The document discusses various aspects of microbial pathogens, particularly focusing on pathogenicity, virulence, and the growing concerns regarding antibiotic resistance in the poultry industry due to clostridium perfringens. It also explores the effects of berberine on controlling infections, the role of biofilms in environmental persistence of shiga-toxin producing E. coli, and the impact of clostridium botulinum and protozoa on bacterial transmission. Overall, it emphasizes the importance of understanding bacterial pathogens in both clinical and non-clinical environments for better control and prevention strategies.

1. MICROBIAL PATHOGENS IN
CLINICAL & NON-CLINICAL
ENVIRONMENTS
PALLABI CHATTERJEE
M.SC. MB(MICROBIOLOGY)-II SEMESTER
ENROLLMENT NO.- A07199318004.

2. INTRODUCTION
• Pathogenicity: Pathogenicity refers to the qualitative ability of the microorganisms
to cause diseases.
• Virulence: Quantitavely describes the extent of a microorganisms ability to cause
diseases. The term is derived from the latin word “virulenia” meaning poison. Eg;
Pilli, Fimbrie, capsule, ACP, TCP, Lecithin etc.
• Infection: The term infection describes the grown on replication of the
microorganisms within the body.
• Disease: Occurs only when the infecting microorganisms disrupt the normal body
functions.
• ID₅₀ : The number of microorganisms required to cause infection in half of the hosts,
eg., ID₅₀ of Shigella sp. is of the order 10,000 orgasnisms. (ID-Infectious Dose)
• LD₅₀ : The number of microorganisms required to kill half of the hosts. (LD-Lethal
Dose)

3. The Effects of Berberine on Clostridium Perfringens
Induced Necrotic Enteritis in Broiler Chickens
• The commercial poultry industry has been facing increasing pressure to
reduce the use of antimicrobial growth promoters due to concerns that the use
of antibiotics in the feed contributes to the spread of antibiotic-resistant genes
by promoting the selection of antibiotic-resistant bacteria in animals.
• Consequently, diseases such as Necrotic Enteritis (NE) have increased in
prevalence, with NE related costs in the international poultry industry
estimated to be in the region of two billion US dollars annually.
• It is understood that the disease is typically caused by toxins produced by the
bacterium Clostridium Perfringens.
• Clinically, NE is characterized by a sudden increase in flock mortality, often
without warning. Subclinically, C. perfringens has been found to cause
chronic damage to the intestinal mucosa, resulting in decreased digestion and
absorption, reduced weight gain and increased feed-conversion ratio.
• As C. perfringens spores are ubiquitous in nature in the environment and are
ingested on a continuous basis via poultry feed, predisposing factors such as
mucosal damage caused by coccidiosis are generally accepted to be required
for this bacterium to cause disease.
C. Purfringes

4. The Effects of Berberine on Clostridium Perfringens
Induced Necrotic Enteritis in Broiler Chickens
• Berberine is an isoquinoline quaternary alkaloid, and
has been identified as the major active component of
many plants such as Coptidis rhizome, Huanglian and
Phellodendri cortex.
• It has been used for thousands of years in traditional
herbal remedies in China and North America for the
treatment of intestinal infections including acute
gastroenteritis, cholera and bacillary dysentery.
• This natural compound has drawn extensive attention
as a scaffold for drug design with extensive literature
and on-going clinical trials against a multitude of
diseases.
Berberine

5. The Effects of Berberine on Clostridium Perfringens
Induced Necrotic Enteritis in Broiler Chickens
• Previous studies demonstrate that Berberine is non-lethal in chickens up to dosages of 2000
mg/kg/ bodyweight and was effective in controlling against experimentally induced coccidial
infection in chicken. This is evident in the significant reduction of sporulated coccidial
oocysts found in the faeces of treated birds.
• However, bloody diarrhea was observed, suggesting the absorptive mucosal surface was still
damaged and does not disallow the notion of a C. perfringens outbreak.
• In view of this, the potential use of Berberine in experimentally induced C. perfringens
infection in broiler chickens is investigated for the first time. In addition to the importance of
C. perfringens infection in livestock animals, the Clostridia genus is also associated with
toxin-related infections in human patients. Thereby, this study can also form the basis for
further studies in drug discovery and development.

