What is emerging infection?What is emerging infection? An An emerging infectious diseaseemerging infectious disease is an is an

infectious diseaseinfectious disease whose incidence has whose incidence has increased in the past 20 years and threatens to increased in the past 20 years and threatens to increase in the near future.increase in the near future.

This include diseases caused by a newly This include diseases caused by a newly identified microorganism or newly identified identified microorganism or newly identified strain of a known microorganism.strain of a known microorganism.

Some examples of emerging infections are Some examples of emerging infections are Ebola virusEbola virus , , LymeLyme disease disease, , SalmonellosisSalmonellosis/Salmonella/Salmonella , , Shigellosis/Shigellosis/ShigellaShigella, , Dengue FeverDengue Fever..

Multi Drug Resistance…..Multi Drug Resistance…..

Multi-drug resistant organisms are bacteria or Multi-drug resistant organisms are bacteria or virus that are resistant to a number of virus that are resistant to a number of antibioticantibiotic..

It is a condition enabling a disease-causing organism to It is a condition enabling a disease-causing organism to resist distinct resist distinct drugsdrugs or chemicals of a wide variety of or chemicals of a wide variety of structure and function targeted at eradicating the structure and function targeted at eradicating the organism. organism.

Many different bacteria now exhibit multidrug resistance, Many different bacteria now exhibit multidrug resistance, including including staphylococcistaphylococci, , enterococcienterococci, , gonococcigonococci, ,

streptococcistreptococci, , salmonella salmonella , , Mycobacterium tuberculosis.Mycobacterium tuberculosis.

Cause for Multi-Resistance??Cause for Multi-Resistance??

The increase in multi antimicrobial resistant has been The increase in multi antimicrobial resistant has been associated with the wide spread use of associated with the wide spread use of antimicrobial antimicrobial agentsagents in food production. in food production.

Multi-resistance organisms arise naturally by Multi-resistance organisms arise naturally by spontaneous mutation.spontaneous mutation.

Over usage of antibioticsOver usage of antibiotics also leads to the resistance also leads to the resistance of bacteria towards antimicrobials.of bacteria towards antimicrobials.

When the When the genes for resistancegenes for resistance are passed on from one are passed on from one bacteria to other, then the bacteria will acquire bacteria to other, then the bacteria will acquire resistance towards antibiotics.resistance towards antibiotics.

Image showing the formation of antibiotic resistance gene in

bacteria

•Efflux pumps are transport proteins involved in the extrusion of toxic substrates from within cells into the external environment.

•Pumps may be specific for one substrate or may transport a range of structurally dissimilar compounds (including antibiotics); such pumps can be associated with multiple drug resistance (MDR)

Salmonella Species….Salmonella Species….

The genus Salmonella contains over 2,000 sero-The genus Salmonella contains over 2,000 sero-species and is one of the most important species and is one of the most important pathogens in the family pathogens in the family EnterobacteriaceaeEnterobacteriaceae. .

Many types of salmonella species are Many types of salmonella species are responsible for salmonellosis, but responsible for salmonellosis, but S. S. typhimuriumtyphimurium and and S. enteritidisS. enteritidis are the two are the two most commonly found. most commonly found.

Salmonella causes Salmonella causes food borne diseasefood borne disease since since salmonella transmits through raw or salmonella transmits through raw or contaminated food products.contaminated food products.

““Salmonella Typhimurium”Salmonella Typhimurium”

Image showing Salmonella Typhimurium

S.Typhimurium……S.Typhimurium…… Salmonella typhimuriumSalmonella typhimurium is a leading cause of human is a leading cause of human

gastroenteritis.gastroenteritis.

It is a It is a Gram-negative , Gram-negative , anaerobic anaerobic bacteria of the family bacteria of the family Enterobacteriaceae, usually motile with peritrichous Enterobacteriaceae, usually motile with peritrichous ( flagella in all direction)flagella.( flagella in all direction)flagella.

S. typhimuriumS. typhimurium, causes a wide range of infections in , causes a wide range of infections in

birds and mammals ranging from self limiting birds and mammals ranging from self limiting gastroenteritis to severe systemic paratyphoid diseases.gastroenteritis to severe systemic paratyphoid diseases.

S. typhimurium acts along with S.enteritidis and cause S. typhimurium acts along with S.enteritidis and cause disease in the environment. disease in the environment.

Transmission of salmonella…Transmission of salmonella…

Salmonella infections are Salmonella infections are zoonotic.zoonotic.

SalmonellaSalmonella bacteria can be found in food bacteria can be found in food products such as raw poultry, eggs, and beef, products such as raw poultry, eggs, and beef, and sometimes on unwashed fruit.and sometimes on unwashed fruit.

The present situation with S. typhimurium is The present situation with S. typhimurium is complicated by the presence of the organism complicated by the presence of the organism inside the egg, inside the egg, in the yolkin the yolk..

