Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (http://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
Journal of Biomedical Engineering and Technology
American Journal of Microbiological Research
Biomedical Science and Engineering

We are pleased to announce that submissions are now being accepted for peer review for all the journals across all our subject areas in SciEP.

Please submit your manuscript via our online submission system:
http://www.sciepub.com/author/signin

To unsubscribe from our mailing list, please click on the following link: unsubscribe

I am looking forward to hearing from you.

Kind regards,

David Rain
Email:join@sciepub.com
Science and Education Publishing (http://www.sciepub.com)

Characterization and Antimicrobial Susceptibility Patterns of Vibrio cholerae and Vibrio cholerae O₁ Isolated in Tropical Waters: A Contribution to Cholera Disease Prevention in Equatorial Region

Blandine Pulchérie Tamatcho Kweyang*, Antoine Tamsa Arfao, Pierre René Fotsing Kwetche, Luciane Marlyse Moungang, Mamert Fils Onana, Siméon Tchakonté, Mireille Ebiane Nougang, Olive Vivien Noah Ewoti, Ajeagah Gideon Aghaindum

Department of Microbiology, University of Yaounde 1, Faculty of Sciences, P.O. Box 812 Yaounde, Cameroon

Abstract: The isolation and characterization of Vibrio strains were carried out in Yaounde (equatorial area). Well water characteristic focused on water temperature, pH, dissolved oxygen, dissolved CO₂, electrical conductivity, suspended solids. Vibrio cholerae, Vibrio fluvialis, Vibrio mimicus, Vibrio parahaemolyticus and Vibrio vulnificus were identified in all four wells investigated. On 50 strains of Vibrio cholerae tested, 8 agglutinated anti O₁ serum; 16% therefore belong to serogroup O₁. Antimicrobial susceptibility tests showed that most of the environmental strains of Vibrio cholerae studied are sensitive to the majority of the antibiotics tested. The percentage of sensitivity for most of the antibiotics tested is above 50%. CPR (98%); CTX (94%); GM (84%); AMC (82%); DOX (72%); AMX (70%); NAL (52%). There were 34% cases of resistant to nalidixic acid, 26% to amoxicillin, 24% to chloramphenicol, and 18% to doxycycline. The percentage of sensitivity of Vibrio cholerae O₁ is always greater than 50% with GM (100%); AMX and DOX (87.5%); CTX and CPR (75%); AMC and NAL (62.5%); CHL (50%). These results contribute to prevention and control of cholera in equatorial region.

Keywords: isolation, characterization, Vibrio strains, antimicrobial susceptibility, physico-chemical parameters, well

Received May 03, 2021; Revised June 09, 2021; Accepted June 18, 2021

Citation: Blandine Pulchérie Tamatcho Kweyang, Antoine Tamsa Arfao, Pierre René Fotsing Kwetche, Luciane Marlyse Moungang, Mamert Fils Onana, Siméon Tchakonté, Mireille Ebiane Nougang, Olive Vivien Noah Ewoti, Ajeagah Gideon Aghaindum, Characterization and Antimicrobial Susceptibility Patterns of Vibrio cholerae and Vibrio cholerae O₁ Isolated in Tropical Waters: A Contribution to Cholera Disease Prevention in Equatorial Region. Applied Ecology and Environmental Sciences, 9 (6). 599-606. January 2021. doi:10.12691/aees-9-6-4

1. Introduction

Water is the main vehicle for many infectious diseases that afflict people and animals around the world. These diseases are more frequent in poor countries and in developing countries, because of the precariousness of hygiene conditions generally associated with the very low purchasing power of the populations [1]. Among the bacteria known to be responsible for contamination in communities, mention may be made of species belonging to the genera Salmonella, Shigella, Escherichia, Yersinia, Vibrio and Campylobacter [2].

