Staphylococcus saprophyticus
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Staphylococcus saprophyticus after Gram stain |
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Staphylococcus saprophyticus is a gram-positive , spherical bacterium from the genus Staphylococcus , whose representatives are also known as staphylococci . It belongs to the large subgroup of staphylococci in which the coagulase reaction is negative (coagulase-negative staphylococci). The subspecies Staphylococcus saprophyticus subsp. saprophyticus , an especially after the women sexual intercourse occurring bladder infection , called honeymoon cystitis cause.
features
Appearance
In the Gram stain , Staphylococcus saprophyticus typically appears in the form of blue spheres (cocci) with a diameter of 0.7-1.4 µm, stored in heaps. These are not actively mobile (not flagellated ), do not form spores and do not cause hemolysis on sheep blood agar . The colonies there are round, white to ocher yellow in color and a few millimeters in size.
Growth and metabolism
The species grows with and without oxygen (optionally anaerobic ). The catalase reaction is positive, the oxidase reaction is negative. The bacteria multiply fastest at 30 to 37 ° C and are halotolerant , so they also grow in the presence of high salt concentrations (e.g. 10% sodium chloride ). You are u. a. equipped with the enzyme urease . The energy metabolism can be operated both oxidatively and fermentatively (by means of fermentation ). Among the staphylococcus species occurring in humans, Staphylococcus saprophyticus is one of the few naturally resistant to the antibiotic novobiocin, which is also used for identification.
genetics
The genome of Staphylococcus saprophyticus is 2.5 million base pairs in length with a low content of guanine and cytosine (31-33%). The complete sequence of the subspecies saprophyticus was published in 2005.
Pathogenicity
Due to the Biological Agents Ordinance in conjunction with the Technical Rules for Biological Agents (TRBA 466), Staphylococcus saprophyticus subsp. bovis to risk group 1, Staphylococcus saprophyticus subsp. saprophyticus is classified in risk group 2. However, there are important differences to other staphylococcal species, which also belong to risk group 2. The species lacks all virulence factors of Staphylococcus aureus , but Staphylococcus saprophyticus subsp. saprophyticus has a unique adhesin anchored in the cell wall that enables it to attach to cell surfaces in the urinary organs of humans. In addition, there is an increasing number of transport systems and strong expression of the urease enzyme, each of which facilitates survival in the urine environment. All in all, this explains why Staphylococcus saprophyticus subsp. saprophyticus commonly causes urinary tract infections in humans , but rarely causes other infections.
proof
The subspecies Staphylococcus saprophyticus subsp. saprophyticus is usually grown from urine samples from patients with a urinary tract infection. The subspecies bovis was detected in the nostrils of 7% of healthy cattle. Suitable nutrient media for the culture are universal nutrient media such as B. sheep blood agar, but also selective media for gram-positive bacteria such. B. CNA agar . There are no special requirements for the culture conditions. The preliminary identification as Staphylococcus saprophyticus can be based on the following criteria: gram-positive cocci, catalase positive, hemolysis and coagulase negative, pigment formation (white or yellow) and resistance to novobiocin. The final identification is possible with biochemical (manual or automated multicolored series ), mass spectrometric ( MALDI-TOF ) or molecular genetic ( 16S rRNA sequencing ) methods. Characteristic biochemical properties that enable the differentiation from other staphylococci species are novobiocin resistance, the presence of β-galactosidase (can also be absent in the subspecies bovis ) and urease, as well as the lack of alkaline phosphatase and acid formation from D- mannose .
Occurrence
The two well-known subspecies Staphylococcus saprophyticus subsp. saprophyticus and subsp. bovis differ greatly from one another in terms of their occurrence. The subspecies saprophyticus , known for decades, is able to colonize the rectum , vagina and urethra in healthy women and various animal species. Such colonization occurs in around 4 to 8% of individuals. The subspecies bovis , which was first described in 1996 , was found in 7% of healthy cows from the nostrils .
In addition to the detection in living animals, Staphylococcus saprophyticus was also isolated from various foods, in a high rate (34%) e.g. B. from raw beef and pork. It is believed that human colonization occurs through contact with animals and / or food.
Systematics
External system
Historically, the genus Staphylococcus belonged to the Micrococcaceae family . Molecular genetic relationship studies then showed that the genera Staphylococcus and Micrococcus are not closely related to one another. This led to the fact that the genus Staphylococcus was classified in the newly created family of Staphylococcaceae in 2010 .
