Multiple Antibiotic Resistance Patterns Research Articles

Bacterial load, multiple antibiotic-resistance patterns, and cytotoxic effects of coliform and coliform-related bacteria associated with the surface water of dhaka city

The surface water quality of Dhaka Metropolitan City was studied from June to December 2022, with special attention to coliform bacterial pollution. The aerobic heterotrophic bacteria, total coliform, and fecal coliform were high in Buriganga and Shitalakshya River water compared to other selected water bodies. The physico-chemical parameters of the selected rivers and lakes were unsatisfactory. A total of 110 isolates were obtained, of which 26 were selected for further study. Twelve Gram-positive isolates belonged to the genera Enterococcus, Micrococcus, Planococcus and Bacillus. Fourteen Gram-negative isolates belonged to the genera Escherichia, Klebsiella, Enterobacter, Alcaligenes, Pseudomonas, Plesiomonas, Aeromonas and Salmonella. Most of the Gram-negative bacteria were multiple antibiotic resistant (MAR). Plesiomonas shigelloides showed the highest MAR (50%). Klebsiella oxytoca (MAR 40%) and E. coli (MAR 30%) showed a positive cytotoxic effect on the non-cancer cell line. Coliform bacteria associated with the surface water of Dhaka City pose a serious health threat to city dwellers. Bangladesh J. Bot. 53(1): 41-48, 2024 (March)

Molecular identification and antibiotic resistance patterns of diverse bacteria associated with shrimp PL nurseries of Bangladesh: suspecting Acinetobacter venetianus as future threat.

Shrimp aquaculture has been accomplished with breeding and nursing of shrimp in an artificial environment to fulfill the increasing demand of shrimp consumption worldwide. However, the microbial diseases appear as a serious problem in this industry. The study was designed to identify the diverse bacteria from shrimp PL (post-larvae) nurseries and to profile antibiotic resistance patterns. The rearing water (raw seawater, treated and outlet water) and shrimp PL were collected from eight nurseries of south-west Bangladesh. Using selective agar plates, thirty representative isolates were selected for 16S rRNA gene sequencing, antibiotic susceptibility test and MAR index calculation. Representative isolates were identified as Aeromonas caviae, Pseudomonas monteilii, Shewanella algae, Vibrio alginolyticus, V. brasiliensis, V. natriegens, V. parahaemolyticus, V. shilonii, V. xuii, Zobellella denitrificans which are Gram-negative, and Bacillus licheniformis and B. pumilus which are Gram-positive. Notably, six strains identified as Acinetobacter venetianus might be a concern of risk for shrimp industry. The antibiotic resistance pattern reveals that the strain YWO8-97 (identified as P. monteilii) was resistant to all twelve antibiotics. Ceftazidime was the most powerful antibiotic since most of the studied strains were sensitive against it. The six strains of A. venetianus showed multiple antibiotic resistance patterns. MAR index were ranged from 0.08 to 1.0, and values of 26 isolates were more than 0.2 which means prior high exposure to the antibiotics. From the present study, it can be concluded that shrimp PL nurseries in southern part of Bangladesh are getting contaminated with antibiotic resistant pathogenic bacteria.

ANTIBACTERIAL ACTIVITY OF VERNONIA AMYGDALINA EXTRACTS AGAINST MULTI-DRUG RESISTANT GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA

Abstract: The incidence of antibiotic resistance is one of the challenges in the treatment of different ailments. Hence, this study focused on the use of V. amygdalina (ethanolic and methanolic) extracts on some selected bacterial isolates. Different concentrations of the extracts were prepared and the residues were re-suspended in the solvents. The zone of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiotic susceptibility patterns were determined according to standard methods. The ethanolic extract appeared to produce better antibacterial effect than methanolic extract. K. pneumoniae and S. marcescens were inhibited by ethanolic extract of 12.5-200mg/ml used. However, only S. aureus was inhibited by all methanolic extract concentrations used. Most of the isolates (83.3%) had lower MIC in ethanolic extract when compared with methanolic extract. The MIC of the isolates in the ethanolic and methanolic extracts ranged from 12.5-100mg/ml and 25-100mg/ml respectively. Two of the isolates, B. cereus and K. pneumoniae did not cease to grow on MBC plates even at the highest concentration of 200mg/ml used. All the isolates showed multiple antibiotic resistance patterns with AMR index range of 0.63-1.0. All the isolates were resistant to augmentin, cefexime, cefuroxime, ceftazidime and nitrofurantoin. The order of susceptibility of the isolates to the antibiotics were gentamicin (83.3%) > ofloxacin (66.7%) > ciprofloxacin (33.3%). It is concluded in this study that the extracts of V. amygdalina inhibited 83% of the isolates at lower concentration of 25mg/ml, were bactericidal at 100-200mg/ml for 66.7% of the isolates and produced higher inhibition zone in comparison with the standard antibiotics on the isolates.

