Multidrug-resistant Enteric Bacteria Research Articles

Multidrug-Resistant Enteric Bacteria in the Water Sources of Kalgo Metropolis, Nigeria

The high incidence of diseases, such as diarrhoea, typhoid fever, cholera, and bacillary dysentery among the populace, especially in remote and developing areas, has been traced to the domestic use of contaminated water. This study aimed to isolate enteric bacteria in major drinking water sources situated within the Kalgo metropolis, Nigeria. Three water samples were aseptically collected in triplicates from three different areas of the city. After serial dilution, the samples were inoculated on nutrient agar and each sample's total viable bacterial count was taken. The enteric bacteria were isolated and identified using standard protocols. The isolates were subjected to antibiotic sensitivity test using the Kirby Bauer disk diffusion method. The inhibition zones were measured in millimeters(mm). Seven (7) different species of bacteria were isolated from the collected water samples.The isolated organisms included Shigella spp., Serratia spp., Klebsiella spp., Escherichia coli, Proteus spp., Yersinia spp., and Salmonella spp. Among these bacterial isolates, E. coli and Salmonella spp.were found to have the highest frequency of 29.63% and 25.93%, respectively. While, Serratia spp.had the lowest frequency of 3.9%. The sensitivity profile showed that E. coli, Salmonella spp.,Klebsiella spp., Shigella spp., and Serratia spp. were resistant to ampicillin. In contrast, Proteus spp. and Yersinia spp. showed high and intermediate susceptibility, respectively.The presence of multidrug-resistant enteric bacteria in water samples suggests the need to improve water quality through its assessment and treatment before use.

Conjugative RP4 Plasmid-Mediated Transfer of Antibiotic Resistance Genes to Commensal and Multidrug-Resistant Enteric Bacteria In Vitro

Many antibiotic-resistant bacteria carry resistance genes on conjugative plasmids that are transferable to commensals and pathogens. We determined the ability of multiple enteric bacteria to acquire and retransfer a broad-host-range plasmid RP4. We used human-derived commensal Escherichia coli LM715-1 carrying a chromosomal red fluorescent protein gene and green fluorescent protein (GFP)-labeled broad-host-range RP4 plasmid with ampR, tetR, and kanR in in vitro matings to rifampicin-resistant recipients, including Escherichia coli MG1655, Dec5α, Vibrio cholerae, Pseudomonas putida, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter rodentium, and Salmonella Typhimurium. Transconjugants were quantified on selective media and confirmed using fluorescence microscopy and PCR for the GFP gene. The plasmid was transferred from E. coli LM715-1 to all tested recipients except P. aeruginosa. Transfer frequencies differed between specific donor-recipient pairings (10-2 to 10-8). Secondary retransfer of plasmid from transconjugants to E. coli LM715-1 occurred at frequencies from 10-2 to 10-7. A serial passage plasmid persistence assay showed plasmid loss over time in the absence of antibiotics, indicating that the plasmid imposed a fitness cost to its host, although some plasmid-bearing cells persisted for at least ten transfers. Thus, the RP4 plasmid can transfer to multiple clinically relevant bacterial species without antibiotic selection pressure.

In-vivo Antibacterial and Synergetic Effect of Garlic (Allium sativum Linn) and Water Lilies (Nymphae lotus Linn) Extracts on Multi-Drug Resistant Enteric Bacteria

Enteric bacterial pathogens are the major causes of food-bourne diseases and remains a crucial global health concern. The emergence of multi-drug resistant enteric bacterial has been a major public health concern especially in developing countries of the world. The in-vivo antibacterial and synergetic effect of garlic (Allium sativum Linn) and water lilies (Nymphae lotus Linn) extracts on multi-drug resistant enteric bacteria was examined using experimental mice obtained from animal house, College of Medicine, Obafemi Awolowo University, Ile-Ife, Nigeria in accordance with laboratory practice regulation and the principle of humane laboratory animal care. The histological effects of treatment with water extract of A. sativum, ethanol extract of N. lotus and combination of water extract of A. sativum and ethanol extract of N. lotus at ratio 1:1 on organs invasion of Salmonella showed that major pathological effects were exerted on the liver and kidney of mice. The findings for this study suggests that the extracts of N. lotus and A. sativum may be used as antibacterial agents in the management of infections that may occur as a result of consumption or contact with faecally impacted surface waters.

