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SSM Newsletter
December 2016 -The Newsletter of the Sri Lankan Society for Microbiology -Issue 08
Content
President’s greetings
Annual Scientific Sessions of the Sri Lankan Society
for Microbiology –Program Schedule
Annual Scientific Sessions of the Sri Lankan Society
for Microbiology –Report
Sri Lankan Journal of Infectious Diseases
Sri Lankan Society for Microbiology -Jaffna chapter
Unusual Microorganisms in Water Ashaolu Joshua Tolulope
Members News
SSM Council members
Contact details
Annual subscription for membership
Greetings from the President SSM
Dear members of the Sri Lankan Society for Microbiology
It seems a long time since we were able to send out a newsletter from SSM and I apologize for
this lapse. As you would remember, one of the key reasons for the existence of SSM is to
create ‘spaces’ for interaction of its members. Through meetings, workshops and the Annual
conference, face to face meetings occur. However, technology has allowed us to interact
though many ‘virtual’ spaces. SSM has a member Gmail group, Facebook page and web site
(www.ssmlk.lk). The newsletter is yet another means through which we can communicate with
one another. All these allow us to inform, discuss and debate topics of interest. They also help
us by letting us know what is being done in the field of microbiology in Sri Lanka and
elsewhere. However, for us to succeed in these interactions, we need participation of our
members! We need you to access SSM Facebook site and the website. We need your
constructive criticisms and comments. We also need your inputs. We can inform our
membership of meetings and workshops if you let us know. We can publicize events held in
your places of work which are of interest to our membership. We can also publish your views,
comments and short articles of interest.
We would welcome those who are willing to be part of the newsletter team to join us. Please
contact me ([email protected]) if you want to be part of the Editorial team. Our
aim is to produce quarterly newsletters. Members of the team will need to work together to
obtain material for each of the newsletters, edit material as required and put together the final
product. All this can be done on-line. If you feel this ‘job description’ excites you, do please
contact me, so that we can start work on the next newsletter!!
Prof. Vasanthi Thevanesam
President SSM
SSM 3rd Annual Conference and Scientific Sessions 2016
Programme
8.00 am – 8.20 am Registration
8.20 am – 8.30 am Welcome Address – Prof Vasanthi Thevanesam President/SSM
Introduction of Keynote speakers – by Prof. V Thevanesam
8.30 am – 9.00 am Keynote Address 1 –Prof NP Sunil Chandra
Senior Professor and Chair,
University of Kelaniya
Immune Dissection into Gamma Herpes Virus Infections
9.00 am – 9.30 am Keynote Address 2 – Prof Tuck Weng Kok
Professor,
University of Adelaide, Australia
The Emergence of HIV- The Current of the Play
9.30 am – 10.00 am Keynote Address 3- Prof Vasanthi Thevanesam
Professor of Emirates,
University of Peradeniya
Scientific Writing-It Is a Chore
10.00 am-10.05 am Vote of Thanks – Mr S Syanthooran/Secretary/SSM
10.05 am – 10.30am Tea break and poster sessions
Check out the poster boards while enjoying your tea
10.00 am – 11.30 am Scientific Session 1 – Viral, Vector-Borne and Parasitic Infections
Chair – Dr S Wickramasinghe and Prof Sunil Chandra
11.30 am – 12.20 am Scientific Session II –Antimicrobial Activity and Resistance Pattern
Chair – Dr V Liyanapathirana and Dr Wasana Kudagammana
12.20 pm –1.30 pm Lunch – please check out the poster boards
1.30 pm – 2.30 pm Scientific Session III – Bacterial, Fungal Infections and Environment
Chair – Dr M Abeywaradane and Dr Anu Dissanayake
2.30 pm – 2.40 pm Remarks – Dr F Noordeen -SSM-2016
2.40 pm – 3.40 pm Meeting the Expert Sessions – SSM 2016
3.40 pm- 4.30 pm Afternoon Tea
Annual Scientific Sessions of the Sri Lankan Society for Microbiology 2016 - Report
The Annual Sessions of the Society was successfully held at Oak Ray Regency Hotel, Kandy on the 21st of
October 2016. The program consisted of 3 keynote lectures, 20 free papers and 12 poster presentations.