Effects!!!!Effects!!!!

Initial symptoms are diarrhea, vomiting, fever Initial symptoms are diarrhea, vomiting, fever and abdominal cramps.and abdominal cramps.

If not treated initially it leads to nausea, loss of If not treated initially it leads to nausea, loss of appetite and gastro intestinal infections.appetite and gastro intestinal infections.

If the salmonella enters the blood stream and If the salmonella enters the blood stream and circulates there, it leads to an infection called circulates there, it leads to an infection called bacteremiabacteremia..

Effects due to drug-resistance…Effects due to drug-resistance…

Chronic stage of salmonellosis leads to Chronic stage of salmonellosis leads to Reiter’s syndrome.Reiter’s syndrome.

Reiter’s syndrome leads to Reiter’s syndrome leads to reactive arthritis, reactive arthritis, eye irritation and urinary tract infection.eye irritation and urinary tract infection.

The symptoms of Reiter’s Syndrome usually The symptoms of Reiter’s Syndrome usually occur between occur between one and three weeksone and three weeks after the after the infection.infection.

Arthritis may even lead to Arthritis may even lead to spondylitisspondylitis, , inflammation of the vertebrae in the spinal inflammation of the vertebrae in the spinal column.column.

Treatment???Treatment???

Persons with severe diarrhea require Persons with severe diarrhea require re-re-hydrationhydration, often with intravenous fluids., often with intravenous fluids.

If the infection spreads to the intestines, the If the infection spreads to the intestines, the infection can be treated with Antibiotics.infection can be treated with Antibiotics.

The antimicrobials most widely regarded as The antimicrobials most widely regarded as optimal for the treatment of salmonellosis in optimal for the treatment of salmonellosis in adults is the group of adults is the group of fluoroquinolonesfluoroquinolones..

The earlier drugs The earlier drugs chloramphenicol,ampicillin and amoxicillin chloramphenicol,ampicillin and amoxicillin and trimethoprim-sulfamethoxazole are and trimethoprim-sulfamethoxazole are occasionally used as alternatives. occasionally used as alternatives.

Test for drug resistance…..Test for drug resistance…..(i) Agar Dilution Method:(i) Agar Dilution Method: This test is done using 80 salmonella strains got from This test is done using 80 salmonella strains got from

chicken carcass and giblet samples. These isolated chicken carcass and giblet samples. These isolated samples were serotyped with slide agglutination and samples were serotyped with slide agglutination and then then tested for resistance to 23 drugstested for resistance to 23 drugs..

Amikacin Amikacin ,Amoxicillin and clavulanic acid, Ampicillin, ,Amoxicillin and clavulanic acid, Ampicillin, ApramycinApramycin,Carbadox,,Carbadox,CeftiofurCeftiofur,Ceftriaxone,,Ceftriaxone,CephalotinCephalotin,C,Chloramphenicol,hloramphenicol,CiprofloxacinCiprofloxacin,Florfenicol,,Florfenicol,Gentamicin,KanGentamicin,Kanamycinamycin,,NalidixicacidNalidixicacid,,NeomycinNeomycin,Nitrofurantoin,Spectinom,Nitrofurantoin,Spectinomycin,Streptomycin,Sulfisoxazole,Tetracycline,ycin,Streptomycin,Sulfisoxazole,Tetracycline,TobramycinTobramycin,Cotrimoxazole,Trimethopri.,Cotrimoxazole,Trimethopri.

(i) Method contd…(i) Method contd…Result:Result: Out of all the 80 strains all the strains were susceptible Out of all the 80 strains all the strains were susceptible

to to Ciprofloxacin, Nalidixic acid, Ceftiofur, Ceftriaxone, Ciprofloxacin, Nalidixic acid, Ceftiofur, Ceftriaxone, Cephalotin, Amikacin, Apramycin, Gentamicin, Cephalotin, Amikacin, Apramycin, Gentamicin, Neomycin, Tobramycin and KanamycinNeomycin, Tobramycin and Kanamycin..

Fifty one strains were resistant to one or more Fifty one strains were resistant to one or more antimicrobials i.e. antimicrobials i.e. 63.7% were multiple drug resistant63.7% were multiple drug resistant..

Less than 21% were resistant to Carbadox, Less than 21% were resistant to Carbadox,

Trimethoprim and CotrimoxazoleTrimethoprim and Cotrimoxazole

(ii) In vitro testing method..(ii) In vitro testing method.. The activities of mecillinam and Ampicillin alone and in The activities of mecillinam and Ampicillin alone and in

combination were evaluated in mice infected with the LT combination were evaluated in mice infected with the LT 2 strain of salmonella typhymurium.2 strain of salmonella typhymurium.

