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Sample records for bacteria resistance patterns

  1. "DRUG RESISTANCE PATTERN IN ISOLATED BACTERIA FROM BLOOD CULTURES"

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    A Sobhani; H. Shodjai S. Javanbakht

    2004-01-01

    Bacteremia is an important infectious disease which may lead to death. Common bacteria and pattern of antibiotic resistance in different communities are different and understanding these differences is important. In the present study, relative frequency and pattern of drug resistance have been examined in bacteria isolated from blood cultures in Razi Hospital laboratory. The method of the study was descriptive. Data collection was carried out retrospectively. Total sample consisted of 311 pos...

  2. Antibiotic Resistance Pattern of Gram-Negative Bacteria in Gorgan

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    Golsha, R. (MD

    2014-06-01

    Full Text Available Background and Objective: The excessive use of broad-spectrum antibiotics will lead to drug resistance of microorganism and specially nosocomial organisms. Because of high incidence of antibiotic resistance in hospitals, we aimed to study antibiotic resistance to gram negative bacteria. Material and Methods: This cross-sectional study was conducted on the data of biological samples (2006-2008, with positive culture result. Using antibiogram, microbial resistance to isolated microorganism was determined, and after culturing the samples, bacteria were identified by using differential media and antiserum. Then, antibiotic resistance was performed by disk diffusion. Results: The most common gram-negative microorganism obtained from all cultures was E.coli with the lowest drug resistance to Nitrofurantoin. Conclusion: Based on the results, antimicrobial resistance pattern is not the same in different places and furthermore it is ever changing. Therefore, further research is needed to be done to have an accurate pattern of antibiotic resistance to provide effective treatment regimens. Key words: Antibiotic Resistance; Disk Diffusion; Gram Negative Bacteria; Gorgan

  3. "DRUG RESISTANCE PATTERN IN ISOLATED BACTERIA FROM BLOOD CULTURES"

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    A. Sobhani

    2004-05-01

    Full Text Available Bacteremia is an important infectious disease which may lead to death. Common bacteria and pattern of antibiotic resistance in different communities are different and understanding these differences is important. In the present study, relative frequency and pattern of drug resistance have been examined in bacteria isolated from blood cultures in Razi Hospital laboratory. The method of the study was descriptive. Data collection was carried out retrospectively. Total sample consisted of 311 positive blood cultures from 1999 to 2001. Variables under study were bacterial strains, antibiotics examined in antibiogram, microbial resistance, and patients' age and sex. The most common isolated bacteria were Salmonella typhi (22.2% and the least common ones were Citrobacter (1.6%. The highest antibiotic resistance was seen against amoxicillin (88.4%. The proportion of males to females was1: 1/1 and the most common age group was 15-44 (47.3%. Common bacteria and pattern of antibiotic resistance were different in some areas and this subject requires further studies in the future.

  4. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION.

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    Reis, Ana Carolina Costa; Santos, Susana Regia da Silva; Souza, Siane Campos de; Saldanha, Milena Góes; Pitanga, Thassila Nogueira; Oliveira, Ricardo Riccio

    2016-07-11

    To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study. A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy.

  5. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

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    Ana Carolina Costa REIS

    2016-01-01

    Full Text Available SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014. All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy.

  6. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

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    REIS, Ana Carolina Costa; SANTOS, Susana Regia da Silva; de SOUZA, Siane Campos; SALDANHA, Milena Góes; PITANGA, Thassila Nogueira; OLIVEIRA, Ricardo Riccio

    2016-01-01

    SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy. PMID:27410913

  7. Antibiotic resistance patterns of bacteria isolated from indwelling Foley catheters following tube cystostomy in goats with obstructive urolithiasis.

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    Chigerwe, Munashe; Mavangira, Vengai; Byrne, Barbara A; Angelos, John A

    2017-05-01

    Tube cystostomy is a surgical method used for managing obstructive urolithiasis and involves placement of a Foley catheter into the urinary bladder. We identified and evaluated the antibiotic resistance patterns of bacteria isolated from indwelling Foley catheters following tube cystostomy in goats with obstructive urolithiasis. Urine samples collected over a 10-y period from catheter tips at the time of removal were submitted for bacteriologic culture and antibiotic susceptibility testing. Resistance patterns to antibiotics, trends in the resistance patterns over the study period, and the probability of a bacterial isolate being resistant as a function of the identity of the isolate and antibiotic tested were determined. A total of 103 urine samples from 103 male goats with obstructive urolithiasis managed surgically with tube cystostomy were included in the study. Aerococcus (36.9%) and Enterococcus (30.1%) were isolated most frequently. The susceptibility patterns of all bacteria isolated did not change over the study period ( p > 0.05). Proportions of isolates resistant to 1, 2, and ≥3 antibiotics were 36.9%, 18.5%, and 23.3%, respectively. Thus, 41.8% of bacterial isolates were resistant to 2 or more antibiotics tested. The probability of Aerococcus spp., Escherichia coli, and Pseudomonas aeruginosa isolates to be resistant to ampicillin, ceftiofur, erythromycin, penicillin, or tetracycline ranged from 0.59 to 0.76.

  8. Resistance patterns to beta-lactams and quinolones in clinical isolates of bacteria from Cuban hospitals.

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    Gonzáles, I; Niebla, A; Vallin, C

    1995-01-01

    The resistance patterns to 26 beta-lactams and 8 quinolones of clinical isolates from Cuban hospitals were evaluated using the disk susceptibility test, according to the NCCLS guidelines (1992). The genera studied were Escherichia sp (320), Enterobacter sp (10), Klebsiella sp (90), Proteus sp (10), Pseudomonas sp (90), Serratia sp (20), and Staphylococcus sp (80). Higher resistance to beta-lactams was observed in the genera Pseudomonas, Escherichia and Klebsiella. For fluoroquinolones we found no significant resistance, with the exception of the genus Klebsiella. The most effective antibiotics were cephalosporins of the second and third generations, fluoroquinolones, and non-classical beta-lactams (cephamycins, moxalactam and monobactams). On the contrary, a pronounced resistance was found to penicillin, oxacillin, ticarcillin, ampicillin, methicillin, nalidixic acid and cinoxacin. These resistance patterns correspond to the high consumption of these antibiotics throughout the country.

  9. Antibiotics and heavy metals resistance patterns of Enterococcus faecalis and faecium bacteria isolated from the human and the livestock sources

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    Yaser Sharifi

    2015-12-01

    Full Text Available Background: Enterococci have emerged as a major cause of nosocomial infections and within this group, Enterococcus faecalis and Enterococcus faecium cause the majority of human and livestock enterococcal infections. In this article, we tried to determine antibiotics and metals resistance patterns of E. faecalis and E. faecium strains. Methods: One hundred sixty different strains of E. faecalis and E. faecium were collected from livestock sewage and the human fecal waste during 15 months. Then bacterial antibiotics sensitivity tests were carried out using the Agar disc diffusion method. Results: Generally, 100% of E. faecalis strains separated from human and livestock sources (i.e. sheep showed penicillin (P/ kanamycin (K/ nitrofurantoin (N/ loracarbef (L/ Ciprofloxacin (Cc/ ampicillin (AN/ nalidixic acid (NA/ sulfamethoxazole (S antibiotics resistance patterns. In addition, 55% of isolated E. faecium showed P/S/AN/NA antibiotics resistance patterns. Each strain showed a resistance to at least two aminoglycoside antibiotics. However, E. faecalis strains from human and the livestock sources showed 94% and 100% of resistance to nitrofurantoin, respectively. The effects of different metal concentrations was evaluated in both strains. The agar dilution method was applied in this stage. Hg at 0.05 mmol/L of minimum inhibitory concentration (MIC showed toxicity to both the human and livestock Enterococcus strains. Cadmium at 1 mmol/L and 0.5 mmol/L concentrations had the most toxicity to E. faecalis and E. faecium strains, respectively. Obviously, toxicity to bacteria is less than other metals. As a result, Zn/Ni/Cu/Co resistance pattern is suggested for both strains. Finally, antibiotics and heavy metals resistance patterns were monitored simultaneously. Conclusion: Almost all E. faecalis strains isolated from humans and livestock showed antibiotics and heavy metals resistance patterns of P/K/L/Cc/S/AN/NA/Zn/Cu/Co simultaneously. Moreover, 55% of E

  10. Electrophoretic pattern of glutathione S-transferase (GST) in antibiotic resistance Gram-positive bacteria from poultry litter.

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    Pugazhendhi, Arivalagan; Dhanarani, Sridevi; Shankar, Congeevaram; Prakash, Piruthiviraj; Ranganathan, Kuppusamy; Saratale, Rijuta Ganesh; Thamaraiselvi, Kaliannan

    2017-09-01

    The present study is aimed to assess the role of glutathione S-transferase (GST) in antibiotic resistance among the bacteria isolated from the poultry litter and to identify the effect of GST to reduce the antimicrobial activity of antibiotics. Induction of various antibiotics to Staphylococcus, Streptococcus and Micrococcus sp. isolated from the poultry litter showed that the activity of GST was three to four folds higher than those of control. Analysis of the isozyme pattern of GST revealed that variation in the expression may be due to antibiotic resistance. The results concluded that GST might play an important role in the protection against the toxic effect of the antimicrobial agents which leads bacteria to become resistant to antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Determination of Drug Resistance Pattern of Prevalent Bacteria Isolated from Patients with UTI

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    H Zandi

    2007-06-01

    Full Text Available Background: Urinary tract infections are the most prevalent bacterial infections in the world and using empiric antibiotic therapy may increase the drug resistance. This cross- sectional study accomplished to determine the prevalence of UTI and related antibiotic resistance pattern. Methods: UTI suspected patients referred to Yazd central laboratory studied. The urine samples cultured colonies with colony count of > 105 cfu/ml identified, and antibiotic resistance patterns determined by the standard disk diffusion method (Kirby-Bauer. Results: Out of 17353 samples 1623 (9.35% were positive culture. The most prevalent microorganisms were as follows: E.coli (47.07%. Enterobacter (12.07%. S. aureus (10.96%, Klebsiella pneumoniae (9.85%, CNS (8.37%, group B streptococci (4.86%. Enterococci (2.09%. Pseudomonas aeruginosa (1.54%. Proteus (1.17%. Nonhemolytic streptococci (0.86%, Citrobacter and α hemolytic Streptococci (0.55%. The antibiogram results showed that isolated strains had the most drug resistance as follows: to ampicillin (80%, SXT (53.66%, tetracycline (50.33%, cephalexin (22.92%, nalidixic acid (19.4%, nitrofruntain (17.12%, ceftizoxime (8.5% and ciprofloxacin (8%. Gram (+ cocci strains were 100% sensitive to vancomycin. Conclusion: selection of proper antibiotic against isolated species though susceptibility testing decreases the dissemination of resistant strains.

  12. ANTIBACTERIAL RESISTANCE PATTERN OF PSEUDOMONAS AERUGINOSA CO - ISOLATED WITH OTHER AEROBIC BACTERIA FROM BURN WOUNDS IN TERTIARY CARE HOSPITAL

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    Kalpana

    2014-01-01

    Full Text Available The antibacterial resistance pattern of 118 isolates from burn wounds in patients with thermal burns showing growth of Pseudomonas aeruginosa mixed with other aerobic bacteria over a period of two years ( January 2009 - Decemb er2010 were studied. Pseudomonas aeruginosa was found to be mixed with Klebsiella pneumoniae 63 ( 53.38% the most followed by Escherichia coli 27 ( 22.88% and other aerobic isolates. Pseudomonas aeruginosa was found to be highly resistant to Ceftazidime ( 72.88% and least to Imipenem ( 9.32%. Klebsiella pneumoniae was found to be most resistant to Ampicillin ( 100% and least to Amikacin ( 23.72%. Antibiotic susceptibility testing was performed for the other isolates as well

  13. Prevalence, resistance patterns, and risk factors for antimicrobial resistance in bacteria from retail chicken meat in Colombia.

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    Donado-Godoy, Pilar; Byrne, Barbara A; León, Maribel; Castellanos, Ricardo; Vanegas, Consuelo; Coral, Adriana; Arevalo, Alejandra; Clavijo, Viviana; Vargas, Mercedes; Romero Zuñiga, Juan J; Tafur, McAllister; Pérez-Gutierrez, Enrique; Smith, Woutrina A

    2015-04-01

    As a step toward implementing the Colombian Integrated Program for Antimicrobial Resistance Surveillance (COIPARS), this study aimed to establish the baseline antimicrobial resistance patterns of Salmonella serovars, Escherichia coli, and Enterococcus spp. isolates in retail poultry meat from independent stores and from a main chain distributor center. MICs of the isolates were determined for antimicrobials used both in humans and animals, using an automated system. Salmonella serovars were isolated from 26% of the meat samples and E. coli from 83%, whereas Enterococcus faecalis and Enterococcus faecium were detected in 81 and 13% of the meat samples, respectively. A principal finding of concern in this study was that almost 98% of isolates tested were multidrug resistant. Ceftiofur, enrofloxacin, nalidixic acid, and tetracycline were the antimicrobials that showed the highest frequency of resistance among Salmonella and E. coli isolates. For enterococci, 61.5% of E. faecium isolates were found to be resistant to quinupristin-dalfopristin; this is significant because it is used to treat nosocomial infections when vancomycin resistance is present. Vancomycin resistance was detected in 4% of the E. faecalis isolates. The results of our study highlight the need for rapid implementation of an integrated program for surveillance of antimicrobial resistance by the Colombian authorities in order to monitor trends, raise awareness, and help promote practices to safeguard later generation antimicrobial agents.

  14. Urinary Tract Infections Due to Catheterization and Drug Resistance Patterns of Isolated Bacteria

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    M. Mosavian

    2004-07-01

    Full Text Available UTI is the most common infection in all ages and urinary catheters especially long-term catheterization are important predisposing factors of UTI. Urinary catheters are used in different hospital wards as a complementary curative method for the patients who are undergone various surgical procedures, such as : cesarean, hysterectomy , laparotomy, etc and they who are unable to control their voided urine . 226 urine specimens were collected from 119 catheterized patients which had been hospitalized in seven wards of Razi and Golestan hospitals in Ahwas city . At least two urine specimens were collected from each patient , before and after the insertion of the catheter . All of the specimens were inoculated to suitable Media, after transportation to the Microbiology Lab . Isolated colonies were identified and their resistance patterns were determined by the standard disk diffusion method (Kirby –Bauer procedure to 8 different antibiotics. 38 cases (43.6% out of 87 patients showed Bacteriuria in the end of catheterization . They had no bacteriuria symptoms or sign before the catheterization. The most cases(28.9% of bacteriuria occured in 30-39 years group and the lowest cases (2.6 % of them occured in 60-69 years group. Out of 50 bacterial strains isolated from urine cultures , E.coil (with 17 cases was the highest (34% and Staphylococcus aureus , Klebsiella pneumoniae , Edwardsiella tarda , Enterobacter sakazakii (with 2% for each were the lowest cases. E.coli, Enterobacter and Kl. rhinoscleromatis , showed the most resistance to Ampicillin, Penicillin , Cephalexin , and the lowest rate to Nalidixic acid, Gentamicin and Nitrofurantoin . Staphylococcus epidermidis isolates ,also,showed the most resistance (100% to Penicillin and Ampicillin , and the lowest rate to Gentamicin (with 66.7%, Cotrimoxazol and Nitrofurantoin (with 50% .The results of this study suggested that catheterization , especially long- term catheterization causes the rise of

  15. Antibiotic-Resistant Bacteria.

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    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

    A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

  16. Drug resistance patterns of bacteria isolated from patients with nosocomial pneumonia at Tehran hospitals during 2009-2011.

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    Haeili, Mehri; Ghodousi, Arash; Nomanpour, Bijan; Omrani, Maryam; Feizabadi, Mohammad Mehdi

    2013-04-17

    Nosocomial pneumonia remains an important cause of mortality and morbidity worldwide. Surveillance programs play an important role in the identification of common etiologic agents and local patterns of antimicrobial resistance. In this study we determined the frequency and antimicrobial susceptibility of pathogens isolated from patients with nosocomial pneumonia during 2009 to 2011. A total of 642 bacteria were isolated from 516 suspected samples. Acinetobacter baumannii (21.1%, n = 136), was the commonest isolated pathogen followed by Pseudomonas aeruginosa (17.4%, n = 112), Staphylococcus aureus (15.8%, n = 102) and enterococci (8.4% n = 54). The most effective therapeutic agents against A. baumannii were polymyxin B (95.5% susceptible), ceftriaxone/tazobactam (72% susceptible) and levofloxacin (52.9% susceptible). Polymixin B (89.2% susceptible), ceftriaxone/tazobactam (89.2% susceptible) and piperacillin-tazobactam (80.3% susceptible) were found to be the most active agents against P. aeruginosa. Extended-spectrum beta-lactamases were detected among isolates of K. pneumoniae (45.4%) and E. coli (20.3%). Overall, the prevalence of methicillin-resistant S. aureus and vancomycin resistant enterococci were 80.4% and 40.7% respectively. Linezolid was found to be the most active antibiotic against these pathogens. The etiology of 50% of the nosocomial infection cases was polymicrobial. The combination of ceftriaxone/tazobactam seems to be beneficial agent against multidrug-resistant Gram-negative bacilli isolated form respiratory tract infections. The results of our study can be used for guiding appropriate empiric therapy in this geographic region.

  17. Maize Leaf Epiphytic Bacteria Diversity Patterns Are Genetically Correlated with Resistance to Fungal Pathogen Infection

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    Plant leaves host a specific set of microbial epiphytes. These phyllosphere organisms form a large community, with annual crops alone covering millions of hectares each year. Host plant genetic factors and abiotic stresses such as UV-B are key in shaping patterns of epiphyte diversity; we analyzed...

  18. The impact of antibiotic use on the incidence and resistance pattern of extended-spectrum beta-lactamase-producing bacteria in primary and secondary healthcare settings.

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    Aldeyab, Mamoon A; Harbarth, Stephan; Vernaz, Nathalie; Kearney, Mary P; Scott, Michael G; Darwish Elhajji, Feras W; Aldiab, Motasem A; McElnay, James C

    2012-07-01

    • The emergence and spread of bacteria producing extended-spectrum beta-lactamases (ESBLs) has important therapeutic and epidemiologic implications. • A key target for the establishment of hospital antibiotic stewardship is reducing the occurrence of additional antibiotic resistance. • Further research is needed to accumulate supporting evidence that reducing antibiotic use will result in a parallel reduction in antibiotic resistance. • Fluoroquinolone restriction reversed ciprofloxacin resistance in primary and secondary healthcare settings. • Fluoroquinolone restriction reduced ESBL-producing bacteria incidence rates in both the primary and secondary healthcare settings. • This study highlights the value of time-series analysis in designing efficient antibiotic stewardship. The objective of the present study was to study the relationship between hospital antibiotic use, community antibiotic use and the incidence of extended-spectrum beta-lactamase (ESBL)-producing bacteria in hospitals, while assessing the impact of a fluoroquinolone restriction policy on ESBL-producing bacteria incidence rates. The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (ARIMA) model was built to relate antibiotic use to ESB-producing bacteria incidence rates and resistance patterns over a 5 year period (January 2005-December 2009). Analysis showed that the hospital incidence of ESBLs had a positive relationship with the use of fluoroquinolones in the hospital (coefficient = 0.174, P= 0.02), amoxicillin-clavulanic acid in the community (coefficient = 1.03, P= 0.03) and mean co-morbidity scores for hospitalized patients (coefficient = 2.15, P= 0.03) with various time lags. The fluoroquinolone restriction policy was implemented successfully with the mean use of fluoroquinolones (mainly ciprofloxacin) being reduced from 133 to 17 defined daily doses (DDDs)/1000 bed days (P < 0.001) and from 0.65 to 0.54 DDDs/1000

  19. Odontogenic bacteria in periodontal disease and resistance patterns to common antibiotics used as treatment and prophylaxis in odontology in Spain.

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    Maestre, J R; Bascones, A; Sánchez, P; Matesanz, P; Aguilar, Lorenzo; Giménez, M J; Pérez-Balcabao, I; Granizo, J J; Prieto, J

    2007-03-01

    Resistance in streptococci or Gram-negative bacteria is associated with antibiotic consumption. Scarce information exists on the antibiotic susceptibility of bacterial isolates from patients with periodontitis in countries with high antibiotic consumption, as this is an area in which microbiological testing is not performed in daily practice. The present study was undertaken to explore the susceptibility of bacterial isolates in periodontitis to antibiotics prescribed in odontology in Spain as treatment for local infections or prophylaxis for distant focal infections. Periodontal samples were prospectively collected in 48 patients classified by pocket depth of or=4 mm. Species were identified by culture, selecting the five most frequent morphotypes per sample, and polymerase chain reaction (PCR). Susceptibility was determined by E-test. A total of 261 isolates were identified: 72.9% patients had Streptococcus oralis; 70.8% Streptococcus mitis; 60.4% Prevotella buccae; 39.6% Prevotella denticola; 37.5% Fusobacterium nucleatum; 35.4% Prevotella intermedia; 25% Capnocytophaga spp.; 23% Veillonella spp.; 22.9% Prevotella melaninogenica and Streptococcus sanguis; and resistance rates were 0% for amoxicillin, approximately 10% for clindamycin, 9-22% for tetracycline, and for azithromycin ranged from 18.2% for S. sanguis to 47.7% for S. mitis. Prevotella isolates were susceptible to amoxicillin-clavulanic acid, with amoxicillin resistance ranging from 17.1% in P. buccae to 26.3% in P. denticola. Metronidazole resistance was resistance ranged from 0 to 21.1%. beta-Lactamase production was positive in 54.1% Prevotella spp., 38.9% F. nucleatum, 30% Capnocytophaga spp., and 10% Veillonella spp. In this study, amoxicillin-clavulanic acid was the most active antibiotic against all species tested, followed by metronidazole in the case of anaerobes.

  20. Association of mutation patterns in GyrA and ParC genes with quinolone resistance levels in lactic acid bacteria.

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    Li, Shaoying; Li, Zhen; Wei, Wan; Ma, Chunyan; Song, Xiaomin; Li, Shufen; He, Wenying; Tian, Jianjun; Huo, Xiaoyan

    2015-02-01

    The quinolone resistance of 19 lactic acid bacterial strains belonging to the genera Enterococcus and Lactobacillus isolated from the natural fermented koumiss and yoghurt were investigated. The objective of this study was to determine the quinolone resistance levels and to explore the association of the resistance with the mutation patterns in gyrA and parC genes, as is currently recommended by the Food and Agriculture Organization/World Health Organization Joint Expert Committee in Guidelines for Evaluation of Probiotics in Food for probiotic lactic acid bacteria drug resistance in 2001. The Oxford Cup method and double-tube dilution method were used to determine the quinolone resistance levels of the isolated strains. Generally, all of the 19 strains showed resistance towards norfloxacin and ciprofloxacin when the Oxford cup method was used, whereas the incidence was lower (to norfloxacin 89.5% and to ciprofloxacin 68.4%) when minimum inhibitory concentration breakpoints (CLSI M100-S23) were tested. Furthermore, gene sequencing was conducted on gyrA and parC of topoisomerase II of these isolated strains. The genetic basis for quinolone resistance may be closely related to mutations in gyrA genes as there were 10 mutation sites in amino-acid sequences encoded by gyrA genes in 10 quinolone resistance strains and 14 mutation sites in Enterococcus durans HZ28, whereas no typical mutations were detected in parC genes.