Occurrence of potentially zoonotic and cephalosporin resistant enteric bacteria among shelter dogs in the Central and South-Central Appalachia

BackgroundAntimicrobial resistance and presence of zoonotic enteropathogens in shelter dogs pose a public health risk to shelter workers and potential adopters alike. In this study we investigated the prevalence of zoonotic bacterial pathogens and cephalosporin resistant (CefR) enteric bacteria in the feces of apparently healthy shelter dogs in the Cumberland Gap Region (CGR) in the US states of Kentucky, Tennessee and Virginia.ResultsFecal samples of 59 dogs from 10 shelters in the CGR of Central and South-Central Appalachia were screened for the presence of Campylobacter jejuni, Clostridium perfringens, Salmonella and CefR enteric bacteria. C. jejuni, C. perfringens were detected by PCR based assays. Culture and PCR were used for Salmonella detection. Of 59 dogs, fecal samples from 14 (23.7%) and 8 (13.6%) dogs tested positive for cpa and hipO genes of C. perfringens and C. jejuni, respectively. Salmonella was not detected in any of the tested samples by PCR or culture. CefR enteric bacteria were isolated on MacConkey agar supplemented with ceftiofur followed by identification using MALDI-TOF. Fecal samples from 16 dogs (27.1%) yielded a total of 18 CefR enteric bacteria. Majority of CefR isolates (14/18, 77.8%) were E. coli followed by, one isolate each of Enterococcus hirae, Acinetobacter baumannii, Acinetobacter pittii, and Pseudomonas aeruginosa. CefR enteric bacteria were tested for resistance against 19- or 24-antibiotic panels using broth microdilution method. Seventeen (94.4%) CefR bacteria were resistant to more than one antimicrobial agent, and 14 (77.8%) displayed multidrug resistance (MDR).ConclusionsThis study shows that shelter dogs within the CGR not only carry zoonotic bacterial pathogens, but also shed multidrug resistant enteric bacteria in their feces that may pose public health risks.

Determination of Bioactive Compounds and Antimicrobial Capabilities of Purified Nymphaea lotus Linn. (Nymphaeaceae) Extract to Multidrug Resistant Enteric Bacteria

The increase in multidrug resistance bacteria is a major issue of concern to researchers and healthcare experts. There is a continuous effort by the researchers to innovate new methods of prevention and treatment of infections caused by multidrug resistance bacteria. The occurrence of bioactive compounds and antimicrobial capabilities of Nymphaea lotus Linn. (Nymphaeaceae) extract against multidrug resistant enteric bacteria were studied by assessing in-vitro antibacterial properties of the extract using agar well diffusion technique. Fourier Transform Infrared Spectrophotometer (FTIR) spectra revealed the presence of thirty (30) functional groups in purified ethanol extract of N. lotus root. Also, Gas Chromatography-Mass Spectrophotometry revealed the presence of different bioactive compounds (5-Nonanol, 2-Pentanone, 4-hydroxy-4-methyl-, Azulene, Tetradecanoic acid, 2-Chloroethyl vinyl sulfide, Decanoic acid, ethyl ester, Phytol, 1-Hexadecyne, 2-octenoic acid, Methyl-n-hexadecyl ketone, Hexadecanoic acid, methyl ester, and n-Hexadecanoic acid) in purified ethanol extract of N. lotus root which can be used in production of antimicrobial drugs. Five fractions of purified ethanol extract of N. lotus root (fraction 3-7) had significant zone of inhibition. Fraction four had the highest zone of inhibition 23.67 ± 0.88 mm while fraction seven had the least zone of inhibition 2.67 ± 1.33 mm.

Determination of Bioactive Compounds and Antimicrobial Capabilities of Purified Allium sativum Extract to Multidrug Resistant Enteric Bacteria

There is much concern on spread of pathogenic enteric bacteria and there resistance to commercially available antibiotics. There is a need for development of a new reliable drug for the treatment of diseases caused by these bacteria. This study determines the antimicrobial capabilities of purified Allim sativum extract to multidrug resistant enteric bacteria. In-vitro antibacterial properties of the extract was carried out using agar well diffusion technique against antibiotics resistant enteric bacteria. The results revealed that Seven fractions of partially purified water extract of Allium sativum (fraction 5-11) had significant zone of inhibition to the test enteric bacteria. The Fourier Transform Infrared Spectrophotometer (FTIR) spectra revealed the presence of 24 functional groups in functional groups in water extract of A. sativum. Also, Gas Chromatography-Mass Spectrophotometry revealed the presence of different compounds in water extract of Allium sativum.

