Multiple Antibiotic-resistant Organisms Research Articles

Ethnopharmacology and phytochemistry of medicinal plants against enterocyte bacteria-linked infections and diarrhoea in some African countries: a systematic review

Abstract Background There is a dearth of relevant bioactive translational progress and post-scientific evidence on the ethnopharmacology and phytochemistry of plants with anti-diarrheal potential in Africa. This study synthesized scientific evidence on commonly used African folkloric medicinal plants in the management/control of diarrhoea and antibiotic-resistant enterocyte-infecting bacteria in some African countries. Main body Published articles from different databases on folk medicinal plants used in the treatment/management of bacteria-linked enterocyte infections and diarrhoea were reviewed systematically. The ethnopharmacology and phytochemistry of 75 folkloric plant species belonging to 67 families and 58 genera, including Asteraceae (10.45%), Myrtaceae (7.46%), (Anacardiaceae, Celastraceae, Fabaceae and Hydnoraceae) (5.97%) are the most used anti-diarrheal folkloric plants in the region. The minimum inhibitory concentration (MIC) (0.018 mg/ml–8.45 mg/ml) or (39 μg/ml–2000 μg/ml) and 14.35 g/kg–8317.64 mg/kg LD50 on enterocyte bacteria strains. A solo author reported MIC of the pure component 6.25 μg/ml. Tree (38%) and tuber (3%) were the highest and least life forms of the folkloric plants used. Leaves (41%) were the most frequently used for folk preparations, while aerial, fruits, seeds and combination of shoots + leaves (1.45%) were the least used. Fourteen authors’ studies revealed the phytochemical profile, while six further elucidated the bioactive components of the folkloric plants used to manage diarrhoea. Conclusion Our findings revealed the antibacterial potency of folkloric plants against diarrhoea and multiple antibiotic-resistant organisms. It suggests a gap in the appropriate documentation, application of such medicinal/folkloric plants, and low post-research advancement of effectively tested plant types or bioactive agents, calling for well-organized future research engagements.

English

This study determined the bacteriological quality of water from the Opa River and assessed the impact of human behaviour on the quality of water along the river course. Twenty five water samples were collected over a period of five weeks at five selected points based on population clusters along the river. A hundred questionnaire items were administered to randomly selected residents to elicit information about the water body and predominant communal behaviours. Water samples were analyzed by standard microbial techniques and isolates were identified. The isolates obtained were tested for their resistance to antibiotics via standard methods. Descriptive statistical techniques were used to obtain the minimum and maximum values of Total Heterotrophic Bacterial (THB) count and Total Coliform Bacterial (TCB) count. The analysis of variance (ANOVA) test was used to compare the means. Heterotrophic bacteria load at the five sampling points ranged between 2 x 106 and 13 x106 cfu/ml while the most probable number of coliforms in 100 ml of samples was between 34 and 1600. The organisms isolated from the samples included those of the Genera Citrobacter Enterobacter Escherichia, Proteus, Klebsiella, Salmonella, Serratia, Yersinia, Shigella, Pseudomonas and Vibrio. Escherichia coli had the highest percentage frequency of occurrence (23.73%) and was isolated at all sampling points. In all areas, communal behaviour towards the river was generally poor. Some respondents reported symptoms associated with water borne illnesses which included vomiting (28.5%), passing out of watery stool (57.2%) and headache and dizziness (14.3%). The Opa River was found to be mostly contaminated by multiple antibiotic resistant organisms. Opa River could be a source of potential pathogens associated with water borne diseases and could consequently; serve as a pathway for human contamination, most especially of dwellers located along its banks that depend on Opa River water. Key words: Pathogens, waterborne disease, contamination, communal behaviours, antibiotic resistance.

Prevalence of and risk factors for multidrug-resistant Acinetobacter baumannii colonization among high-risk nursing home residents.