Isolation, Identification and Antibiotic Susceptibility of Escherichia coli Isolated from Raw Meat from Modake and Ile-Ife, Osun State, Nigeria

The study reported isolation, identification and antibiotic susceptibility of Escherichia coli isolated from raw meat from Modakeke and Ile-ife, Osun State, Nigeria, with the view to determining the antibiogram profiling of the bacterial isolates. 
 In this study, five samples of fresh meat were collected from different abattoirs in Ile-Ife and Modakeke, Osun State. Isolates of Escherichia coli were isolated, identified morphologically based on their growth on nutrient agar and subjected to antibiotic susceptibility test on Mueller Hinton agar. The mean microbial load from the meat samples ranged from 8.85 x 102cfu/ml to 5.77 x 104cfu/ml. A total of 69 E. coli isolates were recovered from the meat sampled. All the isolates appeared cream, translucent, entire, convex, circular, smooth and glistering. The isolates were identified as Gram negative rods, non-motile, lactose fermenters, positive for indole test and negative for citrate utilization test. All the E. coli isolates were resistant to augmentin, ceftriazone, nitrofurantoin and gentamycin. 98.55% of E. coli isolated was resistant to amoxillin and the least resistant was recorded in ofloxacin (8.70%). However, 91.30% of the E. coli isolates was sensitive to ofloxacin, 81.16% to ciprofloxacin and 36.23% to pefloxacin while none was sensitive to augmentin, ceftriazone, nitrofurantoin and gentamycin. A total of 19 different multiple antibiotic resistance patterns were observed among the isolates. Thirty isolates (43.48%) showed multiple antibiotic resistance to 5 and 10 different antibiotic types each.
 The study concluded that occurrence of E. coli infection is high in the study area with high level of multiple antibiotic resistance.

Investigation of TEM and SHV Beta-Lactamase Genes in Escherichia coli Isolated from Strawberry Samples in Sanandaj, Iran

Background: When animal manures are used, food products may include pathogenic bacteria, especially Escherichia coli. The major aim of the current study was to investigate TEM (blaTEM) and SHV beta-lactamase (blaSHV) genes in E. coli isolated from strawberry samples in Sanandaj, Iran.
 Methods: In this study, 150 strawberry samples were collected from farms (traditional), greenhouses, and packages in Sanandaj, Iran. E. coli contamination was done using routine culture methods. Then, isolates were investigated for Extended-Spectrum Beta-Lactamase (ESBL) production and blaTEM or blaSHV genes using phenotypic and genotypic methods, respectively.
 Results: The most susceptibility and resistance of E. coli to antibiotics were related to chloramphenicol and trimethoprim/sulfamethoxazole, respectively. Out of 21 isolates of E. coli, eight were resistant to ceftazidime and cefotaxime; from which, six isolates were ESBL-producer. Furthermore, Polymerase Chain Reaction (PCR) analysis of six ESBL- producing E. coli isolates showed that four isolates included blaTEM gene, while no isolates included blaSHV gene.
 Conclusion: In this study, multiple antibiotic resistance patterns were seen in E. coli isolates, especially ESBL patterns in E. coli isolated from strawberries produced in Iran.