Prof NP Sunil Chandra, Senior Professor and Cadre Chair, Department of Microbiology, Faculty of Medicine,
University of Kelaniya spoke on ‘Immune dissection into gamma herpes virus infections’. Prof Tuck Weng
Kok, Professor, University of Adelaide, Australia gave a fascinating account of ‘The emergence of HIV – the
current state of the play’. As 3rd Key note Speaker, Prof V Thevanesam, Professor Emeritus, University of
Peradeniya addressed particularly the younger members of the audience on ‘Science writing – Is it a chore?’
The free papers and posters covered a wide area of vector borne parasitic and viral infections, antimicrobial
activity of natural products and detection of microbes and their products in clinical disease, food and
interestingly, even in bats!!
The conference was well attended with 90 participants. SSM is a society which creates spaces for interactions
of scientists from many disciplines and the conference amply played this role, with many discussions taking
place during the tea and lunch breaks.
An interesting addition to the conference in 2015 was an interactive session titled ‘Meet the Experts’, where
participants at the conference had an opportunity to spend time with senior colleagues. This has proved to be a
tremendous success and many participants availed themselves of the opportunity to discuss their areas of
interest with experts in environmental microbiology, clinical microbiology and virology.
The Conference committee, headed by Dr Faseeha Noordeen and ably assisted by Dr Susiji Wickremasinghe,
Ms Nadeera Sirisena and many others are to be congratulated and thanked for their effective organization
which involved hours of hard work.
Having successfully completed the Fifth Annual Scientific Sessions of the Sri Lankan Society, we will start
preparations for the Sixth Annual Scientific Sessions which will be held in October 2017. We do hope that all
those who participated this year and those who could not will look forward to this conference and help us to
further expand the space for interdisciplinary interactions.
Vasanthi Thevanesam
Faseeha Noordeen
Meeting the Expert
Meeting the experts
Sri Lankan Journal of Infectious Diseases (ISSN 2012-8169 (Print) 2448-9654 (Online) is the official journal of the Sri Lankan Society for Microbiology (SSM), a multi-disciplinary association of those with an interest in microbiology. Published biannually at present, the journal provides a peer-reviewed medium for communication of findings and perspectives among the professional disciplines involved in the specialist field of Infectious Diseases. Its purpose is to expand knowledge of infectious diseases in order to prevent infection-related illness. The journal’s information available at http://sljid.sljol.info/. Current Issue is Volume 6 - Issue 2 – 2016.
Table of Contents- Volume 6 - Issue 2 - 2016
Editorial Vasanthi Thevanesam 1
Perspectives
Antimicrobial Resistance (AMR) is a key global health challenge. While numerous strategies have been put forward by different organizations to combat this problem, identification of locally relevant issues that drive resistance and addressing them would be the key to success.
V Liyanapathirana and V Thevanesam 72-82
Research Articles Spatial and seasonal analysis of human leptospirosis in the District of Gampaha, Sri Lanka
TH Denipitiya, V Chandrasekharan, W Abeyewickreme, S Viswakula, M Hapugoda 83-93 Clinical manifestations and microbiology of Shigella diarrhoea in children admitted to Teaching Hospital, Jaffna, Sri Lanka
MG Sathiadas, FN Mubarak, SK Arulmoli 94-100
Community acquired pneumonia due to Legionella pneumophila in a tertiary care hospital BN Dissanayake, DE Jayawardena, CG Senevirathna, TM Gamage 101-105
A descriptive analysis of clinico-demographic features and microbiological results of typhoid fever suspected patients in four large hospitals of Bhutan
T Tshokey, N Tshering, K Wangchuk, R Sharma, A Mongar, T Dorji, S Wangchuk, D Damcho, K Wangdi 106-113
Consumption of human rabies immunoglobulin (HRIG) for major animal bites in government hospitals of Sri Lanka.
