International drinking water quality monitoring programs have been established in order to prevent or to reduce the risk of contracting water-related infections. A survey was performed on groundwater-derived drinking water from 13 different hospitals in the Mahabubnagar District. A total of 55 bacterial strains were isolated which belonged to both gram-positive and gram-negative bacteria. All the taxa were identified based on the 16S rRNA gene sequence analysis based on which they are phylogenetically close to 27 different taxa. Many of the strains are closely related to their phylogenetic neighbors and exhibit from 98.4 to 100% sequence similarity at the 16S rRNA gene sequence level. The most common group was similar to
Human population growth wields several and various pressures on the quality and the quantity of drinking and fresh water resources and on the access to them. Safe drinking water remains inaccessible to several millions people in the globe. Safe drinking water, thus, reduces the load of waterborne diseases. Contamination of drinking water due to natural and manmade contaminants is frequently reported in developing countries where mainstream of the inhabitants survive in countryside and uptown areas with meager hygiene and waste clearance practices. In developing countries, poor water quality is the most important risk of child mortalities which are mainly through infectious diarrhea. In India, about 10% of the countryside and city populations do not have access to usual safe drinking water and several others are threatened [
Potable or drinking water is defined as having a satisfactory quality in terms of its physical, chemical, and bacteriological parameters so that it can be securely used for drinking and cooking. The most common and widespread health risks associated with drinking water in developing countries are of biological origin. The WHO estimates that about 1100 million people globally drink unsafe water, and the greater part of diarrheal disease in the globe (88%) is attributable to insecure water, sanitation, and hygiene [
Recently, Suthar et al. [
The results of the recent study on the detection of potentially pathogenic bacteria in the drinking water distribution system of a hospital in Hungary by Felföldi et al. [
Hospitals drinking (potable) water systems are the most important and controllable as well as the most overlooked source of nosocomial pathogens. Conventional culture-based microbiological water quality monitoring techniques take a long time (several days), and usually a small volume of water is sampled (typically 100 mL), which gives rise to inadequate detection limits with regard to drinking water safety. Furthermore, the presence of some important waterborne pathogens (such as
Thirteen drinking water samples were collected from different government hospitals, Mahabubnagar District, Andhra Pradesh, India, on 22nd and 23rd of November, 2009. Fifty five strains were isolated from these 13 drinking water sources on nutrient agar medium at 37°C. For isolation of bacteria, 100
For 16S rRNA gene sequencing, DNA was prepared using the Mo Bio microbial DNA isolation kit (Mo Bio Laboratories Inc., Solano Beach, CA, USA) and sequenced as described previously [
The biochemical tests were performed for all the strains obtained by using the HiMViCTM Biochemical Test Kit (HIMEDIA-KB001) and HiAssorted Biochemical Test Kit (HIMEDIA-KB002).
All these isolates were from different drinking water sources, and all are mesophilic and could grow in the temperature range of 20 to 40°C with optimum growth temperature of 37°C. All the strains could grow without NaCl in the medium, and the tolerance to NaCl varied from 1 to 2%. All strains could grow either in the pH range of 6–8.
A total of 55 bacterial strains were recovered from the 13 drinking water sources (Table
Bacterial abundance from the drinking water samples collected from government hospitals, Mahabubnagar.
Serial number | Sample number | Place of sample collection | Number of isolates | Isolated strains |
---|---|---|---|---|
1 | AL | Alampur | 3 | AL1, AL3, AL4 |
2 | AP | Achampet | 3 | AP1, AP2, AP4 |
3 | D | Shadnagar | 4 | D12, D22, D24, D25 |
4 | GD | Gadwal | 4 | GD2, GD4–D6 |
5 | JD | Jadcherla | 4 | JD1–JD4 |
6 | JU | Jurala | 4 | JU1–JU4 |
7 | KL | Kalwakurthy | 5 | KL1–KL5 |
8 | MB | Mahabubnagar-1 | 4 | MB1–MB4 |
9 | MK | Makthal | 3 | MK2–MK4 |
10 | NG | Nagar Kurnool | 2 | NG1, NG2 |
11 | NR | Narayanpet | 3 | NR2–NR4 |
12 | R | Mahabubnagar-2 | 12 | R1, R2, R5–R8, R21–R23, R26, R30, R31 |
13 | WN | Wanaparthy | 4 | WN1, WN3–WN5 |
Identification of the 55 bacterial strains isolated from the drinking water samples collected from different government hospitals, Mahabubnagar, based on BLAST analysis of the 16S rRNA gene sequences.