In the rough classification of staphylococci, medical microbiology often differentiates between coagulase-positive and coagulase-negative species, with S. saprophyticus belonging to the coagulase-negative staphylococci. These can in turn be classified according to their sensitivity to novobiocin, whereby the species of the Staphylococcus epidermidis group are mostly sensitive, while S. saprophyticus (in addition to Staphylococcus cohnii and some predominantly animal species) are always resistant ("Staphylococcus saprophyticus group") ).
Internal system
The bacteria of the species Staphylococcus saprophyticus described between 1940 and 1996 become the subspecies Staphylococcus saprophyticus subsp. saprophyticus , which is by far the more common and important of the two subspecies. The significance of the subspecies bovis , which was newly described in cattle in 1996, is not yet clear.
etymology
The generic name Staphylococcus is derived from the ancient Greek words σταφυλή staphylé 'grape' and κόκκος kókkos 'core', 'grain', whereby 'grape' refers to the typical storage in grapes or heaps and 'core' or 'grain' refers to the spherical shape. The specific epithet saprophyticus also comes from ancient Greek and is composed of σαπρός saprós 'lazy', 'rotten' and φυτόν phytón 'plant'. Bacteria that live in symbiosis with their host and feed on substances that the host cannot utilize itself (today called saprobionts ) were called saprophytes . The name of the subspecies bovis comes from the Latin bos 'cattle', which refers to the first detection from cattle nostrils.
meaning
Staphylococcus saprophyticus is of great importance as a relatively common causative agent of urinary tract infections in women. In addition, the type of bacteria is part of the normal flora of humans and animals.
ecology
The relationship between Staphylococcus saprophyticus and its hosts such as humans, cattle and pigs is in most cases peaceful in the sense of a symbiosis. Here the type of bacteria is most often found as part of the normal flora of the rectum, in humans also in the vagina, urethra, on the skin and conjunctiva.
medicine
Sources of infection
The existing scientific evidence on urinary tract infections caused by Staphylococcus saprophyticus subsp. saprophyticus allows the following model of the path of infection: First of all, direct contact with animals or consumption of insufficiently cooked meat leads to colonization of the intestine by the bacterial species. This already occurs particularly in young women, with a seasonal increase in summer and autumn. Proceeding from this colonization, some women can develop a urinary tract infection, particularly often after previous sexual intercourse. According to current knowledge, the immediate source of infection is one's own intestines or urinary and sexual organs, not an infected partner. The colonization of the urinary and genital organs by Staphylococcus saprophyticus can be favored by disorders of the physiological vaginal flora.
Infectious diseases
Especially often caused Staphylococcus saprophyticus subsp. saprophyticus, a urinary tract infection in young women. Here, after Escherichia coli , the bacterial species is the second most common pathogen, with the proportion given in the literature as 8–42%. Most of the cases are uncomplicated bladder infections, but ascending infections such as renal pelvic inflammation and urosepsis ("blood poisoning") with complications such as urinary stones or endocarditis (heart inflammation) have also been described. Finally, Staphylococcus saprophyticus also occurs as a causative agent of urinary tract infections in men. In men, the type of bacteria has also been described as causing a non-specific inflammation of the urethra ( urethritis ).
therapy
Urinary tract infections caused by Staphylococcus saprophyticus are usually treated with an antibiotic . In most cases, choosing a suitable drug is not a problem, as the type of bacteria is typically sensitive to a large number of antibiotics. Suitable active ingredients include trimethoprim (alone or in combination with sulfamethoxazole as cotrimoxazole ) or ciprofloxacin .
literature
- Karsten Becker, Georg Peters: "Staphylococcaceae", Micrococcaceae and Dermacoccaceae . In: Birgid Neumeister, Heinrich K. Geiss, Rüdiger W. Braun, Peter Kimmig (eds.): Microbiological diagnostics . 2nd Edition. Georg Thieme Verlag, Stuttgart / New York 2009, ISBN 978-3-13-743602-7 , p. 333-351 .
- Georg Peters, Gerhard Pulverer: The family of the Micrococcaceae . In: Werner Köhler, Hans J. Eggers, Bernhard Fleischer, Reinhard Marre, Herbert Pfister, Gerhard Pulverer (eds.): Medical Microbiology . 8th edition. Urban & Fischer, Munich / Jena 2001, ISBN 3-437-41640-5 , p. 250-260 .