WDNL Amarasinghe, O Wimalaratne, S Nanayakkara, TKGS. Sumathipala, MGK. De Costa 114-118
Short Reports Molecular diagnostics in a tuberculous patient with clinical non response to standard treatment TP Keerthirathne, DK Weerasekera, DN Magana-Arachchi, NLA Dissanayake 119-125
Validation of rapid tests to detect urinary tract infection K Manoharan, T Kumanan, K Murugananthan 126-129
Case Reports Treatment of Autoimmune Haemolytic Anaemia with Hepatitis C Virus-A Real Challenge A Basu, D Nidhi, R Mehebubar, R Yogiraj, G Rama Prosad 130-133
Sri Lankan Journal of Infectious Diseases
Office bearers of the Jaffna Chapter President
Prof. G. Mikunthan
Department of Agricultural Biology, Faculty of Agriculture, UOJ
Email: [email protected]
Vice –President
Dr (Mrs) K. Murugananthan
Division of Microbiology, Faculty of Medicine, UOJ
Email: [email protected]
Secretary
Dr (Mrs)T. Thileepan
Unit of Siddha Medicine, UOJ
Email: [email protected]
Treasurer
Dr (Miss) R. Shivatharshini
Department of Chemistry, Faculty of Science, UOJ
Email: [email protected]
Editor
Mr. M. Pratheesh
Unit of Allied Health Sciences, Faculty of Medicine, UOJ
Email: [email protected]
Committee Members
Dr (Mrs) M. G. Sathiadas
Department of Pediatric, Faculty of Medicine, UOJ
Dr (Mrs) T. Navaratinaraja
Department of Pharmacology, Faculty of Medicine, UOJ
Dr. S. Kannathasan
Division of Parasitology, Faculty of Medicine, UOJ
Dr. T. Manoranjan
Department of Chemistry,Faculty of Science, UOJ
Dr. A. Murugananthan
Division of Parasitology, Faculty of Medicine, UOJ
Mrs. T. Gnanakarunyan Unit of Allied Health Sciences, Faculty of Medicine, UOJ
The Jaffna Chapter has been very active over the past 3 months. Some of their key activities included a live telecast on “Makkal Mandram” program which was aired in DAN TV on 11.6.2016 at 10.00 pm under the title of “Environment and Microbes”. SSM members Prof. G. Mikunthan, Dr. (Mrs.) T. Thileepan and Dr. (Miss) S. Rasalingam contributed to the programme which was well delivered with useful discussions with the audience.
Prof G. Mikunthan contributed an article about SSM which was published in the Valampuri Newspaper on 12.6.2016.
On the 30th of July 2016, Prof. Tim Inglis from the School of Pathology and Laboratory Medicine, University of Western Australia gave a guest lecture on “Emergence, Spread and implementation of antimicrobial resistance” at the Auditorium of Medical Students Hostel, Jaffna.
Dr. (Miss.) Shivatharsiny Rasalingam, Senior Lecturer in Chemistry delivered a lecture on “Extraction techniques for medicinal plants” at the Auditorium of the Unit of Siddha Medicine, University of Jaffna on the 14th of November 2016. This programme was well attended and appreciated by those
who were present. Extraction techniques for Medicinal plants Medicinal plants have been identified as the natural sources for producing medicines. These plants make many chemical compounds, which consist primary and secondary metabolites. The primary metabolites, such as carbohydrate, lipid, protein, chlorophyll, and nucleic acids are produced by all the plants and involve in the primary metabolic processes of building and maintaining plant cells. A smaller range of plants produce secondary metabolites, which have historically been defined as chemicals that are not involved in the process of building and maintaining plant cells. However, recent research has shown a pivotal role of these chemicals in protecting plants from herbivores and microbial infection. Although secondary products have a variety of functions in plants, they also contain beneficial medicinal effects for human. In modern times, secondary metabolites are used to prepare dyes, glues, oils, waxes, flavoring agents, drugs, and perfumes in industries and they are viewed as potential sources of new natural antibiotics. A wide range of technologies is available for the extraction of active components and essential oils from medicinal and aromatic plants. The extracts obtained from plants are relatively complex mixtures of metabolites, in liquid or semisolid state or in dried powder (after removing the solvent) form. The purpose of extraction procedures for crude drugs is to obtain the therapeutically wanted portions. An extract may be further processed through various techniques of fractionation to isolate individual compounds. The various processes of production of medicinal plant extracts will be discussed in this talk.
An “Awareness program on Dengue” with several resource persons and coordinated by Dr (Mrs) K. Murugananthan is being planned for December 2016.