Sl no. | Strain no. | Nearest phylogenetic neighbor | 16S rRNA gene sequence similarity % |
---|---|---|---|
Gram-negative bacterial strains | |||
| |||
|
|||
|
|||
1 | D24 |
|
99.6 |
2 | AL1 |
|
99.7 |
|
|||
3 | AP1 |
|
100.0 |
4 | AL3 |
|
100.0 |
|
|||
5 | JD2 |
|
98.5 |
6 | KL1 |
|
98.5 |
7 | KL5 |
|
98.5 |
8 | MB1 |
|
98.4 |
9 | MK4 |
|
98.5 |
10 | NR4 |
|
98.4 |
11 | GD5 |
|
99.9 |
12 | NG1 |
|
99.5 |
13 | AP2 |
|
100.0 |
14 | AP4 |
|
100.0 |
15 | GD2 |
|
100.0 |
16 | JD4 |
|
100.0 |
17 | KL3 |
|
100.0 |
18 | KL4 |
|
100.0 |
19 | MB3 |
|
100.0 |
20 | R1 |
|
99.9 |
21 | WN1 |
|
99.9 |
22 | WN3 |
|
100.0 |
23 | WN4 |
|
100.0 |
24 | WN5 |
|
99.9 |
25 | MB4 |
|
99.6 |
26 | JD1 |
|
100.0 |
27 | R31 |
|
100.0 |
28 | R30 |
|
99.9 |
29 | GD4 |
|
100.0 |
30 | JD3 |
|
99.8 |
31 | MK2 |
|
99.8 |
32 | R26 |
|
99.2 |
33 | NG2 |
|
98.3 |
34 | R21 |
|
99.8 |
35 | R22 |
|
99.9 |
36 | NR2 |
|
99.9 |
37 | R6 |
|
100.0 |
38 | R7 |
|
99.8 |
39 | R23 |
|
99.8 |
40 | D22 |
|
99.8 |
41 | GD6 |
|
99.8 |
42 | MB2 |
|
99.6 |
43 | MK3 |
|
99.7 |
| |||
Gram-positive bacterial strains | |||
| |||
|
|||
44 | R8 |
|
100.0 |
|
|||
|
|||
45 | D12 |
|
100.0 |
46 | KL2 |
|
98.7 |
47 | NR3 |
|
99.7 |
48 | R5 |
|
100.0 |
49 | JU1 |
|
99.5 |
50 | JU3 |
|
99.9 |
51 | JU4 |
|
98.9 |
52 | AL4 |
|
99.9 |
53 | R2 |
|
100.0 |
54 | D25 |
|
99.9 |
55 | JU2 |
|
99.8 |
The accession numbers of the 55 strains are GU566304 and GU566358.
The affiliation of the strains to the nearest phylogenetic neighbor and the percentage of 16S rRNA gene sequence similarities.
The affiliation of the strains to the nearest phylogenetic neighbor and the percentage of 16S rRNA gene sequence similarities.
Biochemical analysis of the genus
Biochemical tests for the strains obtained.
Sl no. | Strain no. | Nearest phylogenetic neighbor | Biochemical tests | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Ind | MR | VP | Cit | Oxi | Cat | Ure | Gel | |||
1 | D24 |
|
− | − | − | + | − | + | + | − |
2 | AL1 |
|
− | − | − | + | − | − | + | − |
3 | AP1 |
|
− | − | − | + | + | + | + | − |
4 | AL3 |
|
− | − | − | + | − | − | + | − |
5 | JD2 |
|
− | − | − | + | − | − | + | + |
6 | KL1 |
|
− | − | − | + | − | − | − | + |
7 | KL5 |
|
− | − | − | + | − | − | − | + |
8 | MB1 |
|
− | − | − | + | − | − | − | + |
9 | MK4 |
|
− | − | − | + | − | − | − | + |
10 | NR4 |
|
− | − | − | + | − | − | − | + |
11 | GD5 |
|
− | − | − | − | − | − | − | − |
12 | NG1 |
|
− | − | − | − | − | − | − | − |
13 | AP2 |
|
− | − | − | − | − | − | − | − |
14 | AP4 |
|
− | − | − | − | − | − | − | − |
15 | GD2 |
|
− | − | − | − | − | − | − | − |
16 | JD4 |
|
− | − | − | − | − | − | − | − |
17 | KL3 |
|
− | − | − | − | − | − | − | − |
18 | KL4 |
|
− | − | − | − | − | − | − | − |
19 | MB3 |
|
− | − | − | − | − | − | − | − |
20 | R1 |
|
− | − | − | − | − | − | − | − |
21 | WN1 |
|
− | − | − | − | − | − | − | − |
22 | WN3 |
|
− | − | − | − | − | − | − | − |
23 | WN4 |
|
− | − | − | − | − | − | − | − |
24 | WN5 |
|
− | − | − | − | − | − | − | − |
25 | MB4 |
|
− | − | − | + | + | + | − | − |
26 | JD1 |
|
+ | + | + | + | + | − | + | − |
27 | R31 |
|
+ | + | + | + | + | − | + | − |
28 | R30 |
|
+ | + | + | + | + | − | + | − |
29 | GD4 |
|
+ | − | + | + | + | + | + | + |
30 | JD3 |
|
+ | − | + | + | + | + | + | + |
31 | MK2 |
|
+ | − | + | + | + | + | + | + |
32 | R26 |
|
+ | − | + | + | + | + | + | + |
33 | NG2 |
|
− | + | − | − | + | + | + | − |
34 | R21 |
|
− | − | + | + | − | + | − | − |
35 | R22 |
|
− | − | + | + | − | + | − | − |
36 | NR2 |
|
− | − | − | + | + | + | − | + |
37 | R6 |
|
− | − | − | + | + | + | − | + |
38 | R7 |
|
− | − | − | + | + | + | − | + |
39 | R23 |
|
− | − | − | + | + | + | − | + |
40 | D22 |
|
− | − | − | + | + | + | − | + |
41 | GD6 |
|
− | − | − | + | + | + | − | + |
42 | MB2 |
|
− | − | − | + | + | + | − | + |
43 | MK3 |
|
− | − | − | + | + | + | − | + |
44 | R8 |
|
− | − | − | − | + | + | − | − |
45 | D12 |
|
− | + | + | − | − | + | − | + |
46 | KL2 |
|
− | + | + | − | − | + | − | + |
47 | NR3 |
|
− | + | + | − | − | + | − | + |
48 | R5 |
|
− | + | + | − | − | + | − | + |
49 | JU1 |
|
− | + | + | − | − | + | − | + |
50 | JU3 |
|
− | + | + | − | − | + | − | + |
51 | JU4 |
|
− | + | + | − | − | + | − | + |
52 | AL4 | Bacillus stratosphericus 41KF2aT AJ831841 | − | + | + | − | − | + | − | + |
53 | R2 |
|
− | + | + | − | − | + | − | + |
54 | D25 |
|
− | + | − | + | − | + | − | − |
55 | JU2 |
|
− | − | − | − | + | − | − | + |
Ind: Indole; MR: Methyl red; VP: Voges Proskeur; Cit: Citrate; Oxi: Oxidase; Cat: Catalase; Ure: Urease; and Gel: Gelatinase.
