Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

Users Online : 55652

AbstractMaterial and MethodsDiscussionConclusionAcknowledgementReferencesTable and Figures
Readers' Comments (0) Article in PDF Audio Visual Citation Manager Article Statistics Link to PUBMED Print this Article Send to a Friend
Advertisers Access Statistics Resources

Dr Bhanu K Bhakhri

"The Journal of Clinical and Diagnostic Research (JCDR) has been in operation since almost a decade. It has contributed a huge number of peer reviewed articles, across a spectrum of medical disciplines, to the medical literature.
Its wide based indexing and open access publications attracts many authors as well as readers
For authors, the manuscripts can be uploaded online through an easily navigable portal, on other hand, reviewers appreciate the systematic handling of all manuscripts. The way JCDR has emerged as an effective medium for publishing wide array of observations in Indian context, I wish the editorial team success in their endeavour"



Dr Bhanu K Bhakhri
Faculty, Pediatric Medicine
Super Speciality Paediatric Hospital and Post Graduate Teaching Institute, Noida
On Sep 2018




Dr Mohan Z Mani

"Thank you very much for having published my article in record time.I would like to compliment you and your entire staff for your promptness, courtesy, and willingness to be customer friendly, which is quite unusual.I was given your reference by a colleague in pathology,and was able to directly phone your editorial office for clarifications.I would particularly like to thank the publication managers and the Assistant Editor who were following up my article. I would also like to thank you for adjusting the money I paid initially into payment for my modified article,and refunding the balance.
I wish all success to your journal and look forward to sending you any suitable similar article in future"



Dr Mohan Z Mani,
Professor & Head,
Department of Dematolgy,
Believers Church Medical College,
Thiruvalla, Kerala
On Sep 2018




Prof. Somashekhar Nimbalkar

"Over the last few years, we have published our research regularly in Journal of Clinical and Diagnostic Research. Having published in more than 20 high impact journals over the last five years including several high impact ones and reviewing articles for even more journals across my fields of interest, we value our published work in JCDR for their high standards in publishing scientific articles. The ease of submission, the rapid reviews in under a month, the high quality of their reviewers and keen attention to the final process of proofs and publication, ensure that there are no mistakes in the final article. We have been asked clarifications on several occasions and have been happy to provide them and it exemplifies the commitment to quality of the team at JCDR."



Prof. Somashekhar Nimbalkar
Head, Department of Pediatrics, Pramukhswami Medical College, Karamsad
Chairman, Research Group, Charutar Arogya Mandal, Karamsad
National Joint Coordinator - Advanced IAP NNF NRP Program
Ex-Member, Governing Body, National Neonatology Forum, New Delhi
Ex-President - National Neonatology Forum Gujarat State Chapter
Department of Pediatrics, Pramukhswami Medical College, Karamsad, Anand, Gujarat.
On Sep 2018




Dr. Kalyani R

"Journal of Clinical and Diagnostic Research is at present a well-known Indian originated scientific journal which started with a humble beginning. I have been associated with this journal since many years. I appreciate the Editor, Dr. Hemant Jain, for his constant effort in bringing up this journal to the present status right from the scratch. The journal is multidisciplinary. It encourages in publishing the scientific articles from postgraduates and also the beginners who start their career. At the same time the journal also caters for the high quality articles from specialty and super-specialty researchers. Hence it provides a platform for the scientist and researchers to publish. The other aspect of it is, the readers get the information regarding the most recent developments in science which can be used for teaching, research, treating patients and to some extent take preventive measures against certain diseases. The journal is contributing immensely to the society at national and international level."