  1. Frequency and antimicrobial resistance patterns of bacteria implicated in community urinary tract infections: a ten-year surveillance study (2000–2009

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    Linhares Inês

    2013-01-01

    Full Text Available Abstract Background Urinary tract infection (UTI is one of the most common infectious diseases at the community level. In order to assess the adequacy of the empirical therapy, the prevalence and the resistance pattern of the main bacteria responsible for UTI in the community (in Aveiro, Portugal was evaluated throughout a ten-year period. Methods In this retrospective study, all urine samples from patients of the District of Aveiro, in ambulatory regime, collected at the Clinical Analysis Laboratory Avelab during the period 2000–2009 were analysed. Samples with more than 105 CFU/mL bacteria were considered positive and, for these samples, the bacteria were identified and the profile of antibiotic susceptibility was characterized. Results From the 155597 samples analysed, 18797 (12.1% were positive for bacterial infection. UTI was more frequent in women (78.5% and its incidence varied with age, affecting more the elderly patients (38.6%. Although E. coli was, as usual, the most common pathogen implicated in UTI, it were observed differences related to the other bacteria more implicated in UTI relatively to previous studies. The bacteria implicated in the UTI varied with the sex of the patient, being P. aeruginosa a more important cause of infection in men than in women. The incidence of the main bacteria changed over the study period (P. aeruginosa, Klebsiella spp and Providencia spp increased and Enterobacter spp decreased. Although E. coli was responsible for more than an half of UTI, its resistance to antibiotics was low when compared with other pathogens implicated in UTI, showing also the lowest percentage of multidrug resistant (MDR isolates (17%. Bacteria isolated from females were less resistant than those isolated from males and this difference increased with the patient age. Conclusions The differences in sex and age must be taken into account at the moment of empirical prescription of antimicrobials. From the recommended

  2. Aggregation Patterns in Stressed Bacteria

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    Tsimring, L S; Aranson, I S; Ben-Jacob, E; Cohen, I; Shochet, O; Tsimring, Lev; Levine, Herbert; Aranson, Igor; Ben-Jacob, Eshel; Cohen, Inon; Shochet, Ofer

    1995-01-01

    We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.

  3. Resistant bacteria in stem cell transplant recipients

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    Nucci Marcio

    2002-01-01

    Full Text Available Bacterial infections account for most infections in hematopoietic stem cell transplant recipients. While early mortality reduced dramatically with the introduction of the concept of empirical antibiotic therapy in neutropenic patients, no effect of prophylaxis on the mortality was observed in many studies. On the other hand, antibiotic prophylaxis has resulted in the emergence of resistance among bacteria. In addition, the choice of the antibiotic regimen for empirical therapy and the practices of antibiotic therapy during neutropenia may result in a significant shift in the pattern of bacterial infections. The use of quinolones and vancomycin as prophylaxis, and of carbapenems and vancomycin in the empirical antibiotic therapy, are associated with the appearance of resistant Gram-positive and Gram-negative bacteria. Therefore, hematologists must be aware of the impact of these practices on the emergence of infections due to multi-resistant pathogens, since these infections may be associated with increased mortality.

  4. The impact of antibiotic use on the incidence and resistance pattern of extended-spectrum beta-lactamase-producing bacteria in primary and secondary healthcare settings

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    Aldeyab, Mamoon A; Harbarth, Stephan; Vernaz, Nathalie; Kearney, Mary P; Scott, Michael G; Darwish Elhajji, Feras W; Aldiab, Motasem A; McElnay, James C

    2012-01-01

    AIMS The objective of the present study was to study the relationship between hospital antibiotic use, community antibiotic use and the incidence of extended-spectrum beta-lactamase (ESBL)-producing bacteria in hospitals, while assessing the impact of a fluoroquinolone restriction policy on ESBL-producing bacteria incidence rates. METHODS The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (ARIMA) model was built to relate antibiotic use to ESB-producing bacteria incidence rates and resistance patterns over a 5 year period (January 2005–December 2009). RESULTS Analysis showed that the hospital incidence of ESBLs had a positive relationship with the use of fluoroquinolones in the hospital (coefficient = 0.174, P = 0.02), amoxicillin-clavulanic acid in the community (coefficient = 1.03, P = 0.03) and mean co-morbidity scores for hospitalized patients (coefficient = 2.15, P = 0.03) with various time lags. The fluoroquinolone restriction policy was implemented successfully with the mean use of fluoroquinolones (mainly ciprofloxacin) being reduced from 133 to 17 defined daily doses (DDDs)/1000 bed days (P antibiotic restriction. The study also highlights the potential value of the time-series analysis in designing efficient antibiotic stewardship. PMID:22150975

  5. Antibiotic resistance in probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miguel eGueimonde

    2013-07-01

    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.

  6. Multiple antibiotic resistance among gram negative bacteria isolated from poultry.

    Science.gov (United States)

    Ansari, F A; Khatoon, H

    1994-03-01

    Gram negative bacteria, including species of Salmonella, Escherichia, Pseudomonas and Klebsiella, isolated from poultry, were screened for their resistance to the commonly used antibiotics: ampicillin, chloramphenicol, gentamycin, kanamycin, neomycin, polymyxin B, streptomycin and tetracycline. Of the 500 bacteria screened, 351 were found to be resistant to one or more antibiotics at the level of 50 micrograms/ml. Various patterns of antibiotic resistance observed during these studies have been reported.

  7. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carn

  8. Antibiotic resistance patterns in fecal bacteria isolated from Christmas shearwater (Puffinus nativitatis) and masked booby (Sula dactylatra) at remote Easter Island.

    Science.gov (United States)

    Ardiles-Villegas, Karen; González-Acuña, Daniel; Waldenström, Jonas; Olsen, Björn; Hernández, Jorge

    2011-09-01

    Antibiotic use and its implications have been discussed extensively in the past decades. This situation has global consequences when antibiotic resistance becomes widespread in the intestinal bacterial flora of stationary and migratory birds. This study investigated the incidence of fecal bacteria and general antibiotic resistance, with special focus on extended spectrum beta-lactamase (ESBL) isolates, in two species of seabirds at remote Easter Island. We identified 11 species of bacteria from masked booby (Sula dactylatra) and Christmas shearwater (Puffinus nativitatis); five species of gram-negative bacilli, four species of Streptococcus (Enterococcus), and 2 species of Staphylococcus. In addition, 6 types of bacteria were determined barely to the genus level. General antibiotic susceptibility was measured in the 30 isolated Enterobacteriaceae to 11 antibiotics used in human and veterinary medicine. The 10 isolates that showed a phenotypic ESBL profile were verified by clavulanic acid inhibition in double mixture discs with cefpodoxime, and two ESBL strains were found, one strain in masked booby and one strain in Christmas shearwater. The two bacteria harboring the ESBL type were identified as Serratia odorifera biotype 1, which has zoonotic importance. Despite minimal human presence in the masked booby and Christmas shearwater habitats, and the extreme geographic isolation of Easter Island, we found several multiresistant bacteria and even two isolates with ESBL phenotypes. The finding of ESBLs has animal and public health significance and is of potential concern, especially because the investigation was limited in size and indicated that antibiotic-resistant bacteria now are distributed globally.

  9. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

    Directory of Open Access Journals (Sweden)

    Suresh Jaiswal et al.

    2012-03-01

    Full Text Available Drug resistant bacteria have been posing a major challenge to the effective control of bacterial infections for quite some time. One of the main causes of antibiotics drug resistance is antibiotic overuse, abuse, and in some cases, misuse, due to incorrect diagnosis. Bacterial antibiotic resistance is a significant issues faced by various industries, including the food and agricultural industries, the medical and veterinary profession and others. The potential for transfer of antibiotics resistance, or of potentially lethal antibiotic resistant bacteria, for example from a food animal to human consumer, is of particular concern. A method of controlling development and spread of antibiotic-resistant bacteria include changes in antibiotic usage and pattern of usage of different antibiotics. However, the ability of bacteria to adapt to antibiotic usage and to acquire resistance to existing and new antibiotics usage overcomes such conventional measures, and requires the continued development of alternative means of control of antibiotic resistance bacteria. Alternative means for overcoming the tendency of bacteria to acquire resistance to antibiotic control measures have taken various forms. This article explains one method evaluated for control, that is reducing or removing antibiotic resistance is so called “curing” of antibiotic resistance. Antibiotic resistance is formed in the chromosomal elements. Thus elimination of such drug-resistance plasmids results in loss of antibiotics resistance by the bacterial cell. “Curing” of a microorganism refers to the ability of the organism to spontaneously lose a resistance plasmid under the effect of particular compounds and environmental conditions, thus recovering the antibiotic sensitive state.

  10. Biodegradation of 2,4-dichlorophenoxyacetic acid by bacteria with highly antibiotic-resistant pattern isolated from wheat field soils in Kurdistan, Iran.

    Science.gov (United States)

    Karami, Solmaz; Maleki, Afshin; Karimi, Ebrahim; Poormazaheri, Helen; Zandi, Shiva; Davari, Behrooz; Salimi, Yahya Zand; Gharibi, Fardin; Kalantar, Enayatollah

    2016-12-01

    Recently, there has been increasing interest to clean up the soils contaminated with herbicide. Our aim was to determine the bioremediation of 2,4-dichlorophenoxyacetic acid (2,4-D) from wheat fields which have a long history of herbicide in Sanandaj. Based on our literature survey, this study is the first report to isolate and identify antimicrobial resistant bacteria from polluted wheat field soils in Sanandaj which has the capacity to degrade 2,4-D. From 150 2,4-D-exposed soil samples, five different bacteria were isolated and identified based on biochemical tests and 16S ribosomal RNA (rRNA). Pseudomonas has been the most frequently isolated genus. By sequencing the 16S rRNA gene of the isolated bacteria, the strains were detected and identified as a member of the genus Pseudomonas sp, Entrobacter sp, Bacillus sp, Seratia sp, and Staphylococcus sp. The sequence of Sanandaj 1 isolate displayed 87% similarity with the 16S rRNA gene of a Pseudomonas sp (HE995788). Similarly, all the isolates were compared to standard strains based on 16S rRNA. Small amounts of 2,4-D could be transmitted to a depth of 10-20 cm; however, in the depth of 20-40 cm, we could not detect the 2,4-D. The isolates were resistant to various antibiotics particularly, penicillin, ampicillin, and amoxicillin.

  11. Antimicrobial resistant bacteria in the food chain

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar

    2003-01-01

    Antimicrobials are used for treatment and prevention of disease in food animals and as feed additives for growth promotion. All uses lead to the development of resistant bacteria, some of which are pathogenic to humans. Current main concerns are with resistance in Salmonella and Campylobacter...

  12. Mechanisms of polymyxin resistance: acquired and intrinsic resistance in bacteria

    Directory of Open Access Journals (Sweden)

    Abiola Olumuyiwa Olaitan

    2014-11-01

    Full Text Available Polymyxins are polycationic antimicrobial peptides that are currently the last-resort antibiotics for the treatment of multidrug-resistant, Gram-negative bacterial infections. The reintroduction of polymyxins for antimicrobial therapy has been followed by an increase in reports of resistance among Gram-negative bacteria. Some bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii, develop resistance to polymyxins in a process referred to as acquired resistance, whereas other bacteria, such as Proteus spp., Serratia spp. and Burkholderia spp., are naturally resistant to these drugs. Reports of polymyxin resistance in clinical isolates have recently increased, including acquired and intrinsically resistant pathogens. This increase is considered a serious issue, prompting concern due to the low number of currently available effective antibiotics. This review summarizes current knowledge concerning the different strategies bacteria employ to resist the activities of polymyxins.Gram-negative bacteria employ several strategies to protect themselves from polymyxin antibiotics (polymyxin B and colistin, including a variety of lipopolysaccharide (LPS modifications, such as modifications of lipid A with phosphoethanolamine and 4-amino-4-deoxy-L-arabinose, in addition to the use of efflux pumps, the formation of capsules and overexpression of the outer membrane protein OprH, which are all effectively regulated at the molecular level. The increased understanding of these mechanisms is extremely vital and timely to facilitate studies of antimicrobial peptides and find new potential drugs targeting clinically relevant Gram-negative bacteria.

  13. The antibiotics relo in bacteria resistance

    OpenAIRE

    Santana, Vinicius Canato; CESUMAR

    2007-01-01

    The paper explains how antibiotics help us to combat bacteriosis, and also presents a brief historical report about the emergence of the antibiotic era with the discovery of penicillin. It introduces the problem of bacteria resistance, and brings the concept of antibiotics and its that produce these substance, and brings the concept of antibiotics and its main function. It questions about the self-defense of the organisms that produce these substances. relates the bacteria structures attacked...

  14. Bacteriophage biosensors for antibiotic-resistant bacteria.

    Science.gov (United States)

    Sorokulova, Irina; Olsen, Eric; Vodyanoy, Vitaly

    2014-03-01

    An increasing number of disease-causing bacteria are resistant to one or more anti-bacterial drugs utilized for therapy. Early and speedy detection of these pathogens is therefore very important. Traditional pathogen detection techniques, that include microbiological and biochemical assays are long and labor-intensive, while antibody or DNA-based methods require substantial sample preparation and purification. Biosensors based on bacteriophages have demonstrated remarkable potential to surmount these restrictions and to offer rapid, efficient and sensitive detection technique for antibiotic-resistant bacteria.

  15. MULTIDRUG RESISTANT BACTERIA IN A TERTIARY CARE HOS PITAL.

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    Sujata

    2012-12-01

    Full Text Available ABSTRACT: BACKGROUND: Antibiotic resistance is a global problem in the hos pitals as well as in the community. Selection pressure exerted by over use of antimicrobial agents is the commonest predisposing factor of development of resist ance. Problems faced are especially with Methicillin Resistant Staphylococcus aureus (MR SA, Vancomycin Resistant Enterococci (VRE and Multidrug resistant Gram-negative bacilli (MDR-GNB. AIMS: A study was undertaken to find out the prevalence of all bacteri a isolated in this hospital from different specimens, which are resistant to first line antibio tics and their antimicrobial susceptibility pattern with higher antibiotics during a six-month pe riod. MATERIAL AND METHODS: All isolates from different specimens were processed by s tandard techniques and identified by standard biochemical tests. Antibiotic susceptibilit y was performed on Mueller Hinton Agar (MHA by Kirby-Bauer Disc Diffusion Method (KBDDM, according to CLSI guidelines. Those resistant to first line antibiotics were further te sted for higher antibiotics. For Extended Spectrum β -lactamse (ESBL detection, double disc synergy met hod was carried out for all Gram-negative bacilli. RESULTS: Out of 2987 bacteria grown, 904 (30.3% were multi drug resistant bacteria. Resistance to first line antib iotics was 83.4% and resistance to all higher antibiotics tested was 16.6%. Sixty percent of Staph ylococcus aureus was MRSA and all were sensitive to vancomycin. Prevalence of VRE was 5.3 %. Carbapenem resistant Pseudomonas aeruginosa and Acinetobacter species were 19.1% and 9.8% respectively and 10.1% of Klebsiella species was carbapenem resistant. CONCLUSIONS: This study highlights the extensive problem of antibiotic resistance encounter ed in this hospital. Thus, prudent and appropriate uses of antibiotics are required to reduce the emergence of resistance. Each hospital should also have its own antibiotic policy based on the susceptibility pattern of

  16. Beer spoilage bacteria and hop resistance.

    Science.gov (United States)

    Sakamoto, Kanta; Konings, Wil N

    2003-12-31

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

  17. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    1997-01-01

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  18. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  19. Antimicrobial resistance in bacteria from horses: Epidemiology of antimicrobial resistance.

    Science.gov (United States)

    Maddox, T W; Clegg, P D; Williams, N J; Pinchbeck, G L

    2015-11-01

    Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections. While the epidemiology of antimicrobial resistance in bacteria from man has been studied extensively, less work has been undertaken in companion animals, particularly horses. Methicillin-resistant Staphylococcus aureus has been identified as a cause of infections, with a low prevalence of nasal carriage by horses in the community but higher for hospitalised horses. Molecular characterisation has shown methicillin-resistant Staphylococcus aureus strains either to be predominantly of types associated with horses or of sequence type ST398. Antimicrobial-resistant Escherichia coli (including multidrug-resistant and extended spectrum β-lactamase-producing isolates) have caused infections and been documented in faecal carriage by horses, with many significant resistance mechanisms identified. More sporadic reports and molecular characterisation exist for resistance in other bacteria such as enterococci, Salmonella, Acinetobacter and Pseudomonas species. Limited work has been undertaken evaluating risk factors and much of the epidemiology of antimicrobial resistance in bacteria from horses remains to be determined.

  20. Frequency of Resistance and Susceptible Bacteria Isolated from Houseflies

    Directory of Open Access Journals (Sweden)

    B Davari

    2010-12-01

    Conclusion: Houseflies collected from hospitals and slaughterhouse may be involved in the spread of drug resistant bacteria and may increase the potential of human exposure to drug resistant bacteria.

  1. Antimicrobial resistant bacteria in the food chain

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar

    2003-01-01

    Antimicrobials are used for treatment and prevention of disease in food animals and as feed additives for growth promotion. All uses lead to the development of resistant bacteria, some of which are pathogenic to humans. Current main concerns are with resistance in Salmonella and Campylobacter...... to fluoroquinolones, which are used for empirical treatment of diarrhea in humans. Resistance to vancomycin and Synercid((R)) in enterococci is associated with use of similar drugs as growth promoters in food animals. Danish food animal producers have terminated the use of antimicrobial growth promoters. This has...... reduced the total use of antimicrobials by more than 50% and markedly reduced levels of resistance. There is an urgent need to implement globally, WHO principles for prudent use of antimicrobials in food animals. Use of antimicrobials as growth promoters could and should be terminated completely....

  2. Epidemiology of nosocomial bacteria resistant to antimicrobials

    Directory of Open Access Journals (Sweden)

    Cristina E. Cabrera

    2011-03-01

    Full Text Available Nosocomial infections are a major challenge for public health because of the high rates of morbidity and mortality generated. It was considered that the excessive or inappropriate use of antibiotics triggers the emergence of resistant strains. Among the clinically important bacteria that most commonly cause nososcomial infections, Gram positive multiresistant pathogens stand out such as methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus spp (VRE, and the Gram negative strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas spp. and Acinetobacter baumannii producing expanded spectrum b-lactamases (ESbL. This review describes the behavior of the main bacterial pathogens resistant to antibiotics that cause infections in Europe, United States, and Latin America, emphasizing studies of molecular epidemiology on a global scale, including the major epidemiological studies in Colombia. The genetic structure of S. aureus and Enterococcus spp strains shows a clonal characteristic favored by the predominance of a small number of clones with the capacity to spread globally, due probably to cross-infection. However, the introduction of MRSA strains from the community encourages genetic diversity, tending to establish a genetic polyclonal endemic structure in places like the United States. In Gram negative bacteria, the high genetic diversity among isolates, mainly in Latin American countries, indicates that the polyclonal spread is influenced by horizontal transfer of plasmids, by excessive exposure to antibiotics, and prolonged hospital stays. In Colombia, there is information on nosocomial resistant pathogens, but molecular epidemiological information is still scarce.

  3. Epidemiology of nosocomial bacteria resistant to antimicrobials

    Directory of Open Access Journals (Sweden)

    Cristina E Cabrera

    2011-04-01

    Full Text Available Nosocomial infections are a major challenge for public health because of the high rates of morbidity and mortality generated. It was considered that the excessive or inappropriate use of antibiotics triggers the emergence of resistant strains. Among the clinically important bacteria that most commonly cause nososcomial infections, Gram positive multiresistant pathogens stand out such as methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus spp (VRE, and the Gram negative strains of Klebsiella pneumoniae, Escherichia coli, Pseudomonas spp. and Acinetobacter baumannii producing expanded spectrum b-lactamases (ESbL. This review describes the behavior of the main bacterial pathogens resistant to antibiotics that cause infections in Europe, United States, and Latin America, emphasizing studies of molecular epidemiology on a global scale, including the major epidemiological studies in Colombia. The genetic structure of S. aureus and Enterococcus spp strains shows a clonal characteristic favored by the predominance of a small number of clones with the capacity to spread globally, due probably to cross-infection. However, the introduction of MRSA strains from the community encourages genetic diversity, tending to establish a genetic polyclonal endemic structure in places like the United States. In Gram negative bacteria, the high genetic diversity among isolates, mainly in Latin American countries, indicates that the polyclonal spread is influenced by horizontal transfer of plasmids, by excessive exposure to antibiotics, and prolonged hospital stays. In Colombia, there is information on nosocomial resistant pathogens, but molecular epidemiological information is still scarce.

  4. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    Science.gov (United States)

    Kathleen, M. M.; Felecia, C.; Reagan, E. L.; Kasing, A.; Lesley, M.; Toh, S. C.

    2016-01-01

    The administration of antimicrobials in aquaculture provides a selective pressure creating a reservoir of multiple resistant bacteria in the cultured fish and shrimps as well as the aquaculture environment. The objective of this study was to determine the extent of antibiotic resistance in aquaculture products and aquaculture's surrounding environment in Sarawak, Malaysian Borneo. Ninety-four identified bacterial isolates constituted of 17 genera were isolated from sediment, water, and cultured organisms (fish and shrimp) in selected aquaculture farms. These isolates were tested for their antibiotic resistance against 22 antibiotics from several groups using the disk diffusion method. The results show that the highest resistance was observed towards streptomycin (85%, n = 20), while the lowest resistance was towards gentamicin (1.1%, n = 90). The multiple antibiotic resistant (MAR) index of the isolates tested ranged between 0 and 0.63. It was suggested that isolates with MAR index > 0.2 were recovered from sources with high risk of antibiotic resistant contamination. This study revealed low level of antibiotic resistance in the aquaculture bacterial isolates except for streptomycin and ampicillin (>50% resistance, n = 94) which have been used in the aquaculture industry for several decades. Antibiotic resistant patterns should be continuously monitored to predict the emergence and widespread of MAR. Effective action is needed to keep the new resistance from further developing and spreading.

  5. Progress in Research of Bacteria Fertilizer Strengthening Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).

  6. [Travellers and multi-drug resistance bacteria].

