Staphylococcus saprophyticus

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Staphylococcus saprophyticus
Scientific classification
Kingdom: Bacteria
Phylum: Firmicutes
Class: Cocci
Order: Bacillales
Family: Staphylococcaceae
Genus: Staphylococcus
Species: S. saprophyticus
Binomial name
Staphylococcus saprophyticus
(Fairbrother 1940)
Shaw et al. 1951

Staphylococcus saprophyticus is a Gram-positive, coagulase-negative bacterium belonging to the Staphylococcus genus.[1] S. Saprophyticus is a common cause of community-acquired urinary tract infections.[2][3]

History[edit]

Staphylococcus saprophyticus was not recognized as a cause of urinary tract infections until the early 1970s, more than ten years after its original demonstration in urine specimens. Prior to this, the presence of coagulase-negative staphylococci (CoNS) in urine specimens was dismissed as contamination.[citation needed]

Epidemiology and pathogenesis[edit]

In humans, S. saprophyticus is found in the normal flora of the female genital tract[3] and perineum.[4] It has been isolated from other sources too including meat and cheese products, vegetables, the environment, and human and animal gastrointestinal tracts.[4] S. saprophyticus causes 10-20% of urinary tract infections (UTIs). In females 17–27 years old, it is the second most common cause of community-acquired UTI, after Escherichia coli.[5] Sexual activity increases the risk of S. saprophyticus UTI because bacteria are displaced from the normal flora of the vagina and perineum into the urethra.[3] Most cases occur within 24 hours of sex,[3] earning this infection the nickname "honeymoon cystitis".[6] S. saprophyticus has the capacity to selectively adhere to human urothelium. The adhesin for S. saprophyticus is a lactosamine structure. S. saprophyticus produces no exotoxins.[3]

Clinical features[edit]

Patients with urinary tract infections caused by S. saprophyticus usually present with symptomatic cystitis. Symptoms include a burning sensation when passing urine, the urge to urinate more often than usual, a 'dripping effect' after urination, weak bladder, a bloated feeling with sharp razor pains in the lower abdomen around the bladder and ovary areas, and razor-like pains during sexual intercourse. Signs and symptoms of renal involvement are also often registered.[7]

Laboratory diagnosis[edit]

The urine sediment of a patient with a S. saprophyticus urinary tract infection has a characteristic appearance under the microscope. Chemical screening methods for bacteriuria do not always detect S. saprophyticus infection because, even when such an infection occurs above the neck of the bladder, low numbers of colony-forming units (less than 105 cfu/ml) are often present.[citation needed]

S. saprophyticus is identified as belonging to the Staphylococcus genus using the Gram stain and catalase test. It is identitified as a species of coagulase negative staphylococci (CoNS) using the coagulase test. Lastly, S. saprophyticus is differentiated from S. epidermidis, another species of pathogenic CoNS, by testing for susceptibility to the antibiotic novobiocin. S. saprophyticus is novobiocin-resistant, whereas S. epidermidis is novobiocin-sensitive.[3]

Treatment[edit]

S. saprophyticus urinary tract infections are usually treated with trimethoprim-sulfamethoxazole or with a quinolone such as norfloxacin.[3]


Since S. Saprophyticus has begun developing a resistance to antibiotics, and because urinary tract infections often recur after a course of antibiotics is taken, natural treatments for urinary tract infections caused by S. Saprophyticus also must be considered. S. Saprophyticus forms an aggressive biofilm which may protect it from being washed out the bladder and from the ordinary defenses of the immune system. Drinking water with baking soda in appropriate doses may disrupt the biofilms of S. Saprophyticus and inhibit the growth of their bacterial colonies. [1] Cranberry tablets or juice have been shown to inhibit the growth of new biofilms, but have not been shown to disrupt older established biofilms. [2] [3] Perhaps a potential way to disrupt staph saprophyticus biofilms is to 'expand' the bladder by drinking a large volume of water, then forcibly contract it. Curcumin or turmeric supplements may have an antibacterial effect against S. Saprophyticus as they induce the body to produce cAMP. [4] cAMP may kill bacteria by creating pores in bacterial cell membranes. [5] Other ways to combat these infections without antibiotics may include eating raw garlic and cinnamon. [6]

Different sub-species[edit]

Two subspecies of S. saprophyticus exist: S. saprophyticus subsp. bovis and S. saprophyticus subsp. saprophyticus, the latter more commonly found in human UTIs. S. saprophyticus subsp. saprophyticus is nitrate reductase negative and pyrrolidonyl arylamidase negative while S. Saprophyticus subsp. bovis is nitrate reductase positive and pyrolidonyl arymamidase negative.[8]

References[edit]

  1. ^ Schleifer, K. H.; Kloos, W. E. (1975). "Isolation and Characterization of Staphylococci from Human Skin I. Amended Descriptions of Staphylococcus epidermidis and Staphylococcus saprophyticus and Descriptions of Three New Species: Staphylococcus cohnii, Staphylococcus haemolyticus, and Staphylococcus xylosus". International Journal of Systematic Bacteriology 25 (1): 50–61. doi:10.1099/00207713-25-1-50. ISSN 0020-7713. 
  2. ^ Kuroda M, Yamashita A, Hirakawa H, et al. (September 2005). "Whole genome sequence of Staphylococcus saprophyticus reveals the pathogenesis of uncomplicated urinary tract infection". Proc. Natl. Acad. Sci. U.S.A. 102 (37): 13272–7. doi:10.1073/pnas.0502950102. PMC 1201578. PMID 16135568. 
  3. ^ a b c d e f g Levinson, W. (2010). Review of Medical Microbiology and Immunology (11th ed.). pp. 94–99. 
  4. ^ a b Widerström, M; Wiström, J; Sjöstedt, A; Monsen, T (January 2012). "Coagulase-negative staphylococci: update on the molecular epidemiology and clinical presentation, with a focus on Staphylococcus epidermidis and Staphylococcus saprophyticus.". European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology 31 (1): 7–20. doi:10.1007/s10096-011-1270-6. PMID 21533877. 
  5. ^ Rupp, ME; Soper, DE; Archer, GL (November 1992). "Colonization of the female genital tract with Staphylococcus saprophyticus.". Journal of clinical microbiology 30 (11): 2975–9. PMC 270562. PMID 1452668. 
  6. ^ "Understanding Bladder Infections -- the Basics". WebMD. Retrieved 4 December 2013. 
  7. ^ Jordan, PA; Iravani, A; Richard, GA; Baer, H (October 1980). "Urinary tract infection caused by Staphylococcus saprophyticus.". The Journal of infectious diseases 142 (4): 510–5. doi:10.1093/infdis/142.4.510. PMID 7192302. 
  8. ^ Hájek, V; Meugnier, H; Bes, M; Brun, Y; Fiedler, F; Chmela, Z; Lasne, Y; Fleurette, J; Freney, J (July 1996). "Staphylococcus saprophyticus subsp. bovis subsp. nov., isolated from bovine nostrils.". International journal of systematic bacteriology 46 (3): 792–6. doi:10.1099/00207713-46-3-792. PMID 8782691.