Several activities are being planned for 2017. Talks on Antimicrobial activities of plants, microbial
bioagents and their importance and ‘Living Soil’ will be scheduled in the early part of the year. There will be
a workshop on ‘Screening antimicrobial activity from natural products’. In addition, programmes for school
teachers including the handling of equipment in microbiology laboratories are being planned. We hope to
conduct public awareness programmes on the use of antibiotics and training programmes for farmers.
Future Plans of the Jaffna Chapter-2017
Message from Jaffna Chapter; Any member who is interested in being
part of the Jaffna Chapter please
email us and let us know. We would
greatly appreciate new input and the
active participation of members.
Abstract of lecture
Introduction
Constituting about 71% of the earth’s surface,
with the oceans occupying about 96.5%, water is
supposed to be a colorless, transparent, odorless,
liquid which forms the seas, lakes, rivers, and rain and
is the basis of the fluids of living organisms. Water is
vital to life but only 3% of available surface water is
suitable for drinking, cooking and ordinary use.
However, none of this 3% would be appropriate for
use in research industries to process drugs and
biological foods without being treated. This is largely
due to certain microorganisms found in water. Water
can be grouped, depending on the source. With the
exception of the sea, surface waters can be regarded as
a mixture of ground, spring, rain and waste waters.
They represent the most important biotype for an
extreme variety of life on earth. Potable water is often
intended for drinking or cooking purposes. Precipitates
like rain, are merely the waste water of the air.
Microbes are generally referred to as
microscopic i.e. small organisms, which may be
single-celled or multi-celled. Microorganisms are very
diverse and include all the bacteria and archaea and
almost all the protozoa. The single cells may be
prokaryotic or eukaryotic. The prokaryotic microbes
include bacteria and the archaea. The eukaryotic
microbes include the protozoa, fungi and certain
unicellular algae. They also include some animals such
as rotifers. Many macro animals and plants have
juvenile stages which are also microorganisms. Some
microbiologists also classify viruses as
microorganisms, but others consider them as
nonliving. Thus, viruses are considered as mesobiotic
agents or acellular organisms. Most microorganisms
are microscopic, but there are some bacteria such as
Thiomargarita namibiensis and some protozoa such as
Stentor, which are macroscopic and visible to the
naked eye.
Human and animal wastes are a primary
source of microorganisms in water. Additional sources
include seepages or discharges from septic tanks,
sewage treatment facilities and natural soil/plant
bacteria. Common pathogens like Shigella
dysentariae, Escherichia coli, Vibrio choleriae,
Hepatitis B virus and Salmonella typhi could cause
intestinal infections, dysentery, hepatitis, typhoid
fever, cholera and other illnesses.
1Interdisciplinary Graduate School of Nutraceutical
and Functional Food Research and Development
Center (IGS-NFF). 9th Floor, LRC Building, Prince of
Songkla University, Kanchanawanich road, Hat-Yai,
Songkhla, Thailand, 90112 Tell: (+66)-95-6188337
It has been observed that some nitrogen-
fixing, airborne microorganisms which are essential in
the nitrogen cycle may play a role in precipitation and
weather. Major oxidative processes involved in
sewage treatment are characterized by the activities of
some oxidizing microorganisms which digest certain
hydrophilic organic constituents because they would
not sediment. Anaerobic microorganisms which
include methanogens are also used to reduce sludge
solids producing methane gas (amongst other gases)
and a sterile mineralized residue. In potable water
treatment, one method, the slow sand filter, employs a
complex gelatinous layer composed of a wide range of
microorganisms to remove both dissolved and
particulate material from raw water.
Extremophiles are microorganisms that have
adapted so that they can survive and even thrive in
conditions that are normally fatal to most life-forms.
In hostile environments such as the poles, deserts,
geysers, rocks, and the deep sea, some types of
microorganisms have adapted to the extreme
conditions and sustained colonies. Extremophiles are
significant in different ways. They extend terrestrial
life into much of the Earth's hydrosphere, crust and
atmosphere, their specific evolutionary adaptation
mechanisms to their extreme environment can be
exploited. Extremophiles have been isolated from
rocks as many as seven kilometers below the earth's
surface. Extremophiles have also been known to
survive for a prolonged period in a vacuum, and can
be highly resistant to radiation, which may even allow
them to survive in space. This review considers
bacteria, amongst other unusual microorganisms.