English

Phenotypic and molecular characterization of multiple antibiotic resistant Gram-negative bacteria in urine samples of pregnant women in Mother and Child Hospital, Nigeria was reported. In the study, 407 apparently healthy pregnant women were recruited. Structured questionnaire was administered to the patients to obtain their socio-demographic information and the medical history. Urine samples were collected, processed and analysed using standard microbiological procedures. Detailed identification of the bacteria isolates was done using biochemical characterization using Bergey’s Manual of Determinative Bacteriology and Analytical Profile Index (API) Kit. The antimicrobial susceptibility testing of the bacteria isolates was carried out using the Kirby-Bauer’s disk diffusion technique. Detection of the beta lactamase resistance genes (bla CTX-M and Tet A) was done by polymerase chain reactions (PCR) with appropriate primers. The following Gram-negative bacteria were recovered comprising Pseudomonas aeruginosa 48 (34.0%), Escherichia coli 30 (21.3%), Klebsiella sp. 27 (19.1%), Proteus sp. 15 (10.6%), Salmonella sp. 8 (5.7%), Providencia rettgeri, 4 (2.8%) and Enterobacter cloacae 4(2.8%) and other enterobacteriaceae 5 (3.5%). Resistance of the isolates to antibiotics used varied greatly among the isolates. Resistance to antibiotics was highest with P. aeruginosa having 100% to augumentin, tetracylines, amoxicillin, nitrofurantoin, cotrimoxazole, ceftriazone, cefixime (97.9%) and cefuroxime (95.8%). There was diversity in the multiple antibiotic resistance (MAR) patterns among the isolates with 12 different MAR patterns observed. The selected P. aeruginosa profiled for resistance genes harboured bla-CTX-M (585bp) and Tet A (954bp) genes. The multiple antibiotic resistant bacteria recovered could pose great health challenge to the pregnant women and the unborn foetus.   Key words: Gram negative bacteria, antibiotics, enterobacteriaceae, resistance genes.

Prosthetic Joint Infection Microorganism Pattern and Risk Factor Profile: A Single Center Study

Introduction: Prosthetic joint infection (PJI) is a serious complication especially following arthroplasty surgeries. The outcome of these cases is affected by the pattern of infection, causative microorganism, and antibiotic resistance. This study was aimed to evaluate the prevalence of PJI, distribution of causative microorganism, antibiotic resistance, and risk factor profiling.Methods: A retrospective review was performed by arthroplasty registry evaluation from 2008-2018, followed by a medical record review and patient interview. Distribution of causative microorganisms, antibiotic resistance patterns, and the onset of infection was extracted. Risk factor evaluation was performed by assessing preoperative (age, body mass index (BMI), frailty index) and perioperative parameters (duration of surgery, number of previous surgeries, the interval between those surgeries). Results: Seventeen patients were diagnosed with PJI (13 hip and 4 knees), with a prevalence of 1.56% and 1.77% respectively. The most common causative organism was Staphylococcus aureus and Escherichia coli with multiple antibiotic resistance patterns. These infections mostly occurred in patients with the age of 40-60 years, BMI 30kg/m2, and pre-operative frailty index of 4. The perioperative risk factor was the duration of surgery for more than 3 hours, have undergone more than 3 surgeries with an average surgical interval of 2 months.Conclusions: The prevalence of PJI in this series was 1.56% in hip and 1.77% in the knee. The risk factor profile showed that most cases have high BMI, prolonged duration of surgery, and a high number of previous surgeries within a short interval.

Isolation, characterization and antibiotic resistance profile studies of bacteria from an excavated pond in Port Harcourt Metropolis, Nigeria