To characterize the epidemiology of multidrug-resistant (MDR) Acinetobacter baumannii colonization in high-risk nursing home (NH) residents. Nested case-control study within a multicenter prospective intervention trial. Four NHs in Southeast Michigan. PARTICIPANTS Case patients and control subjects were NH residents with an indwelling device (urinary catheter and/or feeding tube) selected from the control arm of the Targeted Infection Prevention study. Cases were residents colonized with MDR (resistant to ≥3 classes of antibiotics) A. baumannii; controls were never colonized with MDR A. baumannii. For active surveillance cultures, specimens from the nares, oropharynx, groin, perianal area, wounds, and device insertion site(s) were collected upon study enrollment, day 14, and monthly thereafter. A. baumannii strains and their susceptibilities were identified using standard microbiologic methods. Of 168 NH residents, 25 (15%) were colonized with MDR A. baumannii. Compared with the 143 controls, cases were more functionally disabled (Physical Self-Maintenance Score >24; odds ratio, 5.1 [95% CI, 1.8-14.9]; P<.004), colonized with Proteus mirabilis (5.8 [1.9-17.9]; P<.003), and diabetic (3.4 [1.2-9.9]; P<.03). Most cases (22 [88%]) were colonized with multiple antibiotic-resistant organisms and 16 (64%) exhibited co-colonization with at least one other resistant gram-negative bacteria. Functional disability, P. mirabilis colonization, and diabetes mellitus are important risk factors for colonization with MDR A. baumannii in high-risk NH residents. A. baumannii exhibits widespread antibiotic resistance and a preference to colonize with other antibiotic-resistant organisms, meriting enhanced attention and improved infection control practices in these residents.

Role of overcrowding in meticillin-resistant Staphylococcus aureus transmission: Bayesian network analysis for a single public hospital

The transmission of multiple antibiotic-resistant organisms (MROs) in hospitals is affected by many inter-related factors. These include the background prevalence of the organism (burden), hand hygiene, the efficiency of patient screening, the isolation or cohorting of carriers, the quality of hospital cleaning, and bed occupancy. In addition, the prevalence of one MRO may influence the transmission of another by occupying isolation beds, and thus reducing isolation resources for the latter. For example, the overuse of third generation cephalosporin antibiotics can increase extended-spectrum β-lactamase-producing Klebsiella pneumoniae, thus indirectly influencing the transmission of meticillin-resistant Staphylococcus aureus (MRSA). In order to study this complex system of interrelationships, we have employed a Bayesian network. We report results of the first two years of analysis for a single public hospital. We conclude that, within this institution, the association between high bed occupancy and increased transmission of MRSA may be subject to a dynamic multidimensional threshold and tipping point. This may be influenced by other factors such as MRSA burden and whether the high bed occupancy interferes with preparation and cleaning of beds for new patients and with hand hygiene and efforts to isolate or cohort carriers.

Isolation ward access block

There is overwhelming evidence that hospitals become unsafe with persistent high bed occupancy. Potentially preventable deaths occur and length of stay is prolonged. Infections and colonisations with multiple antibiotic-resistant organisms increase. It is probable that overall long-term efficiency is impaired. Isolation ward access block may be one of the mechanisms by which transmission of multiple antibioticresistant organisms is enhanced.

Homology modeling of phosphoryl thymidine kinase of enterohemorrhagic Escherichia coli OH: 157.

Enterohemorrhagic Escherichia coli (EHEC) are source of emerging infectious disease in India. Escherichia coli O157:H7 is an EHEC strain showing multiple antibiotic resistances and the cause of infantile diarrhea and hemolytic uremic syndrome worldwide. A novel strategy to counteract multiple antibiotic resistant organisms is to design drugs which specifically target metabolic pathways such as thiamine biosynthetic pathways found exclusively in prokaryotes. Homology modeling was used for model building of a terminal thiamine biosynthesis enzyme phosphoryl thymidine kinase (Thi E) using Geno3D, Swiss Model and Modeller. The best model was selected based on overall stereochemical quality. The potential ligand binding sites in the model were identified by CASTp server. The validated theoretical model of the 3D structure of the thiE protein of E. coli O157:H7 was predicted using a thiamine phosphate pyrophosphatase from Pyrococcus furiosus (PDB ID: 1X13_A) as template. The active pockets of ligand binding sites in the enzyme were identified. In this study, phosphoryl thymidine kinase (thi E), a terminal enzyme in the thiamine biosynthesis pathway in the pathogen has been modeled to be used in future as a potential drug target by the design of suitable inhibitors.