    Science.gov (United States)

    Takeshita, Nozomi

    2012-02-01

    The number of international travellers has increased. There is enormous diversity in medical backgrounds, purposes of travel, and travelling styles among travellers. Travellers are hospitalized abroad because of exotic and common diseases via medical tourism. This is one way of transporting and importing human bacteria between countries, including multi-drug resistant organisms. In developing countries, the antimicrobial resistance in Shigella sp. and Salmonella sp. have been a problem, because of this trend, the first choice of antibiotics has changed in some countries. Community acquired infections as well as hospital acquired infections with MRSA, multi-drug resistance (MDR) Pseudomonas aeruginosa, and ESBL have been a problem. This review will discuss the risk of MDR bacterial infectious diseases for travellers.

  7. Antibiotic resistance: What is so special about multidrug-resistant Gram-negative bacteria?

    Directory of Open Access Journals (Sweden)

    Exner, Martin

    2017-04-01

    Full Text Available In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.

  8. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  9. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Mega

  10. Antibiotic resistance patterns of bacteria causing urinary tract infections in the elderly living in nursing homes versus the elderly living at home: an observational study.

    Science.gov (United States)

    Fagan, Mark; Lindbæk, Morten; Grude, Nils; Reiso, Harald; Romøren, Maria; Skaare, Dagfinn; Berild, Dag

    2015-08-04

    Antibiotic resistance is a problem in nursing homes. Presumed urinary tract infections (UTI) are the most common infection. This study examines urine culture results from elderly patients to see if specific guidelines based on gender or whether the patient resides in a nursing home (NH) are warranted. This is a cross sectional observation study comparing urine cultures from NH patients with urine cultures from patients in the same age group living in the community. There were 232 positive urine cultures in the NH group and 3554 in the community group. Escherichia coli was isolated in 145 urines in the NH group (64%) and 2275 (64%) in the community group. There were no clinically significant differences in resistance. Combined, there were 3016 positive urine cultures from females and 770 from males. Escherichia coli was significantly more common in females 2120 (70%) than in males 303 (39%) (p < 0.05). Enterococcus faecalis was significantly less common in females 223 (7%) than males 137 (18%) (p < 0.05). For females, there were lower resistance rates to ciprofloxacin among Escherichia coli (7% vs 12%; p < 0.05) and to mecillinam among Proteus mirabilis (3% vs 12%; p < 0.05). Differences in resistance rates for patients in the nursing home do not warrant separate recommendations for empiric antibiotic therapy, but recommendations based on gender seem warranted.

  11. Diversity and antibiotic resistance of uropathogenic bacteria from Abidjan

    Directory of Open Access Journals (Sweden)

    J.-L.A. Moroh

    2014-03-01

    Conclusions: The diversity of uropathogenic bacteria obtained appeared to be a characteristic of sub-Saharan African countries. Their resistances to different antibiotics were following a dramatic trend. Waiting to be confronted with therapeutic dead end with the advent of multi-resistant bacteria, identifying the region-specific causes is crucial to adapt antibiotic therapy.

  12. Management of neonatal sepsis at Muhimbili National Hospital in Dar es Salaam: diagnostic accuracy of C-reactive protein and newborn scale of sepsis and antimicrobial resistance pattern of etiological bacteria.

    Science.gov (United States)

    Mkony, Martha Franklin; Mizinduko, Mucho Michael; Massawe, Augustine; Matee, Mecky

    2014-12-05

    We determined the accuracy of Rubarth's newborn scale of sepsis and C- reactive protein in diagnosing neonatal sepsis and assessed antimicrobial susceptibility pattern of etiological bacteria. This cross sectional study was conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania between July 2012 and March 2013. Neonates suspected to have sepsis underwent physical examination using Rubarth's newborn scale of sepsis (RNSOS). Blood was taken for culture and antimicrobial sensitivity testing, full blood picture and C - reactive protein (CRP) performed 12 hours apart. The efficacy of RNSOS and serial CRP was assessed by calculating sensitivity, specificity, negative and positive predictive values, receiver operating characteristics (ROC) analysis as well as likelihood ratios (LHR) with blood culture result used as a gold standard. Out of 208 blood samples, 19.2% had a positive blood culture. Single CRP had sensitivity and specificity of 87.5% and 70.9% respectively, while RNSOS had sensitivity of 65% and specificity of 79.7%. Serial CRP had sensitivity of 69.0% and specificity of 92.9%. Combination of CRP and RNSOS increased sensitivity to 95.6% and specificity of 56.4%. Combination of two CRP and RNSOS decreased sensitivity to 89.1% but increased specificity to 74%. ROC for CRP was 0.86; and for RNSOS was 0.81. For CRP the LHR for positive test was 3 while for negative test was 0.18, while for RNSOS the corresponding values were 3.24 and for negative test was 0.43. Isolated bacteria were Klebsiella spp 14 (35%), Escherichia coli 12 (22.5%), Coagulase negative staphlococci 9 (30%), Staphylococcus aureus 4 (10%), and Pseudomonas spp 1 (2.5%). The overall resistance to the WHO recommended first line antibiotics was 100%, 92% and 42% for cloxacillin, ampicillin and gentamicin, respectively. For the second line drugs resistance was 45%, 40%, and 7% for ceftriaxone, vancomycin and amikacin respectively. Single CRP in combination with RNSOS can be used for rapid

  13. Distribution of Gram Negative Bacteria and Evaluation of Resistance Profiles

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    Serap Pamukcuoglu

    2014-03-01

    Full Text Available Aim: In this study, we aimed to examine the distributon of Gram negative bacteria isolated from urine cultures of out-patients in Afyonkarahisar State Hospital and evaluate the antimicrobial resistance rates of these pathogens. Material and Method: Urine samples of out-patients which were sent to microbiology laboratory between 2012-2013 were retrospectively evaluated. The isolates were identified using conventional methods and/or automated Vitec 2.0 system. Antibiogram sensitivities were determined by Kirby-Bauer disc diffusion method or automated system and interpreted on the basis of Clinical and Laboratory Standards Institute (CSI criteria. Double disc sinergy test (DDST or Vitec 2.0 system was used to detect extended spectrum beta-lactamase (ESBL.When conventional methods could%u2019t be clarified according to their colony morphologies, gram staining patterns, biochemical test; automated system has been used. Results: A total of 671 isolates acquired from urine samples were studied. 427 Escherichia coli (63.6 %, 165 Klebsiella spp. (24.6 %, 22 Pseudomonas spp. (3.3 %, nine Acinetobacter spp. (1.3 %, 41 Proteus spp. (6.1 % and seven Serratia (1.0 % strains were identified among isolates. 97 E.coli (22.8 % and 41 Klebsiella (24.8 % isolates were ESBL positive. Most common bacteria were E.coli, 31.1 % of which were resistant to trimethoprim-sulfamethoxazole, 16 % to ciprofloxacin and 3.6 % to nitrofurantoin. Among Enterobacteriaceae, no resistance aganist carbapenems were detected. Moreover, aminoglicoside sensitivity rate was significantly high in this group. Discussion: Microorganisms that have progressively increasing antimicrobial resistance should be considered in the treatment of urinary tract infections. It is also important to use the most appropriate antibiotics to avoid unnecessary usage of these drugs in order to decrease drug resistance rates and ESBL production which may effect the success of the treatment.

  14. Antibiotic resistance pattern in uropathogens

    Directory of Open Access Journals (Sweden)

    Gupta V

    2002-01-01

    Full Text Available Uropathogenic strains from inpatient and outpatient departments were studied from April 1997 to March 1999 for their susceptibility profiles. The various isolates were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii and Enterococcus faecalis. Antibiotic susceptibility pattern of these isolates revealed that for outpatients, first generation cephalosporins, nitrofurantoin, norfloxacin/ciprofloxacin were effective for treatment of urinary tract infection but for inpatients, parenteral therapy with newer aminoglycosides and third generation cephalosporins need to be advocated as the organisms for nosocomial UTI exhibit a high degree of drug resistance. Trimethoprim and sulphamethoxazole combination was not found to be effective for the treatment of urinary tract infections as all the uropathogens from inpatients and outpatients showed high degree of resistance to co-trimoxazole. Culture and sensitivity of the isolates from urine samples should be done as a routine before advocating the therapy.

  15. Multidrug resistant bacteria isolated from septic arthritis in horses

    Directory of Open Access Journals (Sweden)

    Rodrigo G. Motta

    Full Text Available ABSTRACT: Septic arthritis is a debilitating joint infectious disease of equines that requires early diagnosis and immediate therapeutic intervention to prevent degenerative effects on the articular cartilage, as well as loss of athletic ability and work performance of the animals. Few studies have investigated the etiological complexity of this disease, as well as multidrug resistance of isolates. In this study, 60 horses with arthritis had synovial fluid samples aseptically collected, and tested by microbiological culture and in vitro susceptibility test (disk diffusion using nine antimicrobials belonging to six different pharmacological groups. Bacteria were isolated in 45 (75.0% samples, as follows: Streptococcus equi subsp. equi (11=18.3%, Escherichia coli (9=15.0%, Staphylococcus aureus (6=10.0%, Streptococcus equi subsp. zooepidemicus (5=8.3%, Staphylococcus intermedius (2=3.3%, Proteus vulgaris (2=3.3%, Trueperella pyogenes (2=3.3%, Pseudomonas aeruginosa (2=3.3%, Klebsiella pneumoniae (1=1.7%, Rhodococcus equi (1=1.7%, Staphylococcus epidermidis (1=1.7%, Klebsiella oxytoca (1=1.7%, Nocardia asteroides (1=1.7%, and Enterobacter cloacae (1=1.7%. Ceftiofur was the most effective drug (>70% efficacy against the pathogens in the disk diffusion test. In contrast, high resistance rate (>70% resistance was observed to penicillin (42.2%, enrofloxacin (33.3%, and amikacin (31.2%. Eleven (24.4% isolates were resistant to three or more different pharmacological groups and were considered multidrug resistant strains. The present study emphasizes the etiological complexity of equine septic arthritis, and highlights the need to institute treatment based on the in vitro susceptibility pattern, due to the multidrug resistance of isolates. According to the available literature, this is the first report in Brazil on the investigation of the etiology. of the septic arthritis in a great number of horses associated with multidrug resistance of the isolates.

  16. Transfer of antibiotic resistant bacteria from animals to man

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar; Aarestrup, Frank Møller; Gerner-Smidt, P.

    1999-01-01

    Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used...... for animals either for therapy or for growth promotion. Antibiotic resistance in zoonotic bacteria constitute a public health hazard, primarily through the increased risk of treatment failures. This paper describes the zoonotic bacteria, salmonella, campylobacter, yersinia and enterohaemorrhagic E. coli (EHEC......). Infections with these agents do not generally require antibiotic therapy, but in some cases antibiotics are essential to obtain a successful cure. The levels and types of resistance observed in zoonotic bacteria in some countries, especially the increasing levels of fluoroquinolone resistance in salmonella...

  17. Antibiotic resistance in bacteria from shrimp farming in mangrove areas.

    Science.gov (United States)

    Le, Tuan Xuan; Munekage, Yukihiro; Kato, Shin-ichiro

    2005-10-15

    Shrimp farming is a sufficiently large and mature industry to have an effective range of antimicrobial agents for most bacterial diseases in shrimp culture. However, at present, there exists great concern over the widespread use of antibiotics in aquaculture, which may result in residue of antibiotics in water and mud, and subsequently, the development of antibiotic resistance in bacteria in the environment. There is limited understanding about the effect of antibiotic residues on bacteria resistance in shrimp farming environment. Therefore, a study was conducted to investigate bacterial resistance to Norfloxacin (NFXC), Oxolinic Acid (OXLA), Trimethoprim (TMP) and Sulfamethoxazole (SMX), which were found in four shrimp farming locations in mangrove areas in Vietnam. Findings indicate that there is a relatively high incidence of bacteria resistance to these antibiotics observed in most of the studied sites, particularly to antibiotics with concentration of 0.1 microg/ml. Yet the relation between concentration of antibiotic residues and incidence of antibiotic resistance is not clearly defined. Among individual antibiotics, the incidence of resistance to TMP and SMX was higher than the others. Identification of bacteria isolated from mud samples by DNA analyzer shows that Bacillus and Vibrio are predominant among bacteria resistant to the antibiotics. The result of the study also indicates that these antibiotics in media degraded more rapidly due to the presence of resistant bacteria.

  18. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demaneche, S.; Sanguin, H.; Pote, J.; Navarro, Elisabeth; Bernillon, D.; Mavingui, P.; Wildi, W.; Vogel, T M; Simonet, P

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 110-successive-y...

  19. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy M.; Simonet, Pascal

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-ye...

  20. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy,; Simonet, Pascal

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-y...

  1. Stalking Antibiotic-Resistant Bacteria in Common Vegetables

    Science.gov (United States)

    Brock, David; Boeke, Caroline; Josowitz, Rebecca; Loya, Katherine

    2004-01-01

    The study developed a simple experimental protocol for studying antibiotic resistant bacteria that will allow students to determine the proportion of such bacteria found on common fruit and vegetable crops. This protocol can open up the world of environmental science and show how human behavior can dramatically alter ecosystems.

  2. Unusual rise in mercury-resistant bacteria in coastal environs

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; De, J.

    A sharp rise in mercury-resistant bacteria (MRB) capable of tolerating very high concentration of Hg was observed over the last 3-4 years in the coastal environs of India. While none or negligible colony-forming units (CFU) of bacteria were counted...

  3. Antibiotic-resistant soil bacteria in transgenic plant fields.

    Science.gov (United States)

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy M; Simonet, Pascal

    2008-03-11

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-year culture of the transgenic Bt176 corn, which has a blaTEM marker gene, could have had on the soil bacterial community. The bla gene encoding resistance to ampicillin belongs to the beta-lactam antibiotic family, which is widely used in medicine but is readily compromised by bacterial antibiotic resistance. Our results indicate that soil bacteria are naturally resistant to a broad spectrum of beta-lactam antibiotics, including the third cephalosporin generation, which has a slightly stronger discriminating effect on soil isolates than other cephalosporins. These high resistance levels for a wide range of antibiotics are partly due to the polymorphism of bla genes, which occur frequently among soil bacteria. The blaTEM116 gene of the transgenic corn Bt176 investigated here is among those frequently found, thus reducing any risk of introducing a new bacterial resistance trait from the transgenic material. In addition, no significant differences were observed in bacterial antibiotic-resistance levels between transgenic and nontransgenic corn fields, although the bacterial populations were different.

  4. Transfer of antibiotic resistant bacteria from animals to man

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar; Aarestrup, Frank Møller; Gerner-Smidt, P.

    1999-01-01

    Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used ...

  5. Marine echinoderms as reservoirs of antimicrobial resistant bacteria

    Directory of Open Access Journals (Sweden)

    Catarina Marinho

    2014-06-01

    Full Text Available Echinoderms are benthic animals that play an important ecological role in marine communities occupying diverse trophic levels in the marine food chains. The majority of echinoderms feed on small particles of edible matter, although they can eat many kinds of food (Clark, 1968. Although, some echinoderms species has been facing an emerging demand for human consumption, particularly in Asian and Mediterranean cuisine, where these animals can be eaten raw (Kelly, 2005; Micael et al., 2009. Echinoderms own an innate immune mechanism that allows them to defend themselves from high concentrations of bacteria, viruses and fungus they are often exposed, on marine sediment (Janeway and Medzhitov, 1998, Cooper, 2003. The most frequent genera of gut bacteria in echinoderms are Vibrio, Pseudomonas, Flavobacterium, and Aeromonas; nevertheless Enterococcus spp. and Escherichia coli are also present (Harris, 1993; Marinho et al., 2013. Moreover, fecal resistant bacteria found in the aquatic environment might represent an index of marine pollution (Foti et al., 2009, Kummerer, 2009. Several studies had been lead in order to identify environmental reservoirs for antibiotic-resistant bacteria in populations of fish, echinoderms and marine mammals, and they all support the thesis that these animals may serve as reservoirs since they had acquired resistant microbial species (Johnson et al., 1998, Marinho et al., 2013, Miranda and Zemelman, 2001. However, to our knowledge, there are only available in bibliography one study of antimicrobial resistant bacteria isolated from marine echinoderms (Marinho et al., 2013, which stats that their provenience in this environment is still unclear. Antimicrobial resistance outcomes from the intensive use of antimicrobial drugs in human activities associated with various mechanisms for bacteria genetic transfer (Barbosa and Levy, 2000, Coque et al., 2008. Antibiotic-resistant bacteria enter into water environments where they are

  6. Antibiotic-Resistant Bacteria: There is Hope.

    Science.gov (United States)

    Offner, Susan

    1998-01-01

    Argues that reduction in the use of antibiotics would enable antibiotic-sensitive bacteria to flourish. Presents an activity designed to show students how a small, seemingly unimportant difference in doubling time can, over a period of time, make an enormous difference in population size. (DDR)

  7. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

    OpenAIRE

    Suresh Jaiswal et al.

    2012-01-01

    Drug resistant bacteria have been posing a major challenge to the effective control of bacterial infections for quite some time. One of the main causes of antibiotics drug resistance is antibiotic overuse, abuse, and in some cases, misuse, due to incorrect diagnosis. Bacterial antibiotic resistance is a significant issues faced by various industries, including the food and agricultural industries, the medical and veterinary profession and others. The potential for transfer of antibiotics resi...

  8. [The rise of resistant gram-negative bacteria].

    Science.gov (United States)

    Kuijper, Ed J; van Dissel, Jaap T

    2010-01-01

    During the past few years there has been a global spread of resistant gram-negative bacteria that are insensitive to cephalosporins and carbapenems. Extended spectrum beta-lactamase (ESBL)-producing bacteria are capable of inactivating the newest generation of cephalosporins. It is notable that ESBL-producing bacteria are found predominantly outside the hospital situation in the environment, in food and in meat products, which leads to the presumption that the food chain is contributing to the rapid spread of these bacteria. Several types of carbapenemase-producing bacteria have been distinguished, of which the 'New Delhi metallo beta-lactamase 1 (NDM-1)' type seems to be prevalent in Asia outside the hospital situation in the community, and is now being transmitted to other continents as a result of migration and tourism. With the rise of ESBL- and carbapenemase-producing gram-negative bacteria (which are also often resistant to most other antibiotics) comes the very real concern that treatment of infections such as urinary tract infections that are currently simple to treat with common oral antibiotics will be problematic in the future. The widespread use of antibiotics in animal husbandry is an important factor in the problem of antibiotic resistance. Since economic motives are of importance, a coordinated approach from many parties concerned will be necessary, not just from the medical sector but also from the veterinary and agricultural world, and from food producers and pharmaceutical companies to combat the spread of multiresistant gram-negative bacteria effectively.

  9. How Fitness Reduced, Antimicrobial Resistant Bacteria Survive and Spread

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Nielsen, Søren Saxmose; Toft, Nils;

    2014-01-01

    More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given that there are mul......More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given...... for the individual strains in each pig were implemented. We demonstrate how competitive growth between multiple bacterial strains in individual pigs, and the transmission between pigs in a pen allow for strains of antimicrobial resistant bacteria to persist in a pig population to different extents, and how quickly...... homogenous and how resistant the bacterial population becomes. Most important: resistant bacteria are demonstrated to survive with a disadvantage in growth rate of well over 10%....

  10. Horizontal gene transfer—emerging multidrug resistance in hospital bacteria

    Institute of Scientific and Technical Information of China (English)

    SenkaDZIDIC; VladimirBEDEKOVIC

    2003-01-01

    The frequency and spectrum of antibiotic resistant infections have increased worldwide during the past few decades. This increase has been attributed to a combination of microbial characteristics, the selective pressure of antimicrobial use, and social and technical changes that enhance the transmission of resistant organisms. The resistance is acquired by mutational changer or by the acquisition of resistance-encoding genetic material which is transfered from another bacteria. The spread of antibiotic resistance genes may be causally related to the overuse of antibiotics in human health care and in animal feeds, increased use of invasive devices and procedures, a greater number of susceptible hosts, and lapses in infection control practices leading to increased transmission of resistant organisms. The resistance gene sequences are integrated by recombination into several classes of naturally occurring gene expression cassettes and disseminated within the microbial population by horizontal gene transfer mechanisms: transformation, conjugation or transduction. In the hospital, widespread use of antimicrobials in the intensive care units (ICU) and for immunocompromised patients has resulted in the selection of multidrug-resistant organisms. Methicilin-resistant Staphylococci, vancomycin resistant Enterococci and extended-spectrum betalactamase(ESBL) producing Gram negative bacilli are identified as major phoblem in nosocomial infections. Recent surveillance studies have demonstrated trend towares more seriously ill patients suffering from multidrug-resistant nosocomial infections. Emergence of multiresistant bacteria and spread of resistance genes should enforce the aplication of strict prevention strategies, including changes in antibiotic treatment regimens, hygiene measures, infection prevention and control of horizontal nosocomial transmission of organisms.

  11. Ethanologenic bacteria with increased resistance to furfural

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Elliot Norman; Jarboe, Laura R.; Yomano, Lorraine P.; York, Sean W.; Shanmugam, Keelnatham; Ingram, Lonnie O' Neal

    2015-10-06

    The invention relates to bacterium that have increased resistance to furfural and methods of preparation. The invention also relates to methods of producing ethanol using the bacterium and corresponding kits.

  12. Facing Antimicrobial Resistance in Gastrointestinal Bacteria

    NARCIS (Netherlands)

    R.J. Hassing (Robert)

    2016-01-01

    markdownabstractThe overall aim of this thesis was to study risk factors and treatment options in gastrointestinal infections, especially in typhoidal Salmonella isolates. Primary research questions: 1. To study risk factors of gastrointestinal infections and antimicrobial resistance 2. What

  13. Ultraviolet reduction of erythromycin and tetracycline resistant heterotrophic bacteria and their resistance genes in municipal wastewater.

    Science.gov (United States)

    Guo, Mei-Ting; Yuan, Qing-Bin; Yang, Jian

    2013-11-01

    Antibiotic resistance in wastewater is becoming a major public health concern, but poorly understood about impact of disinfection on antibiotic resistant bacteria and antibiotic resistance genes. The UV disinfection of antibiotic resistant heterotrophic bacteria and their relevant genes in the wastewater of a municipal wastewater treatment plant has been evaluated. Two commonly used antibiotics, erythromycin and tetracycline were selected because of their wide occurrences in regard to the antibiotic resistance problem. After UV treatment at a fluence of 5mJcm(-2), the log reductions of heterotrophic bacteria resistant to erythromycin and tetracycline in the wastewater were found to be 1.4±0.1 and 1.1±0.1, respectively. The proportion of tetracycline-resistant bacteria (5%) was nearly double of that before UV disinfection (3%). Tetracycline-resistant bacteria exhibited more tolerance to UV irradiation compared to the erythromycin-resistant bacteria (pUV treatment at a fluence of 5mJcm(-2) removed the total erythromycin- and tetracycline-resistance genes by 3.0±0.1 log and 1.9±0.1 log, respectively. UV treatment was effective in reducing antibiotic resistance in the wastewater.

