Borrelia

General Characteristics of genus Borrelia

• under the family spirochaetaceae• spiral-shaped / coiled but fewer coils than leptospira(3-10

loose coils)• have a length of 20-30um but a width of only 0.2-0.3um• motile with both rotational and translational movements• stains well with Giemsa stain• obligate aerobes or microaerophilic(grown in vitro)• has periplasmic flagella that determines the shape of the

bacteria.

http://www.cdc.gov/ncidod/dvbid/lyme/ld_Borreliaburgdorferi.htm

General Characteristics of genus Borrelia

• Culture Medium: Barbour-Stoenner-Kelly (BSK) medium• Its optimal growth temperature is 34° to 37°C, and the

organism has a generation time of 11 to 12 hours at 35°C• Viewed through Dark-Field Microscopy

http://en.wikipedia.org/wiki/File:Borrelia_burgdorferi_(CDC-PHIL_-6631)_lores.jpg

Virulence Factors

• Antigenic Variation• Outer Surface Proteins – OspA– OspC– Dbp(Decorin-binding protein)– Erps(Osp E/F-related proteins) and

CRASPs(Complement acquiring surface proteins)– cp32

Diseases Caused by Borrelia species

• LYME DISEASE - inflammatory disease caused by a spirochete that is transmitted by ticks, usually characterized initially by a rash followed by flulike symptoms including fever, joint pain, and headache.

– Caused by: Borrelia burgdorferi, Borrelia afzelii and Borrelia garnii(COLLECTIVELY CALLED: Borrelia burgdorferi sensu lato)

LYME DISEASE

• Symptoms of LYME DISEASE– Fever– Headache– Myalgia– Drowsiness – and the following stages......

LYME DISEASE

• Stages of LYME DISEASE– First stage- The rash caused by a tick’s bite has a

characteristic “bull’s eye” appearance, called Erythema Migrans.

http://www.medicinenet.com/black_widow_brown_recluse_pictures_slideshow/article.htm

LYME DISEASE

• Stages of LYME DISEASE– Second stage- starts weeks to months after

infection and may cause arthritis, neurologic disorders, and carditis

– Third stage- characterized by chronic arthritis

LYME DISEASE

• Transmitted by:– Reservoir Host: rodents/ white-footed mouse– Arthropod vector: Ixodes scapularis (deer ticks, all stages can harbor

the spirochete and transmit disease)- Needs around 24 hours(period of attachment before transmitting of disease).

mouse deer tick

Engorged(infected) tick

LYME DISEASE

• LABORATORY DIAGNOSIS• Specimen used: Blood, biopsy specimen, joint and

cerebrospinal fluid

• TREATMENT:• Doxycycline, amoxicillin, parenteral and broad spectrum

cephalosporins

• VACCINE• LYMErix vaccine

Diseases Caused by Borrelia species

• RELAPSING FEVER– an acute febrile illness caused by Borrelia

recurrentis

– The high fevers of presenting patients spontaneously abate and then recur

Diseases Caused by Borrelia species

• RELAPSING FEVER• Vector: Pediculus humanus (sucking louse)

• B. recurrentis infects the person via either abraded or intact skin (or mucous membranes) and then invades the bloodstream.

Soft-bodied licehttp://emedicine.medscape.com/article/787000-overview

Diseases Caused by Borrelia species

• RELAPSING FEVER• Symptoms: rapid pulse,

headache,weakness,anorexia, weight loss, cough

• Relapses: – primary febrile episode typically ends after 3-6 days – the first relapse occurs abruptly 7-10days later– relapses average to 3, and there can be more than 10

Epidemiology

• LYME DISEASE– Of the total Lyme Disease reports in the world in

2006, 59,770 cases or 93% of it came from 10 states in the US (Connecticut, Delaware, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Rhode Island and Wisconsin. )

• RELAPSING FEVER– prevalent in Ethiopia and Sudan

Laboratory Diagnosis

• SPECIMEN COLLECTION– Sp of choice: Blood or CSF– Examination of live ticks: The midgut of each tick is to be dissected

Laboratory Diagnosis

• MIROSCOPIC EXAMINATION– the midgut of each tick was removed under a

stereomicroscope and homogenized in a 0.9% NaCl

Laboratory Diagnosis

• ANTIBIOTIC SUSCEPTIBILITY– Oral: doxycycline, amoxicillin, clarithromycin– Injection: benzylpenicillin, cefotaxime

and ceftriaxone– Vaccines: LYMErix vaccine

http://www.medicinenet.com/black_widow_brown_recluse_pictures_slideshow/article.htm