Weird Shaped Bacteria
Most bacteria are characteristically circular or
rod-like in shape, not square, with sharp corners. In
1980, a scientist found square bacteria with sharp
corners in concentrated salt solutions. In most bacteria
such a shape would be precluded by the osmotically-
generated internal hydrostatic pressure but this
organism, found in a saturated brine pool, has little or
no cell turgor pressure.1 Its shape is probably
determined by the pattern in which the cell envelope
particles assemble. They are not only square, but very
thin - about 200 nm (0.2 μm) thick. They were
observed to grow as two dimensional objects,
increasing the size of their squares, but not their
thickness. Their thinness increases their surface to
volume ratio which may be important in helping them
to maintain a proper intracellular environment. The
square bacteria are archaea (archaebacteria were
considered a type of bacteria at the time). They have
subsequently been named Haloquadratum walsbyi,
after the British scientist who discovered them. The
Unusual Bacteria in Water Ashaolu Joshua Tolulope1
squares derive buoyancy from their gas vacuoles and
float at the brine surface. The first successful
cultivation of Walsby’s square bacteria was achieved
in 2004, something that scientists had failed to achieve
since they were first discovered in 1980. The bacteria
are the most numerous type of cell found in salt lakes
and are believed to be responsible for their
characteristic red color (for example, Pink Lakes in the
Murray-Sunset National Park, Victoria). Unusually,
they are perfectly square in shape, appearing like small
tiles when viewed under the microscope.2 It is not
known yet why they are square or how they achieve
their squareness.
Extreme heat-loving bacteria
Discoveries of the archaea, and of a new
geological phenomenon, the deep sea thermal vent
around 1977, suggested 60 °C as the highest
temperature (Tmax) in which life can thrive which is the
temperature for growth of Bacillus
stearothermophilus. Later, the known Tmax increased
to about 113 °C, and subsequently to 121 °C. This
increase in known Tmax for life is not simply an
abstract story of some biological limit, but is part of a
broad series of major advances in both biology and
geology. Thermus aquaticus has a maximum growth
temperature of about 80 °C. It was isolated from hot
springs in Yellowstone National Park, and was
reported in 1969. Thermus aquaticus is considered as
the organism that ushered in the new era of the
commercialization of enzymes from thermophiles due
to its heat stability property. On this principle "Taq"
DNA polymerase was made, and is widely used in the
polymerase chain reactions (PCR). Pyrolobus fumarii
was also discovered in the vents as a
hyperthermophilic archaea in 1997, and has been
widely accepted as having the highest known Tmax. It
grows up to 113 °C. In 2003, it was reported that an
archaeon could grow at 121 °C - the normal operating
temperature of an autoclave commonly used to kill
even the most resistant forms of life. This iron-
reducing microorganism has been dubbed simply
Strain 121 for now.
Guinness book bacterium
Deinococcus radiodurans is famous for
radioresistance, surviving cold, dehydration, vacuum,
and acid, and is therefore known as a
polyextremophile and has been listed as the world's
toughest bacterium in The Guinness Book of World
Records.3 D. radiodurans is a rather large, spherical
bacterium, with a diameter of 1.5 to 3.5 µm. Four cells
normally stick together, forming a tetrad. It is an
obligate aerobic chemoorganoheterotroph, i.e., it uses
oxygen to derive energy from organic compounds in
its environment. It is often found in habitats rich in
organic materials, such as soil, feces, meat, or sewage,
but has also been isolated from dried foods, room dust,
medical instruments and textiles. The bacterium seems
to live everywhere and nowhere. It has been found in
environments as diverse as elephant dung and granite
in Antarctic dry valleys (the environment on Earth
thought to most closely resemble Mars), but no one
really knows what the microbe's natural habitat is. It is
believed that D. radiodurans will prove useful in
cleaning up toxic waste and testing hypotheses about
life in extreme environments, among other things. A
persistent question regarding D. radiodurans is how
such a high degree of radio-resistance could
evolve.4,5,6
Magnetotactic Microorganisms
In 1975, Richard P. Blakemore discovered
“Magnetotactic bacteria” (or MTB), which are a
polyphyletic group of bacteria that orient along the
magnetic field lines of Earth's magnetic field. To
perform this task, these bacteria have organelles
called magnetosomes that contain magnetic crystals.
