REISS A. PEREZ

BSMT 3L

REISS A. PEREZ

SERRATIA :-DScientific classification

Kingdom: BacteriaPhylum: ProteobacteriaClass: Gamma Proteobacteria

Order: Enterobacteriales

Family: Enterobacteriaceae

Genus: Serratia

REISS A. PEREZ

Serratia is a genus of Gram-negative, facultatively anaerobic, rod-shaped bacteria of the Enterobacteriaceae family. 

•This is a Gram negative rod that thrives in moist environments.

•It frequently contaminates solutions and hospital equipment and the human reservoirs are the urinary and respiratory tracts as well as the gastrointestinal tract of children.

REISS A. PEREZ

The genus is named after  Serafino Serrati, an Italian physicist.

REISS A. PEREZ

The most common species in the genus, S. marcescens, is normally the only pathogen  and usually causes nosocomial infections.

However, rare strains of S. plymuthica, S. liquefaciens, S. rubidaea, and S. odoriferae have caused diseases through infection.

REISS A. PEREZ

* Members of this genus produce characteristic red pigment, prodigiosin , and can be distinguished from other members of the family Enterobacteriaceae by its unique production of three enzymes: DNase, lipase, and gelatinase.

* In the hospital, Serratia species tend to colonize the respiratory and urinary tracts, rather than the gastrointestinal tract, in adults.

REISS A. PEREZ

•Serratia infection is responsible for about 2% of nosocomial infections of the bloodstream, lower respiratory tract, urinary tract, surgical wounds, and skin and soft tissues in adult patients.

•Outbreaks of S. marcescens meningitis, wound infections, and arthritis have occurred in pediatric wards.

•Serratia infection has caused endocarditis and osteomyelitis in people addicted to heroin.

•Cases of Serratia arthritis have been reported in outpatients receiving intra-articular injections.

REISS A. PEREZ

•S. marcescens was once thought to be a non-pathogenic bacteria.

•Because of the red pigment it produces, it was widely used to trace bacterial transmission and to study settling and drifting of bacteria in air currents.

•In 1950 the US Navy conducted a secret experiment called “Operation Sea-Spray” to study wind currents that might carry biological weapons.

•They filled balloons with S. marcescens and burst them over San Francisco.

•Shortly thereafter, doctors in the area noted a drastic increase in pneumonia and urinary tract infections.

REISS A. PEREZ

•Some strains of S. marcescens are capable of producing a pigment called prodigiosin, which ranges in color from dark red to pale pink, depending on the age of the colonies. 

•S. marcescens has a predilection for growth on starchy foodstuffs, where the pigmented colonies are easily mistaken for drops of blood.

REISS A. PEREZ

•In 1819, Bartolomeo Bizio, a pharmacist from Padua, Italy, discovered and named S. marcescens when he identified the bacterium as the cause of a miraculous bloody discoloration in a cornmeal mush called polenta.

•Bizio named Serratia in honor of an Italian physicist named Serrati, who invented the steamboat, and Bizio chose marcescens (from the Latin word for decaying) because the bloody pigment was found to deteriorate quickly.

REISS A. PEREZ

Bartolomeo, Bizio

REISS A. PEREZ

•Since 1906, physicians have used S marcescens as a biological marker for studying the transmission of microorganisms because, until the 1950s, this bacterium was generally considered a harmless saprophyte.

•Only since the 1960s has S marcescens been recognized as an opportunistic pathogen in humans.

•Derivatives of prodigiosin have recently been found to have immunosuppressive properties and antitumor activity in vivo.

REISS A. PEREZ

International

The yearly incidence of Serratia bacteremia is 1.03 per 100,000 population, with 47% of episodes having their onset in the community.

The prevalence of Serratia species as a cause of nosocomial infections is diminishing, but these bacteria are still able to cause hospital outbreaks, especially in intensive care units.

REISS A. PEREZ

Significance in endoscopy

If more evidence is required ofthe pivotal role of adequate mechanical cleaning in endoscope reprocessing then it is provided by Serratia marcescens.

Several outbreaks of S. marcescens infection have been tracked to bronchoscopic transmission. In an outbreak involving three fatalities, the instrument had been inadequately cleaned but then subjected to a full ethylene oxide sterilising process, underlining the fact that any attempts at sterilisation or disinfection are likely to be ineffective in the presence of inadequate cleaning.

REISS A. PEREZ

Mortality/Morbidity

In a population-based study of Serratia bacteremia, the 7-day and 6-month mortality rates were 5% and 37%, respectively.

Serratia meningitis and Serratia endocarditis carry a high mortality rate.

Serratia species cause less than 6% of cases of hospital-acquired bacterial pneumonia.S marcescens causes 11% of burn-related surgical wound infections.

REISS A. PEREZ

Disease

Significant cause of health care associated pulmonary, urinary, and surgical site infections.

Mode of transmission

The organism is usually transmitted from person to person via the nahds of HCW's or from environmental reservoirs to patients.

REISS A. PEREZ

Sex

Most (68%) episodes of Serratia bacteremia occur in males.

Age

Outbreaks of Serratia infection occur in neonates and infants. In adults, mostSerratia infections are isolated, but occasional nosocomial outbreaks occur.

REISS A. PEREZ

REISS A. PEREZ

http://emedicine.medscape.com/article/228495-overview#showall

http://en.wikipedia.org/wiki/Serratia

http://www.health.qld.gov.au/EndoscopeReprocessing/module_1/1_3d.asp

REFERENCES:

REISS A. PEREZ

THANK YOU, MAM

TESALONA :-D