report of a S. warneri SCV. These subpopulations must be actively sought in the routine diagnosis of implant-associated infections. Moreover, in view of the phenotypic and genetic diversity of some SCV pairs, particular attention should be paid to the investigation of all types of observed colony morphologies, and isolates should be subjected to antimicrobial susceptibility testing.

scholarly journals Bloodstream Infections Caused by Small‐Colony Variants of Coagulase‐Negative Staphylococci Following Pacemaker Implantation

1999 ◽  
Vol 29 (4) ◽  
pp. 932-934 ◽  
Author(s):  
Christof von Eiff ◽  
Pierre Vaudaux ◽  
Barbara C. Kahl ◽  
Daniel Lew ◽  
Stefan Emler ◽  
...  
Keyword(s):  
Pacemaker Implantation ◽  
Bloodstream Infections ◽  
Coagulase Negative Staphylococci ◽  
Small Colony Variants ◽  
Small Colony

scholarly journals Antimicrobial resistance in coagulase-negative staphylococci isolated from subclinical mastitis in Ettawa Crossbred goat (PE) in Yogyakarta, Indonesia

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
Widodo Suwito ◽  
WIDAGDO SRI NUGROHO ◽  
AGNESIA ENDANG TRI HASTUTI WAHYUNI ◽  
BAMBANG SUMIARTO
Keyword(s):  
Antimicrobial Resistance ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Subclinical Mastitis ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Disc Diffusion Method ◽  
Coagulase Negative Staphylococci ◽  
Resistance Patterns

Abstract. Suwito W, Nugroho WS, Wahyuni AETH, Sumiarto B. 2021. Antimicrobial resistance in coagulase-negative staphylococci isolated from subclinical mastitis in Ettawa Crossbred goat (PE) in Yogyakarta, Indonesia. Biodiversitas 22: 3418-3422. Subclinical mastitis (SCM) in Ettawa Crossbred Goat (PE) is most frequently caused by staphylococci with a significant reduction in milk yield. The aim of this study is to determine antimicrobial resistance patterns of coagulase-negative staphylococci (CoNS) from PE goat SCM. A total of 36 CoNS isolates originating from PE goat SCM were collected in semisolid tube use in this study. All CoNS isolates were further examined for antimicrobial susceptibility testing by the Kirby-Bauer disc diffusion method. Antibiotic susceptibility of CoNS isolated samples according to Clinical Laboratory Standards Institute (CLSI). The CoNS isolates showed the highest resistance rate against sulfamethoxazole (65%), ampicillin (55.56%), penicillin (45%), cefoxitin (33.33%), erythromycin (25%), oxytetracycline (20%), tetracycline (15%), gentamicin and neomycin (11.11%), while oxacillin was sensitive. The highest of multiple antimicrobials resistance observed 15% in ampicillin, penicillin and tetracycline, then 5-10% in ampicillin, penicillin, erythromycin, tetracycline and oxytetracycline. The majority of CoNS in this study were resistant to sulfamethoxazole and then, followed by ampicillin, penicillin, cefoxitin, erythromycin, oxytetracycline, tetracycline, gentamicin and neomycin. In addition, most isolates were penicillin-resistant and multidrug-resistant (MDR).

scholarly journals Clinical Significance and Pathogenesis of Staphylococcal Small Colony Variants in Persistent Infections

2016 ◽  
Vol 29 (2) ◽  
pp. 401-427 ◽  
Author(s):  
Barbara C. Kahl ◽  
Karsten Becker ◽  
Bettina Löffler
Keyword(s):  
Molecular Mechanisms ◽  
Diagnostic Procedures ◽  
Resistance Mechanisms ◽  
Future Research ◽  
Coagulase Negative Staphylococci ◽  
Small Colony Variants ◽  
Content Type ◽  
Staphylococcal Infections ◽  
Airway Infections ◽  
Small Colony