  14. Macrolides resistance of common bacteria isolated from Taiwan.

    Science.gov (United States)

    Chang, S C; Chen, Y C; Luh, K T; Hsieh, W C

    1995-12-01

    To determine the susceptibility to macrolides of common pathogenic bacteria isolated from Taiwan, the in vitro activities of erythromycin, roxithromycin, azithromycin, clarithromycin, and dirithromycin were tested against 492 clinical isolates of eight different bacteria, collected from the National Taiwan University Hospital. The results showed high minimum inhibitory concentrations (MICs) against most of the tested bacteria. The MIC90s for Staphylococcus aureus (both methicillin-resistant and -sensitive strains), coagulase-negative staphylococci (both methicillin-resistant and -sensitive strains), Streptococcus pyogenes, Streptococcus pneumoniae, enterococci, peptostreptococci, and Bacteroides fragilis were all > or = 256 micrograms/ml. The MIC50s for methicillin-resistant strains of S. aureus and coagulase-negative staphylococci, and enterococci were > or = 256 micrograms/ml. For S. pneumoniae, peptostreptococci, and B. fragilis, the MIC50s were > 8 micrograms/ml. The resistance rates to macrolides were 80% or more in methicillin-resistant staphylococci and about 30% in methicillin-sensitive staphylococci. Around 55% of S. pneumoniae strains and 37 approximately 42% of S. pyogenes strains were resistant to macrolides. Cross-resistance to different macrolides was clearly demonstrated in most of the resistant strains.

  15. Mechanisms of Antimicrobial Peptide Resistance in Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Victor I. Band

    2014-12-01

    Full Text Available Cationic antimicrobial peptides (CAMPs are important innate immune defenses that inhibit colonization by pathogens and contribute to clearance of infections. Gram-negative bacterial pathogens are a major target, yet many of them have evolved mechanisms to resist these antimicrobials. These resistance mechanisms can be critical contributors to bacterial virulence and are often crucial for survival within the host. Here, we summarize methods used by Gram-negative bacteria to resist CAMPs. Understanding these mechanisms may lead to new therapeutic strategies against pathogens with extensive CAMP resistance.

  16. Plasmid mediated antibiotic resistance in isolated bacteria from burned patients.

    Science.gov (United States)

    Beige, Fahimeh; Baseri Salehi, Majid; Bahador, Nima; Mobasherzadeh, Sina

    2015-01-01

    Nowadays, the treatment of burned patients is difficult because of the high frequency of infection with antibiotic resistance bacteria. This study was conducted to evaluate the level of antibiotic resistance in Gram-negative bacteria and its relation with the existence of plasmid. The samples were collected from two hundred twenty hospitalized burned patients in Isfahan burn hospital during a three-month period (March 2012 to June 2012). The samples were isolated and the Gram-negative bacteria were identified using phenotypic method and API 20E System. Antibiotic susceptibility and plasmid profile were determined by standard Agar disc diffusion and plasmid spin column extraction methods. Totally 117 Gram-negative bacteria were isolated, the most common were Pseudomonas aerugionsa (37.6%), P. fluorescens (25.6%), Acinetobacter baumanii (20/5%) and Klebsiella pneumoniae (7.6%), respectively. The isolates showed high frequency of antibiotic resistance against ceftazidime and co-amoxiclave (100%) and low frequency of antibiotic resistance against amikacin with (70%).The results indicated that 60% of the isolates harboured plasmid. On the other hand, the patients infected with A. baumanii and P. aeruginosa were cured (with 60% frequency) whereas, those infected with P. fluorescens were not cured. Hence, probably antibiotic resistance markers of A. baumanii and P. aeruginosa are plasmid mediated; however, P. fluorescens is chromosomally mediated. Based on our findings, P. aerugionsa is a major causative agent of wound infections and amikacin could be considered as a more effective antibiotic for treatment of the burned patients.

  17. Virulence reduction in Bacteriophage resistant bacteria

    Directory of Open Access Journals (Sweden)

    Marcela eLeón

    2015-04-01

    Full Text Available Bacteriophages can influence the abundance, diversity and evolution of bacterial communities. Several bacteriophages have been reported to add virulence factors to their host and to increase bacterial virulence. However, lytic bacteriophages can also exert a selective pressure allowing the proliferation of strains with reduced virulence. This reduction can be explained because bacteriophages use structures present on the bacterial surface as receptors, which can be virulence factors in different bacterial species. Therefore, strains with modifications in these receptors will be resistant to bacteriophage infection and may also exhibit reduced virulence. This mini-review summarizes the reports on bacteriophage-resistant strains with reductions in virulence, and it discusses the potential consequences in phage therapy and in the use of bacteriophages to select attenuated strains for vaccines.

  18. Chromosome driven spatial patterning of proteins in bacteria.

    Directory of Open Access Journals (Sweden)

    Saeed Saberi

    Full Text Available The spatial patterning of proteins in bacteria plays an important role in many processes, from cell division to chemotaxis. In the asymmetrically dividing bacteria Caulobacter crescentus, a scaffolding protein, PopZ, localizes to both poles and aids the differential patterning of proteins between mother and daughter cells during division. Polar patterning of misfolded proteins in Escherichia coli has also been shown, and likely plays an important role in cellular ageing. Recent experiments on both of the above systems suggest that the presence of chromosome free regions along with protein multimerization may be a mechanism for driving the polar localization of proteins. We have developed a simple physical model for protein localization using only these two driving mechanisms. Our model reproduces all the observed patterns of PopZ and misfolded protein localization--from diffuse, unipolar, and bipolar patterns and can also account for the observed patterns in a variety of mutants. The model also suggests new experiments to further test the role of the chromosome in driving protein patterning, and whether such a mechanism is responsible for helping to drive the differentiation of the cell poles.

  19. Antimicrobial resistance and susceptibility testing of anaerobic bacteria.

    Science.gov (United States)

    Schuetz, Audrey N

    2014-09-01

    Infections due to anaerobic bacteria can be severe and life-threatening. Susceptibility testing of anaerobes is not frequently performed in laboratories, but such testing is important to direct appropriate therapy. Anaerobic resistance is increasing globally, and resistance trends vary by geographic region. An overview of a variety of susceptibility testing methods for anaerobes is provided, and the advantages and disadvantages of each method are reviewed. Specific clinical situations warranting anaerobic susceptibility testing are discussed.

  20. Study of frequency of bacteria isolated from blood culture and their antibiotic susceptibility pattern in a university hospital in Tehran

    Directory of Open Access Journals (Sweden)

    Hoorieh Saderi

    2009-12-01

    Full Text Available Introduction: Determining frequency of bacteria, isolated from blood culture and their antibiotic susceptibility patterns, has epidemiological significance and can help in selecting empirical therapy. This study was aimed to assess, the frequency of bacteria isolated from blood culture of patients suspected to bacteremia and their antibiotic susceptibility patterns. Methods: Culture of blood and determination of antibiotic susceptibility was done by standard methods. In this study, a variety of isolated bacteria types, antibiotic susceptibility, as well as age, sex and type of admission of patients were analyzed in a university hospital from 21 March, 2006 to 20 March, 2007. Results: During one year, blood culture was done for 5116 patients and bacteria were isolated in 912 cases (17.8%. Three most frequently groups of bacteria in blood cultures of patients were non-fermentative gram negative bacteria (Pseudomonas and Acintobacter spp, coliforms (Escherichia coli and enterobacter and klebsiella spp. and coagulase negative staphylococci, respectively, which were isolated in 63.4%, 17.0% and 12.8% of patients, and constituted 93.2% of positive blood cultures. Higher resistance was shown in bacteria isolated from inpatients compare to outpatients. Conclusion: This study showed the influence of age, sex and type of admission (outpatient or inpatient in a variety of isolated bacteria in blood culture. The result of this study were the same as the other studies in Iran and other countries in respect of the variety of isolated bacteria and antibiotic susceptibility and show increase of antibiotic resistance in these bacteria.

  1. Inhibition of Ampicillin-resistance in Bacteria by Modified DNAzymes

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; LI Zhe; YANG Shuo; WANG Rui-jian; LIU Bin; SONG Yu-ming; SUN Yan-hong; HAO Dong-yun; NG Xlao-ping

    2008-01-01

    To overcome ampicillin-resistance of bacteria which is believed to attribute their endogenous β-lactamase,we designed three 10-23 DNAzymes(DZ1,Dz2,Dz3) targeting the coding region of β-lactamase mRNA and examined their inhibitory capabilities of the ampicillin-resistance of TEM-1 and TEM-3 bacteria,Dz1 was a traditional 10-23 DNAzyme,Dz2 was the mutant of Dz1 by addition of the protected nucleotide to each arm of the enzyme,and Dz3 was a mutant of DZ1 at antisense arms of which phosphorothioate modifications were made,Kinetic analysis,bacterial growth,and β-lactamase activity measurement showed that all the three DNAzymes worked efficiently in vitro and in vivo,A 9 hours bacterial growth inhibition test showed that the inhibition rates of TEM-1 bacteria by Dz1,Dz2,and Dz3 were 27%,50%,and 29%,respectively,In addition,the inhibition rates of TEM-3 bacteria by those three DNAzymes were found to be 49%,58%,and 45%,respectively,The current findings suggest that DNAzymes may become potential candidates of alternative inhibitors for bacteria drug-resistance.

  2. Antimicrobial-resistant bacteria in wild game in Slovenia

    Science.gov (United States)

    Križman, M.; Kirbiš, A.; Jamnikar-Ciglenečki, U.

    2017-09-01

    Wildlife is usually not exposed to clinically-used antimicrobial agents but can acquire antimicrobial resistance throughout contact with humans, domesticated animals and environments. Samples of faeces from intestines (80 in total) were collected from roe deer (52), wild boars (11), chamois (10) red deer (6) and moufflon (1). After culture on ChromID extended spectrum β-lactamase (ESBL) plates to select for growth of ESBL-producing bacteria, 25 samples produced bacterial colonies for further study. Six species of bacteria were identified from the 25 samples: Stenotrophomonas maltophilia, Serratia fonticola, Stenotrophomonas nitritireducens, Enterococcus faecium, Enterococcus faecalis and Escherichia coli. Two ESBL enzymes were amplified from group TEM and three from group CTX-M-1. Undercooked game meat and salami can be a source of resistant bacteria when animals are not eviscerated properly.

  3. Triclosan-resistant bacteria isolated from feedlot and residential soils.

    Science.gov (United States)

    Welsch, Tanner T; Gillock, Eric T

    2011-01-01

    Triclosan is an antimicrobial agent that is currently incorporated into hundreds of consumer and medical products. It can be either a bacteriostatic or bactericidal agent, depending on its formulation. It has activity against Gram-positive and Gram-negative bacteria, as well as some viruses and protists. The purpose of this study was to determine whether triclosan-resistant bacteria could be isolated from the soil. Soils from cattle feedlots and residential lawns were collected and assayed for the presence of these organisms by plating samples on growth media containing triclosan. Organisms were subsequently identified by partial 16S rRNA sequencing analysis. All the organisms isolated in this study were Gram-negative rods, with members of genus Pseudomonas being particularly well represented. This result may not be surprising because Gram-negative organisms are generally more resistant to triclosan, and since Pseudomonas bacteria are known to have numerous efflux mechanisms for dealing with harmful substances.

  4. Differential induction of systemic resistance in Arabidopsis by biocontrol bacteria

    NARCIS (Netherlands)

    Wees, A.C.M. van; Pieterse, C.M.J.; Trijssenaar, A.; Westende, Y.A.M. van 't; Hartog, F.; Loon, L.C. van

    1997-01-01

    Differential Induction of Systemic Resistance in Arabidopsis by Biocontrol Bacteria. Saskia C. M. Van Wees (1,2), Corné M. J. Pieterse (1,2), Annemiek Trijssenaar (1), Yvonne A. M. Van 't Westende (1), Femke Hartog (1), and Leendert C. Van Loon (1,2). (1) Department of Plant Ecology and Evolutionary

  5. ANTIBIOTIC RESISTANT BACTERIA FROM HALIOTIS TUBERCULATA AND MYTILUS GALLOPROVINCIALIS

    Directory of Open Access Journals (Sweden)

    F. Conte

    2009-12-01

    Full Text Available The antibiotic resistance (AR of Gram negative bacteria from Haliotis tuberculata (Ht and Mytilus galloprovincialis (Mg was assessed. Essential differences between R profiles of Pseudomonas spp and of other strains was not observed. Strains AR from Ht and Mg was similar.

  6. Antibiotic-Resistant Enteric Bacteria in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Lisa M. Casanova

    2016-11-01

    Full Text Available Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs, may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne. 100 surface and groundwater sites were sampled for Salmonella, E. coli, and enterococci, and the bacteria isolated from these samples were tested for susceptibility to clinically relevant antibiotics. Salmonella were detected at low levels in some surface but not groundwater. E. coli were in surface waters but not ground in both counties. Enterococci were present in surface water and a small number of groundwater sites. Yersinia was not found. Bacterial densities were similar in both counties. For Salmonella in surface water, the most frequent type of resistance was to sulfamethoxazole. There was no ciprofloxacin resistance. There were a few surface water E. coli isolates resistant to chloramphenicol, gentamicin, and ampicillin. Enterococci in surface water had very low levels of resistance to vancomycin, chloramphenicol, ampicillin, and streptomycin. E. coli and enterococci are present more frequently and at higher levels in surface water than Salmonella, but groundwater contamination with any of these organisms was rare, and low levels of resistance can be found sporadically. Resistant bacteria are relatively uncommon in these eastern N.C. surface and groundwaters, but they could pose a risk of human exposure via ingestion or primary contact recreation.

  7. Antibiotic-resistant bacteria: a challenge for the food industry.

    Science.gov (United States)

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

    Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.

  8. Isolation and characterization of bacteria resistant to metallic copper surfaces.

    Science.gov (United States)

    Santo, Christophe Espírito; Morais, Paula Vasconcelos; Grass, Gregor

    2010-03-01

    Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits.

  9. Diversity and antibiotic resistance of uropathogenic bacteria from ...

    African Journals Online (AJOL)

    J.-L.A. Moroh

    Abidjan, Ivory Coast) over a 12-year period ... effective empirical antibiotic therapies, decrease treatment failure .... World Health Organization [2,6] to characterize and quantify the ..... The changing pattern of antimicrobial resistance within 42 033.

  10. Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle

    Science.gov (United States)

    Mir, Raies A.; Weppelmann, Thomas A.; Johnson, Judith A.; Archer, Douglas; Morris, J. Glenn; Jeong, KwangCheol Casey

    2016-01-01

    Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida. The overall prevalence of cefotaxime-resistant bacteria was 15.8% (95% CI: 13.9, 17.8), varied between farms, and ranged from 5.2% to 100%. A subset of isolates (n = 23) was further characterized for the cefotaxime minimum inhibitory concentration (MIC) and antibiotic susceptibility against 10 different antibiotics, sequencing of nine β- lactamase genes, and species identification by 16S rRNA sequencing. Most of the bacterial isolates were resistant to cefotaxime (concentrations, > 64 μg/mL) and showed high levels of multi-drug resistance. Full length 16S rRNA sequences (~1300 bp) revealed that most of the isolates were not primary human or animal pathogens; rather were more typical of commensal, soil, or other environmental origin. Six extended spectrum β-lactamase (ESBL) genes identical to those in clinical human isolates were identified. Our study highlights the potential for carriage of cefotaxime resistance (including “human” ESBL genes) by the bacterial flora of food animals with no history of cefotaxime antibiotic exposure. A better understanding of the origin and transmission of resistance genes in these pre-harvest settings will be critical to development of strategies to prevent the spread of antimicrobial resistant microorganisms to hospitals and communities. PMID:27642751

  11. Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle.

    Science.gov (United States)

    Mir, Raies A; Weppelmann, Thomas A; Johnson, Judith A; Archer, Douglas; Morris, J Glenn; Jeong, KwangCheol Casey

    2016-01-01

    Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida. The overall prevalence of cefotaxime-resistant bacteria was 15.8% (95% CI: 13.9, 17.8), varied between farms, and ranged from 5.2% to 100%. A subset of isolates (n = 23) was further characterized for the cefotaxime minimum inhibitory concentration (MIC) and antibiotic susceptibility against 10 different antibiotics, sequencing of nine β- lactamase genes, and species identification by 16S rRNA sequencing. Most of the bacterial isolates were resistant to cefotaxime (concentrations, > 64 μg/mL) and showed high levels of multi-drug resistance. Full length 16S rRNA sequences (~1300 bp) revealed that most of the isolates were not primary human or animal pathogens; rather were more typical of commensal, soil, or other environmental origin. Six extended spectrum β-lactamase (ESBL) genes identical to those in clinical human isolates were identified. Our study highlights the potential for carriage of cefotaxime resistance (including "human" ESBL genes) by the bacterial flora of food animals with no history of cefotaxime antibiotic exposure. A better understanding of the origin and transmission of resistance genes in these pre-harvest settings will be critical to development of strategies to prevent the spread of antimicrobial resistant microorganisms to hospitals and communities.

  12. Identification of lead- resistant endophytic bacteria isolated from rice.

    Directory of Open Access Journals (Sweden)

    Alexander Pérez-Cordero

    2015-06-01

    Full Text Available   The objective of this study was to evaluate in vitro the endophytic bacteria resistance to different lead concentrations. The sampling was undertaken in the first half of 2013, when tissue samples of commercial varieties of rice at tillering stage were collected in Montería, Cordoba, Colombia. Each tissue was subjected to surface cleaning. Endophytic bacteria in agar R2A medium were isolated. Population density (CFU/g tissue was determined from each tissue, by direct counting of R2A medium surface. morphotypes were classified by shape, color, size, and appearance. A total of 168 morphotypes were isolated from root, tillers, and leaf of different commercial varieties of rice. The lead resistance test was performed in vitro, to do that, suspensions of endophytic bacteria in log phase were prepared and inoculated in minimal medium with five concentrations of lead as Pb(NO32. The experiment was incubated at 32 °C and agitated at 150 rpm, for five days. Every hour afterstarting the test, turbidimetry measuring at 600 nm was conducted. Results showed the ability of endophytic bacteria to grow at concentrations of 100% of Pb as Pb(NO32. The results of the identification with kit API20E confirmed the presence of Burkholderia cepacia and Pseudomonas putida, which showed resistance to different lead concentrations.

  13. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance.

    Science.gov (United States)

    Magiorakos, A-P; Srinivasan, A; Carey, R B; Carmeli, Y; Falagas, M E; Giske, C G; Harbarth, S; Hindler, J F; Kahlmeter, G; Olsson-Liljequist, B; Paterson, D L; Rice, L B; Stelling, J; Struelens, M J; Vatopoulos, A; Weber, J T; Monnet, D L

    2012-03-01

    Many different definitions for multidrug-resistant (MDR), extensively drug-resistant (XDR) and pandrug-resistant (PDR) bacteria are being used in the medical literature to characterize the different patterns of resistance found in healthcare-associated, antimicrobial-resistant bacteria. A group of international experts came together through a joint initiative by the European Centre for Disease Prevention and Control (ECDC) and the Centers for Disease Control and Prevention (CDC), to create a standardized international terminology with which to describe acquired resistance profiles in Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae (other than Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter spp., all bacteria often responsible for healthcare-associated infections and prone to multidrug resistance. Epidemiologically significant antimicrobial categories were constructed for each bacterium. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created using documents and breakpoints from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). MDR was defined as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, XDR was defined as non-susceptibility to at least one agent in all but two or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only one or two categories) and PDR was defined as non-susceptibility to all agents in all antimicrobial categories. To ensure correct application of these definitions, bacterial isolates should be tested against all or nearly all of the antimicrobial agents within the antimicrobial categories and selective reporting and suppression of results should be avoided.

  14. Ionizing radiation resistant bacteria; Des bacteries resistantes aux rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Libert, M. [CEA/Cadarache, Dept. d' Entreposage et de Stockage des Dechets (DESD), 13 - Saint-Paul-lez-Durance (France)

    2000-07-01

    The living being are not equal face to ionizing radiations. The palm of resistance goes to some bacteria. The champion at any category, the Deinococcus radiodurans, tolerates radiations doses whom one thousandth would kill a man. Two reasons to this fact: after irradiation, the DNA replication is stopped in order that the bacteria can use a repair process called multiple recombination. It cuts intact pieces of a injured chromosome and recombines them with other intact pieces, reconstituting a functional chromosome. It has also an ability to endure the extended action of oxygen, large source of damages for DNA. (N.C.)

  15. Staphylococcus aureus: resistance pattern and risk factors

    Directory of Open Access Journals (Sweden)

    Mohammad Naghavi-Behzad

    2015-03-01

    Full Text Available Introduction: Methicillin resistant Staphylococcus aureus (MRSA has emerged as a nosocomial pathogen of major worldwide importance and is an increasingly frequent cause of community-acquired infections. In this study, different risk factors and MRSA resistance pattern were investigated. Methods: In a 24 months period, all of the patients who were confined to bed in the surgery ward were included in the study. Then they were assessed to find out as if they had MRSA infection when hospitalized and once when they were discharged. Almost 48 h after admission, when patients were discharged, social and medical histories were acquired. Acquired samples were examined. Results: During the present study of 475 patients, 108 patients (22.8% had S. aureus. About frequency of antibiotic resistance among collected S. aureus colonies, erythromycin resistance, was the most frequent antibiotic resistance, also resistance to vancomycin was 0.4% that was the least. Only hospitalization duration had statistically significant correlation with antibiotic resistance, also resistance to erythromycin had statistically significant relation with history of surgery and alcohol consumption. Of all 34 MRSA species, 22 (64.7% samples were resistant to erythromycin, 17 (50.0% resistant to cefoxitin, 5 (14.7% resistant to mupirocin, 1 (2.9% resistant to vancomycin and 1 (2.9% resistant to linezolid. Conclusion: The results of the current study show that among hospitalized patients, there is resistance against methicillin. Since based on results of the study there is resistance against oxacillin and erythromycin in most cases, administering appropriate antibiotics have an important role in minimizing the resistance burden among bacterial species.