Coliform is the name of a test adopted in 1914 by the Public Health Service for the
In the present study, species that belonged to the genera
Recent studies on drinking water in rural areas in Northern Rajasthan, India, [
Of the 27 groups, only few (GD4, R5, AP1, and NR2) of the phylogenetic neighbors had been isolated earlier from the drinking water sources including
Isolation of source of the type strains associate with disease.
Sl no. | Nearest phylogenetic neighbor | Isolation source | Associated human disease | Reference |
---|---|---|---|---|
1 |
|
Isolated from a variety of human clinical sources including blood, wounds, sputum, urine, eye, throat, and peritoneal fluid. In addition strains have been isolated from pool water, ground water, and bottled mineral water | Sporadically cause human infections | Vandamme et al., 1999 [ |
| ||||
2 |
|
Isolated from clinical specimens and from eviscerated chickens and may cause ropiness in milk. Isolated from duodenum | Vascular catheter-related bloodstream infection | Seifert et al., 1993 [ |
| ||||
3 |
|
Isolated from human clinical specimens like urine | Septicemia, community-acquired bacterial meningitis, peritoneal dialysis-related peritonitis, and infections associated with corneal perforation | Hung et al., 2009 [ |
| ||||
4 |
|
Isolated from blood of a hospitalized patient with endocarditis | Bacteremia | Loubinoux et al., 2003 [ |
| ||||
5 |
|
Isolated from humans, animals, fish, and fresh water | Acute diarrheal disease | Ljungh et al., 1977 [ |
| ||||
6 |
|
Isolated from canal water | Opportunistic infections like neonatal meningitis | Badger et al., 1999 [ |
| ||||
7 |
|
Found in soil, water, skin flora, and most manmade environments throughout the world | Localized infection of eye, ear, skin, urinary, and respiratory. Bone, joint, gastrointestinal tract, central nervous system, and systemic infection with bacteremia. Secondary pneumonia. Endocarditis | |
| ||||
8 |
|
Common soil and water inhabitant that has rarely been proven a human pathogen | Endocarditis | Valenstein et al., 1983 [ |
| ||||
9 |
|
Isolated from the ears of patients with acute otitis externa (inflammation of the ear) | Inflammation of the ear | Clark et al., 2006 [ |
| ||||
10 |
|
Isolated from the blood of sheep suffering from anthrax | Cutaneous anthrax, pulmonary anthrax, and gastrointestinal anthrax | |
| ||||
11 |
|
Isolated from soil and food materials | Food poisoning |
Todar, 2008 [ |
| ||||
12 |
|
Isolated from a newborn child with sepsis | Sepsis | Ko et al., 2006 [ |
Out of 27 representative taxa are affiliated have eight representative genera in drinking water except for those affiliated with the genera
This study is an overview of drinking water quality in the rural and urban parts of Mahabubnagar District, India. Recent investigations on bacterial contaminations of drinking water in the hospitals suggested risks of secondary infection to the patients, staff, and also patient relatives. These observations were just a drinking water quality assessment, and no data on human health scenario in this region were recorded. Further detailed studies on the health issues of the patients and other people using this contaminated drinking water are still required to trace the impact of this water consumption on people in those hospitals. The lack of awareness about good sanitation and personal hygienic practices, among governmental rural and also urban hospitals is an important factor for poor drinking water quality in these sources.
The authors have no conflict of interests.
The authors are grateful to Profesor Bagyanarayana, Vice-Chancellor, and Profesor K Venkata Chalam, Registrar, Palamuru University, for their encouragement and support. The authors wish to acknowledge the Department of Science and Technology (DST) for their financial assistance for the Project