Bacillary diarrhea is a frequent reason for consultation, especially in poor countries and developing countries where faecal and food hygiene is poor. While some diarrheal episodes are spontaneous, others, on the other hand, are the cause of formidable epidemics. Among bacillary diarrhea, we can cite cholera which has been endemo-epidemic in most of these regions since 1970 [3]. The aquatic environment is the natural habitat for bacteria of the genus Vibrio. The most formidable strains in public health belong to the species Vibrio cholerae [4,5]. Since strains of other species of the genus Vibrio are not very involved in epidemic outbreaks, efforts directed towards their study are very limited. However, the results of the work carried out have shown the impact of some of them on the health of human populations [6,7]. They can be the cause of sporadic cases of diarrhea and extra-intestinal infections [2]. The growing needs for water, linked to the galloping demography, contrast with the unavailability of this resource in the agglomerations of developing regions around the world. This situation forces populations to resort to resources of questionable quality to meet their daily needs, and exposes them to contamination [8].

In 2008, the number of cholera cases declared to the WHO was 190.130 with 5.143 deaths, thus a case fatality rate of 2.7%. This rate is increasing compared to 2007 when it was 2.3% [9]. In Africa, for several years, global climate change has largely contributed to the spread of cholera. In 2007, 2 to 4% of death cases were reported in 34 countries, including Angola, Ethiopia, Democratic Republic of Congo and Somalia. Sudan reported 76% of all cases and deaths [10]. Cameroon experienced the first cholera epidemic in Douala in 1971, which left a lasting impression [11]. During the year 2010, the country recorded 10.759 cases of which 10.102 were successfully treated. There were 657 deaths, a case fatality rate of 6.1% [12]. For the year 2011, 2.052 cases were recorded, including 85 deaths. During these epidemics, drinking water has been identified as the main vehicle for the spread of bacteria and the causative agent is Vibrio cholerae O₁ [13]. Bacterial species of the genus Vibrio are often associated with aquatic environments with particular physical and chemical properties. Recent studies carried out in Yaounde revealed that they could be isolated in other environments with different environmental conditions [14]. The qualitative importance and distribution of species of the genus Vibrio in the aquatic environment of the city of Yaounde are still little explored. Little is known about the environmental and physicochemical factors that could have an impact on the development and distribution of organisms of this species in the aquatic environment. Nowadays, little work has been done on antibiotic sensitivity for Vibrio strains isolated from the environment.

The present study aims to isolate bacteria belonging to the genus Vibrio in some wells of the city of Yaounde, to characterize by serogrouping the strains of Vibrio cholerae belonging to the O₁ serogroup, which is the main cause of epidemics in tropical regions, to understand the importance of physicochemical parameters on the distribution, the frequency of appearance of these organisms and the sensitivity of the isolated strains to some antibiotics commonly used in clinic.

2. Material and Methods

2.1. Study Area and Sampling Stations

Yaounde is the Capital city of the Republic of Cameroon. The Mfoundi is the main waterway in the city and its drainage basin covers about 256 km2 with four watersheds in the Center Region. The city experiences a tropical Equatorial climate characterized by regular abundant rainfall (1600 mm per year), an annual average temperature of 23°C with four distinct seasons (two dry seasons and two rainy seasons). The area is covered by drained red ferrallitic soils on the hill slopes and by colluvial and alluvial deposits in the valleys [15]. With a surface area of about 183 km2, the city has an estimate population of 1817525 inhabitants. Here, only about 20% of the households have access to tape water provided by the water company through the urban network [16]. Others rely on retailers or other doubtful sources like wells and springs to satisfy their needs in terms of water. In order to have a clear idea of the location of the different study sites, the geographical coordinates of all the sampling stations were determined using a Garmin Etrex 30 brand GPS. Figure 1 shows the geographical location of the study area and the sampling stations. The sampling stations were chosen according to the proximity of the dwellings and latrines to the point to assess the impact of human presence, the massive use of water from the point for the domestic needs of the populations.

2.2. Analyses of Water Physicochemical Parameters

At the level of each sampling station, the physicochemical analysis focused on 6 variables. The analysis of these parameters was carried out according to the recommendations of Rodier and APHA [17,18]. Water pH, dissolved oxygen and electrical conductivity were determined in situ (using a multi-parameter analyser kit HANNA Instruments) to estimate their impact on antimicrobial susceptibility. Organic matter was evaluated in laboratory by the chromic acid wet digestion titrimetric method. These parameters were chosen since they are indicators of the organic pollution.