  16. Antibiotic resistance of lactic acid bacteria isolated from Chinese yogurts.

    Science.gov (United States)

    Zhou, N; Zhang, J X; Fan, M T; Wang, J; Guo, G; Wei, X Y

    2012-09-01

    The aim of this study was to evaluate the susceptibility of 43 strains of lactic acid bacteria, isolated from Chinese yogurts made in different geographical areas, to 11 antibiotics (ampicillin, penicillin G, roxithromycin, chloramphenicol, tetracycline, chlortetracycline, lincomycin, kanamycin, streptomycin, neomycin, and gentamycin). The 43 isolates (18 Lactobacillus bulgaricus and 25 Streptococcus thermophilus) were identified at species level and were typed by random amplified polymorphic DNA analysis. Thirty-five genotypically different strains were detected and their antimicrobial resistance to 11 antibiotics was determined using the agar dilution method. Widespread resistance to ampicillin, chloramphenicol, chlortetracycline, tetracyclines, lincomycin, streptomycin, neomycin, and gentamycin was found among the 35 strains tested. All of the Strep. thermophilus strains tested were susceptible to penicillin G and roxithromycin, whereas 23.5 and 64.7% of Lb. bulgaricus strains, respectively, were resistant. All of the Strep. thermophilus and Lb. bulgaricus strains were found to be resistant to kanamycin. The presence of the corresponding resistance genes in the resistant isolates was investigated through PCR, with the following genes detected: tet(M) in 1 Lb. bulgaricus and 2 Strep. thermophilus isolates, ant(6) in 2 Lb. bulgaricus and 2 Strep. thermophilus isolates, and aph(3')-IIIa in 5 Lb. bulgaricus and 2 Strep. thermophilus isolates. The main threat associated with these bacteria is that they may transfer resistance genes to pathogenic bacteria, which has been a major cause of concern to human and animal health. To our knowledge, the aph(3')-IIIa and ant(6) genes were found in Lb. bulgaricus and Strep. thermophilus for the first time. Further investigations are required to analyze whether the genes identified in Lb. bulgaricus and Strep. thermophilus isolates might be horizontally transferred to other species.

  17. Resistance to antimicrobial peptides in Gram-negative bacteria.

    Science.gov (United States)

    Gruenheid, Samantha; Le Moual, Hervé

    2012-05-01

    Antimicrobial peptides (AMPs) are present in virtually all organisms and are an ancient and critical component of innate immunity. In mammals, AMPs are present in phagocytic cells, on body surfaces such as skin and mucosa, and in secretions and body fluids such as sweat, saliva, urine, and breast milk, consistent with their role as part of the first line of defense against a wide range of pathogenic microorganisms including bacteria, viruses, and fungi. AMPs are microbicidal and have also been shown to act as immunomodulators with chemoattractant and signaling activities. During the co-evolution of hosts and bacterial pathogens, bacteria have developed the ability to sense and initiate an adaptive response to AMPs to resist their bactericidal activity. Here, we review the various mechanisms used by Gram-negative bacteria to sense and resist AMP-mediated killing. These mechanisms play an important role in bacterial resistance to host-derived AMPs that are encountered during the course of infection. Bacterial resistance to AMPs should also be taken into consideration in the development and use of AMPs as anti-infective agents, for which there is currently a great deal of academic and commercial interest.

  18. Monitoring of antimicrobial resistance in pathogenic bacteria from livestock animals.

    Science.gov (United States)

    Wallmann, Jürgen

    2006-06-01

    Facing the problem of development and spreading of bacterial resistance, preventive strategies are considered the most appropriate means to counteract. The establishment of corresponding management options relies on scientifically defensible efforts to obtain objective data on the prevalence of bacterial resistance in healthy and diseased livestock. Additionally, detailed statistics are needed on the overall amount of antimicrobial agents dispensed in Germany. The collection of valid data on the prevalence of resistance requires representative and cross-sectional studies. The German national antimicrobial resistance monitoring of the Federal Office of Consumer Protection and Food Safety (BVL) determines the current quantitative resistance level of life-stock pathogens, in order to permit the evaluation and surveillance of the distribution of resistances on a valid basis. Essential key features determining the design of these studies comprise (1) a statistically valid sampling program. This incorporates regional differences in animal population density, (2) the avoidance of "copy strains", (3) testing of no more than two bacterial strains belonging to one species per herd, (4) testing only if no antimicrobial therapy preceded sample collection, and (5) the use of standardized methods [e.g. microdilution broth method to determine the minimal inhibitory concentration (MIC)]. The analysis and interpretation of this data permits reliable identification and definition of epidemiological characteristics of resistance and its development in animal associated bacteria, such as geographically and time wise differentiated profiles on its prevalence, the emergence of unknown phenotypes of resistance and an assessment of the threat resistant bacteria from animals pose for humans. In applied antimicrobial therapy, the data can serve as a decision guidance in choosing the antimicrobial agent most adapted to the prevailing epidemiological situation. The susceptibility testing

  19. 1 in 4 Nursing Home Residents Has Antibiotic-Resistant Bacteria

    Science.gov (United States)

    ... in 4 Nursing Home Residents Has Antibiotic-Resistant Bacteria More infection-prevention education and policies are needed, ... TUESDAY, May 30, 2017 (HealthDay News) -- Multidrug-resistant bacteria, such as E. coli , can be found in ...

  20. plasmid mediated resistance in multidrug resistant bacteria isolated ...

    African Journals Online (AJOL)

    User

    3Department of Paediatrics, Ahmadu Bello University Teaching Hospital, Zaria ... The knowledge of the epidemiological and antimicrobial pattern of common pathogens that cause septicaemia is useful for ..... commonly prescribed antibiotics in the locality investigated. ... to monitor and restrict the use and sale of antibiotics.

  1. “Infectious Supercarelessness” in Discussing Antibiotic-Resistant Bacteria

    Science.gov (United States)

    Greenspan, Neil S.

    2017-01-01

    Many bacterial pathogens are exhibiting resistance to increasing numbers of antibiotics making it much more challenging to treat the infections caused by these microbes. In many reports in the media and perhaps even in discussions among physicians and biomedical scientists, these bacteria are frequently referred to as “bugs” with the prefix “super” appended. This terminology has a high potential to elicit unjustified inferences and fails to highlight the broader evolutionary context. Understanding the full range of biological and evolutionary factors that influence the spread and outcomes of infections is critical to formulating effective individual therapies and public health interventions. Therefore, more accurate terminology should be used to refer these multidrug-resistant bacteria. PMID:28174759

  2. How Fitness Reduced, Antimicrobial Resistant Bacteria Survive and Spread

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Nielsen, Søren Saxmose; Toft, Nils

    2014-01-01

    antimicrobials are used? To investigate these questions, we created a model where multiple strains of bacteria coexist in the intestines of pigs sharing a pen, and explored the parameter limits of a stable system; both with and without an antimicrobial treatment. The approach taken is a deterministic bacterial......More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given...... population model with stochastic elements of bacterial distributions and transmission. The rates that govern the model are process-oriented to represent growth, excretion, and uptake from environment, independent of herd and meta-population structures. Furthermore, an entry barrier and elimination process...

  3. “Infectious Supercarelessness” in Discussing Antibiotic-Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Neil S. Greenspan

    2016-12-01

    Full Text Available Many bacterial pathogens are exhibiting resistance to increasing numbers of antibiotics making it much more challenging to treat the infections caused by these microbes. In many reports in the media and perhaps even in discussions among physicians and biomedical scientists, these bacteria are frequently referred to as “bugs” with the prefix “super” appended. This terminology has a high potential to elicit unjustified inferences and fails to highlight the broader evolutionary context. Understanding the full range of biological and evolutionary factors that influence the spread and outcomes of infections is critical to formulating effective individual therapies and public health interventions. Therefore, more accurate terminology should be used to refer these multidrug-resistant bacteria.

  4. Synthetic RNA silencing in bacteria - antimicrobial discovery and resistance breaking

    Directory of Open Access Journals (Sweden)

    James E.M. Stach

    2011-09-01

    Full Text Available The increasing incidence and prevalence of antibiotic resistance in bacteria threatens the antibiotic miracle. Conventional antimicrobial drug development has failed to replace the armamentarium needed to combat this problem, and novel solutions are urgently required. Here we review both natural and synthetic RNA silencing and its potential to provide new antibacterials through improved target selection, evaluation and screening. Furthermore, we focus on synthetic RNA silencers as a novel class of antibacterials and review their unique properties.

  5. Pattern of skin bacteria in palmar arsenical keratosis

    Directory of Open Access Journals (Sweden)

    Nadia Bintha Khalil

    2016-12-01

    Full Text Available The aim of the present study was to examine the involvement of skin bacteria in the pathogenesis of keratosis. Skin swab of five different sites (palm, dorsum of the hand, chest, axilla and alar crease from arsenic unexposed volunteer (n = 15, arsenic exposed (n = 15 and arsenicosis patients (n= 20 were collected for bacterial culture. The skin of arsenic unexposed volunteers contained Staphylococcus epidermidis and Bacillus spp. Chronic exposure to high concentration of arsenic through drinking water altered the skin bacterial pattern. The growth of Pseudomonas spp. increased in different sites of the skin. But in patient of arsenicosis, the skin of the palm shows the growth of Enterobacter spp.

  6. Prevalence and antimicrobial resistance pattern of bacterial meningitis in Egypt

    Directory of Open Access Journals (Sweden)

    Shaban Lamyaa

    2009-09-01

    Full Text Available Abstract Infectious diseases are the leading cause of morbidity and mortality in the developing world. In Egypt bacterial diseases constitute a great burden, with several particular bacteria sustaining the leading role of multiple serious infections. This article addresses profound bacterial agents causing a wide array of infections including but not limited to pneumonia and meningitis. The epidemiology of such infectious diseases and the prevalence of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae are reviewed in the context of bacterial meningitis. We address prevalent serotypes in Egypt, antimicrobial resistance patterns and efficacy of vaccines to emphasize the importance of periodic surveillance for appropriate preventive and treatment strategies.

  7. Understanding the Patterns of Antibiotic Susceptibility of Bacteria Causing Urinary Tract Infection in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Sunayana eSaha

    2014-09-01

    Full Text Available Urinary tract infection (UTI is one of the most common infectious diseases at the community level. In order to assess the adequacy of empirical therapy, the susceptibility of antibiotics and resistance pattern of bacteria responsible for UTI in West Bengal, India, were evaluated throughout the period of 2008-2013. The infection reports belonging to all age groups and both sexes were considered. E. coli was the most abundant uropathogen with a prevalence rate of 67.1%, followed by Klebsiella spp. (22% and Pseudomonas spp. (6%. Penicillin was least effective against UTI-causing E. coli and maximum susceptibility was recorded for the drugs belonging to fourth generation cephalosporins. Other abundant uropathogens, Klebsiella spp., were maximally resistant to broad-spectrum penicillin, followed by aminoglycosides and third generation cephalosporin. The antibiotic resistance pattern of two principal UTI pathogens, E. coli and Klebsiella spp. in West Bengal, appears in general to be similar to that found in other parts of the Globe. Higher than 50% resistance were observed for broad-spectrum penicillin. Fourth generation cephalosporin and macrolides seems to be the choice of drug in treating UTIs in Eastern India. Furthermore, improved maintenance of infection incident logs is needed in Eastern Indian hospitals in order to facilitate regular surveillance of the occurrence of antibiotic resistance patterns, since such levels continue to change.

  8. Metagenomic Insights into Transferable Antibiotic Resistance in Oral Bacteria.

    Science.gov (United States)

    Sukumar, S; Roberts, A P; Martin, F E; Adler, C J

    2016-08-01

    Antibiotic resistance is considered one of the greatest threats to global public health. Resistance is often conferred by the presence of antibiotic resistance genes (ARGs), which are readily found in the oral microbiome. In-depth genetic analyses of the oral microbiome through metagenomic techniques reveal a broad distribution of ARGs (including novel ARGs) in individuals not recently exposed to antibiotics, including humans in isolated indigenous populations. This has resulted in a paradigm shift from focusing on the carriage of antibiotic resistance in pathogenic bacteria to a broader concept of an oral resistome, which includes all resistance genes in the microbiome. Metagenomics is beginning to demonstrate the role of the oral resistome and horizontal gene transfer within and between commensals in the absence of selective pressure, such as an antibiotic. At the chairside, metagenomic data reinforce our need to adhere to current antibiotic guidelines to minimize the spread of resistance, as such data reveal the extent of ARGs without exposure to antimicrobials and the ecologic changes created in the oral microbiome by even a single dose of antibiotics. The aim of this review is to discuss the role of metagenomics in the investigation of the oral resistome, including the transmission of antibiotic resistance in the oral microbiome. Future perspectives, including clinical implications of the findings from metagenomic investigations of oral ARGs, are also considered. © International & American Associations for Dental Research 2016.

  9. Resistance to bacteriocins produced by Gram-positive bacteria.

    Science.gov (United States)

    Bastos, Maria do Carmo de Freire; Coelho, Marcus Lívio Varella; Santos, Olinda Cabral da Silva

    2015-04-01

    Bacteriocins are prokaryotic proteins or peptides with antimicrobial activity. Most of them exhibit a broad spectrum of activity, inhibiting micro-organisms belonging to different genera and species, including many bacterial pathogens which cause human, animal or plant infections. Therefore, these substances have potential biotechnological applications in either food preservation or prevention and control of bacterial infectious diseases. However, there is concern that continuous exposure of bacteria to bacteriocins may select cells resistant to them, as observed for conventional antimicrobials. Based on the models already investigated, bacteriocin resistance may be either innate or acquired and seems to be a complex phenomenon, arising at different frequencies (generally from 10(-9) to 10(-2)) and by different mechanisms, even amongst strains of the same bacterial species. In the present review, we discuss the prevalence, development and molecular mechanisms involved in resistance to bacteriocins produced by Gram-positive bacteria. These mechanisms generally involve changes in the bacterial cell envelope, which result in (i) reduction or loss of bacteriocin binding or insertion, (ii) bacteriocin sequestering, (iii) bacteriocin efflux pumping (export) and (iv) bacteriocin degradation, amongst others. Strategies that can be used to overcome this resistance are also addressed.

  10. Sulfonamide-resistant bacteria and their resistance genes in soils fertilized with manures from Jiangsu Province, Southeastern China.

    Directory of Open Access Journals (Sweden)

    Na Wang

    Full Text Available Antibiotic-resistant bacteria and genes are recognized as new environmental pollutants that warrant special concern. There were few reports on veterinary antibiotic-resistant bacteria and genes in China. This work systematically analyzed the prevalence and distribution of sulfonamide resistance genes in soils from the environments around poultry and livestock farms in Jiangsu Province, Southeastern China. The results showed that the animal manure application made the spread and abundance of antibiotic resistance genes (ARGs increasingly in the soil. The frequency of sulfonamide resistance genes was sul1 > sul2 > sul3 in pig-manured soil DNA and sul2 > sul1 > sul3 in chicken-manured soil DNA. Further analysis suggested that the frequency distribution of the sul genes in the genomic DNA and plasmids of the SR isolates from manured soil was sul2 > sul1 > sul3 overall (p<0.05. The combination of sul1 and sul2 was the most frequent, and the co-existence of sul1 and sul3 was not found either in the genomic DNA or plasmids. The sample type, animal type and sampling time can influence the prevalence and distribution pattern of sulfonamide resistance genes. The present study also indicated that Bacillus, Pseudomonas and Shigella were the most prevalent sul-positive genera in the soil, suggesting a potential human health risk. The above results could be important in the evaluation of antibiotic-resistant bacteria and genes from manure as sources of agricultural soil pollution; the results also demonstrate the necessity and urgency of the regulation and supervision of veterinary antibiotics in China.

  11. A simple identification method for spore-forming bacteria showing high resistance against [gamma]-rays

    Energy Technology Data Exchange (ETDEWEB)

    Koshikawa, Tomihiko; Sone, Koji; Kobayashi, Toshikazu (Japan Radioisotope Association, Koka, Shiga (Japan). Koka Lab.)

    1993-11-01

    A simple identification method was developed for spore-forming bacteria which are highly resistant against [gamma]-rays. Among 23 species of Bacillus studied, the spores of Bacillus megaterium, B. cereus, B. thuringiensis, B. pumilus and B. aneurinolyticus showed high resistance against [gamma]-rays as compared with other spores of Bacillus species. Combination of the seven kinds of biochemical tests, namely, the citrate utilization test, nitrate reduction test, starch hydrolysis test, Voges-Proskauer reaction test, gelatine hydrolysis test, mannitol utilization test and xylose utilization test showed a characteristic pattern for each species of Bacillus. The combination pattern of each the above tests with a few supplementary test, if necessary, was useful to identify Bacillus species showing high radiation resistance against [gamma]-rays. The method is specific for B. megaterium, B. thuringiensis and B. pumilus, and highly selective for B. aneurinolyticus and B. cereus. (author).

  12. Adaptive resistance in bacteria requires epigenetic inheritance, genetic noise, and cost of efflux pumps.

    Directory of Open Access Journals (Sweden)

    Santiago Sandoval Motta

    Full Text Available Adaptive resistance emerges when populations of bacteria are subjected to gradual increases of antibiotics. It is characterized by a rapid emergence of resistance and fast reversibility to the non-resistant phenotype when the antibiotic is removed from the medium. Recent work shows that adaptive resistance requires epigenetic inheritance and heterogeneity of gene expression patterns that are, in particular, associated with the production of porins and efflux pumps. However, the precise mechanisms by which inheritance and variability govern adaptive resistance, and what processes cause its reversibility remain unclear. Here, using an efflux pump regulatory network (EPRN model, we show that the following three mechanisms are essential to obtain adaptive resistance in a bacterial population: 1 intrinsic variability in the expression of the EPRN transcription factors; 2 epigenetic inheritance of the transcription rate of EPRN associated genes; and 3 energetic cost of the efflux pumps activity that slows down cell growth. While the first two mechanisms acting together are responsible for the emergence and gradual increase of the resistance, the third one accounts for its reversibility. In contrast with the standard assumption, our model predicts that adaptive resistance cannot be explained by increased mutation rates. Our results identify the molecular mechanism of epigenetic inheritance as the main target for therapeutic treatments against the emergence of adaptive resistance. Finally, our theoretical framework unifies known and newly identified determinants such as the burden of efflux pumps that underlie bacterial adaptive resistance to antibiotics.

  13. The carriage of antibiotic resistance by enteric bacteria from imported tokay geckos (Gekko gecko) destined for the pet trade

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Christine L. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Hernandez, Sonia M., E-mail: shernz@uga.edu [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Yabsley, Michael J. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Smith, Katherine F. [Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912 (United States); Sanchez, Susan [The Athens Veterinary Diagnostic Laboratory, Athens, GA 30602 (United States); The Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States)

    2015-02-01

    The emergence of antibiotic-resistant bacteria is a growing public health concern and has serious implications for both human and veterinary medicine. The nature of the global economy encourages the movement of humans, livestock, produce, and wildlife, as well as their potentially antibiotic-resistant bacteria, across international borders. Humans and livestock can be reservoirs for antibiotic-resistant bacteria; however, little is known about the prevalence of antibiotic-resistant bacteria harbored by wildlife and, to our knowledge, limited data has been reported for wild-caught reptiles that were specifically collected for the pet trade. In the current study, we examined the antibiotic resistance of lactose-positive Enterobacteriaceae isolates from wild-caught Tokay geckos (Gekko gecko) imported from Indonesia for use in the pet trade. In addition, we proposed that the conditions under which wild animals are captured, transported, and handled might affect the shedding or fecal prevalence of antibiotic resistance. In particular we were interested in the effects of density; to address this, we experimentally modified densities of geckos after import and documented changes in antibiotic resistance patterns. The commensal enteric bacteria from Tokay geckos (G. gecko) imported for the pet trade displayed resistance against some antibiotics including: ampicillin, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, kanamycin and tetracycline. There was no significant difference in the prevalence of antibiotic-resistant bacteria after experimentally mimicking potentially stressful transportation conditions reptiles experience prior to purchase. There were, however, some interesting trends observed when comparing Tokay geckos housed individually and those housed in groups. Understanding the prevalence of antibiotic resistant commensal enteric flora from common pet reptiles is paramount because of the potential for humans exposed to these animals to acquire antibiotic-resistant

  14. Swimming patterns and dynamics of simulated Escherichia coli bacteria.

    Science.gov (United States)

    Zonia, Laura; Bray, Dennis

    2009-11-06

    A spatially and temporally realistic simulation of Escherichia coli chemotaxis was used to investigate the swimming patterns of wild-type and mutant bacteria within a rectangular arena in response to chemoattractant gradients. Swimming dynamics were analysed during long time series with phase-space trajectories, power spectra and estimations of fractal dimensions (FDs). Cell movement displayed complex trajectories in the phase space owing to interaction of multiple attractors that captured runs and tumbles. Deletion of enzymes responsible for adaptation (CheR and CheB) restricted the pattern of bacterial swimming in the absence of a gradient. In the presence of a gradient, there was a strong increase in trajectories arising from runs and attenuation of those arising from tumbles. Similar dynamics were observed for mutants lacking CheY, which are unable to tumble. The deletion of CheR, CheB and CheY also caused significant shifts in chemotaxis spectral frequencies. Rescaled range analysis and estimation of FD suggest that wild-type bacteria display characteristics of fractional Brownian motion with positive correlation between past and future events. These results reveal an underlying order in bacterial swimming dynamics, which enables a chemotactic search strategy conforming to a fractal walk.

  15. Carriage of antibiotic-resistant enteric bacteria varies among sites in Galapagos reptiles.

    Science.gov (United States)

    Wheeler, Emily; Hong, Pei-Ying; Bedon, Lenin Cruz; Mackie, Roderick I

    2012-01-01

    Increased overlap between humans and wildlife populations has increased the risk for novel disease emergence. Detecting contacts with a high risk for transmission of pathogens requires the identification of dependable measures of microbial exchange. We evaluated antibiotic resistance as a molecular marker for the intensity of human-wildlife microbial connectivity in the Galápagos Islands. We isolated Escherichia coli and Salmonella enterica from the feces of land iguanas (Conolophus sp.), marine iguanas (Amblyrhynchus cristatus), giant tortoises (Geochelone nigra), and seawater, and tested these bacteria with the use of the disk diffusion method for resistance to 10 antibiotics. Antibiotic-resistant bacteria were found in reptile feces from two tourism sites (Isla Plaza Sur and La Galapaguera on Isla San Cristóbal) and from seawater close to a public use beach near Puerto Baquerizo Moreno on Isla San Cristóbal. No resistance was detected at two protected beaches on more isolated islands (El Miedo on Isla Santa Fe and Cape Douglas on Isla Fernandina) and at a coastal tourism site (La Lobería on Isla San Cristóbal). Eighteen E. coli isolates from three locations, all sites relatively proximate to a port town, were resistant to ampicillin, doxycycline, tetracycline, and trimethoprin/sulfamethoxazole. In contrast, only five S. enterica isolates showed a mild decrease in susceptibility to doxycycline and tetracycline from these same sites (i.e., an intermediate resistance phenotype), but no clinical resistance was detected in this bacterial species. These findings suggest that reptiles living in closer proximity to humans potentially have higher exposure to bacteria of human origin; however, it is not clear from this study to what extent this potential exposure translates to ongoing exchange of bacterial strains or genetic traits. Resistance patterns and bacterial exchange in this system warrant further investigation to understand better how human associations

  16. Determinants of Genetic Diversity of Spontaneous Drug Resistance in Bacteria.

    Science.gov (United States)

    Couce, Alejandro; Rodríguez-Rojas, Alexandro; Blázquez, Jesús

    2016-07-01

    Any pathogen population sufficiently large is expected to harbor spontaneous drug-resistant mutants, often responsible for disease relapse after antibiotic therapy. It is seldom appreciated, however, that while larger populations harbor more mutants, the abundance distribution of these mutants is expected to be markedly uneven. This is because a larger population size allows early mutants to expand for longer, exacerbating their predominance in the final mutant subpopulation. Here, we investigate the extent to which this reduction in evenness can constrain the genetic diversity of spontaneous drug resistance in bacteria. Combining theory and experiments, we show that even small variations in growth rate between resistant mutants and the wild type result in orders-of-magnitude differences in genetic diversity. Indeed, only a slight fitness advantage for the mutant is enough to keep diversity low and independent of population size. These results have important clinical implications. Genetic diversity at antibiotic resistance loci can determine a population's capacity to cope with future challenges (i.e., second-line therapy). We thus revealed an unanticipated way in which the fitness effects of antibiotic resistance can affect the evolvability of pathogens surviving a drug-induced bottleneck. This insight will assist in the fight against multidrug-resistant microbes, as well as contribute to theories aimed at predicting cancer evolution.