Each of these particles is a magnet with a north pole
and a south pole. The bacteria arrange these tiny
magnets in a line to make one long magnet. They use
this magnet as a compass to align themselves to the
earth's geomagnetic field. MTB exhibit
microaerophilic characteristic, thus prefer low or no
oxygen to high oxygen concentration. In an aquatic
environment, the level of oxygen decreases with
depth, suggesting why the magnetotactic bacteria live
in the deeper parts of their aquatic environments.
They use their magnetic compass to tell them which
way is down. They do this with the direction of the
geomagnetic field. In the Northern Hemisphere; the
geomagnetic north actually points down at an angle.
So, magnetotactic bacteria that are aligned to this
field are also pointing down. By moving north along
this field, they move deeper into the water, and into
areas with less oxygen. In the Southern Hemisphere,
the geomagnetic north actually points up and at an
angle. So, magnetotactic bacteria in this half of the
world are "south-seeking", which points them
downward. At the equator, the geomagnetic north
doesn't point up or down, so the magnetotactic
bacteria found there is a mixture of north-seeking and
south-seeking bacteria. Blakemore’s originally
isolated MTB was Magnetospirillum. It is Gram-
negative and microaerophilic. It is characterized by a
spirillar, or helical, morphology. It’s polar flagellum
at each end also facilitates its motility. The species
studied so far include Magnetospirillum
magnetotacticum strain MS-1; Magnetospirillum
gryphiswaldense 7 which was previously classified as
Aquaspirillum magnetotacticum; Magnetospirillum
magneticum strain AMB-1; and Magnetospirillum
bellicus. It prefers an oxygen gradient of
approximately 1–3%, in a shallow fresh water
habitat. A more recent MTB studied is Magnetobulus
spp.7-9
Uncommon sizes
Microorganisms (especially bacteria) are
generally known to be small. However, some scientists
have found an archaeon smaller than any cellular
organism previously known, about 200 nm (0.2 μm) in
diameter. It was claimed that there are tiny bacteria
involved in such processes as calcification of arteries,
though not yet confirmed. These bacteria, which have
been termed nanobacteria, are alleged to be even
smaller than the archaeon described. They seem to be
complexes of certain calcium minerals and proteins.
They were identified in humans, animals, wastewater
and the stratosphere. In South Africa they were
detected in people infected with HIV. Experiments
showed that they are excreted via urine, explaining
their presence in the environment. Eradication would
be virtually impossible if they had an extraterrestrial
origin, implying a permanent bombardment from
space. Shotgun sequencing, a technique which was
used to sequence the human genome recently, was
used to study these nanobacteria biofilms on the acidic
mine drainage deep underground from the Richmond
Mine at Iron Mountain, California.10 It has been
classified to a totally new phylum of Archaea,
microorganisms that have been around for billions of
years. The water is almost as acidic as battery acid,
with a pH of about 1.
Certain bacteria found in water are also much
bigger than the normal size of a bacterium which may
be about 1 micrometer. Epulopiscium (first reported
in 1999) and Thiomargarita (first reported in 1985)
are bacteria big enough to be seen with the naked
eye.11 Their size is approximated to be reaching 1
millimeter. Epulopiscium grows in the gut of certain
surgeonfish. It has a complex life cycle, which is
coordinated with the daily rhythm of its host. They
were initially classified as protists on the basis of their
large size, until ribosomal RNA analysis was done.
Thiomargarita (T. namibienus “Sulfur pearl of
Namibia”) reached sizes up to 750 microns. Typical
bacterial physiology prevented them from ever getting
so big. Their size is due to a large vacuole in their
cells, in which they store nitrate, as do some
hydrothermal vent microbes, to survive periods when
oxygen is lacking underwater. Thiomargarita uses
nitrate ions in its respiration, rather than oxygen gas;
the vacuole is a supply of nitrate that lets the bug
continues to respire at great depths.
Bacteria with Several Cells
Some bacteria manifest certain levels of
complexity rather than being simple single-celled.