2.3. Bacteriological Analysis and Serogroupage

The qualitative analysis of bacteria consisted of the isolation of Vibrio sp. The cultures were performed using the culture media recommended by BioMérieux for the growth and isolation of Vibrio species. Specimen enrichment was carried out by suspending 5 ml of the specimen in 10 ml of the culture broth. The mixture was then incubated aerobically for 24 hours at 37°C. From the resulting inoculums, subcultures were performed on Thiosulfate Citrate Bile Salts (TCBS; BioMerieux) agar and re-incubated aerobically at 37°C overnight. At the end of the incubation period, suspected bacterial colonies were either yellow (that is positive, which implies that bacteria used saccharose) or green (that is negative, implying that bacteria did not use saccharose). Subcultures were once again made from these colonies on alkaline nutrient agar and re-incubated aerobically at 37oC overnight. From a pure culture colony on alkaline nutrient agar, a suspension in sterile distilled water was prepared. The bacterial suspension was distributed in the capsules of the API 20E system (BioMérieux, France). The metabolites produced were made evident by color reactions or by addition of reagents, after 24 hours of incubation at 37°C. Corresponding bacterial species was determined numerically with the help of APIDENT 2.0 software. The identification rate was maintained at least at 98%. Serogrouping was performed only on strains of Vibrio cholerae. It differentiates O1 serogroups from non-O₁ Vibrio cholerae. The search for Vibrio cholerae O₁ was carried out using the slide agglutination technique with an anti O₁ antiserum (BIO-RAD, Marne-la-coquette, France). A drop of anti O₁ antiserum was placed on a clean slide. Using a platinum loop, we took a colony of a young and pure culture on solid medium (Müeller Hinton or Hajna Kligler) of Vibrio and we suspended it in the drop (i.e. the bacteria itself which serves as a developer). The drop was then spread and a rocking motion of the slide was performed. If the strain has the antigen corresponding to the antiserum tested, agglutinates are formed which are visible to the naked eye. Agglutination confirms the presence of the desired antigen (Vibrio cholerae O₁).

2.4. Antimicrobial Susceptibility Tests

The method that we used to carry out the antibiograms was that of agar diffusion [19]. It was based on the presence or absence of a zone of inhibition around a disc of blotting paper (agar) impregnated with antibiotic. Strain susceptibility testing to antibiotics was performed on pure strains, following the recommendations of the National Committee of Clinical Laboratory Standards [20]. The antibiotics used belonged to several families. They were in the form of a disc of blotting paper 6mm diameter, impregnated with well-determined quantities of active substances and rigorously controlled for the diffusion method. The antibiotics used, their groups and their characteristics are listed in Table 1. Test results were only validated in the cases where inhibition zone diameters of the control strains were within performance ranges. Inhibition zone diameters of Vibrio cholerae isolates were measured and then compared with the standards of the National Committee of Clinical Laboratory Standards [20]. The sensitive (S) category means that the strain can be reached by the antibiotic treatment applied at the normal dose. For the intermediate (I) category, therapeutic success is unpredictable. Treatment will be effective if the antibiotic is used at a higher dose than normal. Intermediate means moderately susceptible or moderately resistant. The resistant (R) category means that there is a high probability of treatment failure regardless of the type of treatment with the antibiotic, or that the strain will not be affected regardless of the type of treatment. Monthly changes in physicochemical parameters at the different sampling sites and Prevalence of resistant (R), intermediate (I) or sensitive (S) strains to each antibiotic were plotted using Microsoft Excel.