  17. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    Science.gov (United States)

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Antibiotic resistance shaping multi-level population biology of bacteria.

    Science.gov (United States)

    Baquero, Fernando; Tedim, Ana P; Coque, Teresa M

    2013-01-01

    Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent "population biologies." Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of "clinical" antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi

  19. Colistin use and colistin resistance in bacteria from animals.

    Science.gov (United States)

    Kempf, Isabelle; Jouy, Eric; Chauvin, Claire

    2016-12-01

    Colistin has been used in veterinary medicine for decades, mainly for the prevention and treatment of Enterobacteriaceae infections. However, data regarding colistin resistance in bacteria from animals and food of animal origin are relatively scarce, partly because there are methodological difficulties hampering the analysis of susceptibility to colistin. Most data regarding clinical isolates are related to enteropathogenic Escherichia coli and Salmonella. The resistance percentages are sometimes high for pathogenic strains, and the mcr-1 gene has been detected in pathogenic E. coli isolates from pigs, cattle and poultry in different countries. The prevalence of colistin resistance in Salmonella from healthy animals is usually low but depends on the proportion of intrinsically colistin-resistant serotypes. For indicator E. coli, the resistance levels are often very low, although higher levels have been observed in Asia. The mcr-1 gene has been detected in indicator E. coli from pigs, cattle, poultry and their products. Thus, there is an urgent need to re-assess the use of colistin in livestock throughout the world to ensure a global strategy for preserving this last-resort antimicrobial. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  20. Lead resistant bacteria: lead resistance mechanisms, their applications in lead bioremediation and biomonitoring.

    Science.gov (United States)

    Naik, Milind Mohan; Dubey, Santosh Kumar

    2013-12-01

    Lead (Pb) is non-bioessential, persistent and hazardous heavy metal pollutant of environmental concern. Bioremediation has become a potential alternative to the existing technologies for the removal and/or recovery of toxic lead from waste waters before releasing it into natural water bodies for environmental safety. To our best knowledge, this is a first review presenting different mechanisms employed by lead resistant bacteria to resist high levels of lead and their applications in cost effective and eco-friendly ways of lead bioremediation and biomonitoring. Various lead resistant mechanisms employed by lead resistant bacteria includes efflux mechanism, extracellular sequestration, biosorption, precipitation, alteration in cell morphology, enhanced siderophore production and intracellular lead bioaccumulation.

  1. Antibiotic- and heavy-metal resistance in bacteria isolated from deep subsurface in El Callao region, Venezuela

    Directory of Open Access Journals (Sweden)

    Maura Lina Rojas Pirela

    2014-12-01

    Full Text Available The effect of contamination with mercury (Hg in the deep subsurface bacterial communities in the region of El Callao (Bolívar State, Venezuela was investigated. Bacterial communities from two deep levels (-288 m and -388 m in a gold mine were studied with the aim of describe the most relevant features of their colonizing indigenous culturable bacteria. Antibiotic and heavy metals resistance patterns, presence of the merA gene and plasmids in resistant isolates were evaluated. A high frequency of resistant indigenous bacteria to Hg and other heavy metals was found. From 76 Hg-resistant isolates tested 73.7 % were, in addition, resistant to ampicillin, 86.8% to chloramphenicol, 67.1 % for tetracycline, 56.6 % streptomycin, and 51.3 % kanamycin. Furthermore, it was found that 40.74 % (-328 mm and 26.53 % (-388 m of Hg-resistant bacteria were simultaneously resistant to both four and five of these antibiotics. The presence of low and high molecular weight plasmids was detected and, despite that isolated showed resistance to mercurial compounds, the presence of the gene merA was detected only in 71.05 % of strains. These results suggest that exposure to Hg could be a selective pressure on the proliferation of antibiotic-resistant bacteria and promote the preservation and propagation of these resistance genes. However, the existence of such resistances to these depths could also support the idea that antibiotic resistance in these bacteria is natural and has a more ancient origin than their exposure to Hg.

  2. Resistance to antibiotics in Lacid acid bacteria - strain Lactococcus

    Directory of Open Access Journals (Sweden)

    Filipić Brankica

    2015-01-01

    Full Text Available Lactic acid bacteria (LAB are widely used in the food industry, especially in the production of fermented dairy products and meat. The most studied species among Lis Lactococcus lactis. L. lactis strains are of great importance in the production of fermented dairy products such as yogurt, butter, fresh cheese and some kind of semi-hard cheese. Although L. lactis acquired the „Generally Regarded As Safe“ (GRAS status, many investigations indicated that lactococci may act as reservoirs of antibiotic resistance genes, which could be transferred to other bacterial species in human gastrointestinal tract includ­ing pathogens. The genome analysis of L. lactis indicated the presence of at least 40 putative drug transporter genes, and only four multidrug resistance (MDR transporters are functionally characterized: LmrA, LmrP, LmrCD i CmbT. LmrA is the first described MDR transporter in prokaryotes. LmrCD is responsible for resistance to cholate, which is an integral part of human bile and LmrCD is important for intestinal survival of lactococci that are used as probiotics. Secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines. CmbT protein has an effect on the host cell resistance to lincomycin, sulfadiazine, streptomycin, rifampicin, puromycin and sulfametox­azole. Since the food chain is an important way of transmitting resistance genes in human and animal population, it is of great importance to study the mechanisms of resistance in lactococci and other LAB, intended for the food industry. [Projekat Ministarstva nauke Republike Srbije, br. 173019: Izučavanje gena i molekularnih mehanizama u osnovi probiotičke aktivnosti bakterija mlečne kiseline izolovanih sa područja Zapadnog Balkana

  3. Progress in engineering acid stress resistance of lactic acid bacteria.

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-02-01

    Lactic acid bacteria (LAB) are widely used for the production of a variety of fermented foods, and are considered as probiotic due to their health-promoting effect. However, LAB encounter various environmental stresses both in industrial fermentation and application, among which acid stress is one of the most important survival challenges. Improving the acid stress resistance may contribute to the application and function of probiotic action to the host. Recently, the advent of genomics, functional genomics and high-throughput technologies have allowed for the understanding of acid tolerance mechanisms at a systems level, and many method to improve acid tolerance have been developed. This review describes the current progress in engineering acid stress resistance of LAB. Special emphasis is placed on engineering cellular microenvironment (engineering amino acid metabolism, introduction of exogenous biosynthetic capacity, and overproduction of stress response proteins) and maintaining cell membrane functionality. Moreover, strategies to improve acid tolerance and the related physiological mechanisms are also discussed.

  4. Mobile antibiotic resistance - the spread of genes determining the resistance of bacteria through food products.

    Science.gov (United States)

    Godziszewska, Jolanta; Guzek, Dominika; Głąbski, Krzysztof; Wierzbicka, Agnieszka

    2016-07-07

    In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance.

  5. Multidrug resistant bacteria in companion animals: impact on animal health and zoonotic aspects

    DEFF Research Database (Denmark)

    Damborg, Peter Panduro

    The role of companion animals as a source of antibiotic resistant bacteria has historically been given little emphasis when compared with that of food animals. However, various resistant bacteria may cause serious treatment problems in companion animal medicine. Some of the most important multidrug......-resistant bacteria include methicillin-resistant Staphylococcus pseudintermedius (MRSP), methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. These bacteria will be described with focus on their prevalence across Europe, their impact on animal...

  6. A Functional Metagenomic Analysis of Tetracycline Resistance in Cheese Bacteria

    Directory of Open Access Journals (Sweden)

    Ana B. Flórez

    2017-05-01

    Full Text Available Metagenomic techniques have been successfully used to monitor antibiotic resistance genes in environmental, animal and human ecosystems. However, despite the claim that the food chain plays a key role in the spread of antibiotic resistance, metagenomic analysis has scarcely been used to investigate food systems. The present work reports a functional metagenomic analysis of the prevalence and evolution of tetracycline resistance determinants in a raw-milk, blue-veined cheese during manufacturing and ripening. For this, the same cheese batch was sampled and analyzed on days 3 and 60 of manufacture. Samples were diluted and grown in the presence of tetracycline on plate count milk agar (PCMA (non-selective and de Man Rogosa and Sharpe (MRS agar (selective for lactic acid bacteria, LAB. DNA from the cultured bacteria was then isolated and used to construct four fosmid libraries, named after the medium and sampling time: PCMA-3D, PCMA-60D, MRS-3D, and MRS-60D. Clones in the libraries were subjected to restriction enzyme analysis, PCR amplification, and sequencing. Among the 300 fosmid clones analyzed, 268 different EcoRI restriction profiles were encountered. Sequence homology of their extremes clustered the clones into 47 groups. Representative clones of all groups were then screened for the presence of tetracycline resistance genes by PCR, targeting well-recognized genes coding for ribosomal protection proteins and efflux pumps. A single tetracycline resistance gene was detected in each of the clones, with four such resistance genes identified in total: tet(A, tet(L, tet(M, and tet(S. tet(A was the only gene identified in the PCMA-3D library, and tet(L the only one identified in the PCMA-60D and MRS-60D libraries. tet(M and tet(S were both detected in the MRS-3D library and in similar numbers. Six representative clones of the libraries were sequenced and analyzed. Long segments of all clones but one showed extensive homology to plasmids from Gram

  7. Tracking acquired antibiotic resistance in commensal bacteria of Galapagos land iguanas: no man, no resistance.

    Directory of Open Access Journals (Sweden)

    Maria Cristina Thaller

    Full Text Available BACKGROUND: Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. METHODOLOGY/PRINCIPAL FINDINGS: Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i the abiotic conditions ensure to microbes good survival possibilities in the environment; ii the animal density and their habits favour microbial circulation between individuals; and iii there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. CONCLUSIONS/SIGNIFICANCE: Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.

  8. Adaptive resistance to antibiotics in bacteria: a systems biology perspective.

    Science.gov (United States)

    Sandoval-Motta, Santiago; Aldana, Maximino

    2016-05-01

    Despite all the major breakthroughs in antibiotic development and treatment procedures, there is still no long-term solution to the bacterial antibiotic resistance problem. Among all the known types of resistance, adaptive resistance (AdR) is particularly inconvenient. This phenotype is known to emerge as a consequence of concentration gradients, as well as contact with subinhibitory concentrations of antibiotics, both known to occur in human patients and livestock. Moreover, AdR has been repeatedly correlated with the appearance of multidrug resistance, although the biological processes behind its emergence and evolution are not well understood. Epigenetic inheritance, population structure and heterogeneity, high mutation rates, gene amplification, efflux pumps, and biofilm formation have all been reported as possible explanations for its development. Nonetheless, these concepts taken independently have not been sufficient to prevent AdR's fast emergence or to predict its low stability. New strains of resistant pathogens continue to appear, and none of the new approaches used to kill them (mixed antibiotics, sequential treatments, and efflux inhibitors) are completely efficient. With the advent of systems biology and its toolsets, integrative models that combine experimentally known features with computational simulations have significantly improved our understanding of the emergence and evolution of the adaptive-resistant phenotype. Apart from outlining these findings, we propose that one of the main cornerstones of AdR in bacteria, is the conjunction of two types of mechanisms: one rapidly responding to transient environmental challenges but not very efficient, and another much more effective and specific, but developing on longer time scales. WIREs Syst Biol Med 2016, 8:253-267. doi: 10.1002/wsbm.1335 For further resources related to this article, please visit the WIREs website.

  9. The role of midgut symbiotic bacteria in resistance of Anopheles stephensi (Diptera: Culicidae) to organophosphate insecticides.

    Science.gov (United States)

    Soltani, Aboozar; Vatandoost, Hassan; Oshaghi, Mohammad Ali; Enayati, Ahmad Ali; Chavshin, Ali Reza

    2017-07-26

    In the current study, the effects of the presence of symbiotic bacteria on the activity of the enzymes involved in An. stephensi resistance to temephos are evaluated for the first time. Four different strains (I. susceptible strain, II. resistant strain, III. resistant strain + antibiotic, and IV. resistant strain + bacteria) were considered in order to determine the possible effects of the symbiotic bacteria on their hosts' resistance to temephos. The median values of all enzymes of susceptible strain were compared with those of other resistant strains. The results of this study indicated a direct relationship between the presence of bacteria in the symbiotic organs of An. stephensi and resistance to temephos. The profile of enzymatic activities in the resistant strain changed to a susceptible status after adding antibiotic. The resistance of An. stephensi to temephos could be completely broken artificially by removing their bacterial symbionts in a resistant population.

  10. Isolation rate and drug resistance patterns of Shigella species ...

    African Journals Online (AJOL)

    Isolation rate and drug resistance patterns of Shigella species among ... use of water from unprotected sources and absence of latrine were the risk factors that ... to identify changes in the prevalence and antimicrobial resistance patterns of ...

  11. [Travels and spreading of multi-resistant bacteria].

    Science.gov (United States)

    Nitsch-Osuch, Aneta

    2017-05-23

    The increasing number of international travel for tourism, business and for medical reasons rises the risk of spreading of multi-resistant bacteria. It has been shown that an intercontinental travel, mainly to Asia (Indian Subcontinent), promotes a colonization of the digestive tract, mainly by multi-resistant Enterobacteriaceae (MRE) and increases the risk of symptomatic infections caused by these agents. The colonization of the digestive tract by MRE is reported in 29-88% of travelers. It sustains 3 to 12 months, respectively in 10% and 2% of travelers. Risk factors for the acquisition of colonization with MRE include: travel duration and destination, treatment with betalactam antibiotics during the travel, the use of local medical services, including hospitalization, presence of gastrointestinal symptoms during the travel (mainly diarrhea), age >65 years. The need of the hospitalization during the travel increases the risk of colonization, but is not a prerequisite factor for the acquisition of the colonization, as cases of the MRE carriage are reported in patients who had never used medical services outside the country. It indicates other possible transmission routes, including food. In order to reduce the risk of MRE spreading, it is recommended to ask patients about a history of travel and treatment within the last 12 months. All patient who report such events and require hospitalization in their home countries should be microbiologically screened. Hospitalized patients colonized with multiple resistant bacteria require an isolation or cohortation. Educational activities related to the hand hygiene compliance should be performed. The risk of the home transmission of MRE is not high, it lasts for a short period (up to 3 months). Routine microbiological testing for all persons returning from an international or intercontinental travel is not recommended, neither microbiological screening among their households.

  12. Antimicrobial resistance of zoonotic and commensal bacteria in Europe: The missing link between consumption and resistance in veterinary medicine

    DEFF Research Database (Denmark)

    Garcia-Migura, Lourdes; Hendriksen, Rene S.; Fraile, Lorenzo

    2014-01-01

    The emergence of resistance in food animals has been associated to the consumption of antimicrobials in veterinary medicine. Consequently, monitoring programs have been designed to monitor the occurrence of antimicrobial resistant bacteria. This study analyses the amount of antimicrobial agents...

  13. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes.

    Science.gov (United States)

    Hong, Pei-Ying; Al-Jassim, Nada; Ansari, Mohd Ikram; Mackie, Roderick I

    2013-07-31

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the "perfect microbial storm". Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  14. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    Directory of Open Access Journals (Sweden)

    Roderick I. Mackie

    2013-07-01

    Full Text Available Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  15. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    KAUST Repository

    Hong, Pei-Ying

    2013-07-31

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  16. A bioinformatic approach to understanding antibiotic resistance in intracellular bacteria through whole genome analysis

    OpenAIRE

    Biswas, S.(National Institute of Science Education and Research, Bhubaneswar, India); Raoult, Didier; Rolain, J. M.

    2008-01-01

    Intracellular bacteria survive within eukaryotic host cells and are difficult to kill with certain antibiotics. As a result, antibiotic resistance in intracellular bacteria is becoming commonplace in healthcare institutions. Owing to the lack of methods available for transforming these bacteria, we evaluated the mechanisms of resistance using molecular methods and in silico genome analysis. The objective of this review was to understand the molecular mechanisms of antibiotic resistance throug...

  17. A review of the influence of treatment strategies on antibiotic resistant bacteria and antibiotic resistance genes.

    Science.gov (United States)

    Sharma, Virender K; Johnson, Natalie; Cizmas, Leslie; McDonald, Thomas J; Kim, Hyunook

    2016-05-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in the aquatic environment have become an emerging contaminant issue, which has implications for human and ecological health. This review begins with an introduction to the occurrence of ARB and ARG in different environmental systems such as natural environments and drinking water resources. For example, ARG or ARB with resistance to ciprofloxacin, sulfamethoxazole, trimethoprim, quinolone, vancomycin, or tetracycline (e.g., tet(A), tet(B), tet(C), tet(G), tet(O), tet(M), tet(W), sul I, and sul II) have been detected in the environment. The development of resistance may be intrinsic, may be acquired through spontaneous mutations (de novo), or may occur due to horizontal gene transfer from donor bacteria, phages, or free DNA to recipient bacteria. An overview is also provided of the current knowledge regarding inactivation of ARB and ARG, and the mechanism of the effects of different disinfection processes in water and wastewater (chlorination, UV irradiation, Fenton reaction, ozonation, and photocatalytic oxidation). The effects of constructed wetlands and nanotechnology on ARB and ARG are also summarized.

  18. Relationship between antibiotic- and disinfectant-resistance profiles in bacteria harvested from tap water.

    Science.gov (United States)

    Khan, Sadia; Beattie, Tara K; Knapp, Charles W

    2016-06-01

    Chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What is concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population. Here, we investigated the relationship between chlorine- and antibiotic-resistances by harvesting 148 surviving bacteria from chlorinated drinking-water systems and compared their susceptibilities against chlorine disinfectants and antibiotics. Twenty-two genera were isolated, including members of Paenibacillus, Burkholderia, Escherichia, Sphingomonas and Dermacoccus species. Weak (but significant) correlations were found between chlorine-tolerance and minimum inhibitory concentrations against the antibiotics tetracycline, sulfamethoxazole and amoxicillin, but not against ciprofloxacin; this suggest that chlorine-tolerant bacteria are more likely to also be antibiotic resistant. Further, antibiotic-resistant bacteria survived longer than antibiotic-sensitive organisms when exposed to free chlorine in a contact-time assay; however, there were little differences in susceptibility when exposed to monochloramine. Irrespective of antibiotic-resistance, spore-forming bacteria had higher tolerance against disinfection compounds. The presence of chlorine-resistant bacteria surviving in drinking-water systems may carry additional risk of antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Bacteriophages as potential treatment option for antibiotic resistant bacteria.

    Science.gov (United States)

    Bragg, Robert; van der Westhuizen, Wouter; Lee, Ji-Yun; Coetsee, Elke; Boucher, Charlotte

    2014-01-01

    The world is facing an ever-increasing problem with antibiotic resistant bacteria and we are rapidly heading for a post-antibiotic era. There is an urgent need to investigate alterative treatment options while there are still a few antibiotics left. Bacteriophages are viruses that specifically target bacteria. Before the development of antibiotics, some efforts were made to use bacteriophages as a treatment option, but most of this research stopped soon after the discovery of antibiotics. There are two different replication options which bacteriophages employ. These are the lytic and lysogenic life cycles. Both these life cycles have potential as treatment options. There are various advantages and disadvantages to the use of bacteriophages as treatment options. The main advantage is the specificity of bacteriophages and treatments can be designed to specifically target pathogenic bacteria while not negatively affecting the normal microbiota. There are various advantages to this. However, the high level of specificity also creates potential problems, the main being the requirement of highly specific diagnostic procedures. Another potential problem with phage therapy includes the development of immunity and limitations with the registration of phage therapy options. The latter is driving research toward the expression of phage genes which break the bacterial cell wall, which could then be used as a treatment option. Various aspects of phage therapy have been investigated in studies undertaken by our research group. We have investigated specificity of phages to various avian pathogenic E. coli isolates. Furthermore, the exciting NanoSAM technology has been employed to investigate bacteriophage replication and aspects of this will be discussed.

  20. Computational modeling of drug-resistant bacteria. Final report

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Preston [Middle Tennessee State Univ., Murfreesboro, TN (United States)

    2015-03-12

    Initial proposal summary: The evolution of antibiotic-resistant mutants among bacteria (superbugs) is a persistent and growing threat to public health. In many ways, we are engaged in a war with these microorganisms, where the corresponding arms race involves chemical weapons and biological targets. Just as advances in microelectronics, imaging technology and feature recognition software have turned conventional munitions into smart bombs, the long-term objectives of this proposal are to develop highly effective antibiotics using next-generation biomolecular modeling capabilities in tandem with novel subatomic feature detection software. Using model compounds and targets, our design methodology will be validated with correspondingly ultra-high resolution structure-determination methods at premier DOE facilities (single-crystal X-ray diffraction at Argonne National Laboratory, and neutron diffraction at Oak Ridge National Laboratory). The objectives and accomplishments are summarized.

  1. Sustainable control of pea bacterial blight : approaches for durable genetic resistance and biocontrol by endophytic bacteria

    NARCIS (Netherlands)

    Elvira-Recuenco, M.

    2000-01-01

    Key-words: bacterial blight, biological control, biodiversity, endophytic bacteria, L-form, pea, PDRl retrotransposon, Pisum sativum, Pisum abyssinicum, Pseudomonas syringae pv. pisi, race specific resistance, race non-specific resistance, Spanish

  2. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria.

    Science.gov (United States)

    Geisinger, Edward; Isberg, Ralph R

    2017-02-15

    Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, email: journals.permissions@oup.com.

  3. Prevalence and persistence of potentially pathogenic and antibiotic resistant bacteria during anaerobic digestion treatment of cattle manure.