Myxobacteria are widely distributed in soil and
oceanic sediment with a phylogeographic separation at
high levels of classification. However, it is yet unclear
whether myxobacteria are found in fresh water
habitats. The myxobacteria probably have the most
complex bacterial life cycle. They spend part of their
life as free-living individual bacterial cells, then
aggregate to form a fruiting body, an organized
multicellular structure visible to the naked eye. In fact,
their life cycle is rather similar to that of the cellular
slime molds, such as Dictyostelium - the
myxomycetes.12
Communicating Microorganisms
Certain bacteria use some signaling
molecules to pass messages such as light emission, as
found in Vibrio fischerii. This phenomenon is called
bioluminescence. To do this, they need an "inducer"
which is a substance that turns on the light-producing
system. They make an inducer, and secrete it into the
external environment. They then take it up from the
environment. Some fish cultivate these bacteria in a
special pouch, called a light organ. The light organ
emits light only when it contains enough bacteria to do
so usefully. The phenomenon discussed above is often
called quorum sensing. The bacteria check to see if a
quorum is present before emitting light. Common
classes of signaling molecules involved in quorum
sensing are oligopeptides in Gram-positive bacteria,
N-Acyl Homoserine Lactones (AHL) in Gram-
negative bacteria, and a family of autoinducers known
as autoinducer-2 (AI-2) in both Gram-negative and
Gram-positive bacteria. The purpose of these
molecules is for the bacteria to communicate their
population size to their own kind. But more broadly,
bacteria signal their presence and numbers to other
types of bacteria too.13,14 Bacteria use quorum sensing
to coordinate certain behaviors such as biofilm
formation, virulence, and antibiotic resistance, based
on the local density of the bacterial population.
Examples of such bacteria are Vibrio fischeri,
Salmonella enterica, Escherichia coli, Acinetobacter
sp. Aeromonas sp, Yirwinia, and Pseudomonas
aeruginosa. Archeon Methanosaeta harundinacea
6Ac, is another example.15
Certain Uncommon Organisms Found In Potable
Water
Legionella pneumophila is a thin, aerobic,
pleomorphic, flagellated, non-spore forming, and
Gram-negative bacterium of the genus Legionella. L.
pneumophila was named after an American Legion
convention in 1976 where it was responsible for 34
deaths and a total of 221 infections. This suggested the
nomenclature of legionellosis or Legionnaires' disease.
It is an aerobic bacillus with a single, polar flagellum
often characterized as being a coccobacillus; and
unable to hydrolyze gelatin or produce urease. It is
also non-fermentative. L. pneumophila is neither
pigmented nor does it autofluoresce. It is oxidase
positive and catalase-negative, and produces beta-
lactamase. L. pneumophila has a colony morphology
that is gray-white with a textured, cut-glass
appearance; it also requires cysteine and iron to thrive.
It will grow on yeast extract in "opal-like"
colonies.16,17
Conclusion
There are far more findings to be made on
bacteria associated with different water forms.
Although some of them have been studied and well
researched by scientists, yet, there seems to be
unlimited issues to be further unraveled. Certain
characteristics are exhibited by some bacteria which
make them unusual – ranging from simplicity to
complexity in sizes, shapes, genes, number, symbiotic
associations and certain dynamism of their choice of
habitat and life cycle.
Conflict of Interest
I hereby declare that I have no conflict of interest on
this article.
References
1. Walsby E. 1980. Marine Science Laboratories,
Menai Bridge, Gwynedd, UK Nature 283: 69 – 71.
2. David, G. B., Peter, H. J., Takashi, I., et al. 2004.
Cultivation of Walsby’s square haloarchaeon
FEMS Microbiology Letters, 238: 469-473.
3. Battista, J. R. 1997. Against all odds: the survival
strategies of Deinococcus radiodurans. Annual
Review of Microbiology, 51: 203–24.
4. DeWeerdt, S. E. 2002. The World’s Toughest
Bacterium Deinococcus radiodurans may be a tool
for cleaning up toxic waste and more. Genome
News.
5. Kim, J. I., Sharma, A. K., Abbott, S. N. et al.
2002. RecA Protein from the extremely radio-
resistant bacterium Deinococcus radiodurans:
expression, purification, and characterization. J
Bacteriol 184: 1649-1660.
6. Makarova, K. S., Aravind, L., Wolf, Y. I., et al.
2001. Genome of the extremely radiation-resistant
bacterium Deinococcus radiodurans viewed from
the perspective of comparative genomics.
