Gram Negative Bacilli Gram Negative Bacilli

(GNB)(GNB)(GNB)(GNB)

Professor Md. Akram HossainProfessor Md. Akram Hossain

Mymensingh Medical CollegeMymensingh Medical College

12/24/13 1Prof. Muhammad Akram, Gram

negative bacilli -Introduction

Enterobacteriaceae with peritrichous flagella or no flagella

12/24/13 2Prof. Muhammad Akram, Gram

negative bacilli -Introduction

12/24/13 3Prof. Muhammad Akram, Gram

negative bacilli -Introduction

Salmonella12/24/13 4

Prof. Muhammad Akram, Gram negative bacilli -Introduction

Shigella with no flagella

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negative bacilli -Introduction

Yersinia pestis

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negative bacilli -Introduction

Vibrio cholerae with polar flagella

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negative bacilli -Introduction

Helicobacter- curved bacilli with polar flagella12/24/13 8

Prof. Muhammad Akram, Gram negative bacilli -Introduction

Pseudomonas with lophotrichous flagella

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negative bacilli -Introduction

H. Influenzae – a cocco bacilli12/24/13 10

Prof. Muhammad Akram, Gram negative bacilli -Introduction

Bordetella

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negative bacilli -Introduction

Legionella

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negative bacilli -Introduction

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negative bacilli -Introduction

Francisella

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negative bacilli -Introduction

Categories of GNBCategories of GNB

1.1. Related to Enteric tractRelated to Enteric tract•• Enterobacteriaceae Enterobacteriaceae –– Esch coli, SalmonellaEsch coli, Salmonella

•• Vibrionaceae Vibrionaceae –– Vibrio cholerae etcVibrio cholerae etc

•• Pseudomonadaceae Pseudomonadaceae –– Pseudomonas aeroginosa Pseudomonas aeroginosa

•• Bacteroidaceae Bacteroidaceae –– Bacteroides fragillis etcBacteroides fragillis etc•• Bacteroidaceae Bacteroidaceae –– Bacteroides fragillis etcBacteroides fragillis etc

•• Helicobactor/ campylobacterHelicobactor/ campylobacter--

2.2. Related to Respiratory tractRelated to Respiratory tract•• Haemophilus, Legionella, BordetellaHaemophilus, Legionella, Bordetella

3.3. Animal sourcesAnimal sources•• Brucella, Francisella, pasteurella, YersiniaBrucella, Francisella, pasteurella, Yersinia

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negative bacilli -Introduction

EnterobacteriaceaeEnterobacteriaceae

�� Large, heterogeneous familyLarge, heterogeneous family

�� Found mainly in the colon of humans and other Found mainly in the colon of humans and other animalsanimals-- many of them as normal flora of the gut.many of them as normal flora of the gut.

�� Family propertiesFamily propertiesAll Facultative anaerobeAll Facultative anaerobe1.1. All Facultative anaerobeAll Facultative anaerobe

2.2. All ferment glucose (With or without gas)All ferment glucose (With or without gas)

3.3. All reduce nitrate to nitriteAll reduce nitrate to nitrite

4.4. All oxidase negative ( other enterics are oxidase positive)All oxidase negative ( other enterics are oxidase positive)

5.5. Some are Motile with peritrichous flagella and some are Some are Motile with peritrichous flagella and some are nonmotile.nonmotile.

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negative bacilli -Introduction

Members of EnterobacteriaceaeMembers of Enterobacteriaceae

1.1. EscherichiaEscherichia Esch. coliEsch. coli

2.2. SalmonellaSalmonella S. typhi, S.paratyphi.S. typhi, S.paratyphi.

3.3. ShigellaShigella Sh.sonni,Sh.boydiiSh.sonni,Sh.boydii

4.4. KlebsiellaKlebsiella K. pneumonae,K. aerogenesK. pneumonae,K. aerogenes

5.5. ProteusProteus Pr. mirabilis, Pr.vulgarisPr. mirabilis, Pr.vulgaris

6.6. EnterobacterEnterobacter E. cloacaeE. cloacae6.6. EnterobacterEnterobacter E. cloacaeE. cloacae

7.7. CitrobacterCitrobacter C. freundiC. freundi

8.8. HafniaHafnia H. alveiH. alvei

9.9. SerratiaSerratia S.marcescensS.marcescens

10.10. YersiniaYersinia Y.pestis , Y.enterocoliticaY.pestis , Y.enterocolitica

11.11. ProvidenciaProvidencia P. rettgeriP. rettgeri

12.12. MorganellaMorganella M.morganiiM.morganii

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ClassificationClassification

�� Clinical classificationClinical classification�� Primarily intestinal pathogenPrimarily intestinal pathogen

�� Primarily extraPrimarily extra--intestinal pathogenintestinal pathogen

�� Both intestinal and extraBoth intestinal and extra--intestinal intestinal Both intestinal and extraBoth intestinal and extra--intestinal intestinal

�� Classification based on lactose fermentationClassification based on lactose fermentation�� Lactose fermentersLactose fermenters

�� Lactose non fermentersLactose non fermenters

�� Late fermentersLate fermenters

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negative bacilli -Introduction

Clinical classificationClinical classification

�� Primarily Intestinal Pathogen Primarily Intestinal Pathogen 1. Shigella 2. Y. enterocolitica1. Shigella 2. Y. enterocolitica

�� Intestinal & Extraintestinal PathogenIntestinal & Extraintestinal Pathogen1. Salmonella 2. Esch. coli1. Salmonella 2. Esch. coli

�� Extra Intestinal pathogenExtra Intestinal pathogen--1.1. Klebsiella 2. Proteus 3.Enterobacter Klebsiella 2. Proteus 3.Enterobacter

4. Citrobacter 5. Y. pestis etc...4. Citrobacter 5. Y. pestis etc...

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Classification based on lactose fermentationClassification based on lactose fermentation

�� Lactose fermenters Lactose fermenters

11. . Esch coli 2. Klebsiella, 3. Enterobacter Esch coli 2. Klebsiella, 3. Enterobacter

4. Citrobacter 5. Serratia4. Citrobacter 5. Serratia

�� Lactose non fermentersLactose non fermenters�� Lactose non fermentersLactose non fermenters

11. . Salmonella 2. Shigella except Sh.sonni 3. ProteusSalmonella 2. Shigella except Sh.sonni 3. Proteus

�� Late lactose ferments Late lactose ferments ––

11. . Sh.sonni 2. Citrobacter 3.Providencia 4. SerratiaSh.sonni 2. Citrobacter 3.Providencia 4. Serratia

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Antigenic structureAntigenic structure

�� 3 major surface antigens3 major surface antigens

�� “O” “O” –– antigen or somatic antigen, outer component antigen or somatic antigen, outer component

of LPS.of LPS.

�� “H” “H” –– antigen or flagellar antigen antigen or flagellar antigen �� “H” “H” –– antigen or flagellar antigen antigen or flagellar antigen

�� “K” or “Vi”“K” or “Vi”-- antigen antigen –– capsular antigen capsular antigen

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Clinical importanceClinical importance

�� Produce two types of diseasesProduce two types of diseases

�� Diarrheal diseasesDiarrheal diseases

�� Other infectionsOther infections

�� UTIUTI

PneumoniaPneumonia�� PneumoniaPneumonia

�� BacterimiaBacterimia

�� SepticemiaSepticemia

�� SepsisSepsis

�� Menintigits Menintigits

�� Wound infectionWound infection

�� Hospital infectionsHospital infections

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