Bioactive extracts of Carum copticum and thymol inhibit biofilm development by multidrug-resistant extended spectrum β-lactamase producing enteric bacteria

The emergence and spread of multidrug-resistant (MDR) pathogenic bacteria is a clinical problem that requires novel anti-infective agents. Targeting pathogenic biofilms is considered a promising strategy to control bacterial infections. In this study, bioactive extracts of Carum copticum were investigated for their anti-biofilm efficacy against extended spectrum β-lactamase (ESβL) producing MDR enteric bacteria. Thymol was also tested for its anti-biofilm properties, as gas chromatography-mass spectrometry revealed a high content (65.8%) of this phytochemical in the C. copticum methanolic extract. Biofilm inhibition was assessed in microtitre plates and further validated by light, electron and confocal laser microscopy. Sub-inhibitory concentrations of bioactive extracts of C. copticum and thymol significantly prevented biofilm development, ranging from 78.6 to 83.9% reductions. Microscopic analysis revealed that biofilms made by ESβL producing MDR enteric bacteria had a weakened structure, scattered microcolonies, and reduced cell density and thickness after exposure to the bioactive extracts and thymol.

Rectal swab screening assays of public health importance in molecular diagnostics: Sample adequacy control.

Rectal swabs are routinely used by public health authorities to screen for multi-drug resistant enteric bacteria including vancomycin-resistant enterococci (VRE) and carbapenem-resistant enterobacteriaceae (CRE). Screening sensitivity can be influenced by the quality of the swabbing, whether performed by the patient (self-swabbing) or a healthcare practitioner. One common exclusion criterion for rectal swabs is absence of "visible soiling" from fecal matter. In our institution, this criterion excludes almost 10% of rectal swabs received in the microbiology laboratory. Furthermore, over 30% of patients in whom rectal swabs are cancelled will not be re-screened within the next 48h, resulting in delays in removing infection prevention measures. We describe two quantitative polymerase chain reaction (qPCR)-based assays, human RNAse P and eubacterial 16S rDNA, which might serve as suitable controls for sampling adequacy. However, lower amounts of amplifiable human DNA make the 16s rDNA assay a better candidate for sample adequacy control.

Antibacterial and Antibiotic-Modifying Activity of Methanol Extracts from Six Cameroonian Food Plants against Multidrug-Resistant Enteric Bacteria.

The present work was designed to investigate the antibacterial activities of methanol extracts from six Cameroonian edible plants and their synergistic effects with some commonly used antibiotics against multidrug-resistant (MDR) Gram-negative bacteria expressing active efflux pumps. The extracts were subjected to qualitative phytochemical screening and the microdilution broth method was used for antibacterial assays. The results of phytochemical tests indicate that all tested crude extracts contained polyphenols, flavonoids, triterpenes, and steroids. Extracts displayed selective antibacterial activities with the minimal inhibitory concentration (MIC) values ranging from 32 to 1024 μg/mL. The lowest MIC value (32 μg/mL) was recorded with Coula edulis extract against E. coli AG102 and K. pneumoniae K2 and with Mangifera indica bark extract against P. aeruginosa PA01 and Citrus sinensis extract against E. coli W3110 which also displayed the best MBC (256 μg/mL) value against E. coli ATCC8739. In combination with antibiotics, extracts from M. indica leaves showed synergistic effects with 75% (6/8) of the tested antibiotics against more than 80% of the tested bacteria. The findings of the present work indicate that the tested plants may be used alone or in combination in the treatment of bacterial infections including the multidrug-resistant bacteria.

Intestinal decolonization of Enterobacteriaceae producing extended-spectrum β-lactamases (ESBL): a retrospective observational study in patients at risk for infection and a brief review of the literature.

