Ch31 33 Recent site activity Bac_Pathog

Non–spore-forming anaerobic bacteria

Spirochaetales

Mycoplasma

and

Ureaplasma

Chapter 31, 32, 33

江倪全

https://sites.google.com/a/gap.cgu.edu.tw/bac_pathog/lecture

醫學⼆ (2018/04/17)、中醫⼆ (2018/05/02)

References

31. Non–spore-forming anaerobic bacteria

✓

_{Anaerobic gram-positive/negative}

cocci and rods

-

Opportunistic pathogens

-

Typically responsible for endogenous

infections

-

Fastidious nutritional requirements

Anaerobic gram-positive cocci

✓

_{Peptostreptococcus}

₍

消化鏈球菌

₎

-

Normally colonize the oral cavity, gastrointestinal tract, genitourinary

tract, and skin

✓ _{Clinical diseases}

✓ _{Laboratory diagnosis}

- Prevent contamination

- Oxygen-free container

- Cultured for a prolonged period (i.e., 5 to 7 days)

✓ _Treatment

Anaerobic gram-positive rods

✓

_{Opportunistic pathogens}

-

Actinomyces, Mobiluncus, Lactobacillus, and Propionibacterium

✓

_{Rarely cause human disease}

Actinomyces

(

放線菌

)

✓

_{Almost 50 species have been described}

✓

_{Facultatively anaerobic or strictly anaerobic}

gram-positive rods

Clinical diseases

✓

_{Classic disease caused by}

_Actinomyces

_is

termed actinomycosis

✓

_{Chronic granulomatous lesions that become}

suppurative and form abscesses connected by

sinus tracts

✓

_{Most actinomycetes infections are}

cervicofacial (

頸顏型

)

-

Thoracic (胸椎) actinomycosis

-

Abdominal (腹部) actinomycosis

-

Pelvic (⾻盆) actinomycosis

Epidemiology & Laboratory diagnosis

✓

_Epidemiology

-

Actinomyces organisms colonize the upper respiratory, GI, and female genital tracts but are not normally

present on the skin surface

-

Infections caused by actinomycetes are endogenous

-

No evidence of person-to-person spread or disease

✓

_{Laboratory diagnosis}

-

Actinomyces are fastidious and grow slowly (2 weeks or more) under anaerobic conditions

-

If sulfur granules (硫磺顆粒) are detected in a sinus

Treatment, prevention, and control

✓

_Treatment

-

Surgical debridement

-

Actinomyces are uniformly susceptible to penicillin (considered the antibiotic of choice), carbapenems, macrolides, and clindamycin

✓

_{Prevention and control}

-

Maintenance of good oral hygiene

-

Antibiotic prophylaxis: when the mouth or GI tract is

Laboratory diagnosis

✓ _Nocardia

- Branching filaments

- Aerobe

- Acid-fast stain: weak positive

- Granule: sometimes

- Disease: Pulmonary diseases

✓ _Actinomyces

- Branching filaments

- Anaerobe

- Acid-fast stain: negative

- Granule: Positive

- Disease: Oral cavity and intestines

✓

_{Physiology and structure}

-

Facultatively anaerobic or strictly anaerobic rods

✓

_{Clinical diseases (Invasion into blood)}

-

Transient bacteremia from a genitourinary source

-

Endocarditis

-

Opportunistic septicemia in an immunocompromised patient

✓

_{Epidemiology and Laboratory diagnosis}

-

Normal flora of the mouth, stomach, intestines, and genitourinary tract

-

Most commonly isolated in urine specimens and blood cultures

✓

_{Treatment, prevention, and control}

-

A combination of penicillin with an aminoglycoside is required for bactericidal activity

✓

_{Physiology and structure}

-

Obligate anaerobic, gram-variable or gram-negative, curved

rods with tapered ends

-

Fastidious, growing slowly even on enriched media

✓

_{Clinical diseases}

-

Bacterial vaginosis (vaginitis)

-

M. curtisii

✓

_{Epidemiology and Laboratory diagnosis}

-

Their microscopic appearance is a useful marker for vaginitis

✓

_{Treatment, prevention, and control}

-

Susceptible to vancomycin, clindamycin, erythromycin, and

ampicillin

✓ _{Physiology and structure}

-

Small gram-positive rods often arranged in short chains or clumps

✓ _{Clinical diseases}

-

Propionibacterium acnes

✓ _{Acne vulgaris (}青春痘_{) in teenagers and young adults}

✓ _{Opportunistic infections in patients with prosthetic devices or}

intravascular lines

✓ _{Epidemiology and Laboratory diagnosis}

-

Commonly found on the skin, conjunctiva, and external ear, and in the oropharynx and female genital tract

✓ _{Treatment, prevention, and control}

-

Acne is unrelated to the effectiveness of skin cleaning

-

Erythromycin and clindamycin have proved effective for treatment

Bifidobacterium

(

雙岐桿菌

) and

Eubacterium

(

真桿菌

)

✓

_{Very low virulence potential and usually represent}

clinically insignificant contaminants.

