Multiple Antibiotic Resistant Bacteria Research Articles

In vitro inhibitory potentials of crude plant extracts on multidrug resistant bacterial species from infected human wounds

Background: Scientific data on usage of plants to promote wound healing is exclusively scare in Nigeria. AIM: The aim of this study was to determine in vitro inhibitory potentials of crude extracts of garlic (Allium sativum) and ginger (Zingiber officinale) on multiple antibiotic resistant bacteria isolated from deep and superficial human wounds. Materials and Methods: Using agar disc‑ and modified agar well‑diffusion methods, 87 wound‑borne bacterial strains, Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa were screened for in vitro susceptibility to 15 commonly‑available antibiotic discs, 18 antibiotic drugs and three plant extracts. Results: Staph. aureus strains exhibited 52.5‑97.4% resistance to antibiotic (discs), with multiple antibiotic resistance (MAR) of 25.0 ‑100%. Between 39.1 and 95.7% of Proteus mirabilis strains resisted the antibiotics (discs), while MAR was 37.5‑100%. Resistance rates displayed by Ps. aeruginosa strains were 61.5‑100% with MAR of 50.0‑100%. Overall antibiotic resistance patterns of respective bacterial species recorded for the antibiotic drugs were Staph. aureus (11.1‑83.3%), Pr. mirabilis (16.7‑77.8%) and Ps. aeruginosa (16.7‑50.0%) and the most‑resisted antibiotic drugs were axacef (55.3‑82.6%), septrin (84.2‑92.3%), primpex (78.3‑84.6%), mediphenicol (63.2‑73.1%) and augmentin 1 (43.2‑76.9%). All the multidrug resistant wound‑borne bacterial strains exhibited minimal to moderate susceptibility towards crude extracts of garlic (17.4‑34.6%) and ginger (57.7‑60.8%). Conclusion: Human wound‑borne bacterial strains, which were multi‑resistant to commonly available antibiotics (discs/drugs) were minimally or moderately susceptible to crude extracts of garlic (Allium sativum) and ginger (Zingiber officinale), which can be of clinical importance as herbal therapy in wound dressings or other forms of wound treatments. Key words: Antibiotic resistance, herbal wound treatment, skin wounds, wound care, wound dressing

Microbiological Quality and Antibiogram of E. coli, Salmonella and Vibrio of Salad and Water from Restaurants of Chittagong

The study aimed at examining the microbial quality of restaurant salad and the water used for salad preparation and their role as a source of antibiotic resistant bacteria. Samples were collected from 15 different restaurants located in Chittagong city. The range of Total Viable Count was 1.86×104 to7.28×105 CFU/g and 1.60×104 CFU/ml to 4.38×105 CFU/ml for salad and water respectively. Total colifrm and fecal coliform count > 1100 CFU/100 ml were found in 73.33% of salad and 33.33% water samples. Salmonella spp was present in 46.67% of restaurants salad and water. Vibrio spp. was present in 66.67% of salad and 53.33% of water. A total of 102 isolates belonging to genus Vibrio, Salmonella and E. coli were subjected to antibiotic sensitivity test by disc diffusion method by using nine different types of antibiotic discs. Salmonella spp. from salad and water showed resistance against Amoxicillin (75%), Cephradine and Cephalexin (68.75%). 85.71% Vibrio spp. isolated from salad and water were resistant to Amoxicillin respectively. Multiple drug resistance was seen in 39 and 51 isolates of Salmonella and Vibrio isolates, respectively. The results suggest the necessity to follow the hygienic practices in salad preparation and salad might have an important role as a source of multiple antibiotic resistant bacteria. DOI: http://dx.doi.org/10.3329/jesnr.v5i1.11571 J. Environ. Sci. & Natural Resources, 5(1): 159 - 166, 2012

Prevalence of multiple antibiotic-resistant Gram-negative bacteria on bagged, ready-to-eat baby spinach