BackgroundMultidrug-resistant Escherichia coli and other enteric bacteria producing extended-spectrum β-lactamases (ESBL) have emerged as an important cause of invasive infection. Targeting the primary (intestinal) niche by decolonization may be a valuable approach to decrease the risk of relapsing infections and to reduce transmission of ESBL-producing enteric pathogens.MethodsIn a retrospective observational study we evaluated the efficacy of intestinal decolonization treatment using orally administered colistin or other non-absorbable agents given for 2 to 4 weeks in adult patients with previous relapsing infection and persistent intestinal colonization with ESBL-positive Enterobacteriaceae (ESBL-E). Eradication success was defined as negative rectal swab or stool culture at the end of treatment and at follow up-2 weeks after treatment discontinuation.ResultsFirst-line decolonization treatment led to eradication of ESBL-E in 19/45 patients (42 %, 7/18 low-dose [4 × 1 million units] colistin, 3/12 high-dose [4 × 2 million units] colistin, 9/15 rifaximin [2 × 400 mg]), and secondary/salvage treatment was successful in 8/13 patients (62 %, 20 treatment episodes). Late follow-up showed that 7/13 patients (54 %) with successful initial or salvage decolonization became recolonized within 3 months after post-treatment assessment while all eight of the patients failing initial or salvage decolonization treatment with late follow-up remained colonized. A narrative review of the literature confirms the limited efficacy of non-absorbable antibiotics including conventional selective digestive tract decolonization (SDD)-like combination regimens for eradicating multidrug-resistant enteric bacteria from the intestinal tract.ConclusionsAt present, there is no clear evidence of a significant decolonization efficacy using single-drug treatment with oral non-absorbable antibiotics. More effective regimens are needed and a better definition of at risk patients is required for planning meaningful randomized controlled studies in this field.

Antibiotic Sensitivity and Sequence Amplification Patterns of Genes in Multidrug Resistant Enterobacteria Isolates from Processed Foods in Some West African Countries

Diarrhoea, dysentery and other diseases due to other enteric bacteria have reportedly been found to resist chemotherapeutic treatment in some West African communities with fatal consequences in some cases. This study was carried out to determine multidrug resistance patterns of Enterobacteria isolates from processed ready-to-eat foods. Indigenously processed food samples of different types were collected from two Francophone and two Anglophone countries in the West African sub-region during the wet and dry seasons of a sampling period of two years. Enterobacteria were isolated from the samples using standard techniques. Amplification of chromosomal DNA of the isolates using the Polymerase Chain Reaction was carried out. The results obtained were subjected to statistical analyses. All isolates showed resistance to cefuroxime (90.7%), nitrofurantoin (90.6%), augmentin (86.1%) and ampicillin (51.2%) while all were sensitive to gentamycin and ciprofloxacin. There was amplification indicating the presence of invA gene at a position of 240 bp. There was no amplification at all for the spvC gene in any of the isolates tested. Multidrug resistant enteric bacteria in these foods containing the invA gene could lead to infections with uncontrolled antibiotic use. The presence of enteric bacteria in the foods analyzed which provide undeniable evidence of the poor microbiological quality of these foods could form the basis of a useful databank in formulation of food-borne disease control and prevention strategies.

In vitro efficacy of bioactive extracts of 15 medicinal plants against ES βL-producing multidrug-resistant enteric bacteria

Alcoholic crude extracts and some fractions from 15 traditionally used Indian medicinal plants were investigated for their ability to inhibit the growth of extended spectrum beta-lactamases (ESbetaL)-producing multidrug-resistant enteric bacteria. The test bacteria Eschrichia coli and Shigella were resistant to 16-23 antibiotics with intermediate or resistance to beta-lactams (minimum inhibitory concentration (MIC) value range 16-1024 microg/ml). The crude plant extracts demonstrated zone of inhibition in the range of 11-29 mm against one or more test bacteria. On the basis of promising activity, 12 plants were selected to determine their efficacy in terms of MIC, which ranged from 0.64 mg/ml to 10.24 mg/ml. The extracts of Acorus calamus, Hemidesmus indicus, Holarrhena antidysenterica and Plumbago zeylanica demonstrated relatively high activity as compared to other plant extracts and were fractionated into acetone, ethyl acetate and methanol. Acetone fraction in most of the cases exhibited higher potency (low MIC value) as compared to ethyl acetate and methanol fraction. However, in Plumbago zeylanica, ethyl acetate fraction was most active. Synergistic interactions among crude extracts were demonstrated in the 12 different combinations against ESbetaL-producing E. coli (ESbetaL-02). Certain combinations exhibited significant synergy with enlargement of combined inhibition zone size by 5 mm. Interaction of crude extracts with five antibiotics (Tetracycline, ciprofloxacin, nalidixic acid, chloramphenicol and streptomycin) demonstrated synergistic interaction with tetracycline and ciprofloxacin by 10 and 3 plant extracts respectively. Phytochemical analysis and thin layer chromatography (TLC) bioautography of crude extracts showed the presence of alkaloids, phenols and flavonoids as active phytoconstituents. Most active fractions of four plants were subjected to Infrared spectroscopy and the major groups of compounds were detected. The plant extracts were further tested for their in vitro haemolytic activity to sheep erythrocytes and demonstrated no haemolysis at recommended doses. Further activity-guided fractionation of active fractions is needed to isolate and characterize the active principle in order to establish the mode of action against the ESbetaL-producing multidrug-resistant enteric bacteria and the mechanism of synergy.