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Members News
The American Society for Microbiology hosted its first Agar Art Competition in 2015. With the help of Prof. Jennifer Perera and the staff of the Department of Microbiology at the University of Colombo, Dharshika Jayasooriya was able to submit an entry called “The Violet Louis Pasteur”. A portrait of the renowned chemist and microbiologist Louis Pasteur was plated on Muller Hinton agar with Chromobacterium violaceum. Dharshika writes ‘This was my first attempt in using bacteria to paint, after a lot of trials on cell density, incubation conditions and plating techniques I was able to come up with his portrait. The second submissions for the contest in 2016 was more focussed on our Sri Lankan culture and heritage. The submission included the entries “ The Noble Tusker” based on the Kandyan Raja elephant of the Sri Dalada Maligawa annual perehara and “ Unseen Devil” a depiction of the Raksha mask used in traditional dance dramas better known as devil dancing in Sri Lanka. Both submissions used the organism with Chromobacterium violaceum, Staphylococcus aureus and a Micrococcus sp. on blood agar. http://www.microbeworld.org/component/jlibrary/?view=article&id=14231 https://www.facebook.com/asmfan/photos/a.10154367491515200.1073741836.62453295199/10154367522665200/?type=1&theater https://www.facebook.com/asmfan/photos/a.10155021120285200.1073741837.62453295199/10155021164290200/?type=3&theater
Prof. S.B. Agampodi – Professor in Community Medicine, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka delivered the Sir Marcus Fernando Oration during the Foundations Sessions of Sri Lanka Medical Association, 2016.
The title was “Etiological Agents causing human leptospirosis in Sri Lanka. The oration was based on series of studies done in Kandy, Kegalle, Matale and Anuradhapura using serological and molecular methods for culture independent identification of leptospira. In addition, a systematic review to describe and summarize the 50 years work in Sri Lanka on identification of causative agent was also included as a part of this oration.
On the 15th of November 2016, Suneth delivered the Vicenzo Marcolongo lecture at the 65th Annual Meeting of the American Society of Tropical Medicine and Hygiene at Atlanta, Georgia. This lecture is one of the four keynote speeches in the world’s largest conference on tropical medicine. Established in 1990, every year an eminent researcher outside USA is invited to talk about a tropical disease and his or her contribution to the particular area of research. This was the first time a Sri Lankan researcher was invited to deliver this lecture. The lecture was on the challenge of leptospirosis in tropical countries.
Annual subscription for 2016
SSM Council Members
President Prof. Vasanthi Thevanesam
Department of Microbiology, Faculty of
Medicine, University of Peradeniya.
Tel : +94812396541, +94773157451
Email: [email protected]
Council Members Dr. Faseeha Noordeen
Department of Microbiology,
Faculty of Medicine, University of
Peradeniya
Tel : +94812396541
Vice President Prof. Jennifer Perera
Department of Microbiology, Faculty of
Medicine, University of Colombo
Tel : +94112697513
Email: [email protected]
Prof. Sunil Chandra
Department of Medical Microbiology,
Faculty of Medicine, University of
Kelaniya.
Tel : +94 112961137
Email: [email protected]
Secretary Mr. Sayan Saravanabavan
Cell Biology Project, National Institute of
Fundamental Studies, Kandy
Tel : +94778768706
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Dr. Enoka Corea
Faculty of Medicine, University of
Colombo.
Tel : +94 011 2697513
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Prof. Nadira Karunaweera
Department of Parasitology, Faculty of
Medicine, University of Colombo.
Tel : +94112699284,
Email: [email protected]
Editor Prof. Vasanthi Thevanesam
Assistant Treasurer Dr. Susiji Wickramasinghe
Department of Microbiology, Faculty of
Medicine, University of Peradeniya.
Tel : +94812396541
Email: [email protected]
Contact details
Sri Lankan Society for Microbiology
Department of Microbiology,
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University of Peradeniya,
Peradeniya
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Annual Subscriptions for membership SSM Members are requested to submit their annual subscription for 2016 (Rs 1000). Subscriptions can be directly paid into the following account. Please send the receipt of your payment with your details (including SSM membership no.) to, Dr. Susiji Wickramasinghe, Department of Parasitology, Faculty of Medicine, University of Peradeniya. Keep a copy of your receipt!
Account No: 026212016510 Name: The Sri Lankan Society for Microbiology Bank: Nations Trust Bank Branch: Peradeniya Branch