The Antibiotic Resistance profile of bacteria isolated from Rumuola pond water in the Port Harcourt metropolis, Rivers State, Nigeria was investigated. Total of 48 bacterial species were isolated on Nutrient Agar and a set of selective diagnostic media. The isolates were identified as Escherichia coli , Staphylococcus sp.; Shigella sp.; Klebsiella sp.; Vibrio sp.; and Salmonella sp. The total culturable heterotrophic bacterial count (TCHB) and faecal coliform count of the water samples ranged from 1.02 x 10 6 – 1.90 x 10 6 cfu/ml and 3.70x 10 5 – 8.15x10 5 cfu/ml respectively. The sensitivity of the isolates from the water samples to 12 different antibiotics selected was ascertained on Muller-Hinton agar using the Kirby-Bauer disc diffusion method. The zone diameter obtained was interpreted using the Clinical Laboratory Standard International (CLSI) and British Society for Antimicrobial Chemotherapy (BSAC) zone diameter breakpoints. Isolates were recorded as susceptible (S), intermediate susceptible (I) or resistant (R) based on the guidelines. The level of resistance exhibited by the isolates to specific antibiotics used were; Lincocin 74.8%, Rifampicin 71.4%, Augumentin 71.2%, Chloramphnicol 68.2%, Erythromycin 64.3%, Cotrimoxazole 55.8%, Streptomycin 50.2%, Pefloxacin 48.6%, Gentamycin 43%, Norfloxacin 42.9%, Ofloxacin 16.2%, Ciprofloxacin 13%. The resistance to Lincocin (74.8%) was the highest followed by Rifampicin (71.4%). The highest level of bacterial resistance pattern to all tested antibiotics was observed in sites with highest human activities. The result showed multiple antibiotic resistance patterns among the bacterial isolates suggesting a pool of resistance genes among isolates in the pond. Most of the bacterial isolates are potential pathogens. Modern health services for effective disease management for this community would include antibiotic/drug mapping for individuals. Keywords: Antibiotic Resistance, Rumuola Pond, Port Harcourt

Safety Evaluation of Enterocin Producer Enterococcus sp. Strains Isolated from Traditional Turkish Cheeses

The purpose of this study was to determine the antimicrobial activity and occurrence of bacteriocin structural genes in Enterococcus spp. isolated from different cheeses and also investigate some of their virulence factors. Enterococcus strains were isolated from 33 different cheeses. Enterococcus faecium (6 strains) and Enterococcus faecalis (5 strains) enterocin-producing strains were identified by 16S rDNA analyses. Structural genes entA, entB, entP and entX were detected in some isolates. Multiple enterocin structural genes were found in 7 strains. None of the tested enterococci demonstrated anyβ-haemolytic activity and only one strain had gelatinase activity. Six strains showed multiple antibiotic resistance patterns and in addition, vanA and several virulence genes were detected in many strains. Only E. faecalis MBE1-9 showed tyrosine decarboxylase activity and tdc gene was detected only in this strain.

Induction of Shiga Toxins in Escherichia coli O157: H7 Isolated from Groundwater in the North West Province, South Africa Intended for Human Consumption Using Ampicillin and Tetracycline

AbstractA total of 67 isolates from groundwater were used to determine their susceptibilities against 7 antibiotics and the Multiple Antibiotic Resistance (MAR) patterns were compiled. Most isolates were resistant to amocyxillin, ampicillin, chloramphenicol and penicillin G. MAR phenotype A-AP-K-NE-OT-C-PG was dominant among isolates from Rustenburg. However, in Carletonville and Delareyville the phenotypes A-AP-C-PG and A-AP-OT-PG were obtained at 87.5 percent and eighty percent, respectively. The isolates were screened for the presence of shiga toxin genes by PCR analysis and none were positive. Moreover, when the E. coli O157:H7 isolates were subjected to antibiotic treatment for the induction of shiga toxins using both ampicillin and tetracycline in broth cultures, no shiga toxins were detected with an ELISA assay after 24 hours of incubation. However, after 72 hours of treatment with these antibiotics shiga toxins were detected in a large proportion (89.6%) of E. coli O157:H7 isolates with ampicillin...

Resistance to antimicrobial agents among enterococci isolated from fecal samples of wild marine species in the southern coast of Brazil

The purpose of this study was to evaluate species distribution, antimicrobial resistance profiles, and presence of resistance genes in enterococci isolated from fecal samples of wild marine species, including seabirds (n=12), sea turtles (n=8), and mammals (n=3) found alive or dead in southern coast of Brazil. Enterococci were classified based on phenotypic and genotypic characteristics, tested for antibiotic susceptibility, and the presence of tet(S), tet(M), tet(L), mrsC, and erm(B) genes by PCR. Enterococcus faecalis and Enterococcus faecium were the most common species. Single (37.09%), double (25.80%), and multiple (16.12%) antibiotic resistance patterns were observed. Resistance to rifampicin occurred most frequently. The msrC, tet(M), and/or tet(L) genes were detected in 60.15%, 73.07%, and 23.07% of the resistant strains, respectively. In conclusion, the presence of antibiotic resistant strains in these species could be related to food web interactions and aquatic pollutants or linked to environmental resistome.