In this study, multiple antibiotic-resistant (MAR) Gram-negative bacteria (GNB) were isolated from triple-washed, bagged, ready-to-eat (RTE) baby spinach. Biochemical identification of randomly selected bacterial colonies showed the predominance of cytochrome oxidase-positive Pseudomonas species. Among the GNB, a higher prevalence of resistance was observed against cefoxitin (93.1%) followed by ampicillin (79.4%), chloramphenicol (72.6%), ceftizoxime (65.7%), aztreonam (64.9%), cefotaxime (53.6%), imipenem (38.3%), ceftazidime (33.5%), gentamicin (32.6%), tetracycline (22.2%), and ciprofloxacin (19.8%). Multiple antibiotic resistance (MAR) linked to two or more antibiotics was found in 95.3% of isolates, and resistance was transferable in the strains tested. These findings confirm the presence of MAR bacteria on RTE baby spinach and suggest that human consumption of this produce would amplify the MAR gene pool via conjugal transfer of MAR genes to commensal gut microflora and bacterial pathogens.

Adjuvant strategies for potentiation of antibiotics to overcome antimicrobial resistance

Alarming facts about the occurrence and spreading of multiple antibiotic resistant bacteria have caught the attention of global surveillance authorities and public media. The demand for novel effective antimicrobial drugs is high and on the rise while, at the same time, the supply of fresh 'magic bullets' is drying up. This review summarizes examples of recent strategies for development of adjunctive antibiotic therapies that overcome microbial resistance and thus rejuvenate the existing arsenal of drugs. Recent studies have demonstrated the potential of compounds that inhibit the action of the repressor protein implicated in ethionamide resistance, thus stimulating activation of the drug and thereby restoring the activity of the antibiotic for treatment of Mycobacterium tuberculosis. Such specific interference with regulators or signal transduction mechanisms involved in antibiotic resistance or virulence provides a new toolbox for novel combinations of antimicrobial drugs with adjuvant molecules lacking intrinsic antibiotic activity. In addition to the development of new antibiotics and vaccination initiatives this strategy of restoring or potentiating the activity of existing antibiotics may help to postpone the day when antibiotics are no longer generally efficacious.

Strengthening foodborne diseases surveillance in the WHO African region: An essential need for disease control and food safety assurance

Several devastating outbreaks of foodborne diseases have been reported in the African region including acute aflatoxicosis in Kenya in 2004 and bromide poisoning in Angola in 2007. There are concerns about transmission of multiple antibiotic resistant bacteria and pesticide residues in foods. The globalization of the food trade which could increase the spread of food contaminants internationally is an emerging issue. The new International Health Regulations (IHR) (2005) cover events of international importance including contaminated food and outbreaks of foodborne disease. The IHR (2005) and other international as well as regional agreements require Member States to strengthen surveillance systems including surveillance for foodborne diseases. WHO has been supporting countries to strengthen foodborne disease surveillance since 2003. This paper reports on the work of WHO and partners in the area of foodborne disease surveillance, the challenges and opportunities and provides perspectives for the area of its work. The paper shows that laboratory-based surveillance is the preferred system for foodborne disease surveillance since it allows early detection of outbreak strains and identification of risk factors with laboratory services as the cornerstone. Foodborne disease surveillance has been included in the revised Integrated Disease Surveillance and Response (IDSR) Strategy and there are guidelines for use by countries. WHO in collaboration with partners, especially the Global Food Infections Network (GFN), has been supporting countries to strengthen national analytical capacity for foodborne disease surveillance and research. Training for countries to detect, control and prevent foodborne and other enteric infections from farm to table has been conducted. The training for microbiologists and epidemiologists from public health, veterinary and food sectors involved in isolation, identification and typing of Salmonella sp, Campylobacter sp., Vibrio cholerae, Vibrio sp. and Shigella from human and food samples have been carried out. Research into specific topics in microbiology and chemical contaminants has been conducted. Three institutions in Cameroun, Mali and Nigeria have been designated as centres of excellence for chemical contaminants. Despite these significant achievements, a number of challenges remain. Most food safety programmes and food safety systems remain fragmented resulting in duplication of efforts and inefficient use of resources; and most laboratories in the African Region are poorly resourced. In countries where facilities exist, there is underutilization and lack of synergy among laboratories. Countries should, therefore, conduct audits of existing laboratories to determine their strengths and weaknesses and strategize as appropriate. It is also imperative to continue to strengthen partnerships and forge new ones and increase resources for food safety, in general, and for foodborne disease surveillance, in particular, and continue capacity building, both human and institutional.