Ampicillin in doses of >=0.03 mg and mecillinam in Ampicillin in doses of >=0.03 mg and mecillinam in doses of >= 0.5 mg reduced mortality rates from 77% in doses of >= 0.5 mg reduced mortality rates from 77% in saline treated controls to a range of 0-47% (P<0.05). saline treated controls to a range of 0-47% (P<0.05).

The same doses of antibiotics also extended the median The same doses of antibiotics also extended the median times to death and lowered significantly the means of times to death and lowered significantly the means of splenic bacterial counts. splenic bacterial counts.

(ii) Method contd…(ii) Method contd…

When both drugs were combined in doses that were When both drugs were combined in doses that were partially effective or sub inhibitory alone, no synergistic partially effective or sub inhibitory alone, no synergistic effects were observed. effects were observed.

These results showed that mecillinam and Ampicillin These results showed that mecillinam and Ampicillin given alone were effective in treating S. typhymurium given alone were effective in treating S. typhymurium infection but that combinations of two drugs were not infection but that combinations of two drugs were not synergistic in controlling the course of infections. synergistic in controlling the course of infections.

About PCR Technique….About PCR Technique….

In molecular biology, the In molecular biology, the polymerase chain reactionpolymerase chain reaction ((PCRPCR) is a technique to amplify a single or few copies of ) is a technique to amplify a single or few copies of a piece of DNA across several orders of magnitude, a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular generating thousands to millions of copies of a particular DNA sequence. DNA sequence.

In the PCR procedure trace amounts of DNA can be quickly and repeatedly copied to produce a quantity sufficient to investigate using conventional laboratory methods.

The PCR technique enables early diagnosis of malignant diseases.

Image of PCR!!!!!Image of PCR!!!!!

Diagnosis using PCR Technique…Diagnosis using PCR Technique…

Multiplex PCR assay for Multiplex PCR assay for SalmonellaSalmonella detection has been detection has been developed.developed.

Six sets of primers were designed to detect the major Six sets of primers were designed to detect the major SalmonellaSalmonella serotypes and phage types in Spain. serotypes and phage types in Spain.

The different amplification profiles obtained allowed us to The different amplification profiles obtained allowed us to detect detect SalmonellaSalmonella bacteria and to distinguish the bacteria and to distinguish the clinically prevalent clinically prevalent Salmonella entericaSalmonella enterica serotypes serotypes Enteritidis, Typhimurium.Enteritidis, Typhimurium.

Using this method, we could detect a specific band for Using this method, we could detect a specific band for DT104 and U302 phage types in DT104 and U302 phage types in SalmonellaSalmonella serotype serotype Typhimurium. Typhimurium.

Vaccination…….Vaccination…….

Salmonella is resistant to antibiotics and not to vaccines. Salmonella is resistant to antibiotics and not to vaccines. Hence vaccines can be taken to prevent salmonellosis.Hence vaccines can be taken to prevent salmonellosis.

A single-dose, oral salmonella typhi vaccine strain has A single-dose, oral salmonella typhi vaccine strain has been sought as a carrier or vector of cloned genes been sought as a carrier or vector of cloned genes encoding protective antigens of other pathogens.encoding protective antigens of other pathogens.

Such a hybrid vaccine, administered orally, would Such a hybrid vaccine, administered orally, would stimulate immune responses both at the mucosal stimulate immune responses both at the mucosal surface and in the systemic compartment and would surface and in the systemic compartment and would potentially provide protection against multiple pathogens. potentially provide protection against multiple pathogens.

Prevention!!!Prevention!!!

Do not eat or drink foods containing raw eggs.Do not eat or drink foods containing raw eggs. Should not drink Should not drink unpasteurizedunpasteurized milk or raw milk. milk or raw milk. Under cookedUnder cooked meat or poultry shouldn’t be consumed, meat or poultry shouldn’t be consumed,

as this meat may carry bacteria. as this meat may carry bacteria. Frequent and Frequent and over consumption of antibioticsover consumption of antibiotics should should

be avoided so that resistance of the pathogen to the be avoided so that resistance of the pathogen to the antibiotic can be controlled.antibiotic can be controlled.

Food prepared for infants must be very hygienic and Food prepared for infants must be very hygienic and bottles must be sterilized before usage, since infants are bottles must be sterilized before usage, since infants are easily prone to bacterialeasily prone to bacterial infections.infections.

Conclusion!!!!Conclusion!!!!

Control of multi-drug resistant Control of multi-drug resistant Salmonella Salmonella typhimurium DT 104typhimurium DT 104 requires reducing requires reducing infection in food animals and lowering the infection in food animals and lowering the risk of contamination at all stages in the risk of contamination at all stages in the food production chain. food production chain.

It is required to create an awareness It is required to create an awareness amoung the public about the multi amoung the public about the multi resistant pathogen and complications due resistant pathogen and complications due to these pathogens.to these pathogens.