Presence Of Antibiotic-resistant Bacteria Research Articles

Presence of Antibiotic Resistant Bacteria in Sachet Water Produced and Sold in the Eastern Nigeria

Presence of Antibiotic Resistant Bacteria in Sachet Water Produced and Sold in the Eastern Nigeria

Urban wastewater reuse: a pilot plant experience

The results of a preliminary verification of domestic wastewater reusability in L'Aquila (Italy) are reported. A Tertiary Treatment Pilot Plant (TTPP), rotary filtration and Ultraviolet Radiation (UV) disinfection, was added to an Urban WasteWater Treatment Plant (UWWTP) to test the compliance with water quality indicated for reuse by the enforced Italian regulation. The TTPP was managed varying UV dosages to evaluate disinfection effectiveness. A comparative analysis on two different disinfection systems, UV radiation and chlorination, was carried out. Moreover, a preliminary investigation to detect the presence of antibiotic-resistant bacteria and their sensitivity to the different disinfection systems was carried out.

Antibiotic Susceptibility of Bacteria Isolated from Pasteurized Milk and Characterization of Macrolide-Lincosamide-Streptogramin Resistance Genes

The presence of antibiotic-resistant bacteria in pasteurized milk was detected by plating 18 milk samples on selective media containing β-lactams, macrolides, or a glycopeptide. Most samples contained gram-positive bacteria that grew on agar plates containing oxacillin, erythromycin, and/or spiramycin. The disk-diffusion method confirmed resistance to erythromycin and/or spiramycin in 86 and 65% of the coryneform bacteria and Micrococcaceae tested, respectively. PCR and sequence analysis revealed the presence of an ermC gene in 2 of the 25 Micrococcaceae strains investigated for their resistance to erythromycin and/or spiramycin. None of the 14 corynebacteria strains resistant to erythromycin and/or spiramycin harbored the erm(X) gene. No gene transfer could be demonstrated between the two erm(C) staphylococcal isolates and recipient strains of Enterococcus faecalis JH2-2 or Staphylococcus aureus 80CR5.

Drug resistant bacteria in non carbonated mineral waters

The presence of antibiotic resistant bacteria was revealed among bacteria isolated from non carbonated mineral waters bottled in plastic (PVC) and in glass containers. Heterotrophic plate count values ranged between < 10 and 4.3 × 10 3 and between < 10 and 1.2 × 10 4 colony forming units/ml for the waters bottled in PVC and glass, respectively. The greatest resistance to a single antibiotic, 39.1% of 320 isolates from mineral waters, was found for nalidixic acid. Resistance to the other antibiotics was as follows: ampicillin (26.2%), bacitracin (19.7%), cotrimoxazole (18.7%), streptomycin (15.0%), tetracycline (14.4%), gentamycin (11.6%), chloramphenicol and rifampin (9.7%). The strains resistant to two or more antibiotics (multiple antibiotic resistant, MAR) provided 51% of the total isolates. Identification of 127 MAR strains showed that in the mineral waters gram-positive cocci dominated. The second, third and fourth group of identified MAR pheno-types were, in order to importance, gram-negative non-fermentative rods, gram-positive rods and gram-negative fermentative rods. The importance of the antibiotic resistant bacteria in mineral water is discussed.

Antibiotic resistant gram-negative bacteria in rural groundwater supplies

More than 250 coliform and noncoliform bacteria, isolated by standard membrane filtration methods from rural, untreated groundwater supplies, were examined for resistance to 16 antibiotics. All of the noncoliforms and 87% of the coliforms were resistant to at least one antibiotic, with resistance most commonly directed toward novobiocin, cephalothin, and ampicillin. The frequency of multiple antibiotic resistance (MAR) within each species was also determined. Approximately 60% of the coliforms were MAR, including 14, 64, and 94% of Escherichia coli, Citrobacter freundii, and Enterobacter cloacae isolates, respectively. In comparison, MAR was demonstrated by more than 95% of the noncoliforms and included isolates of Acinetobacter calcoaceticus, Aeromonas hydrophila, and Serratia marcescens. Ampicillin-resistant environmental isolates were assayed for ability to transfer resistance to ampicillin-sensitive strains of E. coli and Salmonella typhimurium. Environmental E. coli isolates were capable of in vitro transfer to both recipients in a nutrient-rich environment (trypticase soy broth) at frequencies ranging from 1.1 × 10 −5 to 1.0 × 10 −4. Isolates of C. freundii and Klebsiella pneumoniae exhibited resistance transfer to the E. coli recipient under similar conditions at reduced rates. None of the environmental isolates demonstrated transfer of ampicillin resistance when placed in an environment containing filter-sterilized well water. The presence of antibiotic resistant bacteria, and particularly MAR bacteria, in rural groundwater supplies used as drinking water sources may have important public health implications.

The Need for New Microbiological Water Quality Criteria

The microbiological criteria for water quality have been directed towards protection of consumers from possible microbial pollution which may cause public health hazards. Therefore, the bacteriological standards for drinking water are based mainly on bacterial indicators. Another problem of prime concern to public health is the presence of antibiotic-resistant bacteria in drinking water Antibiotic–resistant bacteria were found among standard plate count populations of Chlorinated drinking water from two districts in Cairo. Most strains appeared to be ampicillin resistant (89%). Those were followed by sulfaguanidine (78%) and streptomycin (57%). The majority of the tested strains (62.4 to 98%) were multiple antibiotic resistant (MAR). Identification of 363 MAR strains revealed that Gram-positive rods were dominant, while Gram-negative fermentative rods, Gram-positive cocci and Gram-negative nonfermentative rods represent the second, third and fourth group. A total of 101 strains isolated from underground water pumped from three water works in Cairo were classified and tested for their resistance towards four commonly used antibiotics; chloramphenicol, tetracycline, neomycin, penicillin and one chemotherapeutic agent namely sulfanilamide pyrimidine. Results showed that 77, 64 and 32 isolates have resistance towards penicillin, sulfanilamide pyrimidine and tetracycline, respectively. Only 18 and 8 isolates were resistant to chloramphenicol and neomycin, respectively. It was also found that 19 isolates belonging to 6 genera or groups were sensitive towards all of the tested compounds. Therefore, any source of antibiotic~resistant bacteria must be viewed with concern and use of data on MAR bacteria should be made in future water quality deliberations and in regulating effluent quality discharges.

Incidence of antibiotic resistant bacteria in drinking water in Cairo

The presence of antibiotic resistant bacteria was found among standard plate count (SPC) populations of chlorinated drinking water from two districts in Cairo. SPC values obtained were low, ranging between 20 and 3 800 mL−1. Most strains appeared to be ampicillin resistant (89.7%). Those were followed by sulfaguanidine (78.1%) and streptomycin (56.9%). The majority of the tested strains were resistant to two or more antibiotics (multiple antibiotic resistant, MAR) which represent 62.4 to 98 % of the total isolates of the mean obtained in a month. Identification of 363 MAR strains revealed that gram-positive rods were dominant in chlorinated drinking water. Gram-negative fermentative-rods, gram-positive cocci and gramnegative nonfermentative rods represent the second, third and fourth group of the identified MAR phenotypes. The impact of the antibiotic resistant bacteria in drinking water as a health hazard is discussed.