Efficacy of Bacteriophage Treatment in Murine Burn Wound Infection Induced by Klebsiella pneumoniae

In the present study, the therapeutic potential of purified and well-characterized bacteriophages was evaluated in thermally injured mice infected with Klebsiella pneumoniae B5055. The efficacy of five Klebsiella phages (Kpn5, Kpn12, Kpn13, Kpn17, and Kpn22) was evaluated on the basis of survival rate, decrease in bacterial counts in different organs of phage-treated animals, and regeneration of skin cells as observed by histopathological examination of phage-treated skin. Toxicity studies performed with all the phages showed them to be non-toxic, as no signs of morbidity and mortality were observed in phage-treated mice. The results of the study indicate that a single dose of phages, intraperitoneally (i.p.) at an MOI of 1.0, resulted in significant decrease in mortality, and this dose was found to be sufficient to completely cure K. pneumoniae infection in the burn wound model. Maximum decrease in bacterial counts in different organs was observed at 72 h post infection. Histopathological examination of skin of phage-treated mice showed complete recovery of burn infection. Kpn5 phage was found to be highly effective among all the phages and equally effective when compared with a cocktail of all the phages. From these results, it can be concluded that phase therapy may have the potential to be used as stand-alone therapy for K.pneumoniae induces burn wound infection, especially in situations where multiple antibiotic-resistant organisms are encountered.

New control chart methods for monitoring MROs in Hospitals

Routine surveillance of colonisations with multiple antibiotic resistant organisms (MROs) is now widespread and these data are increasingly summarised in control charts. The purpose of their analysis in this manner is to provide early warning of outbreaks or to judge the response to system changes designed to reduce colonisation rates. Conventional statistical process control (SPC) charts assume independence of observations. In addition, there needs to be a run of stable, non-trended (stationary) data values to obtain accurate control limits.Colonisation with an MRO is not an independent event as it must involve transmission from a carrier and this can lead to excessive variation. In addition, non-linear trends are often present and MRO prevalence data display temporal correlation. The latter occurs when data at particular times are more like data at related, usually contiguous times, than data from more distant times; thus they are not temporally independent. These characteristics make it difficult to implement conventional SPC charts with MRO data. To overcome these problems, we suggest the use of generalised additive models (GAMs) when there is no temporal correlation, as with new colonisations, and generalised additive mixed models (GAMMs) when temporal correlation is present; as occurs commonly with prevalence data. We illustrate their use with multi-resistant methicillin-resistant Staphylococcus aureus (mMRSA) prevalence and new colonisation data. These methods are able to deal with excess variability, trends and temporal correlation. They are easily implemented in the freely available R software package.Our analysis demonstrates an upward non-linear trend in mMRSA prevalence between January 2004 and October 2006. The mMRSA new colonisation data also display an upward trend between September 2005 and May 2006. Monthly new colonisation rates exceeded the upper control limit in April 2005 and equalled it in May 2006. There was a modest downward trend in the new colonisation rate in the latter part of 2006.

Efflux-mediated antimicrobial resistance

Antibiotic resistance continues to plague antimicrobial chemotherapy of infectious disease. And while true biocide resistance is as yet unrealized, in vitro and in vivo episodes of reduced biocide susceptibility are common and the history of antibiotic resistance should not be ignored in the development and use of biocidal agents. Efflux mechanisms of resistance, both drug specific and multidrug, are important determinants of intrinsic and/or acquired resistance to these antimicrobials, with some accommodating both antibiotics and biocides. This latter raises the spectre (as yet generally unrealized) of biocide selection of multiple antibiotic-resistant organisms. Multidrug efflux mechanisms are broadly conserved in bacteria, are almost invariably chromosome-encoded and their expression in many instances results from mutations in regulatory genes. In contrast, drug-specific efflux mechanisms are generally encoded by plasmids and/or other mobile genetic elements (transposons, integrons) that carry additional resistance genes, and so their ready acquisition is compounded by their association with multidrug resistance. While there is some support for the latter efflux systems arising from efflux determinants of self-protection in antibiotic-producing Streptomyces spp. and, thus, intended as drug exporters, increasingly, chromosomal multidrug efflux determinants, at least in Gram-negative bacteria, appear not to be intended as drug exporters but as exporters with, perhaps, a variety of other roles in bacterial cells. Still, given the clinical significance of multidrug (and drug-specific) exporters, efflux must be considered in formulating strategies/approaches to treating drug-resistant infections, both in the development of new agents, for example, less impacted by efflux and in targeting efflux directly with efflux inhibitors.