Multiple Antibiotic Resistance Patterns of the Enterobacteriaceae in the Untreated Municipal Sewage.

Multiple Antibiotic Resistance Patterns of the Enterobacteriaceae in the Untreated Municipal Sewage.

Detection of Gelatinase and Haemolysin among clinical isolates of Enterococci

Enterococci are normally considered as bacteria with low pathogenicity, which could cause infections in persons with immunodeficiency diseases. Conversely, enterococci have emerged as nosocomial pathogens and cause serious dreadful diseases in individuals with increasing antibiotic resistance. A sum of 20 clinical isolates of Enterococci spp were determined for antibiotic sensitivity pattern and detected for gelatinase and haemolysin production. We have observed multiple antibiotic resistant pattern to most of the drug used in this study and varied pattern of positivity for gelatinase and hemolysin. This indicates that the extracellular enzymes are playing a crucial role in causing infections in human beings.

Relatively high antibiotic resistance among heterotrophic bacteria from arctic fjord sediments than water – Evidence towards better selection pressure in the fjord sediments

The objective of this study was to determine the prevalence of antibiotic resistance among aerobic heterotrophic bacteria and coliform bacteria from water and sediment of Kongsfjord. The study was based on the assumption that arctic fjord environments are relatively pristine and offer very little selection pressure for drug resistant mutants. In order to test the hypothesis, 200 isolates belonging to aerobic heterotrophic bacteria and 114 isolates belonging to coliforms were tested against 15 antibiotics belonging to 5 different classes such as beta lactams, aminoglycosides, quinolones, sulpha drugs and tetracyclines. Resistance to beta lactam and extended spectrum beta lactam (ESBL) antibiotics was considerably high and they found to vary significantly (p < 0.05) between heterotrophic and coliform bacteria. Though the coliforms showed significantly high level of antibiotic resistance against ESBL's extent and diversity of antibiotic resistance (as revealed by multiple antibiotic resistance index and resistance patterns), was high in the aerobic heterotrophic bacteria. Most striking observation was that isolates from fjord sediments (both heterotrophic bacteria and coliforms) in general showed relatively high prevalence of antibiotic resistance against most of the antibiotics tested, indicating to better selection pressure for drug resistance mutants in the fjord sediments.

Environmental waters as a source of antibiotic-resistant Enterococcus species in Belgrade, Serbia.

Despite the number of studies on antibiotic-resistant enterococci from Serbian clinical settings, there are no data about environmental contamination with these bacteria. Thus, this study investigated the prevalence of antibiotic-resistant enterococci in Belgrade, Serbia. Enterococcus species collected from ten surface water sites, including a lake, two major river systems, and springs, were tested. Among enterococci, we found single (21.7 %), double (17.4 %), and multiple antibiotic resistance patterns (56.3 %). Vancomycin-resistant strains were not found, indicating that their abundance in Belgrade is tightly linked to clinical settings. The multiple drug-resistant strains Enterococcus faecalis, Enterococcus faecium, and Enterococcus mundtii were frequently detected in the lake during the swimming season and in the rivers near industrial zones. We confirmed the presence of ermB, ermC, ant(6)-Ia, tetM, and tetL and mutations in gyrA genes. The phylogenetic analysis of 16S rRNA gene of E. faecium isolates that harbor esp gene classified them into two groups based on high-bootstraps scores in the tree analysis. Pulsed-field gel electrophoresis analysis of antibiotic-resistant enterococci revealed genomic similarity ranging from 75 to 100 %. This study indicates the importance of anthropogenic impact to the spread of antibiotic-resistant enterococci in environmental waters of Belgrade, Serbia.

Transferable antibiotic resistance plasmids from biogas plant digestates often belong to the IncP-1ε subgroup.