Multidrug-Resistant Klebsiella pneumoniae Isolated from Farm Environments and Retail Products in Oklahoma

Multidrug-resistant enteric bacteria were isolated from turkey, cattle, and chicken farms and retail meat products in Oklahoma. Among the isolated species, multidrug-resistant Klebsiella pneumoniae was prevalently isolated from most of the collected samples. Therefore, a total of 132 isolates of K. pneumoniae were characterized to understand their potential roles in the dissemination of antibiotic-resistance genes in the food chains. Multidrug-resistant K. pneumoniae was most frequently recovered from a turkey farm and ground turkey products among the tested samples. All isolates were resistant to ampicillin, tetracycline, streptomycin, gentamycin, and kanamycin. Class 1 integrons located in plasmids were identified as a common carrier of the aadA1 gene, encoding resistance to streptomycin and spectinomycin. Production of β-lactamase in the K. pneumoniae isolates played a major role in the resistance to β-lactam agents. Most isolates (96%) possessed blaSHV-1. Five strains were able to express both SHV-11 (pI 6.2) and TEM-1 (pI 5.2) β-lactamase. Transfer of these antibiotic-resistance genes to Escherichia coli was demonstrated by transconjugation. The bacterial genomic DNA restriction patterns by pulsed-field gel electrophoresis showed that the same clones of multidrug-resistant K. pneumoniae remained in feathers, feed, feces, and drinking water in turkey environments, indicating the possible dissemination of antibiotic-resistance genes in the ecosystem and cross-contamination of antibiotic-resistant bacteria during processing and distribution of products.

Presence of Multidrug-Resistant Enteric Bacteria in Dairy Farm Topsoil

In addition to human and veterinary medicine, antibiotics are extensively used in agricultural settings, such as for treatment of infections, growth enhancement, and prophylaxis in food animals, leading to selection of drug and multidrug-resistant bacteria. To help circumvent the problem of bacterial antibiotic resistance, it is first necessary to understand the scope of the problem. However, it is not fully understood how widespread antibiotic-resistant bacteria are in agricultural settings. The lack of such surveillance data is especially evident in dairy farm environments, such as soil. It is also unknown to what extent various physiological modulators, such as salicylate, a component of aspirin and known model modulator of multiple antibiotic resistance (mar) genes, influence bacterial multi-drug resistance. We isolated and identified enteric soil bacteria from local dairy farms within Roosevelt County, NM, determined the resistance profiles to antibiotics associated with mar, such as chloramphenicol, nalidixic acid, penicillin G, and tetracycline. We then purified and characterized plasmid DNA and detected mar phenotypic activity. The minimal inhibitory concentrations (MIC) of antibiotics for the isolates ranged from 6 to >50μg/mL for chloramphenicol, 2 to 8μg/mL for nalidixic acid, 25 to >300μg/mL for penicillin G, and 1 to >80μg/mL for tetracycline. On the other hand, many of the isolates had significantly enhanced MIC for the same antibiotics in the presence of 5mM salicylate. Plasmid DNA extracted from 12 randomly chosen isolates ranged in size from 6 to 12.5kb and, in several cases, conferred resistance to chloramphenicol and penicillin G. It is concluded that enteric bacteria from dairy farm topsoil are multidrug resistant and harbor antibiotic-resistance plasmids. A role for dairy topsoil in zoonoses is suggested, implicating this environment as a reservoir for development of bacterial resistance against clinically relevant antibiotics.