Dr Kalyani R
Professor and Head
Department of Pathology
Sri Devaraj Urs Medical College
Sri Devaraj Urs Academy of Higher Education and Research , Kolar, Karnataka
On Sep 2018




Dr. Saumya Navit

"As a peer-reviewed journal, the Journal of Clinical and Diagnostic Research provides an opportunity to researchers, scientists and budding professionals to explore the developments in the field of medicine and dentistry and their varied specialities, thus extending our view on biological diversities of living species in relation to medicine.
‘Knowledge is treasure of a wise man.’ The free access of this journal provides an immense scope of learning for the both the old and the young in field of medicine and dentistry as well. The multidisciplinary nature of the journal makes it a better platform to absorb all that is being researched and developed. The publication process is systematic and professional. Online submission, publication and peer reviewing makes it a user-friendly journal.
As an experienced dentist and an academician, I proudly recommend this journal to the dental fraternity as a good quality open access platform for rapid communication of their cutting-edge research progress and discovery.
I wish JCDR a great success and I hope that journal will soar higher with the passing time."



Dr Saumya Navit
Professor and Head
Department of Pediatric Dentistry
Saraswati Dental College
Lucknow
On Sep 2018




Dr. Arunava Biswas

"My sincere attachment with JCDR as an author as well as reviewer is a learning experience . Their systematic approach in publication of article in various categories is really praiseworthy.
Their prompt and timely response to review's query and the manner in which they have set the reviewing process helps in extracting the best possible scientific writings for publication.
It's a honour and pride to be a part of the JCDR team. My very best wishes to JCDR and hope it will sparkle up above the sky as a high indexed journal in near future."



Dr. Arunava Biswas
MD, DM (Clinical Pharmacology)
Assistant Professor
Department of Pharmacology
Calcutta National Medical College & Hospital , Kolkata




Dr. C.S. Ramesh Babu
" Journal of Clinical and Diagnostic Research (JCDR) is a multi-specialty medical and dental journal publishing high quality research articles in almost all branches of medicine. The quality of printing of figures and tables is excellent and comparable to any International journal. An added advantage is nominal publication charges and monthly issue of the journal and more chances of an article being accepted for publication. Moreover being a multi-specialty journal an article concerning a particular specialty has a wider reach of readers of other related specialties also. As an author and reviewer for several years I find this Journal most suitable and highly recommend this Journal."
Best regards,
C.S. Ramesh Babu,
Associate Professor of Anatomy,
Muzaffarnagar Medical College,
Muzaffarnagar.
On Aug 2018




Dr. Arundhathi. S
"Journal of Clinical and Diagnostic Research (JCDR) is a reputed peer reviewed journal and is constantly involved in publishing high quality research articles related to medicine. Its been a great pleasure to be associated with this esteemed journal as a reviewer and as an author for a couple of years. The editorial board consists of many dedicated and reputed experts as its members and they are doing an appreciable work in guiding budding researchers. JCDR is doing a commendable job in scientific research by promoting excellent quality research & review articles and case reports & series. The reviewers provide appropriate suggestions that improve the quality of articles. I strongly recommend my fraternity to encourage JCDR by contributing their valuable research work in this widely accepted, user friendly journal. I hope my collaboration with JCDR will continue for a long time".



Dr. Arundhathi. S
MBBS, MD (Pathology),
Sanjay Gandhi institute of trauma and orthopedics,
Bengaluru.
On Aug 2018




Dr. Mamta Gupta,
"It gives me great pleasure to be associated with JCDR, since last 2-3 years. Since then I have authored, co-authored and reviewed about 25 articles in JCDR. I thank JCDR for giving me an opportunity to improve my own skills as an author and a reviewer.
It 's a multispecialty journal, publishing high quality articles. It gives a platform to the authors to publish their research work which can be available for everyone across the globe to read. The best thing about JCDR is that the full articles of all medical specialties are available as pdf/html for reading free of cost or without institutional subscription, which is not there for other journals. For those who have problem in writing manuscript or do statistical work, JCDR comes for their rescue.
The journal has a monthly publication and the articles are published quite fast. In time compared to other journals. The on-line first publication is also a great advantage and facility to review one's own articles before going to print. The response to any query and permission if required, is quite fast; this is quite commendable. I have a very good experience about seeking quick permission for quoting a photograph (Fig.) from a JCDR article for my chapter authored in an E book. I never thought it would be so easy. No hassles.
Reviewing articles is no less a pain staking process and requires in depth perception, knowledge about the topic for review. It requires time and concentration, yet I enjoy doing it. The JCDR website especially for the reviewers is quite user friendly. My suggestions for improving the journal is, more strict review process, so that only high quality articles are published. I find a a good number of articles in Obst. Gynae, hence, a new journal for this specialty titled JCDR-OG can be started. May be a bimonthly or quarterly publication to begin with. Only selected articles should find a place in it.
An yearly reward for the best article authored can also incentivize the authors. Though the process of finding the best article will be not be very easy. I do not know how reviewing process can be improved. If an article is being reviewed by two reviewers, then opinion of one can be communicated to the other or the final opinion of the editor can be communicated to the reviewer if requested for. This will help one’s reviewing skills.
My best wishes to Dr. Hemant Jain and all the editorial staff of JCDR for their untiring efforts to bring out this journal. I strongly recommend medical fraternity to publish their valuable research work in this esteemed journal, JCDR".



