Staphylococcus haemolyticus is a Gram-positive, coconut-shaped bacterium. It is part of the normal microbiota of the skin in humans, primates and domestic animals. It falls under the classification of coagulase negative Staphylococcus and until recently it was not much mentioned.
However, this species has become important because it has been isolated from a wide variety of clinical samples. In recent times its great capacity to acquire resistance to antibiotics commonly used in hospitals has been studied.
This has increased the numbers of nosocomial infections and with it the morbidity and mortality rate caused by coagulase negative Staphylococcus. In some health centers, endemic strains that cause bacteremia have been isolated in intensive care units.
These infections are probably due to contamination of prosthetic materials such as heart valves, vascular grafts, pacemakers, intracranial pump implants, mesh, breast, joint or penile prostheses.
Also due to contamination of medical devices such as venous catheters, CSF shunt, peritoneal dialysis catheters, urinary catheter, suture material, among others.
It affects immunosuppressed patients, especially neutropenic patients and newborns. However, Staphylococcus haemolyticus infections can be of nosocomial or community origin. That is, it is viable in both environments.
General characteristics
On the other hand, multi-resistant strains of S. haemolyticus also pose a serious problem in animal pathology, since they have been isolated from both ruminants and domestic animals.
Therefore, there is a great possibility of transmission between animals, their owners and veterinarians. Animals can act as reservoirs for multi-resistant S. haemolyticus strains.
Furthermore, S. haemolitycus could be the reservoir of resistance genes for other staphylococci, including S. aureus.
Diagnosis
Coagulase negative Staphylococcus strains including Staphylococcus haemolyticus can be identified with the semi-automated MicroSscan® or ALPI-Staph (Biomerieux ©) system to name a few.
This system allows the identification of Staphylococcus species by means of:
- Detection of bacterial growth by turbidity.
- Detection of pH changes.
- Use of substrates.
- Growth against certain antimicrobial agents.
All this after 16-48 hours of incubation at 37 ° C.
Treatment
In venous catheter infections, the possibility of removal should be considered, if this is not possible then it should be sealed.
Concomitant with this, antibiotic therapy with vacomycin, linezolid or daptomycin should be administered. The use of cloxacillin is restricted to strains that are sensitive to methicillin.
In the case of prosthetic infections, prolonged treatment should be administered, combining rifampicin and a fluoroquinolone or linezolid.
This treatment almost always avoids the need to remove the prosthesis. However, if the infection does not subside, it should be removed.
In meningitis and postsurgical endophthalmitis, it can be treated with linezolid.
References
- Alvarado L. Sensitivity and resistance profile of Staphylococcus haemolyticus, Staphylococcus epidermidis and Staphylococcus aureus at Hospital II Chocope. EsSalud. Degree work to qualify for the title of Pharmaceutical Chemist. 2016. pp 1-46
- Castro N, Loaiza-Loeza M, Calderón-Navarro A, Sánchez A, Silva-Sánchez J. Study of Staphylococcus haemolyticus resistant to methicillin. Rev Invest Clin 2006; 58 (6): 580-585.
- Czekaj T, Ciszewski M and Szewczyk E. Staphylococcus haemolyticus - an emerging threat in the twilight of the antibiotics age. Microbiology 2015; 161 (1) 2061–2068
- Fariña N, Carpinelli L, Samudio M, Guillén R, Laspina F, Sanabria R, Abente S, Rodas L, et al. Clinically significant coagulase-negative staphylococcus. Most frequent species and virulence factors Rev. chil. infectol. 2013; 30 (5): 480-488
- Forbes B, Sahm D, Weissfeld A. Bailey & Scott Microbiological Diagnosis. 12 ed. Argentina. Editorial Panamericana SA; 2009.
- Koneman, E, Allen, S, Janda, W, Schreckenberger, P, Winn, W. (2004). Microbiological Diagnosis. (5th ed.). Argentina, Editorial Panamericana SA
- Wikipedia contributors. Staphylococcus haemolyticus. Wikipedia, The Free Encyclopedia. July 15, 2018, 22:11 UTC. Available at: en.wikipedia.org/ Accessed September 23, 2018.