- Karsten Becker, Christof von Eiff: Staphylococcus, Micrococcus, and Other Catalase-Positive Cocci . In: James Versalovic, Karen C. Carroll, Guido Funke, James H. Jorgensen, Marie Louise Landry, David W. Warnock (eds.): Manual of Clinical Microbiology . 10th edition. ASM Press, Washington, DC 2011, ISBN 978-1-55581-463-2 .
Web links
Individual evidence
- ↑ a b c d e V. Hájek, H. Meugnier, M. Bes, Y. Brun, F. Fiedler, Z. Chmela, Y. Lasne, J. Fleurette, J. Freney: Staphylococcus saprophyticus subsp. bovis subsp. nov., isolated from bovine nostrils. In: International journal of systematic bacteriology. Volume 46, Number 3, July 1996, pp. 792-796, ISSN 0020-7713 . PMID 8782691 .
- ^ SY Loo, AL Adam, AG Scottolini: Presumptive identification of Staphylococcus saprophyticus from urine specimens by colony appearance and coagulase testing: an evaluation. In: American Journal of Clinical Pathology . Volume 81, Number 5, May 1984, pp. 647-650, ISSN 0002-9173 . PMID 6372435 .
- ↑ a b c Georg Peters, Gerhard Pulverer: The family of the Micrococcaceae . In: Werner Köhler, Hans J. Eggers, Bernhard Fleischer, Reinhard Marre, Herbert Pfister, Gerhard Pulverer (eds.): Medical Microbiology . 8th edition. Urban & Fischer, Munich / Jena 2001, ISBN 3-437-41640-5 , p. 250-260 .
- ↑ a b M. Kuroda, A. Yamashita, H. Hirakawa, M. Kumano, K. Morikawa, M. Higashide, A. Maruyama, Y. Inose, K. Matoba, H. Toh, S. Kuhara, M. Hattori , T. Ohta: Whole genome sequence of Staphylococcus saprophyticus reveals the pathogenesis of uncomplicated urinary tract infection. In: Proceedings of the National Academy of Sciences . Volume 102, Number 37, September 2005, pp. 13272-13277, ISSN 0027-8424 . doi: 10.1073 / pnas.0502950102 . PMID 16135568 . PMC 1201578 (free full text).
- ↑ TRBA (Technical Rules for Biological Agents) 466: Classification of prokaryotes (Bacteria and Archaea) into risk groups. In: Website of the Federal Institute for Occupational Safety and Health (BAuA). April 25, 2012, accessed December 26, 2013 .
- ↑ a b c d e R. Raz, R. Colodner, CM Kunin: Who are you – Staphylococcus saprophyticus? In: Clinical infectious diseases: an official publication of the Infectious Diseases Society of America. Volume 40, Number 6, March 2005, pp. 896-898, ISSN 1537-6591 . doi: 10.1086 / 428353 . PMID 15736028 . (Review).
- ↑ a b c d Karsten Becker, Christof von Eiff: Staphylococcus, Micrococcus, and Other Catalase-Positive Cocci . In: James Versalovic, Karen C. Carroll, Guido Funke, James H. Jorgensen, Marie Louise Landry, David W. Warnock (eds.): Manual of Clinical Microbiology . 10th edition. ASM Press, Washington DC 2011, ISBN 978-1-55581-463-2 .
- ^ Jean Euzéby: List of new names and new combinations previously effectively, but not validly, published - Validation List no.132 . In: International Journal of Systematic and Evolutionary Microbiology . tape 60 , no. 3 , March 8, 2010, ISSN 1466-5026 , p. 469-472 , doi : 10.1099 / ijs.0.022855-0 .
- ↑ a b c d Karsten Becker, Georg Peters: "Staphylococcaceae", Micrococcaceae and Dermacoccaceae . In: Birgid Neumeister, Heinrich K. Geiss, Rüdiger W. Braun, Peter Kimmig (eds.): Microbiological diagnostics . 2nd Edition. Georg Thieme Verlag, Stuttgart / New York 2009, ISBN 978-3-13-743602-7 , p. 333-351 .
- ^ A b c Jean Euzéby, Aidan C. Parte: Genus Staphylococcus. In: List of Prokaryotic names with Standing in Nomenclature ( LPSN ). Retrieved December 28, 2013 .
- ^ Hans G. Schlegel, Christiane Zaborosch: General microbiology . 7th edition. Thieme Verlag, Stuttgart / New York 1992, ISBN 3-13-444607-3 , p. 23-25, 99 .