Speciation and antimicrobial resistance of Enterococci isolated from recreational beaches in Malaysia

We report the first study on the occurrence of antibiotic-resistant enterococci in coastal bathing waters in Malaysia. One hundred and sixty-five enterococci isolates recovered from two popular recreational beaches in Malaysia were speciated and screened for antibiotic resistance to a total of eight antibiotics. Prevalence of Enterococcus faecalis and Enterococcus faecium was highest in both beaches. E. faecalis/E. faecium ratio was 0.384:1 and 0.375:1, respectively, for isolates from Port Dickson (PD) and Bagan Lalang (BL). Analysis of Fisher's exact test showed that association of prevalence of E. faecalis and E. faecium with considered locations was not statistically significant (p < 0.05). Chi-square test revealed significant differences (χ(2) = 82.630, df = 20, p < 0.001) in the frequency of occurrence of enterococci isolates from the considered sites. Resistance was highest to nalidixic acid (94.84 %) and least for chloramphenicol (8.38 %). One-way ANOVA using Tukey-Kramer multiple comparison test showed that resistance to ampicillin was higher in PD beach isolates than BL isolates and the difference was extremely statistically significant (p < 0.0001). Frequency of occurrence of multiple antibiotic resistance (MAR) isolates were higher for PD beach water (64.29 %) as compared to BL beach water (13.51 %), while MAR indices ranged between 0.198 and 0.48. The results suggest that samples from Port Dickson may contain MAR bacteria and that this could be due to high-risk faecal contamination from sewage discharge pipes that drain into the sea water.

Bacteriophage: time to re-evaluate the potential of phage therapy as a promising agent to control multidrug-resistant bacteria.

Nowadays the most difficult problem in treatment of bacterial infections is the appearance of resistant bacteria to the antimicrobial agents so that the attention is being drawn to other potential targets. In view of the positive findings of phage therapy, many advantages have been mentioned which utilizes phage therapy over chemotherapy and it seems to be a promising agent to replace the antibiotics. This review focuses on an understanding of phages for the treatment of bacterial infectious diseases as a new alternative treatment of infections caused by multiple antibiotic resistant bacteria. Therefore, utilizing bacteriophage may be accounted as an alternative therapy. It is appropriate time to re-evaluate the potential of phage therapy as an effective bactericidal and a promising agent to control multidrug-resistant bacteria.

Identification of shiga toxin and intimin coding genes in Escherichia coli isolates from pigeons (Columba livia) in relation to phylotypes and antibiotic resistance patterns

Shiga toxin-producing Escherichia coli (STEC) strains are responsible for outbreaks of human intestinal diseases worldwide. Pigeons are distributed in public areas and are potential reservoirs for pathogenic bacteria. One hundred fifty-four fresh fecal samples were obtained from trapped pigeons in southeast of Iran and were cultured for isolation of E. coli. The isolates were examined to determine the prevalence of stx1, stx2, and eae genes, antimicrobial resistance, and their phylotypes. The confirmed E. coli isolates (138) belong to four phylogenetic groups: A (54.34%), B1 (34.05%), B2 (3.62%), and D (7.79%). Thirteen (9.42%) isolates were positive for one of the examined genes. Eight isolates (5.79%) were positive for eae, four (2.89%) for stx2, and one isolate (1.44%) for stx1 gene. Phylotyping assays showed that eight eae-positive isolates fall into three phylogroups; A (three isolates), B1 (three isolates), and D (two isolates), whereas four stx2-positive isolates belonged to the A (three isolates) and D (one isolate) groups. The stx1-positive isolate belonged to phylogroup A. One hundred six isolates (76.81%) showed resistance to at least one of the selected antibacterial agents. The maximum resistance rate was against oxytetracycline (73.91%), and the minimum was against flumequine (2.17%). Twenty different patterns of drug resistance were observed. According to the results, pigeons could be considered as carriers of STEC strains. However, E. coli isolates of pigeon feces increase the potential of these birds to act as a reservoir of multiple antibiotic resistant bacteria.