Efficacy of a non‐vancomycin‐based peritoneal dialysis peritonitis protocol

Peritonitis has a significant impact upon morbidity and mortality of peritoneal dialysis (PD) patients. Gram-positive organisms account for the majority of infections and vancomycin is a cost effective broad-spectrum antimicrobial treatment for PD peritonitis, but this may lead to the emergence of multiple antibiotic-resistant organisms. The purpose of the present paper was to evaluate the efficacy of a non-vancomycin-based protocol comprising cephazolin and gentamicin, which was introduced in the present PD population as empirical treatment for peritonitis. The study involved 82 peritonitis episodes over a 4-year period in 58 patients, excluding those with previous methicillin-resistant staphylococcal peritonitis. With cephazolin and gentamicin there was no apparent difference in response or relapse rates in comparison to reported studies using vancomycin-based first-line therapy protocols. We advocate initial treatment of PD peritonitis with non-vancomycin-based therapy given similar efficacy and the potential for reduction of resistant organisms.

Characteristics, epidemiology and clinical importance of emerging strains of Gram-negative bacilli producing extended-spectrum β-lactamases

β-Lactam antimicrobial agents represent the most common treatment for bacterial infections and continue to be the leading cause of resistance to β-lactam antibiotics among Gram-negative bacteria worldwide. The persistent exposure of bacterial strains to a multitude of β-lactams has induced dynamic and continuous production and mutation of β-lactamases in these bacteria, expanding their activity even against the newly developed β-lactam antibiotics. These enzymes are known as extended-spectrum β-lactamases (ESBLs). The majority of ESBLs are derived from the widespread broad-spectrum β-lactamases TEM-1 and SHV-1. There are also new families of ESBLs, including the CTX-M and OXA-type enzymes as well as novel unrelated β-lactamases. In recent years, there has been an increased incidence and prevalence of ESBLs. ESBLs are mainly found in strains of Escherichia coli and Klebsiella pneumoniae but have also been reported in other Enterobacteriaceae strains and Pseudomonas aeruginosa. Infections with ESBL-producing bacterial strains are encountered singly or in outbreaks, especially in critical care units in hospitals, resulting in increasing cost of treatment and prolonged hospital stays. Not only may nursing home patients be an important reservoir of ESBL-containing multiple antibiotic-resistant organisms, but ambulatory patients with chronic conditions may also harbor ESBL-producing organisms.

Extended-Spectrum β-Lactamases (ESBLs): Characterization, Epidemiology and Detection

β-lactamases of Enterobacteriaceae are the most important mechanism of resistance against β-lactam drugs. Two types of β-lactamases can confer resistance against 3rd generation cephalosporins. Chromosomally mediated β-lactamases are inducible and are not inhibited by clavulanic acid. Resistance due to these enzymes is non-transferable. The 2nd type of enzyme is plasmid-mediated β-lactamases, which are inhibited by clavulanic acid. These enzymes are more important clinically as these can be transferred between various species of Enterobacteria ceae. These enzymes are called extended-spectrum β-lactamases (ESBLs). ESBL-producing Enterobacteriaceae have been responsible for numerous outbreaks of infection throughout the world and pose challenging infection control issues. Antibacterial choice is often complicated by multi-resistance. ESBLs can confer resistance against all β-lactam drugs except carbapenems and cephamycins. Nursing home patients may be an important reservoir of ESBL-containing multiple antibiotic-resistant organisms. Use of broad-spectrum oral antibiotics and probably poor infection control practices may facilitate spread of this plasmid-mediated resistance. In addition to known populations at risk, ambulatory patients with chronic conditions represent another patient population that may harbor ESBL-producing organisms. Various methods can be used for detection of ESBLs in the laboratory. These tests include double disc diffusion test, Vitek ESBL test, E Tests, MIC Determination, genetic method, and isoelectric focusing (IEF).