✓

_{Epidemiology and Laboratory diagnosis}

-

Commonly found in the oropharynx, large intestine, and

vagina

-

Confirmation of their etiologic role in an infection requires

their repeated isolation in large numbers from multiple

Anaerobic Gram-negative cocci

✓

_{Rarely isolated in clinical specimens}

✓

_Veillonella

_{are the predominant anaerobes in the}

Anaerobic Gram-negative rods

✓

_Bacteroides

₍

類桿菌屬

₎

-

Bacteroides fragilis (鬆脆類桿菌)

✓

_{Fusobacterium}

₍

梭桿菌屬

₎

✓

_{Parabacteroides}

✓

_{Porphyromonas}

₍

紫單胞菌屬

₎

✓

_Prevotella

-

These anaerobes are the predominant bacteria on most mucosal surfaces

-

Most gram-negative anaerobes respond weakly to Gram stain

-

Most anaerobic gram-negative rods are fastidious and grow slowly in culture

Epidemiology

✓

_{Normal flora}

-

Only produce disease when they move from their endogenous

homes to normally sterile sites

-

Endogenous infections are characterized by the presence of a

polymicrobial mixture of organisms

-

In the disease state, the mixture changes to less diversity

✓

_B

_.

_fragilis

_{is commonly associated with pleuropulmonary,}

Physiology and Structure

✓

_Bacteroides

_fragilis

₍

鬆脆桿菌

₎

-

Gram-negative cell wall structure surrounded by a

polysaccharide capsule

-

Bacteroides LPS has little or no endotoxin activity

-

Growth is stimulated by bile

-

Strains of enterotoxigenic B. fragilis that cause diarrheal

disease produce a heat-labile zinc metalloprotease toxin (B.

Clinical diseases

✓

_{Respiratory tract infections}

-

Infected by Prevotella, Porphyromonas, Fusobacterium, and

non-fragilis Bacteroides

✓

_{Brain abscess (}

腦膿瘡/瘍

₎

-

Associated with a history of chronic sinusitis or otitis

-

Prevotella, Porphyromonas, and Fusobacterium

✓

_{Intraabdominal infections (}

腹腔內感染症

₎

Clinical diseases

✓

_{Gynecologic infections (}

婦科感染症

₎

-

Prevotella bivia and Prevotella disiens are the most important

-

B. fragilis is commonly responsible for abscess formation

✓

_{Skin and soft-Tissue Infections}

-

Introduced by a bite or through contamination of a

traumatized surface

Clinical diseases

✓

_Bacteremia

-

B. fragilis is the anaerobe most commonly isolated in blood cultures

✓

_{Gastroenteritis}

-

Strains of enterotoxin-producing B. fragilis

✓ _{heat-labile zinc metalloprotease toxin}

Laboratory Diagnosis

✓

_Microscopy

-

Gram stain: faintly and irregularly

✓

_Culture

-

Specimens should also be kept in a moist

environment

-

Most Bacteroides grow rapidly and should be

detected within 2 days

-

Media supplemented with bile: recover of

important anaerobes

Treatment, prevention, and control

✓

_Treatment

-

Virtually all members of the B. fragilis group produce β

-lactamases

-

Antibiotics against gram-negative anaerobic rods are

metronidazole, carbapenems, and β-lactam–β-lactamase

inhibitors

✓

_{Prevention and control}

-

Disease is virtually impossible to control

-

If the barriers are invaded, prophylactic treatment with

32.