Manure is known to contain residues of antibiotics administered to farm animals as well as bacteria carrying antibiotic resistance genes (ARGs). These genes are often located on mobile genetic elements. In biogas plants (BGPs), organic substrates such as manure and plant material are mixed and fermented in order to provide energy, and resulting digestates are used for soil fertilization. The fate of plasmid carrying bacteria from manure during the fermentation process is unknown. The present study focused on transferable antibiotic resistance plasmids from digestates of seven BGPs, using manure as a co-substrate, and their phenotypic and genotypic characterization. Plasmids conferring resistance to either tetracycline or sulfadiazine were captured by means of exogenous plasmid isolation from digestates into Pseudomonas putida KT2442 and Escherichia coli CV601 recipients, at transfer frequencies ranging from 10-5 to 10-7. Transconjugants (n = 101) were screened by PCR-Southern blot hybridization and real-time PCR for the presence of IncP-1, IncP-1ε, IncW, IncN, IncP-7, IncP-9, LowGC, and IncQ plasmids. While 61 plasmids remained unassigned, 40 plasmids belonged to the IncP-1ε subgroup. All these IncP-1ε plasmids were shown to harbor the genes tet(A), sul1, qacEΔ1, intI1, and integron gene cassette amplicons of different size. Further analysis of 16 representative IncP-1ε plasmids showed that they conferred six different multiple antibiotic resistance patterns and their diversity seemed to be driven by the gene cassette arrays. IncP-1ε plasmids displaying similar restriction and antibiotic resistance patterns were captured from different BGPs, suggesting that they may be typical of this environment. Our study showed that BGP digestates are a potential source of transferable antibiotic resistance plasmids, and in particular the broad host range IncP-1ε plasmids might contribute to the spread of ARGs when digestates are used as fertilizer.

Determination of Antibiotic Resistance and Biogenic Amine Production of Lactic Acid Bacteria Isolated from Fermented Turkish Sausage (Sucuk)

AbstractThe aim of this study was to isolate lactic acid bacteria (LAB) from sucuk and to determine their antibiotic resistance and biogenic amine production abilities. A total of 65 presumptive LAB were isolated and they were molecularly identified as Pediococcus acidilactici (47.7%), Enterococcus faecium (36.9%), Lactobacillus sakei ssp. carnosus (4.6%), Lactobacillus sakei ssp. sakei (4.6%), Pediococcus pentosaceus (3.1%), Enterococcus faecalis (1.5%) and Weissella viridescens (1.5%) by sequencing 16S rDNA. The LAB were found resistant to clinically relevant antibiotics to cure infections. Sixty‐eight percent of the Enterococcus strains and the other entire LAB displayed resistance from 2 to 8 of the antibiotics tested. All LAB did not decarboxylate histidine, lysine or ornithine. The decarboxylase genes (hdc, ldc and odc) were not detected in LAB. However, 68.0% of the Enterococcus strains decarboxylated tyrosine. The tyrosine decarboxylase gene (tdc) was also detected in these tyraminogenic strains.Practical ApplicationsLactic acid bacteria (LAB) are one of the most important groups of bacteria that are known to be technologically important in the production of dry‐fermented sausages such as sucuk. The present study describes isolation, identification of LAB from sucuk and determines their antibiotic resistance and biogenic amine production abilities. LAB isolated from sucuk samples were found resistant to clinically important antibiotics and most of them have multiple antibiotic resistance patterns. The findings of our study suggest that LAB in sucuk may play a role to spread the antibiotic resistance between other bacteria including pathogens. In addition, most of the Enterococcus strains isolated from sucuk produce tyramine. For these reasons, LAB isolated from sucuk may have a potential risk to consumer health indirectly.

Phenotypic Identification and Phylogenetic Characterization of Uropathogenic Escherichia coli in Symptomatic Pregnant Women With Urinary Tract Infections in South-Western Nigeria

The study reports the characterization of uropathogenic E. coli (UPEC) in urine samples of pregnant women with confirmed urinary tract infections (UTIs) in Ondo and Ekiti States, Nigeria. Voided mid-stream urine samples were cultured on eosin methylene blue agar plates at 37oC and identified by conventional biochemical tests. Antibiotic susceptibility testing of isolates was by Kirby-Bauer’s disc diffusion technique. Phylogenetic typing of the isolates was by multiplex polymerase chain reaction (PCR). The occurrence of UPEC in pregnant women in age group 25-35 years (66.0%) was high. Two hundred and sixty four uropathogenic E. coli comprising 133 (50.38%) in Ondo and 131 (49.62%) in Ekiti States were recovered from 400 samlpes analyzed. In all, prevalence of UTIs with positive cultures was 66.0%. Escherichia coli only was 56.5%, mixed-infection (9.5%), non-E. coli infection (12.5%) and no growth (21.5%). Resistance to antibiotics was high with diverse multiple antibiotic resistance patterns. Greater percentage of the screened representative UPEC isolates belonged to phylogenetic group D (65.0%), group A (28.0%), group B1 (6.7%) and none to group B2. Escherichia coli belonging to phylogenetic group D appears to be a predominant uropathogen in this study area. Presence of chuA gene in most of the isolates shows the significance of iron acquisition in the pathogenesis and urovirulence of UPEC.