Dr. Mamta Gupta
Consultant
(Ex HOD Obs &Gynae, Hindu Rao Hospital and associated NDMC Medical College, Delhi)
Aug 2018




Dr. Rajendra Kumar Ghritlaharey

"I wish to thank Dr. Hemant Jain, Editor-in-Chief Journal of Clinical and Diagnostic Research (JCDR), for asking me to write up few words.
Writing is the representation of language in a textual medium i e; into the words and sentences on paper. Quality medical manuscript writing in particular, demands not only a high-quality research, but also requires accurate and concise communication of findings and conclusions, with adherence to particular journal guidelines. In medical field whether working in teaching, private, or in corporate institution, everyone wants to excel in his / her own field and get recognised by making manuscripts publication.


Authors are the souls of any journal, and deserve much respect. To publish a journal manuscripts are needed from authors. Authors have a great responsibility for producing facts of their work in terms of number and results truthfully and an individual honesty is expected from authors in this regards. Both ways its true "No authors-No manuscripts-No journals" and "No journals–No manuscripts–No authors". Reviewing a manuscript is also a very responsible and important task of any peer-reviewed journal and to be taken seriously. It needs knowledge on the subject, sincerity, honesty and determination. Although the process of reviewing a manuscript is a time consuming task butit is expected to give one's best remarks within the time frame of the journal.
Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
Timely publication of journal: Publication of manuscripts and bringing out the issue in time is one of the positive aspects of JCDR and is possible with strong support team in terms of peer reviewers, proof reading, language check, computer operators, etc. This is one of the great reasons for authors to submit their work with JCDR. Another best part of JCDR is "Online first Publications" facilities available for the authors. This facility not only provides the prompt publications of the manuscripts but at the same time also early availability of the manuscripts for the readers.
Indexation and online availability: Indexation transforms the journal in some sense from its local ownership to the worldwide professional community and to the public.JCDR is indexed with Embase & EMbiology, Google Scholar, Index Copernicus, Chemical Abstracts Service, Journal seek Database, Indian Science Abstracts, to name few of them. Manuscriptspublished in JCDR are available on major search engines ie; google, yahoo, msn.
In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
It is well said that "happy beginning is half done" and it fits perfectly with JCDR. It has grown considerably and I feel it has already grown up from its infancy to adolescence, achieving the status of standard online e-journal form Indian continent since its inception in Feb 2007. This had been made possible due to the efforts and the hard work put in it. The way the JCDR is improving with every new volume, with good quality original manuscripts, makes it a quality journal for readers. I must thank and congratulate Dr Hemant Jain, Editor-in-Chief JCDR and his team for their sincere efforts, dedication, and determination for making JCDR a fast growing journal.
Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."



Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
E-mail: drrajendrak1@rediffmail.com
On May 11,2011




Dr. Shankar P.R.

"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."



Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
E-mail: ravi.dr.shankar@gmail.com
On April 2011

Important Notice

Original article / research
Year : 2012 | Month : August | Volume : 6 | Issue : 6 | Page : 967 - 969

Effect of pH on the Adherence, Surface Hydrophobicity and the Biofilm Formation of Gardnerella Vaginalis

Udayalaxmi, Gopalkrishna Bhat, Subbannayya Kotigadde, Shashidhar Kotian

1. Selection Grade Lecturer, Department of Microbiology, Kasturba Medical College, Manipal University, Mangalore, India. 2. Associate Professor, Department of Microbiology, Kasturba Medical College, Manipal University, Mangalore, India. 3. Professor, Department of Microbiology, KVG Medical College, Sullia, India. 4. Department of Community Medicine, Kasturba Medical College, Manipal University, Mangalore, India.

Correspondence Address :
Dr. J. Udayalaxmi
Selection Grade lecturer, Department of Microbiology,
Kasturba Medical College, Mangalore-575001, India.
E-mail: udayalaxmi68@gmail.com

Abstract

Background: Bacterial vaginosis is a common cause of the abnormal vaginal discharge in women of the reproductive age group. Although bacterial vaginosis is prevalent, not much progress has been made in identifying the factors which are responsible for and those which are associated with bacterial vaginosis and its pathophysiology. Here, we would like to evaluate the effect of the change in the pH of the vagina on the virulence factors of Gardnerella vaginalis, the main organism which has been indicated in this vaginal condition.

Objective: The objective of the present study was to observe the effect of pH on the adherence, surface hydrophobicity and the biofilm formation of 10 strains of Gardnerella vaginalis which were isolated from cases of bacterial vaginosis.

Result: We found that the adherence to the vaginal epithelial cells and the surface hydrophobicity was maximum at a lower pH (pH- 3,4,5) and minimum at a higher pH (pH- 6,7), but the pH did not have a significant effect on the biofilm formation.

Conclusion: An increase in the pH of the vagina which is observed during bacterial vaginosis, probably occurs much later during the disease. During the early part of the disease, the bacteria adhere to the vaginal epithelium, multiply in large numbers and form a thick biofilm which is not affected by the rise in pH, which occurs probably due to the metabolic activities of this large bacterial population. This also explains the fact that all women with bacterial vaginosis do not have an elevated vaginal pH.

Keywords

Adherence, Bacterial vaginosis, Biofilm, Gardnerella vaginalis, pH, Surface Hydrophobicity

How to cite this article :

Udayalaxmi, Gopalkrishna Bhat, Subbannayya Kotigadde, Shashidhar Kotian. EFFECT OF PH ON THE ADHERENCE, SURFACE HYDROPHOBICITY AND THE BIOFILM FORMATION OF GARDNERELLA VAGINALIS. Journal of Clinical and Diagnostic Research [serial online] 2012 August [cited: 2018 Oct 18 ]; 6:967-969. Available from
http://jcdr.net/back_issues.asp?issn=0973-709x&year=2012&month=August&volume=6&issue=6&page=967-969&id=2306

INTRODUCTION
Bacterial vaginosis represents a unique and complex change in the flora of the vagina, which is characterized by a reduction in the prevalence and the number of lactobacilli and an increase in the concentration of Gardnerella vaginalis and the resident anaerobic bacteria (1),(2). Gardnerella vaginalis, Bacteroides spp, Peptostreptococcus spp, Mobiluncus spp. Prevotella spp. Porphyromonas spp., Atopobium vaginae and Mycoplasma hominis are the microorganisms which are usually associated with cases of bacterial vaginosis (1),(2). G.vaginalis is considered as an indicator organism for bacterial vaginosis because of its regular association with it (3),(4). In a study, most of the isolates of G.vaginalis which were isolated from cases of bacterial vaginosis showed good adherence to the vaginal epithelial cells, they formed a biofilm, they showed good surface hydrophobicity and they produced phospholipase C and protease enzymes (5). Another study confirmed a greater virulence potential of Gardnerella vaginalis which was related to that of other bacterial vaginosis associated anaerobes (6).