SUMMARYSmall colony variants (SCVs) were first described more than 100 years ago forStaphylococcus aureusand various coagulase-negative staphylococci. Two decades ago, an association between chronic staphylococcal infections and the presence of SCVs was observed. Since then, many clinical studies and observations have been published which tie recurrent, persistent staphylococcal infections, including device-associated infections, bone and tissue infections, and airway infections of cystic fibrosis patients, to this special phenotype. By their intracellular lifestyle, SCVs exhibit so-called phenotypic (or functional) resistance beyond the classical resistance mechanisms, and they can often be retrieved from therapy-refractory courses of infection. In this review, the various clinical infections where SCVs can be expected and isolated, diagnostic procedures for optimized species confirmation, and the pathogenesis of SCVs, including defined underlying molecular mechanisms and the phenotype switch phenomenon, are presented. Moreover, relevant animal models and suggested treatment regimens, as well as the requirements for future research areas, are highlighted.

scholarly journals The road to success of coagulase-negative staphylococci: clinical significance of small colony variants and their pathogenic role in persistent infections

2021 ◽  
Author(s):  
Agnieszka Bogut ◽  
Agnieszka Magryś
Keyword(s):  
Clinical Significance ◽  
Host Cells ◽  
Cell Uptake ◽  
Chronic Infections ◽  
Coagulase Negative Staphylococci ◽  
Antimicrobial Drugs ◽  
Small Colony Variants ◽  
The Road ◽  
Host Immune Responses ◽  
Small Colony

AbstractBacterial small colony variants represent an important aspect of bacterial variability. They are naturally occurring microbial subpopulations with distinctive phenotypic and pathogenic traits, reported for many clinically important bacteria. In clinical terms, SCVs tend to be associated with persistence in host cells and tissues and are less susceptible to antibiotics than their wild-type (WT) counterparts. The increased tendency of SCVs to reside intracellularly where they are protected against the host immune responses and antimicrobial drugs is one of the crucial aspects linking SCVs to recurrent or chronic infections, which are difficult to treat. An important aspect of the SCV ability to persist in the host is the quiescent metabolic state, reduced immune response and expression a changed pattern of virulence factors, including a reduced expression of exotoxins and an increased expression of adhesins facilitating host cell uptake. The purpose of this review is to describe in greater detail the currently available data regarding CoNS SCV and, in particular, their clinical significance and possible mechanisms by which SCVs contribute to the pathogenesis of the chronic infections. It should be emphasized that in spite of an increasing clinical significance of this group of staphylococci, the number of studies unraveling the mechanisms of CoNS SCVs formation and their impact on the course of the infectious process is still scarce, lagging behind the studies on S. aureus SCVs.

scholarly journals Laboratory, clinical, and epidemiological aspects of coagulase-negative staphylococci.

1988 ◽  
Vol 1 (3) ◽  
pp. 281-299 ◽  
Author(s):  
M A Pfaller ◽  
L A Herwaldt
Keyword(s):  
Nosocomial Infection ◽  
Antimicrobial Susceptibility ◽  
Staphylococcus Epidermidis ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Time Frame ◽  
Coagulase Negative Staphylococci ◽  
Plasmid Analysis ◽  
Routine Identification ◽  
Diagnosis Of Infection

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are increasingly important causes of nosocomial infection. Microbiologists and clinicians no longer can afford to disregard clinical isolates of coagulase-negative staphylococci as contaminants. Accurate species identification and antimicrobial susceptibility testing, in a clinically relevant time frame, are important aids in the diagnosis and management of serious coagulase-negative staphylococcal infections. Emphasis in the clinical laboratory should be placed on the routine identification of S. epidermidis and Staphylococcus saprophyticus, with identification of other species of coagulase-negative staphylococci as clinically indicated. The application of newer techniques, such as plasmid analysis and tests for slime production and adherence, contribute to our understanding of the epidemiology and pathogenesis of coagulase-negative staphylococci and may also be helpful in establishing the diagnosis of infection.

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