Local delivery of antimicrobial peptides using self‐organized TiO2 nanotube arrays for peri‐implant infections

Peri-implant infections have been reported as one of the major complications that lead to the failure of orthopedic implants. An ideal solution to the peri-implant infection is to locally deliver antimicrobial agents through the implant surface. The rising problem of infections caused by multiple antibiotic-resistant bacteria makes traditional antibiotics less desirable for the prevention of peri-implant infections. One of the promising alternatives is the family of antimicrobial peptides (AMPs). In this study, we report the local delivery of AMPs through the nanotubular structure processed on titanium surface. Self-organized and vertically oriented TiO2 nanotubes, about 80 nm in diameter and 7 μm thick, were prepared by the anodization technique. HHC-36 (KRWWKWWRR), one of the most potent broad-spectrum AMPs, was loaded onto the TiO2 nanotubes via a simple vacuum-assisted physical adsorption method. Antimicrobial activity testing against Gram-positive bacterium, Staphylococcus aureus, demonstrated that this AMP-loaded nanotubular surface could effectively kill the bacteria (≈ 99.9% killing) and reduce the total bacterial number adhered to the surface after 4 h of culture. In vitro AMP elution from the nanotubes was investigated using liquid chromatography-mass spectrometry (LC-MS). The release profiles strongly depended on the crystallinity of the TiO2 nanotubes. Anatase TiO2 nanotubes released significantly higher amounts of AMP than amorphous nanotubes during the initial burst release stage. Both followed almost the same slow release profile from 4 h up to 7 days. Despite the differences in release kinetics, no significant difference was observed between these two groups in bactericidal efficiency.

A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs

BackgroundThe aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs) as bactericidal agent on MB45.MethodsDiluted Luria broth/Agar (10-3) media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs.Results and conclusionsThe facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.

Antibacterial activity of chloroform and ethanol extracts of black cumin seeds (Nigella sativa) against multi-drug resistant human pathogens under laboratory conditions.

Chloroform and ethanol extracts of black cumin seeds (Nigella sativa) were analyzed for antibacterial activity against five food and water borne pathogens, namely, Staphylococcus aureus, Bacillus cereus, Vibrio cholerae, Klebsiella pneumoniae, Escherichia coli, and one food spoilage bacteria Bacillus subtilis, all of which were previously found to be resistant to different antibiotics. The antibacterial activities of the extracts were determined by disc diffusion and tube dilution methods. All the bacterial strains except E. coli and K. pneumoniae, showed sensitivity to the chloroform extract as well as the bacterial strains except the K. pneumoniae showed sensitivities to ethanol extract. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of both extracts were also evaluated. Ethanol extract of black cumin was as found to be highly effective for B. subtilis (MIC value 375 µg/ml), followed by S. aureus (MIC value 1125 µg/ml). The highest concentration of extract was required for E. coli for complete inhibition of their growth. MIC value for E. coli was 3000 µg/ml. These results suggest that black cumin seeds may have potential antibacterial activity against multiple antibiotic-resistant bacteria. Key words: Black cumin, multi-drug resistant bacteria, ethanol extract, chloroform extract.

Microbial evaluation and public health implications of urine as alternative therapy in clinical pediatric cases: health implication of urine therapy