Figure 1. Map of the study area showing sampling stations

Table 1. List of antibiotics used in the study of antibiotic resistance of strains of Vibrio cholerae Source: NCCLS (2002)

3. Results and Discussion

3.1. The Physicochemical Characteristics of Wells

The above parameters were accessed in water samples collected from wells. The temperature values of the sampled water varied between 22°C and 24.5°C throughout our study (Figure 2A). These values fluctuated little from one well to another. The highest values were observed in P₁ and P₂, and the lowest in P₃. The range of temperature observed here common in tropical areas is conducive to bacterial growth [21,22]. Temperature probably plays a major role in the distribution of the bacteria in most of the wells. The pH varies from 5.27 to 7.01 CU. The lowest value was recorded at the level of P₃ in May (rainy season) and the highest value at the level of P₁ in July corresponding to the dry season (Figure 2B). Since bacterial isolation was also observed in sample with lower pH and, assuming that the most frequently isolated species are those for which environmental conditions were most conducive for growth and spread, strains of V. cholerae probably adapted better to lower pH but less than V. parahaemolyticus. The pH did not, however, differ significantly from one geographic area to the other as already noticed by former investigator although the values recorded were significantly higher during the dry season [23,24]. The conductivity values have varied a lot. They fluctuate between 97 and 524 µS/cm. We note here a low mineralization (< at 200 µS/cm) to medium (≥ at 200 µS/cm). The highest value was recorded at P₁ in March and the lowest at P₃ in May. The average values of electrical conductivity are high (Figure 2C). This is in agreement with other investigators who asserted that water sources in Yaoundé contain higher concentration of minerals including iron, calcium, magnesium and aluminum compared to the norms with the highest values obtained during the dry season [17,25]. In fact, minerals are important factors in bacterial growth. Because outbreaks are mostly documented during dry seasons when the highest values of pH and electrical conductivity are obtained, isolation rates observed in the present study suggest that they are favorable to Vibrio growth and dissemination [26]. This is consistent with other reports that environmental factors that positively correlate the recovery rates of Vibrio isolates in water included temperature, electrical conductivity and draught, although bacterial strains may actively be disseminated with flood during the rainy season [27]. Suspended solids values varied between 2 and 147 mg/L. The lowest value was recorded at P₃. These values varied greatly from one well to another. The maximum value is recorded at P₂ where the average is quite high (84.7 mg/L) compared to other wells where the average does not exceed 43 mg/L (Figure 2D). Studies reported that the presence of suspended solids favored bacterial biofilm formation with increased grazing/predatory activity of zooplankton that eventually eliminates of planktonic Vibrio isolates. This may explain why isolation rates were low in highly polluted samples. The values of the dissolved oxygen content generally vary between 0.4 mg/L and 2 mg/L. The highest value is recorded at P₂ and P₄ and the lowest at P₁. We note here an average oxygenation of the well water studied (Figure 2E). Concerning Dissolved CO₂, values recorded in all the wells in the city of Yaoundé reached 12.6 mg/L (Figure 2F). The highest value is recorded in P₁ in May and the lowest in P₂ in February.

3.2. Biochemical Characteristics of Isolated Bacteria

On the basis of the biochemical characteristics, we have identified 5 species belonging to the genus Vibrio. These are V. cholerae, V. fluvialis, V. mimicus, V. parahaemolyticus et V. vulnificus. Table 2 shows the biochemical profiles of the strains studied, as well as these different species identified. The cultural characters of the different Vibrio species listed were yellow and flat colonies of 2 to 3 mm in diameter for the presumptive of V. cholerae, then yellow or translucent colonies presumptive. of V. fluvialis and V. vulnificus and finally those which were colorless with green center, presumptive of V. parahaemolyticus.

3.3. Recovery Frequency of Bacteria Isolated in Each Sampling Sites

Collectively, Vibrio was isolated from all wells but the specific diversity was also less common. The highest species diversity was observed in P₁ where isolates from five species were recovered and P₂ with two species. V. parahaemolyticus was isolated from all the four wells, V. fluvialis from two and, V. cholerae, V. mimicus and V. vulnificus from only one, P₁ (overall population least exposed). The following diagrams (Figure 3) display the rates of isolation in various settings.