Although bacterial vaginosis is prevalent, not much progress has been made in identifying the factors which are responsible for and are associated with bacterial vaginosis and its pathophysiology (7). The normal vaginal ecosystem in mature women is maintained by lactobacilli that secrete lactic acid and hydrogen peroxide. The resulting pH < 4.5 is thought to limit the overgrowth of opportunistic microbes (7), (8). The lactobacilli maintain their dominance through a combination of acidity, hydrogen peroxide, lactocins, and other bacteriocins to inhibit the growth of other bacteria (8). In the present study, we intended to learn the effect of pH on the adherence, surface hydrophobicity and the biofilm formation of G.vaginalis.

Material and Methods

Vaginal swabs were collected from 10 women who were known cases of bacterial vaginosis. The swabs were inoculated onto human blood bilayer agar with Tween 80 and a G.vaginalis selective supplement and the agar plates were incubated at 37ºC for 2 days (9). G.vaginalis was isolated and identified on the basis of the colony morphology, gram staining and standard biochemical reactions (9). This study had the approval of the institutional ethics committee.

Bacterial strains:
This study was conducted on 10 vaginal isolates of G.vaginalis which were isolated from cases of bacterial vaginosis. A control strain, G.vaginalis ATCC14018 was included in every assay.

Effect of pH on the adherence of G.vaginalis to the vaginal epithelial cells: The adherence of G.vaginalis to the vaginal epithelial cells was studied by performing an adherence assay, as has been described previously (10). Vaginal swabs were collected from healthy volunteer women. The vaginal discharge was eluted into 2ml of 0.85% sterile saline. The vaginal epithelial cells were washed in sterile saline 3 times until the vaginal epithelial cells were washed free of the adherent bacteria. Finally, the cells were suspended in citrate phosphate buffered saline of 5 different pH values (pH 3–pH 7).

The vaginal isolates of G.vaginalis were inoculated on human blood agar plates and these were incubated at 37ºC for 48 hours in a candle jar (9). The colonies were harvested from 3 human blood agar plates by using 0.15 M sterile saline and they were centrifuged at 2500 rpm for 15 minutes. The pellet was resuspended in 0.15 Msterile saline. This process was repeated 2 times and the pellet was then suspended in citrate phosphate buffered saline of 5 different pH values (pH 3–pH 7). The concentration of the bacterial cells was adjusted to give an OD540 of 0.1. 1ml of the standard bacterial suspension was mixed with an equal volume of the standard vaginal epithelial cell suspension and this was incubated at 37ºC in a shaker water bath at a speed of 35 rotations per minute for 45 minutes. The epithelial cells were washed free of the non-adherent bacteria by passing them through a membrane filter of pore size, 8 μm. The membrane filter was carefully removed and inverted over a slide, air dried, alcohol fixed and gram stained. The average number of bacteria which were adherent to 30 cells was counted. We considered an average of > 10 adherent bacilli /cell as moderate adherence (10).

Effect of pH on the surface hydrophobicity of G.vaginalis:
A standard bacterial suspension was prepared in citrate phosphate buffered saline of pH 3–7, as has been described above. The concentration of the bacterial cells was adjusted to an OD600 of 0.3 (OD initial). To 3ml of the bacterial suspension, 300 μl of ρ-Xylene was added and this was vortexed for 1 minute. The suspension was allowed to stand at 25ºC for 30 minutes. The aqueous and the hydrocarbon phases got separated. The OD600 of the aqueous phase was determined (OD final) (10),(11). The hydrophobicity index was calculated by using the following formula (10).

OD initial – OD final Hydrophobicity index = --------------------------- × 100 OD initial Surface hydrophobicity index ≤ 20 was graded as low and >20 as high (10),(11).

Effect of pH on the biofilm formation of G.vaginalis:
A standard bacterial suspension was prepared in citrate phosphate buffered saline of pH 3–7, as has been described above. Then, 200 μl of the suspension was dispensed into microtitre plate wells. The plate was incubated at 37ºC for 18 hours. The microtitre plate wells were washed with 0.85% sterile saline and 100 μl of Bouin’s fixative was added. The plate was incubated at room temperature for 10 minutes. The contents were aspirated and washed in 0.85% saline, 20 μl of 1% crystal violet was added to this and it was kept for 1 minute. The plate was vigorously washed with water and air dried. The absorbance was read at 490 nm by using an ELISA reader. All the tests were performed in duplicate. The biofilm formation was graded as, OD of < 0.1 – weak or non-biofilm producers; OD of 0.1–0.2 – moderate and an OD of > 0.2 – high. Sterile saline which was incorporated into one of the wells, served as a blank. P. aeruginosa ATCC 27853 was used as a positive control (12),(13).