BACKGROUND: Cultural means of pediatric treatment during ill health is a mainstay in Africa, and though urine has been known to contain enteric pathogens, urine therapy is still culturally applicable in some health conditions and also advocated as alternative therapy. The study therefore, is to evaluate the microbial contents and safety of urine. METHODS: Urinary bacteria from cows and healthy children aged 5-11 years were identified by conventional phenotypic methods and antimicrobial susceptibility testing was performed using modified agar disc and well-diffusion methods. RESULTS: A total of 116 bacterial isolates (n = 77 children; n = 39 cows) were identified as Bacillus (10.4%; 5.1%)), Staphylococcus (2.6%; 2.6%), Citrobacter (3.9%; 12.8%), Escherichia coli (36.4%; 23.1%), Klebsiella (7.8%; 12.8%), Proteus (18.2%; 23.1%), Pseudomonas (9.1%; 2.6%), Salmonella (3.9%; 5.1%) and Shigella (7.8%; 12.8%) spp. Antibiotic resistance rates of the Gram-positive bacteria were high (50.0-100%), except in Bacillus strains against chloramphenicol, gentamicin and tetracycline (14.3%), while higher resistance rates were recorded among the Gram-negative bacteria except in Citrobacter (0.0%) and Proteus (8.5%) spp. against gentamicin and tetracycline respectively. The Gram-negative bacteria from ito malu (cow urine) were more resistant bacteria except in Citrobacter (20.0%) and Shigella spp. (0.0%) against tetracycline and Proteus spp. (11.1%), (22.2%) against amoxicillin and tetracycline respectively. Multiple antibiotic resistance (MAR) rates recorded in children urinal bacterial species were 37.5-100% (Gram-positive) and 12.5-100% (Gramnegative), while MAR among the cow urinal bacteria was 12.5-75.0% (Gram-positive) and 25.0-100% (Gram-negative). Similar higher resistance rates were also recorded among the Gram-negative bacterial species from urine specimens against the paediatric antibiotic suspensions. CONCLUSION: The study reported presence of multiple antibiotic-resistant indicator bacteria in human urine and ito malu used as alternative remedy in pediatric health conditions like febrile convulsion

Viability of multiple antibiotic resistant bacteria in distribution lines of treated sewage effluent used for irrigation

Viability of multiple antibiotic resistant bacteria (MARB) in tertiary treated sewage effluent (TTSE) used for irrigation, was investigated at the Sultan Qaboos University sewage treatment plant (STP). This water recycle system is used here as a model for the systems commonly used throughout Oman and the Gulf region. Samples of TTSE were collected weekly from four sites, 1.5 km from each other. Chlorine levels declined gradually at the three sites with increasing distance from the STP. Viable bacteria, coliforms and nitrate concentrations increased significantly while biological oxygen demand (BOD) declined after STP chlorination. Mean values of turbidity changed slightly. Trace elements values were insignificant. A total of 336 bacteria from 8 genera revealed that the dominant isolates were Enterobacter spp., Pseudomonas spp., and Aeromonas spp. Among the isolates 59.8% were multiply resistant to several antibiotics. Resistance was higher to ampicillin followed by sulphamethoxazole, carbenicillin, streptomycine and minocycline. Frequency of resistance to the 14 antibiotics varied among the isolates. The present system related to the viability of MARB in TTSE used for irrigation may have serious implications for public health and wildlife. Results of this investigation will be of value in modifying current STPs systems and thus avoiding serious health issues.

The benefits of silver in hygiene, personal care and healthcare

Silver has been used for centuries as an antimicrobial agent to reduce bioburden and prevent infection. Its usage diminished when antibiotics were introduced but remained one of the most popular agents for wound infections, especially in burned patients. Incorporation of silver into a range of hygiene and healthcare applications has increased, and this has raised concerns over the development of silver resistance, toxicity, methods of testing products and evidence of efficacy. The published evidence for resistance and toxicity is limited and associated with frequent and high levels of silver used. Increasing evidence of improved antimicrobial activity of nanoparticles of silver and possible dual immunomodulatory effects are exciting. This may lead to further product development as potential alternative preservatives as some currently available preservatives have an increasing incidence of allergic reactions. Acknowledging the role of the carrier is important, and as silver is active when in solution, opens a window of opportunity in personal hygiene area. This is important in an age when multiple antibiotic-resistant bacteria are becoming prevalent.