Figure 2. Temporal variation with respect to the sampling site of the Temperature (A), pH (B), Electrical conductivity (C), Suspended solids (D), Dissolved oxygen (E) and Carbon dioxide (F)

Table 2. Biochemical characteristics of different species isolated

Figure 3. Rates of isolation of bacteria isolated from various wells

3.4. Serogrouping Test

The serogrouping test was performed on 50 strains of Vibrio cholerae. Of the strains tested, 8 agglutinated anti O₁ serum; 16% therefore belong to serogroup O₁. Endemic cholera is typically associated with serogroup O₁. However, cases of cholera due to V. cholerae O₁₃₉ have been recorded in Asia [28]. During the 2004 epidemic in Douala, 60% of isolated strains were still Vibrio cholerae O₁ biovar el Tor [16,29]. These are the strains responsible for major epidemic outbreaks in sub-Saharan Africa and other regions of the world [5]. The proportion (16%) obtained during our work is indicative because the study is purely qualitative (it showed the presence of V. cholerae O₁). V. cholerae O₁ is isolated from the Yaounde environment. This could explain the outbreaks recorded in recent years [14,23].

3.5. Antimicrobial Susceptibility Patterns of Vibrio cholerae and Vibrio cholerae O₁

The sensitivity profile of the strains of Vibrio cholerae and Vibrio cholerae O₁ tested to the different molecules are illustrated by Figure 4. The antibiograms carried out show that most of the environmental strains of Vibrio cholerae studied are sensitive to the majority of the antibiotics tested (Figure 4A). The percentage of sensitivity for most of the antibiotics tested is above 50%. CPR (98%); CTX (94%); GM (84%); AMC (82%); DOX (72%); AMX (70%); NAL (52%). However, 34% of the isolates were resistant to nalidixic acid, 26% to amoxicillin, 24% to chloramphenicol, and 18% to doxycycline. As regards Vibrio cholerae O₁, the strains exhibit a very high sensitivity to the various antibiotics tested (Figure 4B). The percentage of sensitivity in this case is always greater than 50%, regardless of the antibiotic tested: GM (100%); AMX and DOX (87.5%); CTX and CPR (75%); AMC and NAL (62.5%); CHL (50%). In addition, the susceptibility test to the vibriostatic compound showed that 78% of Vibrio cholerae strains tested showed resistance on the one hand. On the other hand, the strains of Vibrio cholerae O₁ tested showed good sensitivity to this compound (75%).

Vibrio cholerae isolated from the aquatic environment of Yaounde is overall very sensitive to the majority of the antibiotics tested. The strains of Vibrio cholerae O₁ show an even higher sensitivity when compared to the first ones. However, it is important to note the relatively low sensitivity to chloramphenicol (46%) and to the vibriostatic compound O/129 (22%) in Vibrio cholerae. For the strains belonging to serogoup O₁, the sensitivity to the vibriostatic compound is high (75%). The wild strain of Vibrio cholerea is naturally sensitive to the vibriostatic compound.

These results are similar to those obtained during the 2004 epidemic in Douala. The isolated Vibrio was sensitive to the following antibiotics: amoxicillin, amoxicillin + clavulanic acid, cefotaxime, doxycycline, gentamicin, nalidixic acid, pefloxacin [13]. This high sensitivity is also similar to the results obtained in 1992 in Senegal during a 10-years assessment which showed a sensitivity of Vibrio cholerae strains to chloramphenicol and associated sulfonamides, greater than 80% [30]. However, these were strains clinically isolated from patients.

During our study, relatively low resistance phenotypes were noted in the strains of Vibrio cholerae tested against amoxycillin (AMX: R = 26%, I = 4%), amoxycillin + clavulanic acid. (AMC: R = 4%, I = 14%), doxycicline (DOX: R = 18%, I = 10%), nalidixic acid (NAL: R = 34%, I = 14%) and chloramphenicol (CHL: R = 24%, I = 30%). As regards the strains of Vibrio cholerae O₁, phenotypes of resistance to AMC were also noted (R = 25%, I = 12.5%), DOX (R = 12.5%), Ciprofloxaxine (CPR: R = 25%) and NAL (R = 37.5%). The resistance to β-lactams observed here would be due to a production of bêta-lactamase of the penicillinase type. Studies report that ampicillin is generally inactive against the majority of vibrios [31]. Our results are different from those obtained by some authors whose work on Gram-negative bacilli in hospitals in Yaounde rather shows a strong resistance of the latter to the antibiotics tested [32]. This is in agreement with the fact that different bacterial types have different abilities to acquire the genotypes and develop the associated phenotypes. These resistances were much higher in internal patients than in external ones.