Treponema

,

Borrelia

, and

Leptospira

密螺旋體、包⽒螺旋體、鉤端螺旋體

✓

_{Spirochaetales (}

螺旋體⽬

₎

-

Gram-negative

-

Spirochaetaceae

✓

_T

_reponema

_(Anaerobic)

✓

_Borrelia

_{(Microaerophilic)}

-

Leptospiraceae

✓

_Leptospira

_(Aerobic)

Treponema

密螺旋體

✓

_{T. pallidum}

-

Syphilis- T. pallidum subspecies pallidum (梅毒螺旋體)

-

Bejel- T. pallidum subspecies endemicum

-

Yaws- T. pallidum subspecies pertenue

✓

_{Non-venereal diseases}

-

Bejel

Clinical diseases-

T.

pallidum

✓

_{Primary phase}

-

Painless ulcer > chancre (下疳)

✓

_{Secondary phase}

-

Flulike syndrome > disseminated skin rash

-

Condylomata lata (扁平濕疣)- highly infectious

✓

_{Tertiary (Late) phase}

-

Diffuse, chronic inflammation > destruction of virtually any

organ or tissue (gumma-梅毒腫)

-

Neurosyphilis is not exclusively a late manifestation

Epidemiology-

T. pallidum

✓

_{Sexually transmitted bacterial disease}

-

Neisseria gonorrhoeae, Chlamydia trachomatis, T. pallidum

-

Patients infected with syphilis are at increased risk for transmitting

and acquiring HIV when genital lesions are present

✓

_T

_.

_pallidum

_{is extremely labile, unable to survive exposure to}

drying or disinfectants.

✓

_{Other transmission routes}

-

From cutaneous, or mucosal lesions

-

Blood transfusion

-

Congenital transmission

✓ _{Desquamating maculopapular rash, malformations, blindness,}

Laboratory diagnosis

✓

_{Too thin to be seen with light microscopy}

✓

_{Darkfield microscopy, direct fluorescent antibody (DFA) test}

✓

_{Antibody detection}

-

Nontreponemal tests (antigen: cardiolipin)

✓ _{Screening tests}

✓ _{Venereal disease research laboratory (VDRL) test}

-

Use for CSF samples (highly specific but not sensitive)

✓ _{Rapid plasma reagin (RPR) test}

-

Treponemal tests (antigen: T. pallidum)

✓ _{Fluorescent treponemal antibody-absorption (FTA-ABS) test}

- CSF test has high sensitivity but low specificity

✓ _{Treponema pallidum particle agglutination (TP-PA) test}

http://www.bionor.com/veterinary.htm

False negative reactions

Infection Primary phase Secondary phase Late phase

Nontreponemal test

3 months

Negative Positive 25-30% Negative

Treponemal test

Positive

False positive reactions

✓

_{Nontreponemal tests (antigen: cardiolipin)}

-

Transient false-positive: acute febrile diseases, after

immunization, and in pregnant women

-

Long-term false-positive: chronic autoimmune diseases; liver

or have extensive tissue destruction

✓

_{Treponemal tests (antigen:}

_{T. pallidum}

₎

Treatment, prevention, and control

✓

_{Penicillin is the drug of choice for}

treating

T

.

pallidum

infections

✓

_{Doxycycline or azithromycin can be}

used as alternative antibiotics for

patients allergic to penicillin

✓

_{Only penicillin can be used for the}

Other Treponemes

✓

_{T. pallidum}

-

Bejel- T. pallidum subspecies endemicum

✓ _{Transmit by direct contact, contaminated eating utensils}

✓ _{Gummas of the skin, bones, and nasopharynx}

-

Yaws- T. pallidum subspecies pertenue

✓ _{Transmit by direct contact}

✓ _{Destructive lesions of the skin, lymph nodes, and bones}

Yaws

Borrelia

包⽒螺旋體

✓

_{Gram-negative (stain poorly with the Gram stain}

reagents)

✓

_{Microaerophilic}

✓

_{Lyme disease}

-

B. burgdorferi, B. garinii, B. afzelii

-

Tick-borne disease

✓

_{Relapsing fever}

-

Endemic tick-borne relapsing fever

-

Epidemic louse-borne relapsing fever- B. recurrentis

Clinical diseases

✓

_{Lyme disease}

-

Early localized infection

✓ _{Erythema migrans (5-50 cm)}

✓ _{The lesion fades and disappears within weeks}

-

Early disseminated stage

✓ _{Arthritis (Knee; 60%)}

✓ _{Neurologic manifestations (facial nerve palsy; 10-20%)}

✓ _{Cardiac complication (atrioventricular block; 5%)}

-

Late manifestation stage

✓ _{Arthritis (one or more joints)}

✓ _{Acrodermatitis chronica atrophicans (}慢性萎縮性肢端⽪膚炎₎

Clinical diseases

✓

_{Relapsing fever}

-

Febrile (resolve after 3-7 days) > 1-week afebrile > febrile

-

Splenomegaly and hepatomegaly are common

-

Epidemic relapsing fever (louse-borne)

✓ _{Pathogen: B. recurrentis}

✓ _{Single relapse}

✓ _{Mortality rate: 70%}

-

may be related to the patients’ underlying poor state of health

-

Endemic relapsing fever (tick-borne)

✓ _{as many as 10 relapses}

✓ _{Mortality rate: 5%}

Epidemiology

Infection occurs when the lice are crushed during feeding

✓

_B

_.