Statistical analysis:
The statistical analysis was done by the Kruskal Wallis test. We used SPSS, version 11.5 software for the statistical analysis.

Discussion

Effect of pH on the adherence of G. vaginalis to the vaginal epithelial cells: The presence of clue cells in the vaginal discharge of the cases of bacterial vaginosis indicated the role of the adherence which was exhibited by G.vaginalis in the pathogenesis of bacterial vaginosis. In the present study, the rate of the adherence differed in the different vaginal isolates. All the isolates showed good adherence at an optimum pH of 5. We found that the average adherence was better at a lower pH (pH- 3,4,5) than at a higher pH (pH- 6,7) P < 0.001 (Table/Fig 1). Adherence is notalways a property of pathogens, because some studies showed that lactobacilli which are the predominant normal flora in normal women, also exhibited good adherence. The vaginal epithelial cells and the bacteria have a net negative charge that creates an electrostatic repulsive force which is reduced at a lowered pH (14). It is known that the optimum adherence of G.vaginalis to the vaginal epithelial cells is at pH-5.4 and that of lactobacilli is at pH- 4.4. At a higher pH (4.8 and 5.4), the lactobacilli do not compete for the binding sites which are occupied by G.vaginalis (15).

Effect of pH on the Surface hydrophobicity index:
The surface hydrophobicity and adherence are directly proportional to each other. All the isolates showed a good surface hydrophobicity at an optimum pH of 5. We found that the average surface hydrophobicity index increased at a lower pH (pH -3, 4, 5) and that it decreased at higher pH (pH- 6, 7) P < 0.05 (Table/Fig 2).

Effect of pH on the biofilm formation:
A recent study which investigated the composition and the spatial organization of the bacteria which were associated with the vaginal epithelium in biopsy specimens by using a broad range of fluorescent bacterial group-specific rRNA-targeted oligonucleotide probes, concluded that even though bacterial vaginosis was associated with a variety of bacterial groups, only G.vaginalis developed a characteristic adherent biofilm that was specific for bacterial vaginosis (16). A biofilm which was comprised of confluent G.vaginalis, with other bacterial groups being incorporated in the adherent layer was a prominent feature of bacterial vaginosis (15). In the present study, all the isolates were found to be good biofilm producers at the pH range which was under study. So, a change in the pH did not affect the biofilm formation p = 0.1 (Table/Fig 3). Another study showed that the biofilm type of growth protected G.vaginalis from the lactic acid and the hydrogen peroxide which were produced by lactobacilli (17). Thus, the biofilm formation is a protective virulence factor of G.vaginalis.

Conclusion

An increase in the pH of the vagina which is observed during bacterial vaginosis probably occurs much later during the disease. During the early part of the disease, the bacteria adhere to the vaginal epithelium, multiply in large numbers and form a thick biofilm which is not affected by the rise in pH, which occurs probably due to the metabolic activities of this large bacterial population. This also explains the fact that all women with bacterial vaginosis do not have an elevated vaginal pH.

Acknowledgement

The authors are deeply indebted to Manipal University for providing the necessary infrastructure which was required for this study.