Population-based assessment of intensive care unit-acquired bloodstream infections in adults: Incidence, risk factors, and associated mortality rate.

Nosocomial bloodstream infections have been extensively investigated, but relatively few studies have specifically evaluated the epidemiology of intensive care unit-acquired bloodstream infections. The study objective was to define the incidence, risk factors, microbiology, and clinical outcomes of intensive care unit-acquired bloodstream infections. Population-based prospective cohort. Multidisciplinary intensive care units. All Calgary Health Region (population 930,000) adult patients admitted to multidisciplinary intensive care units (>/=48 hrs) from May 1, 1999, to April 30, 2000. Blood sample analysis. There were 1,158 admission episodes in 1,017 patients; 37% involved females, and mean +/- sd age and Acute Physiology and Chronic Health Evaluation II scores were 59.6 +/- 18.7 yrs and 23.4 +/- 7.7, respectively. Fifty-one patients developed intensive care unit-acquired bloodstream infections (first positive blood culture >/=48 hrs after intensive care unit admission) for an incidence of 4.4% and an incidence density of 5.2 per 1000 intensive care unit days. Younger age (adjusted odds ratio, 0.98; 95% confidence interval, 0.96-1.00, p =.01), longer intensive care unit length of stay (adjusted odds ratio, 4.74; 95% CI, 3.26-6.90, p <.001), and lower hematocrit (adjusted odds ratio, 0.95; 95% confidence interval, 0.90-1.00, p =.04) were significant independent predictors of intensive care unit-acquired bloodstream infections, and these infections were associated with an increased intensive care unit length of stay of 2.86 days (95% confidence interval, 2.29-3.57, p <.001). Staphylococcus aureus (27%), coagulase-negative staphylococci (14%), and Enterococcus faecium (12%) were most commonly isolated. Four (8%) bloodstream infections involved antibiotic-resistant organisms, and ten (20%) were polymicrobial. In multivariate analysis, intensive care unit-acquired bloodstream infection was associated with an increased intensive care unit mortality rate (adjusted odds ratio, 2.03; 95% confidence interval, 1.03-4.00, p = 0.04) but not overall hospital mortality rate. One patient in 20 admitted to Calgary Health Region intensive care units acquires bloodstream infection and suffers longer intensive care unit stay and increased mortality rates. In our region, multiple antibiotic-resistant organisms are uncommon causes of bloodstream infections, suggesting that it may be safe to use narrower spectrum empirical treatment regimens than current guidelines recommend.

The bacteriology of neonatal septicaemia in Ile-Ife, Nigeria.

The incidence of septicaemia among neonates categorized as being at high risk was 55 per cent in Ile-Ife, Nigeria. Gram-positive organisms, specifically Staphylococcus aureus, were predominant (33.8 per cent) among bacteria cultured from proven cases of septicaemia. Other coagulase-negative staphylococci also contributed 21 per cent, with Staphylococcus epidermidis occurring in 5 per cent of the isolates. Listeria monocytogenes was cultured from 8.4 per cent of septic neonates. Pseudomonas aeruginosa was cultured from 3 per cent, Klebsiella pneumoniae from 14 per cent, and Escherichia coli from 7 per cent. Other Gram-negative bacilli cultured were Enterobacter aerogenes (5 per cent), Citrobacter freundii, Salmonella sp., and Proteus sp. (2 per cent each). The bacterial isolates were relatively resistant to antibiotics traditionally employed to treat cases of septicaemia. The study shows a high prevalence of neonatal bacterial sepsis at the centre and the emerging role of Listeria monocytogenes in the aetiology of neonatal sepsis. It highlights the preponderance of multiple antibiotic resistant organisms among these neonates early in life which is of epidemiological importance in the control of the infectious agents.

Antibacterial resistance in the intensive care unit: mechanisms and management.