_burgdorferi

_{: United}

states and Europe

✓

_B

_.

_garinii

_and

_B

_.

_afzelii

_:

Europe and Japan

✓

_B

_.

_recurrentis

_{: epidemic}

Laboratory diagnosis

✓

_Microscopy

-

Not recommend for Lyme disease

-

Relapsing fever: positive for organisms in febrile period

✓

_{Antibody detection}

-

Not recommend for relapsing fever

-

Lyme disease

✓ _{Although cross-reactions are uncommon, positive serologic results}

must be interpreted carefully, particularly if the titers are low

✓ _{Most false-positive reactions occur in patients with syphilis}

Leptospira

鉤端螺旋體

✓

_Leptospira

-

Obligate aerobes; optimal growth at 28-30ºC

-

Pathogenic and non-pathogenic Leptospires

✓

_{Clinical diseases}

-

Initial phase (remit after 1 week)

✓ _{Mild influenza-like febrile illness}

✓ _{Bacteremia; organisms can frequently be isolated in CSF}

-

Second phase

✓ _{Sudden onset of headache, chills, abdominal pain, conjunctival}

suffusion, fever, diffuse rash

Epidemiology

✓

_{Reservoir host}

-

Chronic infections

-

Rodents and other small mammals

-

Spirochetes colonize the renal tubules and shed in urine in the

large numbers

-

Survival in environment for as long as 6 weeks

✓

_{Incidental host}

-

Exposure to contaminated water, moist soil

Laboratory diagnosis

✓

_{Culture: 2 weeks-4 months}

-

Leptospira can be found in blood and CSF early in the disease

and in urine during the late stages

-

Urine must be treated to neutralized the pH and concentrated

by centrifugation

✓

_{Antibody detection}

-

Microscopic agglutination test (MAT)

33.

Mycoplasma

and

Ureaplasma

黴漿菌和尿漿菌

✓

_{Smallest free-living bacteria (0.2-0.3}

_µ

_m)

✓

_{Do not have a cell wall}

-

Resistance to penicillins, cephalosporins, vancomycin

✓

_{Cell membrane contains sterols}

-

Require exogenous sterols for culture

✓

_Mycoplasma

_pneumoniae

_;

_M

_.

_hominis

_;

_M

_.

_genitalium

-

Facultative anaerobic bacteria (except M. pneumoniae: strict

aerobic)

Epidemiology and clinical diseases

✓

_M

_.

_pneumoniae

_{(strict human pathogen): Respiratory diseases}

-

Asymptomatic carriage

-

Tracheobronchitis

-

Atypical/walking pneumonia: dry, nonproductive cough, do not produce sputum

-

Most common in 5-15 years children and young adults

-

Aerosol transmission

✓

_M

_.

_hominis

_,

_M

_.

_genitalium

_{, and}

_Ureaplasma

_{spp (normal}

flora: infants, particular females)

Nongonococcal urethritis (NGU)

Pelvic (⾻盆腔) inflammatory disease

Pyelonephritis (腎㿻腎炎)

Spontaneous abortion or

premature birth

Postpartum fever

M. hominis _{✔ ✔}

M. genitalium _{✔ ✔}

典型肺炎與⾮典型肺炎

✓

典型肺炎

-

發燒

-

胸痛、畏寒

-

咳嗽帶痰 

-

通常可在痰中找到致病菌

✓

⾮典型肺炎

-

發燒

-

較少胸痛及畏寒

-

乾咳 

Laboratory diagnosis

✓

_{Microscopy is no diagnostic value}

✓

_{Antibody-specific tests are available only for}

_M

_.

pneumoniae

https://lookfordiagnosis.com

M. hominis: fire-egg morphology

M. pneumoniae: mulberry shaped

Treatment

✓

_M

_.

_pneumoniae

_{: Erythromycin, doxycycline,}

fluoroquinolones

✓

_Other

_Mycoplasma

_{spp: tetracycline}

-

M. hominis: Clindamycin (resistance to erythromycin and occasionally to the tetracycline)