    Science.gov (United States)

    Resende, Juliana Alves; Silva, Vânia Lúcia; de Oliveira, Tamara Lopes Rocha; de Oliveira Fortunato, Samuel; da Costa Carneiro, Jailton; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo

    2014-02-01

    Anaerobic digestion figures as a sustainable alternative to avoid discharge of cattle manure in the environment, which results in biogas and biofertilizer. Persistence of potentially pathogenic and drug-resistant bacteria during anaerobic digestion of cattle manure was evaluated. Selective cultures were performed for enterobacteria (ENT), non-fermenting Gram-negative rods (NFR) and Gram-positive cocci (GPC). Antimicrobial susceptibility patterns were determined and a decay of all bacterial groups was observed after 60days. Multidrug-resistant bacteria were detected both the influent and effluent. GPC, the most prevalent group was highly resistant against penicillin and levofloxacin, whereas resistance to ampicillin, ampicillin-sulbactam and chloramphenicol was frequently observed in the ENT and NFR groups. The data point out the need of discussions to better address management of biodigesters and the implementation of sanitary and microbiological safe treatments of animal manures to avoid consequences to human, animal and environmental health. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Combination therapy for carbapenem-resistant Gram-negative bacteria.

    Science.gov (United States)

    Paul, Mical; Carmeli, Yehuda; Durante-Mangoni, Emanuele; Mouton, Johan W; Tacconelli, Evelina; Theuretzbacher, Ursula; Mussini, Cristina; Leibovici, Leonard

    2014-09-01

    Carbapenem-resistant Gram-negative bacteria (CR-GNB) represent an increasing hazard in healthcare settings. A central question concerning the treatment of invasive infections caused by CR-GNB involves the use of combination therapy. Potential advantages of combination therapy include improved efficacy due to synergy, while the disadvantages include adverse events and increased antibiotic use with a potential drive towards resistance. Several observational studies have examined whether combination therapy offers an advantage over colistin/polymyxin monotherapy. We highlight the inherent limitations of these studies related to their observational design and sample size to show why they do not at present provide an answer to the question of combination versus monotherapy. This distinction is important to guide clinical practice until solid evidence has been obtained and to enable the recruitment of patients into randomized controlled trials. A few randomized controlled trials examining specific combinations have recently been completed or are ongoing. Currently, however, there is no evidence-based support for most combination therapies against CR-GNB, including colistin/carbapenem combination therapy.

  5. Selection of antibiotic-resistant standard plate count bacteria during water treatment.

    Science.gov (United States)

    Armstrong, J L; Calomiris, J J; Seidler, R J

    1982-08-01

    Standard plate count (SPC) bacteria were isolated from a drinking-water treatment facility and from the river supplying the facility. All isolates were identified and tested for their resistance to six antibiotics to determine if drug-resistant bacteria were selected for as a consequence of water treatment. Among the isolates surviving our test procedures, there was a significant selection (P less than 0.05) of gram-negative SPC organisms resistant to two or more of the test antibiotics. These bacteria were isolated from the flash mix tank, where chlorine, alum, and lime are added to the water. Streptomycin resistance in particular was more frequent in this population as compared with bacteria in the untreated river water (P less than 0.01). SPC bacteria from the clear well, which is a tank holding the finished drinking water at the treatment facility, were also more frequently antibiotic resistant than were the respective river water populations. When 15.8 and 18.2% of the river water bacteria were multiply antibiotic resistant, 57.1 and 43.5%, respectively, of the SPC bacteria in the clear well were multiply antibiotic resistant. Selection for bacteria exhibiting resistance to streptomycin was achieved by chlorinating river water in the laboratory. We concluded that the selective factors operating in the aquatic environment of a water treatment facility can act to increase the proportion of antibiotic-resistant members of the SPC bacterial population in treated drinking water.

  6. ACTION OF NEWER DISINFECTANTS ON MULTIDRUG RESISTANT BACTERIA

    Directory of Open Access Journals (Sweden)

    Bipasa

    2014-03-01

    Full Text Available BACKGROUND: Current procedures for infection control in hospital environments have not been successful in curbing the rise in infections by multi-drug-resistant (MDR pathogens. Emergence of resistance to chemical disinfectants is increasing steadily and has been reported worldwide. So prevention of multidrug-resistant health care associated infections (HAI has become a priority issue and great challenge to clinicians. This requires appropriate sterilization and disinfection procedures and strict adherence to protocol in infection control policy. There is a need to evaluate the efficacy of newer disinfectants which have come into the market for better control of HAI. AIMS AND OBJECTIVES: The aim of this study was to evaluate and compare disinfection efficacy of three newer disinfectants– Novacide (didecyldimethylammonium chloride and polyhexamethylene biguanide, Silvicide a strong oxidizing agent (hydrogen peroxide and silver nitrate and Virkon, a powerful oxidizing agent (a stabilized blend of peroxygen compounds and potassium salts, pitting them against two time-honored conventional disinfectants phenol and lysol and testing them against common MDR clinical isolates, reference strains and spores. MATERIALS AND METHODS: All the disinfectants at different dilutions were tested for bactericidal efficacy by liquid suspension time-kill tests. A heavy initial microbial load was simulated by preparing bacterial inoculum. Numbers of viable cells were counted and reduction in microbial colony counts before and after disinfectant exposure was expressed as log reduction. RESULTS: Among the disinfectants, Novacide was most effective. All clinical MDR bacterial isolates and reference strains were killed within 30 seconds of exposure at 0.156% solution, whereas spores got killed after 30 minutes of exposure at 2.5% solution which is the recommended concentration. For Silvicide all vegetative bacteria were killed at 5% solution after 20 minutes contact time

  7. Resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients.

    Science.gov (United States)

    Ahmad, Nafees; Javaid, Arshad; Sulaiman, Syed Azhar Syed; Ming, Long Chiau; Ahmad, Izaz; Khan, Amer Hayat

    2016-01-01

    Fluoroquinolones are the backbone of multidrug resistant tuberculosis treatment regimens. Despite the high burden of multidrug resistant tuberculosis in the country, little is known about drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance among multidrug resistant tuberculosis patients from Pakistan. To evaluate drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients. This was a cross-sectional study conducted at a programmatic management unit of drug resistant tuberculosis, Lady Reading Hospital Peshawar, Pakistan. Two hundred and forty-three newly diagnosed multidrug resistant tuberculosis patients consecutively enrolled for treatment at study site from January 1, 2012 to July 28, 2013 were included in the study. A standardized data collection form was used to collect patients' socio-demographic, microbiological, and clinical data. SPSS 16 was used for data analysis. High degree of drug resistance (median 5 drugs, range 2-8) was observed. High proportion of patients was resistant to all five first-line anti-tuberculosis drugs (62.6%), and more than half were resistant to second line drugs (55.1%). The majority of the patients were ofloxacin resistant (52.7%). Upon multivariate analysis previous tuberculosis treatment at private (OR=1.953, p=0.034) and public private mix (OR=2.824, p=0.046) sectors were predictors of ofloxacin resistance. The high degree of drug resistance observed, particularly to fluoroquinolones, is alarming. We recommend the adoption of more restrictive policies to control non-prescription sale of fluoroquinolones, its rational use by physicians, and training doctors in both private and public-private mix sectors to prevent further increase in fluoroquinolones resistant Mycobacterium tuberculosis strains. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

  8. Resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients

    Directory of Open Access Journals (Sweden)

    Nafees Ahmad

    Full Text Available Abstract Background Fluoroquinolones are the backbone of multidrug resistant tuberculosis treatment regimens. Despite the high burden of multidrug resistant tuberculosis in the country, little is known about drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance among multidrug resistant tuberculosis patients from Pakistan. Objective To evaluate drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients. Methods This was a cross-sectional study conducted at a programmatic management unit of drug resistant tuberculosis, Lady Reading Hospital Peshawar, Pakistan. Two hundred and forty-three newly diagnosed multidrug resistant tuberculosis patients consecutively enrolled for treatment at study site from January 1, 2012 to July 28, 2013 were included in the study. A standardized data collection form was used to collect patients’ socio-demographic, microbiological, and clinical data. SPSS 16 was used for data analysis. Results High degree of drug resistance (median 5 drugs, range 2–8 was observed. High proportion of patients was resistant to all five first-line anti-tuberculosis drugs (62.6%, and more than half were resistant to second line drugs (55.1%. The majority of the patients were ofloxacin resistant (52.7%. Upon multivariate analysis previous tuberculosis treatment at private (OR = 1.953, p = 0.034 and public private mix (OR = 2.824, p = 0.046 sectors were predictors of ofloxacin resistance. Conclusion The high degree of drug resistance observed, particularly to fluoroquinolones, is alarming. We recommend the adoption of more restrictive policies to control non-prescription sale of fluoroquinolones, its rational use by physicians, and training doctors in both private and public–private mix sectors to prevent further increase in fluoroquinolones resistant Mycobacterium tuberculosis strains.

  9. Using experimental evolution to explore natural patterns between bacterial motility and resistance to bacteriophages.

    Science.gov (United States)

    Koskella, Britt; Taylor, Tiffany B; Bates, Jennifer; Buckling, Angus

    2011-11-01

    Resistance of bacteria to phages may be gained by alteration of surface proteins to which phages bind, a mechanism that is likely to be costly as these molecules typically have critical functions such as movement or nutrient uptake. To address this potential trade-off, we combine a systematic study of natural bacteria and phage populations with an experimental evolution approach. We compare motility, growth rate and susceptibility to local phages for 80 bacteria isolated from horse chestnut leaves and, contrary to expectation, find no negative association between resistance to phages and bacterial motility or growth rate. However, because correlational patterns (and their absence) are open to numerous interpretations, we test for any causal association between resistance to phages and bacterial motility using experimental evolution of a subset of bacteria in both the presence and absence of naturally associated phages. Again, we find no clear link between the acquisition of resistance and bacterial motility, suggesting that for these natural bacterial populations, phage-mediated selection is unlikely to shape bacterial motility, a key fitness trait for many bacteria in the phyllosphere. The agreement between the observed natural pattern and the experimental evolution results presented here demonstrates the power of this combined approach for testing evolutionary trade-offs.

  10. The Design of Simple Bacterial Microarrays: Development towards Immobilizing Single Living Bacteria on Predefined Micro-Sized Spots on Patterned Surfaces.

    Directory of Open Access Journals (Sweden)

    Nina Bjørk Arnfinnsdottir

    Full Text Available In this paper we demonstrate a procedure for preparing bacterial arrays that is fast, easy, and applicable in a standard molecular biology laboratory. Microcontact printing is used to deposit chemicals promoting bacterial adherence in predefined positions on glass surfaces coated with polymers known for their resistance to bacterial adhesion. Highly ordered arrays of immobilized bacteria were obtained using microcontact printed islands of polydopamine (PD on glass surfaces coated with the antiadhesive polymer polyethylene glycol (PEG. On such PEG-coated glass surfaces, bacteria were attached to 97 to 100% of the PD islands, 21 to 62% of which were occupied by a single bacterium. A viability test revealed that 99% of the bacteria were alive following immobilization onto patterned surfaces. Time series imaging of bacteria on such arrays revealed that the attached bacteria both divided and expressed green fluorescent protein, both of which indicates that this method of patterning of bacteria is a suitable method for single-cell analysis.

  11. The Design of Simple Bacterial Microarrays: Development towards Immobilizing Single Living Bacteria on Predefined Micro-Sized Spots on Patterned Surfaces

    Science.gov (United States)

    Arnfinnsdottir, Nina Bjørk; Ottesen, Vegar; Lale, Rahmi; Sletmoen, Marit

    2015-01-01

    In this paper we demonstrate a procedure for preparing bacterial arrays that is fast, easy, and applicable in a standard molecular biology laboratory. Microcontact printing is used to deposit chemicals promoting bacterial adherence in predefined positions on glass surfaces coated with polymers known for their resistance to bacterial adhesion. Highly ordered arrays of immobilized bacteria were obtained using microcontact printed islands of polydopamine (PD) on glass surfaces coated with the antiadhesive polymer polyethylene glycol (PEG). On such PEG-coated glass surfaces, bacteria were attached to 97 to 100% of the PD islands, 21 to 62% of which were occupied by a single bacterium. A viability test revealed that 99% of the bacteria were alive following immobilization onto patterned surfaces. Time series imaging of bacteria on such arrays revealed that the attached bacteria both divided and expressed green fluorescent protein, both of which indicates that this method of patterning of bacteria is a suitable method for single-cell analysis. PMID:26039378

  12. Health risks associated with the presence of antibiotic resistant bacteria in greywater

    Directory of Open Access Journals (Sweden)

    Juan Moretton

    2012-04-01

    Full Text Available The removal and disposal of waste from domestic activities is a major health problem in densely populated urban areas. In many areas of Greater Buenos Aires, greywater is disposed in open ditches and risk potential of this has not been adequately quantified. The aim of this study was to evaluate the prevalence of antibiotic-resistant bacteria and its resistance profile present in raw greywater obtained from a channel located in the area of Ingeniero Budge Buenos Aires Province. Thus, the prevalence of heterotrophic bacteria, Gram-negative bacteria resistant to beta-lactam antibiotics and vancomycin-resistant enterococci in greywater, their typing, and resistance to other antibiotics were determined. The prevalence of resistant bacteria was determined by the agar dilution method. Of all the antibiotics tested, the highest prevalence of resistant heterotrophic bacteria was detected with cephalothin (19% and ampicillin (8%. With regard to Gram-negative bacteria, the highest prevalence of resistance was given by coliforms ampicillin (34% and cephalothin (17%. A total of 38% of enterococci with low level resistance to vancomycin was detected. The multiresistant isolates were identified as Escherichia coli, Alcaligenes faecalis y Stenotrophomonas maltophilia. These results indicate that greywater can be considered as a reservoir of bacteria resistant to antibiotics, thus increasing their health risk.

  13. [From the discovery of antibiotics to emerging highly drug-resistant bacteria].

    Science.gov (United States)

    Meunier, Olivier

    2015-01-01

    The discovery of antibiotics has enabled serious infections to be treated. However, bacteria resistant to several families of antibiotics and the emergence of new highly drug-resistant bacteria constitute a public health issue in France and across the world. Actions to prevent their transmission are being put in place. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. [The role of hospital teams in the management of patients carrying highly drug-resistant bacteria].

    Science.gov (United States)

    Clément, Agnès; Denis, Christine

    2015-01-01

    The increase in antibiotic-resistant bacteria and emerging highly drug-resistant bacteria is resulting in alarming situations of treatment failure. In hospitals, precautionary measures to control nosocomial infections are put in place through the collaboration between caregivers, the operational hygiene team and the nosocomial infection control committee, in accordance with official recommendations. Copyright © 2015. Published by Elsevier Masson SAS.

  15. Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian

    Directory of Open Access Journals (Sweden)

    Monali Priyadarsini Mishra

    2013-04-01

    Conclusions: Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and S. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern.

  16. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria

    Science.gov (United States)

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater- and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hotspot for pr...

  17. The in-vitro antimicrobial activity of some medicinal plants against beta-lactam-resistant bacteria

    OpenAIRE

    Gangoue Pieboji, Joseph; Eze, N.; Ngongang Djintchui, A.; Ngameni, B; Tsabang, N.; Pegnyemb, D. E.; Biyiti, L.; Ngassam, P.; Koulla-Shiro, S.; Galleni, Moreno

    2009-01-01

    BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant bacteria. METHODOLOGY: The antimicrobial activities of plant extracts were evaluated against clinically proved beta-lactam-resistant bacteria (Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus and Enterococcus sp.)...

  18. Influence of Chicken Manure Fertilization on Antibiotic-Resistant Bacteria in Soil and the Endophytic Bacteria of Pakchoi.

    Science.gov (United States)

    Yang, Qingxiang; Zhang, Hao; Guo, Yuhui; Tian, Tiantian

    2016-01-01

    Animal manure is commonly used as fertilizer for agricultural crops worldwide, even though it is believed to contribute to the spread of antibiotic resistance from animal intestines to the soil environment. However, it is unclear whether and how there is any impact of manure fertilization on populations and community structure of antibiotic-resistant endophytic bacteria (AREB) in plant tissues. To investigate the effect of manure and organic fertilizer on endophytic bacterial communities, pot experiments were performed with pakchoi grown with the following treatments: (1) non-treated; (2) chicken manure-treated and (3) organic fertilizer-treated. Manure or organic fertilizer significantly increased the abundances of total cultivable endophytic bacteria (TCEB) and AREB in pakchoi, and the effect of chicken manure was greater than that of organic fertilizer. Further, 16S rDNA sequencing and the phylogenetic analysis indicated that chicken manure or organic fertilizer application increased the populations of multiple antibiotic-resistant bacteria (MARB) in soil and multiple antibiotic-resistant endophytic bacteria (MAREB) in pakchoi. The identical multiple antibiotic-resistant bacterial populations detected in chicken manure, manure- or organic fertilizer-amended soil and the vegetable endophytic system were Brevundimonas diminuta, Brachybacterium sp. and Bordetella sp., suggesting that MARB from manure could enter and colonize the vegetable tissues through manure fertilization. The fact that some human pathogens with multiple antibiotic resistance were detected in harvested vegetables after growing in manure-amended soil demonstrated a potential threat to human health.

  19. The impact of different antibiotic regimens on the emergence of antimicrobial-resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Erika M C D'Agata

    Full Text Available BACKGROUND: The emergence and ongoing spread of antimicrobial-resistant bacteria is a major public health threat. Infections caused by antimicrobial-resistant bacteria are associated with substantially higher rates of morbidity and mortality compared to infections caused by antimicrobial-susceptible bacteria. The emergence and spread of these bacteria is complex and requires incorporating numerous interrelated factors which clinical studies cannot adequately address. METHODS/PRINCIPAL FINDINGS: A model is created which incorporates several key factors contributing to the emergence and spread of resistant bacteria including the effects of the immune system, acquisition of resistance genes and antimicrobial exposure. The model identifies key strategies which would limit the emergence of antimicrobial-resistant bacterial strains. Specifically, the simulations show that early initiation of antimicrobial therapy and combination therapy with two antibiotics prevents the emergence of resistant bacteria, whereas shorter courses of therapy and sequential administration of antibiotics promote the emergence of resistant strains. CONCLUSIONS/SIGNIFICANCE: The principal findings suggest that (i shorter lengths of antibiotic therapy and early interruption of antibiotic therapy provide an advantage for the resistant strains, (ii combination therapy with two antibiotics prevents the emergence of resistance strains in contrast to sequential antibiotic therapy, and (iii early initiation of antibiotics is among the most important factors preventing the emergence of resistant strains. These findings provide new insights into strategies aimed at optimizing the administration of antimicrobials for the treatment of infections and the prevention of the emergence of antimicrobial resistance.

  20. Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter.

    Science.gov (United States)

    Li, Lili; Heidemann Olsen, Rikke; Ye, Lei; Yan, He; Nie, Qing; Meng, Hecheng; Shi, Lei

    2016-04-01

    The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies.

  1. Amoeba-resisting bacteria found in multilamellar bodies secreted by Dictyostelium discoideum: social amoebae can also package bacteria.

    Science.gov (United States)

    Paquet, Valérie E; Charette, Steve J

    2016-03-01

    Many bacteria can resist phagocytic digestion by various protozoa. Some of these bacteria (all human pathogens) are known to be packaged in multilamellar bodies produced in the phagocytic pathway of the protozoa and that are secreted into the extracellular milieu. Packaged bacteria are protected from harsh conditions, and the packaging process is suspected to promote bacterial persistence in the environment. To date, only a limited number of protozoa, belonging to free-living amoebae and ciliates, have been shown to perform bacteria packaging. It is still unknown if social amoebae can do bacteria packaging. The link between the capacity of 136 bacterial isolates to resist the grazing of the social amoeba Dictyostelium discoideum and to be packaged by this amoeba was investigated in the present study. The 45 bacterial isolates displaying a resisting phenotype were tested for their capacity to be packaged. A total of seven isolates from Cupriavidus, Micrococcus, Microbacterium and Rathayibacter genera seemed to be packaged and secreted by D. discoideum based on immunofluorescence results. Electron microscopy confirmed that the Cupriavidus and Rathayibacter isolates were formally packaged. These results show that social amoebae can package some bacteria from the environment revealing a new aspect of microbial ecology.

  2. Radiation-resistant bacteria and their application to metal and radionuclides bioremediation

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-Long

    2004-01-01

    Microorganisms have a number of applications in the nuclear industry, which would benefit from the use of radiation-resistant microorganisms. Environmentally isolated bacteria have shown to be resistant to gamma irradiation up to a dose of 30,000 Gy. It has also been reported that the presence of ionizing radiation may induce radio-resistance in bacteria. Recent demonstrations of the removal and immobilization of inorganic contaminants by microbial transformations, sorption and mineralization show the potential of both natural and engineered microorganisms as bioremedial tools. This review is to provide an overview of the application of radiation-resistant bacteria to decontamination of metal and radionuclide.

  3. Possible impact of treated wastewater discharge on incidence of antibiotic resistant bacteria in river water.

    Science.gov (United States)

    Iwane, T; Urase, T; Yamamoto, K

    2001-01-01

    Escherichia coli and coliform group bacteria resistant to seven antibiotics were investigated in the Tama River, a typical urbanized river in Tokyo, Japan, and at a wastewater treatment plant located on the river. The percentages of antibiotic resistance in the wastewater effluent were, in most cases, higher than the percentages in the river water, which were observed increasing downstream. Since the possible increase in the percentages in the river was associated with treated wastewater discharges, it was concluded that the river, which is contaminated by treated wastewater with many kinds of pollutants, is also contaminated with antibiotic resistant coliform group bacteria and E. coli. The percentages of resistant bacteria in the wastewater treatment plant were mostly observed decreasing during the treatment process. It was also demonstrated that the percentages of resistance in raw sewage are significantly higher than those in the river water and that the wastewater treatment process investigated in this study works against most of resistant bacteria in sewage.

  4. Isolation and characterization of arsenic resistant bacteria from wastewater

    Directory of Open Access Journals (Sweden)

    Syed Zaghum Abbas

    2014-12-01

    Full Text Available The present study proposed the isolation of arsenic resistant bacteria from wastewater. Only three bacterial isolates (MNZ1, MNZ4 and MNZ6 were able to grow in high concentrations of arsenic. The minimum inhibitory concentrations of arsenic against MNZ1, MNZ4 and MNZ6 were 300 mg/L, 300 mg/L and 370 mg/L respectively. The isolated strains showed maximum growth at 37 ºC and at 7.0 pH in control but in arsenite stress Luria Bertani broth the bacterial growth is lower than control. All strains were arsenite oxidizing. All strains were biochemically characterized and ribotyping (16S rRNA was done for the purpose of identification which confirmed that MNZ1 was homologous to Enterobacter sp. while MNZ4 and MNZ6 showed their maximum homology with Klebsiella pneumoniae. The protein profiling of these strains showed in arsenic stressed and non stressed conditions, so no bands of induced proteins appeared in stressed conditions. The bacterial isolates can be exploited for bioremediation of arsenic containing wastes, since they seem to have the potential to oxidize the arsenite (more toxic into arsenate (less toxic form.