Incidence of multiple antibiotic resistant Gram-negative bacteria isolated from surface and underground water sources in south western region of Nigeria

In most rural and urban settlements, particularly in Nigeria, wells, spring, streams or rivers and lakes serves as major sources of water supply for drinking and other domestic purposes. Unfortunately, many of the available water sources are not potable without some form of treatment which is seldom available in most settings. The use of untreated surface water sources for drinking and for domestic purposes remains a major threat to public health as these could serve as reservoirs the for transfer of antibiotic resistant pathogens. The incidence of resistant bacteria isolated from surface and underground water in six rural settlements in Ekiti State Nigeria was thus investigated. Gram-negative bacteria were isolated from wells, streams and boreholes in six rural settlements in Ekiti State Nigeria between January and April, 2006 and the prevalence of organisms exhibiting multiple antibiotic resistance to tetracycline, amoxicillin, cotrimoxazole, nitofurantoin, gentamicin, nalidixic acid and ofloxacin was observed. Gram-negative bacterial isolates comprised Escherichia coli (22.7%), Enterobacter aerogenes (2.5%), Salmonella spp. (13.3%), Shigella spp. (19.3%), Proteus spp. (18.5%), Klebsiella spp. (19.3%) and Pseudomonas aeruginosa (4.2%). Over 10% of the bacteria were resistant to four or more antibiotic. Antibiotic resistance was highest in members of the genera Enterobacter, Pseudomonas, and Proteus. Given the prevalence of appalling sanitary facilities and inappropriate public antibiotic use, the possibility of antibiotic resistance selection, faecal dissemination and subsequent contamination of local water sources available for rural residents of the developing world is highlighted. The implication for clinical practice of infections caused by antibiotic resistant strains especially among immunodeficient individuals is also discussed.

Plasmid-mediated multiple antibiotic resistance of Escherichia coli in crude and treated wastewater used in agriculture

A total of 273 Escherichia coli isolates from raw and treated municipal wastewaters were investigated to evaluate the frequency and persistence of antibiotic resistance and to detect the occurrence of conjugative R plasmids and integrons. The highest resistance rates were against ampicillin (22.71%), tetracycline (19.41%), sulfamethoxazole (16.84%) and streptomycin (14.28%). Multiple antibiotic resistance was present in 24.17% of the isolates. Several multiple antibiotic-resistant isolates proved to be able to transfer en bloc their resistance patterns by conjugative R plasmids with different molecular sizes and restriction profiles. Class 1 integrons of 1 or 1.5 kbp were found in 5 out of 24 representative multiresistant E. coli isolates. Although wastewater treatments proved to be effective in eliminating Salmonella spp. and in reaching WHO microbiological standards for safe use of wastewater in agriculture, they were ineffective in reducing significantly the frequency of plasmid-mediated multiple antibiotic resistance in surviving E. coli. Since multiple antibiotic-resistant bacteria carrying integrons and conjugative R plasmids can constitute a reservoir of antibiotic-resistance genes in wastewater reclaimed for irrigation, risks for public health should be considered. Bacterial strains carrying R plasmids and integrons could contaminate crops irrigated with reclaimed wastewater and transfer their resistances to the consumers' intestinal bacteria.

Chemical composition, antimicrobial and antioxidant activities of Centaurea ensiformis Hub.-Mor. (Asteraceae), a species endemic to Mugla (Turkey)

The n-hexane, chloroform, ethyl acetate and ethyl alcohol extracts of the aerial parts of Centaurea ensiformis, endemic to Turkey, have been assessed for antimicrobial and antioxidant activities. The chemical composition of the hexane extract of this plant was determined. The antimicrobial activities on microorganisms, including multiple antibiotic resistant bacteria, were evaluated using the disc diffusion method. The antioxidant activities were determined by using four complementary in vitro assays: inhibition of 2,2-diphenyl-1-picrylhydrazyl radical, total antioxidant activity, and the total amount of phenolic and flavonoid compounds. The structure of the active extract was elucidated by: thin layer chromatography, column chromatography, gas chromatography or gas chromatography-mass spectrometry. The various extracts of C. ensiformis inhibited the growth of tested bacteria. All the C. ensiformis extracts had no effect on the yeasts. The total antioxidant activity increased with the increasing amount of the extracts (20, 40, 80 and 160 µg), which contained linoleic acid emulsion. The major compounds of the hexane extract of the plant were caryophyllene oxide (28.72%), spathulenol (17.81%), eudesmol (13.03%) and β–bourbonene (8.51%).