English

The presence of Salmonella and human pathogens in unpasteurized milk remains a public health hazard. The study reported the phenotypic and molecular characterization of Salmonella serotypes in cow raw milk, cheese and traditional yoghurt marketed for man’s consumption in Nigeria. Isolation of Salmonella was done on Salmonella and Shigella agar by pour plate method at 37°C. Susceptibility to antibiotics was determined by the disc diffusion method. Molecular characterization of the Salmonella serotypes and detection of some target genes was done by the polymerase chain reaction. All the isolates were sensitive to ofloxacin and nalidixic acid. Resistance to antibiotics was in varying proportions with amoxicillin (95.2%), tetracycline (90.4%) and augumentin (28.5%). Ten (10) different multiple antibiotic resistance patterns were observed among the serotypes. The serotypes identified include Salmonella typhi , Salmonella typhimurium and Salmonella enteritidis , and the serogroups include D (28.6%), B (52.4%), D 1 (28.6%), respectively. The invA genes were amplified in all the Salmonella serotypes while fliC and fliB genes were absent. The rfbJ gene was detected only in S . Typhimurium. The recovery of multiple antibiotic resistant pathogenic Salmonella serotypes in cheese and yoghurt samples in the study is of great health concern. Keywords: Salmonella serotype, molecular characterization, virulence genes, antibiotics African Journal of Biotechnology , Vol 13(37) 3774-3789

Prevalence and characterisation of non-cholerae Vibrio spp. in final effluents of wastewater treatment facilities in two districts of the Eastern Cape Province of South Africa: implications for public health.

Vibrios and other enteric pathogens can be found in wastewater effluents of a healthy population. We assessed the prevalence of three non-cholerae vibrios in wastewater effluents of 14 wastewater treatment plants (WWTP) in Chris Hani and Amathole district municipalities in the Eastern Cape Province of South Africa for a period of 12 months. With the exception of WWTP10 where presumptive vibrios were not detected in summer and spring, presumptive vibrios were detected in all seasons in other WWTP effluents. When a sample of 1,000 presumptive Vibrio isolates taken from across all sampling sites were subjected to molecular confirmation for Vibrio, 668 were confirmed to belong to the genus Vibrio, giving a prevalence rate of 66.8 %. Further, molecular characterisation of 300 confirmed Vibrio isolates revealed that 11.6 % (35) were Vibrio parahaemolyticus, 28.6 % (86) were Vibrio fluvialis and 28 % (84) were Vibrio vulnificus while 31.8 % (95) belonged to other Vibrio spp. not assayed for in this study. Antibiogram profiling of the three Vibrio species showed that V. parahaemolyticus was ≥50 % susceptible to 8 of the test antibiotics and ≥50 % resistant to only 5 of the 13 test antibiotics, while V. vulnificus showed a susceptibility profile of ≥50 % to 7 of the test antibiotics and a resistance profile of ≥50 % to 6 of the 13 test antibiotics. V. fluvialis showed ≥50 % resistance to 8 of the 13 antibiotics used while showing ≥50 % susceptibility to only 4 antibiotics used. All three Vibrio species were susceptible to gentamycin, cefuroxime, meropenem and imipenem. Multiple antibiotic resistance patterns were also evident especially against such antibiotics as tetracyclin, polymixin B, penicillin G, sulfamethazole and erythromycin against which all Vibrio species were resistant. These results indicate a significant threat to public health, more so in the Eastern Cape Province of South Africa which is characterised by widespread poverty, with more than a third of the population directly relying on surface water sources for drinking and daily use.