Figure 4. Antimicrobial susceptibility patterns among Vibrio cholerae strains (A) and Vibrio cholerae O1 (B) isolated from wells in Yaounde (AMX : Amoxycilline, AMC : Amoxycilline + acide clavulanique, GM : Gentamicine, CTX : Cefotaxime, DOX : Doxycycline, CPR : Ciprofloxacine, NAL : Acide nalidixique, CHL :(Chloramphénicol, CO129 : Vibriostatic compound O129)

The selection of resistant vibrios has been demonstrated in the extensive use of antibiotics. This resistance is due to multiple mechanisms including transferable plasmid and chromosomal resistance [13].

During our study, we noted a high resistance to the vibriostatic compound O / 129 (78%) for the strains of V. cholerae tested. Throughout the world, resistance to the compound O / 129 is reported and is generally accompanied by resistance to other antibiotics [33]. In total 22% of the strains isolated are sensitive to this compound. Some studies showed the relationship between the sensitivity of environmental strains towards the vibriostatic compound O/129, tetracycline and chloramphenicol [34]. In fact, the resistance of the strains of Vibrio cholerae to these two antibiotics would be crossed and associated with the presence of the plasmid which codes for resistance to the compound O/129.

The test of sensitivity to the vibriostatic compound for V. cholerae of serogoup O₁ showed a relatively high sensitivity to the vibriostatic compound when compared to the test on V. cholerae in general. The 25% resistance is not negligible and can always be explained by the mutation of the wild strain which is naturally sensitive to the vibriostatic compound. This decrease in sensitivity to compound O/129 significantly contributes to the loss of its value in the differential diagnosis of species of the genus Vibrio and is such as to make the management of infected persons and the control of epidemics more and more complicated, knowing that the antibiotic prophylaxis retains an undisputed place in some specific situations because it has made it possible, in a well-defined environment, to prevent the transmission of cholera, within families or closed communities (hospital, prison) [13].

4. Conclusion

Microbiological analyzes of the well water show that the wells harbor bacteria belonging to the Vibrio genus. The results of isolation and identification of strains determined the existence of five species belonging to the genus Vibrio. These are V. cholerae, V. fluvialis, V. mimicus, V. parahaemolyticus and V. vulnificus. Among the isolated species, Vibrio cholerae, responsible for cholera diarrhea and gastroenteritis, has been the subject of special attention on our part. The results of serogrouping showed that 16% of Vibrio cholerae tested belong to serogroup O₁, responsible for cholera epidemics. The presence of the latter in the water points studied would pose a real public health problem for the user populations. This danger is all the more relevant given that well water constitutes one of the sources of drinking water supply by many layers of the population. The presence of Vibrio in a water point implies a focus from which a possible cholera epidemic can start. The study of resistance profiles has shown that more than 50% of the strains studied are sensitive to the different antibiotics tested; however, resistance to varying degrees has been noted to some antibiotics. The wild strain naturally sensitive to the vibriostatic compound O/129 would have mutated, but nevertheless remains controllable in the event of an epidemic, by antibiotic therapy.

Statement of Competing Interest

The authors have no competing interest.