References

1.
Rein MF. Vulvovaginitis and cervicitis. In Principles and practice of infectious diseases. Mandell GL, Bennett JE and Dolin R (eds.). Churchill Livingstone: Harcourt, Inc. United States of America. 2000;1218–34.
2.
Sobel JD. Bacterial vaginosis. Annu Rev Med. 2000;51:349-56.
3.
Menard JP, Fenollar F, Henry M, Bretelle F, Raoult D. Molecular quantification of the Gardnerella vaginalis and the Atopobium vaginae loads to predict bacterial vaginosis. Clin Infect Dis. 2008;47:33-43.
4.
Demba E, Morison L, Maartem Schim VDL, Awasana AA, Goodling E, Bailey R, et al. Bacterial vaginosis, the vaginal flora patterns and the vaginal hygiene practices in patients who presented with the vaginal discharge syndrome in Gambia, west Africa. BMC Infect Dis. 2005;5:12-24.
5.
Udayalaxmi J, Bhat GK, Kotigadde S. The biotypes and the virulence factors of Gardnerella vaginalis which was isolated from cases of bacterial vaginosis. Indian J Med Microbiol. 2011; 29: 165-68.
6.
Patterson JL, Stull-Lane A, Girerd PH, Jefferson KK. Analysis of the adherence, biofilm formation and the cytotoxicity suggests the greater virulence potential of Gardnerella vaginalis which is relative to that of other bacterial-vaginosis-associated anaerobes. Microbiol. 2010;156:392-99.
7.
Hay P. Life in the littoral zone: lactobacilli losing the plot. Sex Transm Infect. 2005;81:100-02.
8.
Aroutcheva A, Gariti D, Simon M, Shott S, Faro J, Simoes JA, et al. The defence factors of vaginal lactobacilli. Am J Obstet Gynaecol. 2001;185:375-79.
9.
Udayalaxmi, Bhat G, Kotigadde S, Shenoy S. Comparison of the methods of the diagnosis of bacterial vaginosis. JCDR. 2011; 5: 498-501.
10.
Pascual LM, Daniele MB, Ruiz F, Giordano W, Pajaro C, Barberis L. Lactobacillus rhamnosus L60, a potential probiotic which was isolated from the human vagina. J Gen Appl Microbiol. 2008;54:141-48.
11.
Kaushik JK, Kumar A, Duary RK, Mohanty AK, Grover S, Batish VK. The functional and the probiotic attributes of an indigenous isolate of Lactobacillus plantarum. PLoS One. 2009; e8099.
12.
Mathur T, Singhal S, Khan S, Upadhayay DJ, Fatma T, Rattan A. Detection of the biofilm formation among the clinical isolates of Staphylococci: An evaluation of three different screening methods. Indian J Med Microbiol. 2006;24:25-29.
13.
Suman E, Singh S, Kotian S. Pseudomonas aeruginosa biofilms in hospital water systems and the effect of a sub-inhibitory concentration of chlorine. J Hosp Infect. 2008;70:199-201.
14.
Sobel JD, Schneider J, Kaye D, Levision ME. Adherence of bacteria to the vaginal epithelial cells at various times of the menstrual cycle. Infect Immun. 1981;32:194-97.
15.
Boskey ER, Telsch KM, Whaley KJ, Moench TR, Cone RA. Acid production by the vaginal flora in vitro is consistent with the rate and the extent of the vaginal acidification. Infect Immun. 1999; 67:5170-75.
16.
Swidsinski A, Mendling W, Loening-Baucke V, Ladhoff A, Swidsinski S, Hale LP, et al. Adherent biofilms in bacterial vaginosis. Obstet Gynecol. 2005;106:1013-23.
17.
Jennifer LP, Philippe HG, Nicole WK, Kimberly KJ. Effect of the biofilm phenotype on the resistance of Gardnerella vaginalis to hydrogen peroxide and lactic acid. Am J Obstet Gynaecol. 2007;197:170-77.

JCDR is now Monthly and more widely Indexed .
  • Emerging Sources Citation Index (Web of Science, thomsonreuters)
  • Index Copernicus ICV 2016: 132.37
  • SCOPUS
  • Academic Search Complete Database
  • Directory of Open Access Journals (DOAJ)
  • EBSCOhost
  • Embase & EMbiology
  • Google Scholar
  • HINARI Access to Research in Health Programme
  • Indian Science Abstracts (ISA)
  • Journal seek Database
  • Google
  • Popline (reproductive health literature)
  • www.omnimedicalsearch.com