Prevalence of multiple antibiotic resistant bacteria and chromosomal determinants in surface water of Bangladesh

A total of 210 different bacteria were isolated from water samples collected in different surveillance sites in Bangladesh between May and July 2004. Of these, 147 isolates were analyzed and 103 were identified by different biochemical tests as well as stereotyped with specific antiserum. Sixty five percent of these isolates were identified as Escherichia coli which were resistant to multiple drugs including tetracycline, nalidixic acid, kanamycin, streptomycin and sulphamethoxazole-trimethoprim. The remaining thirty five percent of the isolates were Vibrio cholerae, Pseudomonas, Aeromonas, Staphylococcus and Klebsiella. Most of the V. cholerae were nalidixic acid, streptomycin and sulphamethoxazole-trimethoprim resistant. Almost 90% of nalidixic acid resistant V. cholera were stereotyped as non O1. The remaining 10% were O1 and O139. All bacteria were used to isolate plasmid DNA to compare plasmid patterns. The plasmid contents of representative drug resistant strains were analyzed by electroporation to determine the location of antibiotic resistant gene whether it was chromosomal or extrachromosomal. The results of these experiments suggested that Bangladeshi environmental water including rivers, lakes and ponds contained a large number of multiple antibiotic resistant bacteria and almost all antibiotic resistant determinants were located in the chromosome instead of plasmid.

The leading causes of death after burn injury in a single pediatric burn center

IntroductionSevere thermal injury is characterized by profound morbidity and mortality. Advances in burn and critical care, including early excision and grafting, aggressive resuscitation and advances in antimicrobial therapy have made substantial contributions to decrease morbidity and mortality. Despite these advances, death still occurs. Our aim was to determine the predominant causes of death in burned pediatric patients in order to develop new treatment avenues and future trajectories associated with increased survival.MethodsPrimary causes of death were reviewed from 144 pediatric autopsy reports. Percentages of patients that died from anoxic brain injuries, sepsis, or multi-organ failure were calculated by comparing to the total number of deaths. Data was stratified by time (from 1989 to 1999, and 1999 to 2009), and gender. Statistical analysis was done by chi-squared, Student's t-test and Kaplan-Meier for survival where applicable. Significance was accepted as P < 0.05.ResultsFive-thousand two-hundred-sixty patients were admitted after burn injury from July 1989 to June 2009, and of those, 145 patients died after burn injury. Of these patients, 144 patients had an autopsy. The leading causes of death over 20 years were sepsis (47%), respiratory failure (29%), anoxic brain injury (16%), and shock (8%). From 1989 to 1999, sepsis accounted for 35% of deaths but increased to 54% from 1999 to 2009, with a significant increase in the proportion due to antibiotic resistant organisms (P < 0.05).ConclusionsSepsis is the leading cause of death after burn injury. Multiple antibiotic resistant bacteria now account for the bulk of deaths due to sepsis. Further improvement in survival may require improved strategies to deal with this problem.

Antimicrobial activity and chemical composition of the essential oils of Thymbra spicata var. intricata.

In this study, T. spicata var. intricata, endemic to Turkey, were collected from various localities of Mugla, Turkey. The essential oils were obtained using the hydrodistillation method. The antimicrobial activities of the essential oils on micro-organisms, including multiple antibiotic resistant bacteria, were evaluated using the disc diffusion method. The chemical composition of the essential oil was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oils were effective against Gram-positive and Gram-negative bacteria, which included multiple antibiotic resistant strains. However, Pseudomonas aeruginosa ATCC 27853 and Pseudomonas fluorescens MU 87 were resistant to these oils. The essential oils were very effective against Candida albicans. The antimicrobial activity of the essential oils showed some variations depending on the localities from which they were collected. A total 24 components were identified in the essential oil. The main components were characterized as carvacrol (75.74%), γ-terpinene (9.28%), p-cymene (7.17%), myrcene (1.39%), β-caryophyllene (1.13%) and thymol (0.15%), respectively. Key words: Antimicrobial activity, chemical composition, Thymbra spicata var. intricata