References

[1]   | Nguendo, Yongsi. H.B, Salem, G. and Thouez, J.P. “Risques sanitaires liés aux modes d’assainissement des excréta à Yaoundé, Cameroun”, Nature Sciences Sociétés, (2008), 16(1): 3-12.
[2]   | Leclerc, H., “Y a-t-il des infections bactériennes opportunistes transmises par l’eau d’alimentation?”, European Journal of Water Quality, (2003), 34 (1): 11-14.
[3]   | Dosso, M., Coulibaly, M. and Kadio, A.. “Place des diarrhées bactériennes dans les pays en développement”. Manuscrit n° PFO2. Journée en hommage au professeur Dodin A, (1998).
[4]   | Fournier, J.M. and Quilici, M.L. “Infections à vibrion non cholériques”. In Encycl. Med. Chir. (Editions scientifiques et médicales Elsevier, Paris), Maladies infectieuses. (2002), 8-026-F-15.
[5]   | Fournier, J.M. “Choléra”. In Encycl. Med. Chir. (Elsevier, Paris), Maladies infectieuses, (1998), 8-028-F-10, 5.
[6]   | Duraku, E. and Panariti, A. “A case of acute gastroenteritis cause by Vibrio cholerae non O1”. Rev. Inter. Serv. Santé des forces armées, (1998), 71(10-12): 298-300.
[7]   | Lemoine, T., Germanetto, P. and Giraud, P., “Toxi-infection alimentaire collective à Vibrio parahaemolyticus”, Bulletin Epidémiologique Hebdomadaire, (1999), 10: 37-45.
[8]   | Nola, M., Njiné, T. and Boutin, C. “Variabilité de la qualité des eaux souterraines dans quelques stations de Yaoundé (Cameroun)”. Mémoires de Biospéologie, 1998. 25: 183-191.
[9]   | World Health Organization (WHO)., “Choléra: bilan de la surveillance mondiale, Weekly epidemiological record, (2009), 84(31): 309-324.
[10]   | World Health Organization (WHO). “Choléra, 2007”, Weekly epidemiological record, (2008), 83: 269-284.
[11]   | Dutertre, J., Huet, M., Gateff, C. and Durant, B. “Le choléra au Cameroun”. Medécine Tropicale, (1972), 32: 607-624.
[12]   | World Health Organization (WHO), “Lutte contre l’épidémie de choléra à Yaoundé et dans la région du centre”. Santé au quotidien. (2011), 66: 1-3.
[13]   | Guévart, E., Noeske J, Solle, J, Essomba, J.M., Mbonji, Edjenguele., Bita, A., Mouangue, A. and Manga, B, “Déterminants du choléra à Douala”, Médecine Tropicale, (2006) 66 (3): 283-291.
[14]   | Tamatcho, Kweyang, B.P., Fotsing, Kwetché, P.R., Njine, T., Nola, M. and Djogo, P. “Quelques facteurs déterminant la distribution des bactéries du genre Vibrio dans l’environnement aquatique de Yaoundé, Cameroun”. Cameroon Journal of Experimental Biology, (2009), 5(2): 96-103.
[15]   | Yongue-Fouateu, R., “Contribution à l’étude pétrographique de l’altération et des faciès de cuirassement ferrugineux des gneiss migmatitiques de la région de Yaoundé”. Thèse de Doctorat d’Etat, Université de Yaoundé, (1986).
[16]   | Mpakam, H. G., Kamgang, K. B., Kouam, K, G-R., Tamo, T. and Ekodeck G. E, “L’acces à l’eau potable et à l’assainissement dans les villes des pays en développement: Cas de Bafoussam (Cameroun)”. La revue électronique en sciences de l’environnement, (2006), 7(2).
[17]   | Rodier, J., Legube, B., Marlet, N. and Brunet, R. “L’analyse de l’eau”. 9e édition, DUNOD, Paris, (2009)
[18]   | America Public Health Association (APHA), “Standard Methods for the Examination of Water and Wastewater”, APHA-AWWAWPCF (Eds.), Pennsylvania, Washington, (2009).
[19]   | Bauer, A.W., Kirby, W.M.M., Sherris J.C. and Turck, M., “Antibiotic susceptibility testing by a standardized single disc method”, American Journal of Clinical Pathology, (1996), 45(4): 493-496.
[20]   | National Committee for Clinical laboratory Standards (NCCLS). “Performance standards for antimicrobial susceptibility testing. Twelfth Informational supplement. Approved standards M₂₋A₇ and M₇-A₅ (M₁₀₀-S₁₂)”, Wayne, Pa. (2002), 22 (22).
[21]   | David, E.J. and Joan, B.R., “Review of factors affecting microbial survival in ground water”, Environmental Science and Technology, (2005), 39(19): 7345-7365.
[22]   | Dumontet S, Krovacek K, Svenson BS, Pasquale V, Baloda BS. and Figliuolo G. “Prevalence and diversity of Aeromonas and Vibrio spp. In coastal waters of southern Italy”. Comparative Immunology, Microbiology and Infectious Disease, (2000), 23 (1): 53-72.