The incidence of multiple antimicrobial resistance of bacteria which cause infections in the intensive care unit is increasing. These include methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, penicillin-resistant Streptococcus pneumoniae and cephalosporin and quinolone resistant coliforms. More recently, pan antibiotic resistant coliforms, including carbapenems, have emerged. The rapidity of emergence of these multiple antibiotic-resistant organisms is not being reflected by the same rate of development of new antimicrobial agents. It is, therefore, conceivable that patients with serious infections will soon no longer be treatable with currently available antimicrobials. Strict management of antibiotic policies and surveillance programmes for multiple resistant organisms, together with infection control procedures, need to be implemented and continuously audited. As intensive care units provide a nidus of infection for other areas within hospitals, this is critically important for prevention of further spread and selection of these resistant bacteria.

Multiple Antibiotic Resistant Organisms in Burn Patients Treated with Cephalosporins

Multiple Antibiotic Resistant Organisms in Burn Patients Treated with Cephalosporins

Incidence of Multiple Antibiotic Resistant Organisms Isolated from Retail Milk Products in Hermosillo, Mexico

Retail milk samples (231) of pasteurized, whole milk powder (WMP), and ultrapasteurized (UP) were collected in Hermosillo, Sonora, Mexico, to determine the incidence of multiple antibiotic resistance. Pathogens such as Escherichia coli, Staphylococcus aureus, and Salmonella were determined as well as nonpathogens such as Pseudomonas, Klebsiella, Serratia, and Hafnia alvei. Drug resistance of each isolated culture was tested using the Kirby-Bauer technique. The following antibiotic discs and concentrations were used: amikacin 30 mcg, ampicillin 10 mcg, carbenicillin 100 mcg, cefamandole 30 mcg, chloramphenicol 30 mcg, erythromycin 15 mcg, gentamicin 10 mcg, kanamycin 30 mcg, nitrofurantoin 300 mcg, penicillin 10 U, polymixin B 300 U, tetracycline 30 mcg, and tobramycin 10 mcg.Sixty-seven percent of the pasteurized milk samples contained fecal coliforms with multiple drug resistance. Four percent contained Salmonella which was 100% resistant to penicillin and showed some resistance to polymixin B and chloramphenicol. S. aureus which was drug resistant was present in 2.9% of the samples. The WMP and UP samples were relatively pathogenic free; however, nonenteric coliforms were detected showing multiple drug resistance. E. coli isolated in 1 UP showed resistance to ampicillin, chloramphenicol, gentamycin, polymixin B, and tetracycline.A high incidence of drug-resistant organisms in milk products represents a public health hazard in that food poisoning outbreaks would be difficult to treat and this pool of multidrug-resistant organisms in the food supply represents a reservoir for transferable resistant genes. An active surveillance and monitoring program should be mandated to minimize this risk for the consumer.

The challenge: Patients with multiple antibiotic-resistant organisms

The challenge: Patients with multiple antibiotic-resistant organisms

The isolation of Escherichia coli from a sheep slaughtering line in an abattoir

During the slaughtering process of sheep in an abattoir the level of spread of Escherichia coli was monitored. Strains isolated were serotyped and their antibiotic resistances monitored. E coli were isolated from many sites and it was shown that rectal serotypes were generally washed away and that the sheep were recontaminated subsequently by other E. coli in the environment. Multiple antibiotic resistant organisms were rarely isolated. Most strains were either fully sensitive or resistant to one antimicrobial agent, most commonly sulphonamide.

Trimethoprim-Sulfamethoxazole Compared to Ampicillin in the Treatment of Shigellosis

Twenty hospitalized children between 1 and 11 years of age were enrolled in a comparative randomized evaluation of trimethoprim-sulfamethoxazole (TM-SM) and ampicillin for the treatment of shigellosis. Each drug was provided for five days. The group treated with ampicillin had significantly more stools per day (mean 21.25) compared to the TM-SM group (8.64). Treatment with TM-SM appeared to be associated with a more rapid reversion of stool cultures to normal, but these differences compared to ampicillin were not statistically significant. Review of all isolates of Shigella from our hospital revealed a marked decrease in sensitivity to ampicillin over the last six years. This pattern has been observed in other centers. TM-SM may be the best drug for the treatment of shigellosis in areas where multiple antibiotic-resistant organisms are common.