6. Role of biofilms in environmental persistence of Shiga-
toxin producing Escherichia coli (STEC)
• Among pathogenic members, Shiga-toxin producing E.coli (STEC) are some
of the more prominent pathogenic E.coli within the public sphere. STEC
disease outbreaks are typically associated with contaminated beef,
contaminated drinking, etc. These water-and food borne pathogens usually
colonize cattle asymptomatically.
• STEC can survive for prolonged periods of time outside its host in
environments such as water, produce, and farm soil. Several factors involved
in biofilm formation such as curli, cellulose, poly-N-acetylglucosamine, and
colanic acid are involved in plant colonization and adherence to different
surfaces often found different at processing plants. In food processing plants,
contamination of beef carcasses occurs at different stages of processing and
this is often caused by the formation of STEC biofilms on the surface of
several pieces of equipment associated with slaughtering and processing.
• Biofilms protect bacteria against several challenges, including biocides used
in industrial processes. STEC biofilms are less sensitive than planktonic cells
to several chemical sanitizers such as quaternary ammonium compounds,
peroxyacetic acid, and chlorine compounds.
• Increased resistance to sanitizers by STEC growing in a biofilm is likely to be
a source of contamination in the processing plant.
Shiga-toxinproducing E. coli

7. Botulism outbreaks in natural environments
• Clostridium botulinum comprises adverse group of botulinum
toxin-producing anaerobic rod-shaped spore-forming bacteria
that are ubiquitously distributed in soil sand aquatic sediments.
• Decomposition of plants, algae, and animals create anaerobic
environments that facilitate growth of C. botulinum, which may
then enter into food webs leading to intoxication.
• We also outline cases involving specific environments and their
biota. In wetlands, it has been found that some C. botulinum
strains can associate with toxin-unaffected organisms—
including algae, plants, and invertebrates—in which the bacteria
appear to germinate and stay in the vegetative form for longer
periods of time.
• We suggest the need for future investigations to resolve issues
related to the environments in which C. botulinum spores may
accumulate and germinate, and where the vegetative forms may
multiply.
Clostridium botulinum

8. Potential role of bacteria packaging by protozoa in the
persistence and transmission of pathogenic bacteria
• Many pathogenic bacterial live in close association with protozoa. The unicellular
eukaryotic microorganisms are ubiquitous in various environments. A number of
protozoa such as amoebae and ciliates ingest pathogenic bacteria, package usually in
membrane structures.
• Packaged bacteria are more resistant to various stresses and are more apt to survive
than free bacteria. New evidence in indicates that protozoa and not bacteria control
the packaging process. It is possible that packaging is more common than suspected
and may play a major role in the persistence and transmission of pathogenic bacteria.
• To confirm the role of packaging in the propagation of infections, it is vital that the
molecular mechanisms governing the packaging of bacteria by protozoa be identified
as well as elements related to the ecology of this process in order to determine
whether packaging acts as a Trojan Horse.

9. CONCLUSION
• When thinking about bacterial pathogens, most will consider the interaction with
humans. Nevertheless, many pathogens affecting humans will not be transmitted
directly from one individual to another but will rather come from or transit through the
environment to infect the human host.
• Outside their hosts, bacterial pathogens must be able to resist environmental stresses and
perhaps grow in order to get to another hosts. The environment outside the host is
referred the rein as the non-clinical environment(NCE).
• In this research topic, a collection of articles is presented that covers some of the
strategies and factors that influence the survival and growth of bacterial pathogens in the
NCE, and therefore affects transmission to humans, and outbreaks. Such knowledge
could be important to limit the transmission during an outbreak.

10. REFERENCES
• Medical Microbiology – Murray, 7th edition
• www.acmicrob.com/microbiology/the-effects-of-berberine-onclostridium-
perfringens-inducednecrotic-enteritis-in-broiler-chickens.php?aid=19249
• https://www.ncbi.nlm.nih.gov/pubmed/?term=Nigam%20A%5BAuthor%5D&cauth
or=true&cauthor_uid=20418969
• www.rroij.com/open-access/bacterial-biofilm-its-composition-formation-and-role-
in-human-infections.php?aid=61426
• https://www.researchgate.net/publication/230691609_Effects_of_protozoa-
bacteria_interactions_Protozoa_and_plant_growth_trophic_links_and_mutualism

11. THANK YOU
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