[23]  
Tamatcho, Kweyang B.P., Fotsing, Kwetche P.R., Nougang, M.E., Zébazé Togouet, S.H. and Njiné, T., “Species Richness and Spatial Distribution of Pathogenic Vibrio (Bacteria, vibrionaceae) in Tropical Surface Waters: Yaoundé Metropolis Case (Cameroon, Central Africa). Current Research Journal of Biological Sciences, (2012), 4(5): 584-591

[24]   | Tamatcho Kweyang B.P., “Bactéries du genre Vibrio dans l’environnement aquatique de Yaoundé: fréquence, antibiorésistance et implication de certains facteurs du milieu”. Thèse de Doctorat /Ph.D, Université de Yaoundé I, (2016).
[25]   | Chowdhury, M.A., Yamanaka, H., Miyoshi, S., Aziz, K.M. and Shinoda, S. “Ecology of Vibrio mimicus in aquatic environments”, Applied and Environmental Microbiology, (1989), 55(8): 2073-2078.
[26]   | Huq, A., Sack, R.B., Nizam A, Longini IM, Nair GB, Ali A, ., , H, , K, , M., , J., , D. and , R, “Critical Factors Inﬂuencing the Occurrence of Vibrio cholerae in the Environment of Bangladesh” Applied and Environmental Microbiology, (2005), 71(8): 4645-4654.

[27]  
Dalsgaard, A., Serichantalers, O., Forslund, A., Lin, W., Mekalanos, J., Mintz E., Shimada, T. and Wells, J.D. “Clinical and environmental isolates of Vibrio cholerae Serogroup O141 Carry the CTX phage and the genes encoding the toxin-coregulated pili”, Journal of Clinical Microbiology. (2001), 39(11): 4086-4092.

[28]   | Cohen, N., Karib, H., Ait, S.J., Lemee, L., Guenole, A., and Quilici, M.L., “Prévalence des vibrions potentiellement pathogènes dans les produits de pêches commercialisés à Casablanca (Maroc)”, Revue de médecine vétérinaire, (2007), 158 (11): 562-568.
[29]   | Solle, J., Mouangue A., Bita, fouda. A., Noeske and Guévart, E., “L’endémo-épidémie de choléra à Douala (2004): historique et caractéristiques épidémiologiques”. Société de Pathologie Exotique, (2005), 92 (2): 143-144.
[30]   | Sow, A. I., Cissé, M. F., Gaye-Diallo., Diop., “Bilan de l’isolement de Vibrio cholerae sur 10 ans au CHU de Fann, Dakar”. Dakar médical, (1992), 37: 113-116.
[31]   | Aucher, P., Dugaz, G., Missonnier, F., Fortas, N., “A propos d’un cas d’infection autochtone à Vibrio cholerae non O1 et non O139”. Annales de Biologie clinique, (1998), 56 (2): 213-214.
[32]   | Gangoué, Piéboji. J., Koulla-shiro, S., Ngassam, P., Adiogo, D., Njine, T. and Ndumbe P., (2004). “Antimicrobial resistance of Gram-negative bacilli isolates from inpatients and outpatients at Yaoundé Central Hospital, Cameroon”. International Journal of Infectious diseases, (2004), 8:147-154.
[33]   | Sow, A. I., Cissé, M. F., Gaye, M., Kébé, A., Sy, O. K., Dia N. M. and Komo A., “Diversité bactérienne au cours de l’épidémie de choléra à Dakar, Sénégal (1995-1996)”, Bactériologie, (1997), 2.

[34]  
Tiekoura, K.B., Guessennd, K.A.N., Anne, Blessa J.C., Oussou, Kouamé R., Ekaza, E., Adingra, A.A., Dosso, M., “Caractérisation moléculaire des souches de Vibrio cholerae non O1, non O139 isolées dans les eaux lagunaires de Grand-Lahou (Côte d’Ivoire). European Journal of Scientific Research, (2010), 45 (3): 333-345.