  5. Isolation and characterization of arsenic resistant bacteria from wastewater.

    Science.gov (United States)

    Abbas, Syed Zaghum; Riaz, Mehwish; Ramzan, Naseem; Zahid, M Tariq; Shakoori, Farah R; Rafatullah, Mohd

    2014-01-01

    The present study proposed the isolation of arsenic resistant bacteria from wastewater. Only three bacterial isolates (MNZ1, MNZ4 and MNZ6) were able to grow in high concentrations of arsenic. The minimum inhibitory concentrations of arsenic against MNZ1, MNZ4 and MNZ6 were 300 mg/L, 300 mg/L and 370 mg/L respectively. The isolated strains showed maximum growth at 37 °C and at 7.0 pH in control but in arsenite stress Luria Bertani broth the bacterial growth is lower than control. All strains were arsenite oxidizing. All strains were biochemically characterized and ribotyping (16S rRNA) was done for the purpose of identification which confirmed that MNZ1 was homologous to Enterobacter sp. while MNZ4 and MNZ6 showed their maximum homology with Klebsiella pneumoniae. The protein profiling of these strains showed in arsenic stressed and non stressed conditions, so no bands of induced proteins appeared in stressed conditions. The bacterial isolates can be exploited for bioremediation of arsenic containing wastes, since they seem to have the potential to oxidize the arsenite (more toxic) into arsenate (less toxic) form.

  6. Copper-resistant bacteria enhance plant growth and copper phytoextraction.

    Science.gov (United States)

    Yang, Renxiu; Luo, Chunling; Chen, Yahua; Wang, Guiping; Xu, Yue; Shen, Zhenguo

    2013-01-01

    In this study, we investigated the role of rhizospheric bacteria in solubilizing soil copper (Cu) and promoting plant growth. The Cu-resistant bacterium DGS6 was isolated from a natural Cu-contaminated soil and was identified as Pseudomonas sp. DGS6. This isolate solubilized Cu in Cu-contaminated soil and stimulated root elongation of maize and sunflower. Maize was more sensitive to inoculation with DGS6 than was sunflower and exhibited greater root elongation. In pot experiment, inoculation with DGS6 increased the shoot dry weight of maize by 49% and sunflower by 34%, and increased the root dry weight of maize by 85% and sunflower by 45%. Although the concentrations of Cu in inoculated and non-inoculated seedlings did not differ significantly, the total accumulation of Cu in the plants increased after inoculation. DGS6 showed a high ability to solubilize P and produce iron-chelating siderophores, as well as significantly improved the accumulation of P and Fe in both maize and sunflower shoots. In addition, DGS6 produced indole-3-acetic acid (IAA) and ACC deaminase, which suggests that it may modulate ethylene levels in plants. The bacterial strain DGS6 could be a good candidate for re-vegetation of Cu-contaminated sites. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

  7. Antibiotic resistant pattern of methicillin resistant and sensitive Staphylococcus aureus isolated from patients durining 2009-2010, Ahvaz, Iran.

    Directory of Open Access Journals (Sweden)

    N Parhizgari

    2013-12-01

    Full Text Available Abstract Background & aim: Staphylococcus aureus is one of the most important nosocomial infecting agents resistant to commonly used antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA is considered one of the main causes of nosocomial infections. The aim of this study was to identify the antibiotic resistance pattern of methicicllin- resistant and susceptible strains in Ahwaz, Iran. Methods: In the present cross - sectional study, a number of 255 clinically suspected cases of Staphylococcus aureus were collected during a 19 month period. The bacteria were investigated using standard biochemical tests such as catalase, mannitol fermentation, coagulase and Dnase. Sensitive strains were confirmed by disk diffusion method compared to commonly used antibiotics. The collected data were analyzed using descriptive statistical tests. Results: of 255 suspected cases, 180 were confirmed as S.aureus, a total of 59 strains of S. aureus (2/37 percent were resistant to methicillin. Resistance to S. aureus strains resistant to methicillin included: chloramphenicol (3.38%, rifampin (45.76%, norfloxacin (89.83%, gentamicin (89.83%, ciprofloxacin, (91.52%, azithromycin, (88.13%, cotrimoxazole (86.44% and all isolates strains were sensitive to vancomycin and nitrofurantoin. A total of 10 different patterns of antibiotic resistance in methicillin-resistant Staphylococcus aureus strains were identified. Conclusion: Expression of new resistance factor in nosocomial infection is one of the major challenges in treating these infections. This study showed a high prevalence of resistance against some class of antibiotics in MRSA isolated from Imam Khomeini and Golestan hospital of Ahwaz, Iran. Key words: Nosocomial infection, Methicillin Resistant Staphylococcus aureus (MRSA, Antibiotic Resistant Pattern

  8. Antibiotics use and resistance patterns of Salmonella species in ...

    African Journals Online (AJOL)

    Antibiotics use and resistance patterns of Salmonella species in poultry from Ibadan, ... in self medication without veterinary diagnosis of diseases or prescription. ... There are urgent needs for national monitoring of antimicrobial resistance in ...

  9. Occurrence of antimicrobial resistance in bacteria from diagnostic samples from dogs

    DEFF Research Database (Denmark)

    Pedersen, Karl; Pedersen, Kristina; Jensen, Helene

    2007-01-01

    Objectives: To study the occurrence of antimicrobial resistance among common bacterial pathogens from dogs and relate resistance patterns to data on consumption of antimicrobials. Methods: The antimicrobial susceptibility patterns of 201 Staphylococcus intermedius, 37 Streptococcus canis, 39 Pseu...

  10. Do antibiotic residues in soils play a role in amplification and transmission of antibiotic resistant bacteria in cattle populations?

    Directory of Open Access Journals (Sweden)

    Douglas Ruben Call

    2013-07-01

    Full Text Available When we consider factors that contribute to the emergence, amplification, and persistence of antibiotic resistant bacteria, the conventional assumption is that antibiotic use is the primary driver in these processes and that selection occurs primarily in the patient or animal. Evidence suggests that this may not always be the case. Experimental trials show that parenteral administration of a third-generation cephalosporin (ceftiofur in cattle has limited or short-term effects on the prevalence of ceftiofur-resistant bacteria in the gastrointestinal tract. While this response may be sufficient to explain a pattern of widespread resistance to cephalosporins, approximately two-thirds of ceftiofur metabolites are excreted in the urine raising the possibility that environmental selection plays an important additive role in the amplification and maintenance of antibiotic resistant E. coli on farms. Consequently, we present a rationale for an environmental selection hypothesis whereby excreted antibiotic residues such as ceftiofur are a significant contributor to the proliferation of antibiotic resistant bacteria in food animal systems. We also present a mathematical model of our hypothesized system as a guide for designing experiments to test this hypothesis. If supported for antibiotics such as ceftiofur, then there may be new approaches to combat the proliferation of antibiotic resistance beyond the prudent use mantra.

  11. Antibiotic Resistant Bacteria And Their Associated Resistance Genes in a Conventional Municipal Wastewater Treatment Plant

    KAUST Repository

    Aljassim, Nada I.

    2013-12-01

    With water scarcity as a pressing issue in Saudi Arabia and other Middle Eastern countries, the treatment and reuse of municipal wastewater is increasingly being used as an alternative water source to supplement country water needs. Standards are in place to ensure a safe treated wastewater quality, however they do not regulate pathogenic bacteria and emerging contaminants. Information is lacking on the levels of risk to public health associated with these factors, the efficiency of conventional treatment strategies in removing them, and on wastewater treatment in Saudi Arabia in general. In this study, a municipal wastewater treatment plant in Saudi Arabia is investigated to assess the efficiency of conventional treatment in meeting regulations and removing pathogens and emerging contaminants. The study found pathogenic bacterial genera, antibiotic resistance genes and antibiotic resistant bacteria, many of which were multi-resistant in plant discharges. It was found that although the treatments are able to meet traditional quality guidelines, there remains a risk from the discussed contaminants with wastewater reuse. A deeper understanding of this risk, and suggestions for more thorough guidelines and monitoring are needed.

  12. Ultraviolet disinfection of antibiotic resistant bacteria and their antibiotic resistance genes in water and wastewater.

    Science.gov (United States)

    McKinney, Chad W; Pruden, Amy

    2012-12-18

    Disinfection of wastewater treatment plant effluent may be an important barrier for limiting the spread of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). While ideally disinfection should destroy ARGs, to prevent horizontal gene transfer to downstream bacteria, little is known about the effect of conventional water disinfection technologies on ARGs. This study examined the potential of UV disinfection to damage four ARGs, mec(A), van(A), tet(A), and amp(C), both in extracellular form and present within a host ARBs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Escherichia coli SMS-3-5, and Pseudomonas aeruginosa 01, respectively. An extended amplicon-length quantitative polymerase chain reaction assay was developed to enhance capture of ARG damage events and also to normalize to an equivalent length of target DNA (∼1000 bp) for comparison. It was found that the two Gram-positive ARBs (MRSA and VRE) were more resistant to UV disinfection than the two Gram-negative ARBs (E. coli and P. aeruginosa). The two Gram-positive organisms also possessed smaller total genome sizes, which could also have reduced their susceptibility to UV because of fewer potential pyrimidine dimer targets. An effect of cell type on damage to ARGs was only observed in VRE and P. aeruginosa, the latter potentially because of extracellular polymeric substances. In general, damage of ARGs required much greater UV doses (200-400 mJ/cm² for 3- to 4-log reduction) than ARB inactivation (10-20 mJ/cm² for 4- to 5-log reduction). The proportion of amplifiable ARGs following UV treatment exhibited a strong negative correlation with the number of adjacent thymines (Pearson r 0.85; p disinfection technologies should be explored.

  13. Computer-based classification of bacteria species by analysis of their colonies Fresnel diffraction patterns

    Science.gov (United States)

    Suchwalko, Agnieszka; Buzalewicz, Igor; Podbielska, Halina

    2012-01-01

    In the presented paper the optical system with converging spherical wave illumination for classification of bacteria species, is proposed. It allows for compression of the observation space, observation of Fresnel patterns, diffraction pattern scaling and low level of optical aberrations, which are not possessed by other optical configurations. Obtained experimental results have shown that colonies of specific bacteria species generate unique diffraction signatures. Analysis of Fresnel diffraction patterns of bacteria colonies can be fast and reliable method for classification and recognition of bacteria species. To determine the unique features of bacteria colonies diffraction patterns the image processing analysis was proposed. Classification can be performed by analyzing the spatial structure of diffraction patterns, which can be characterized by set of concentric rings. The characteristics of such rings depends on the bacteria species. In the paper, the influence of basic features and ring partitioning number on the bacteria classification, is analyzed. It is demonstrated that Fresnel patterns can be used for classification of following species: Salmonella enteritidis, Staplyococcus aureus, Proteus mirabilis and Citrobacter freundii. Image processing is performed by free ImageJ software, for which a special macro with human interaction, was written. LDA classification, CV method, ANOVA and PCA visualizations preceded by image data extraction were conducted using the free software R.

  14. Microbial Etiology of Pneumonia: Epidemiology, Diagnosis and Resistance Patterns

    Science.gov (United States)

    Cilloniz, Catia; Martin-Loeches, Ignacio; Garcia-Vidal, Carolina; San Jose, Alicia; Torres, Antoni

    2016-01-01

    Globally, pneumonia is a serious public health concern and a major cause of mortality and morbidity. Despite advances in antimicrobial therapies, microbiological diagnostic tests and prevention measures, pneumonia remains the main cause of death from infectious disease in the world. An important reason for the increased global mortality is the impact of pneumonia on chronic diseases, along with the increasing age of the population and the virulence factors of the causative microorganism. The increasing number of multidrug-resistant bacteria, difficult-to-treat microorganisms, and the emergence of new pathogens are a major problem for clinicians when deciding antimicrobial therapy. A key factor for managing and effectively guiding appropriate antimicrobial therapy is an understanding of the role of the different causative microorganisms in the etiology of pneumonia, since it has been shown that the adequacy of initial antimicrobial therapy is a key factor for prognosis in pneumonia. Furthermore, broad-spectrum antibiotic therapies are sometimes given until microbiological results are available and de-escalation cannot be performed quickly. This review provides an overview of microbial etiology, resistance patterns, epidemiology and microbial diagnosis of pneumonia. PMID:27999274

  15. Microbial Etiology of Pneumonia: Epidemiology, Diagnosis and Resistance Patterns

    Directory of Open Access Journals (Sweden)

    Catia Cilloniz

    2016-12-01

    Full Text Available Globally, pneumonia is a serious public health concern and a major cause of mortality and morbidity. Despite advances in antimicrobial therapies, microbiological diagnostic tests and prevention measures, pneumonia remains the main cause of death from infectious disease in the world. An important reason for the increased global mortality is the impact of pneumonia on chronic diseases, along with the increasing age of the population and the virulence factors of the causative microorganism. The increasing number of multidrug-resistant bacteria, difficult-to-treat microorganisms, and the emergence of new pathogens are a major problem for clinicians when deciding antimicrobial therapy. A key factor for managing and effectively guiding appropriate antimicrobial therapy is an understanding of the role of the different causative microorganisms in the etiology of pneumonia, since it has been shown that the adequacy of initial antimicrobial therapy is a key factor for prognosis in pneumonia. Furthermore, broad-spectrum antibiotic therapies are sometimes given until microbiological results are available and de-escalation cannot be performed quickly. This review provides an overview of microbial etiology, resistance patterns, epidemiology and microbial diagnosis of pneumonia.

  16. Microbial Etiology of Pneumonia: Epidemiology, Diagnosis and Resistance Patterns.

    Science.gov (United States)

    Cilloniz, Catia; Martin-Loeches, Ignacio; Garcia-Vidal, Carolina; San Jose, Alicia; Torres, Antoni

    2016-12-16

    Globally, pneumonia is a serious public health concern and a major cause of mortality and morbidity. Despite advances in antimicrobial therapies, microbiological diagnostic tests and prevention measures, pneumonia remains the main cause of death from infectious disease in the world. An important reason for the increased global mortality is the impact of pneumonia on chronic diseases, along with the increasing age of the population and the virulence factors of the causative microorganism. The increasing number of multidrug-resistant bacteria, difficult-to-treat microorganisms, and the emergence of new pathogens are a major problem for clinicians when deciding antimicrobial therapy. A key factor for managing and effectively guiding appropriate antimicrobial therapy is an understanding of the role of the different causative microorganisms in the etiology of pneumonia, since it has been shown that the adequacy of initial antimicrobial therapy is a key factor for prognosis in pneumonia. Furthermore, broad-spectrum antibiotic therapies are sometimes given until microbiological results are available and de-escalation cannot be performed quickly. This review provides an overview of microbial etiology, resistance patterns, epidemiology and microbial diagnosis of pneumonia.

  17. 46 . original article trends in the resistance pattern of bacterial ...

    African Journals Online (AJOL)

    User

    media in our environment and their pattern of antibiotic susceptibility. Between November ... Key words: Otitis media, bacterial pathogens, resistance pattern. INTRODUCTION .... attributed to the shorter, wider, and horizontal. Eustachian tube ...

  18. The First Report of Drug Resistant Bacteria Isolated from the Brown-Banded Cockroach, Supella longipalpa, in Ahvaz, South-western Iran.

    Directory of Open Access Journals (Sweden)

    Babak Vazirianzadeh

    2014-06-01

    Full Text Available The brown-banded cockroach, Supella longipalpa is known as a carrier of pathogenic bacteria in urban environments, but its role is not well documented regarding the carriage of antibiotic-resistant pathogenic bacteria in Iran. The aim of this study was to determine the resistance bacteria isolated from the brown-banded cockroach in Ahvaz, south west of Iran.Totally 39 cockroaches were collected from kitchen area of houses and identified. All specimens were cultured to isolate the bacterial agents on blood agar and MacConky agar media. The microorganisms were identified using necessary differential and biochemical tests. Antimicrobial susceptibility tests were performed for isolated organisms by Kirby-Bauer's disk diffusion according to NCLI guideline, using 18 antibiotics.From the 39 collected S. langipalpa, 179 bacterial agents were isolated, 92 of alimentary ducts and 87 of external body surfaces. Isolated bacteria from cockroaches were identified as Enterobacter spp., Klebsiella spp., Citrobacter spp., Escherichia coli, Salmonella spp., Proteus spp., coagulase negative staphylococci, Serratia marcescens, Staphylococcus aureus, and Bacillus species. The pattern resistance rates were determined for gram negative bacilli and gram positive cocci regarding 18 antibiotics.The brown-banded cockroach can be involved in the spread of drug resistant bacteria and increases the possibility of contacting human environment to drug resistant bacteria. Therefore, the potential of removing this insect should be improved. This is the first original report of drug resistant bacteria isolated from the brown-banded cockroach of Iran.

  19. [Regulating acid stress resistance of lactic acid bacteria--a review].

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-07-04

    As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

  20. Separation of Mercury Resistant Bacteria from Wastewater of Milk, Detergent and Ceramic Industry

    Directory of Open Access Journals (Sweden)

    M. Moghbeli , F. Shakeri and H. Hashemi-Moghaddam

    2011-09-01

    Full Text Available Use of microorganisms for removing mercury is an effective technology for the treatment of industrial wastewaters and can become an effective tool for the remediation of man-impacted coastal ecosystems with this metal. In this study, seven types of mercury resistant bacteria were separated from industrial waste and minimum inhibitory concentration (MIC, were determined for these bacteria. Results showed that two strains of bacteria, which isolated from waste water detergent plants, are more resistant to mercury and able to grow at the presence of 52 ppm of mercuric chloride. These bacteria could be used for biological treatment of mercury in contaminated wastewater.

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

    Science.gov (United States)

    Hatha, A. A. Mohamed; Neethu, C. S.; Nikhil, S. M.; Rahiman, K. M. Mujeeb; Krishnan, K. P.; Saramma, A. V.

    2015-12-01

    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 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.

  2. Motility patterns of filamentous sulfur bacteria, Beggiatoa spp

    DEFF Research Database (Denmark)

    Dunker, Rita; Røy, Hans; Kamp, Anja

    2011-01-01

    The large sulfur bacteria, Beggiatoa spp., live on the oxidation of sulfide with oxygen or nitrate, but avoid high concentrations of both sulfide and oxygen. As gliding filaments, they rely on reversals in the gliding direction to find their preferred environment, the oxygen–sulfide interface.We ...... Beggiatoa accumulate high nitrate concentrations in internal vacuoles as an alternative electron acceptor to oxygen....

  3. Antibiogram pattern of bacteria causing endometritis in cows

    Directory of Open Access Journals (Sweden)

    S. Udhayavel

    2013-04-01

    Full Text Available Aim : To find out the organisms causing endometritis in cattle and to determine their in vitro sensitivity to various antibiotics Materials and methods: Thirty uterine secretion samples, 9 from Holstein Friesian and 21 from Jersey cows were collected in and around Namakkal district of Tamil Nadu from clinical cases of endometritis. The bacteria isolated both aerobically and anaerobically from endometritis showed the characteristic colony, were gram stained and confirmed by standard biochemical tests. The invitro antibiotic sensitivity test with different antibiotic discs were carried out. Results and Discussion: Out of 30 samples, 25 contained different strains of bacteria and 5 were found bacteriologically sterile. Different species of bacteria isolated from these samples were, Escherichia coli (36.66%, Klebsiella spp (30%, Proteus spp (13.33%, Pseudomonas aeruginosa (6.66%, Clostridium spp (3.33%. The in vitro antibiotic sensitivity test indicated that the highest number of isolates (64% were sensitive to Ceftriaxone, followed by Gentamicin, Enrofloxacin and Chlortetracycline (32%. Chloramphenicol showed sensitivity in minimum number (8% of isolates. Conclusion : This study revealed that the bacteria E.coli and Klebisella spp are more commonly isolated in endometritis in cows and the drug Ceftriaxone is highly effective. [Vet World 2013; 6(2.000: 100-102

  4. Distribution and quantification of antibiotic resistant genes and bacteria across agricultural and non-agricultural metagenomes.

    Science.gov (United States)

    Durso, Lisa M; Miller, Daniel N; Wienhold, Brian J

    2012-01-01

    There is concern that antibiotic resistance can potentially be transferred from animals to humans through the food chain. The relationship between specific antibiotic resistant bacteria and the genes they carry remains to be described. Few details are known about the ecology of antibiotic resistant genes and bacteria in food production systems, or how antibiotic resistance genes in food animals compare to antibiotic resistance genes in other ecosystems. Here we report the distribution of antibiotic resistant genes in publicly available agricultural and non-agricultural metagenomic samples and identify which bacteria are likely to be carrying those genes. Antibiotic resistance, as coded for in the genes used in this study, is a process that was associated with all natural, agricultural, and human-impacted ecosystems examined, with between 0.7 to 4.4% of all classified genes in each habitat coding for resistance to antibiotic and toxic compounds (RATC). Agricultural, human, and coastal-marine metagenomes have characteristic distributions of antibiotic resistance genes, and different bacteria that carry the genes. There is a larger percentage of the total genome associated with antibiotic resistance in gastrointestinal-associated and agricultural metagenomes compared to marine and Antarctic samples. Since antibiotic resistance genes are a natural part of both human-impacted and pristine habitats, presence of these resistance genes in any specific habitat is therefore not sufficient to indicate or determine impact of anthropogenic antibiotic use. We recommend that baseline studies and control samples be taken in order to determine natural background levels of antibiotic resistant bacteria and/or antibiotic resistance genes when investigating the impacts of veterinary use of antibiotics on human health. We raise questions regarding whether the underlying biology of each type of bacteria contributes to the likelihood of transfer via the food chain.

  5. Perinatal vertical transmission of antibiotic-resistant bacteria: a systematic review and proposed research strategy.

    Science.gov (United States)

    Seale, J; Millar, M

    2014-07-01

    Antibiotic-resistant bacteria contribute to both early- and late-onset sepsis and outbreaks in neonatal intensive care units (NICUs). The extent to which vertical transmission of these resistant bacteria contributes to colonisation or infection of vulnerable infants in NICUs is unclear. Risk factors for vertical transmission of antibiotic-resistant bacteria are not well described. To identify studies describing vertical transmission of antibiotic-resistant bacteria, risk factors for transmission and the impact of colonisation on neonatal outcomes. EMBASE, CINAHL, Cochrane, PubMed, and MEDLINE databases were searched using selected terminology. Titles and abstracts were screened by two reviewers. Selected papers were reviewed in full by two individuals to ascertain whether they fulfilled the inclusion criteria. Any original article investigating perinatal vertical transmission of antibiotic-resistant bacteria between a mother and neonate was included. Data were extracted on study design, organism, antibiotic resistance, and means of ascertaining vertical transmission. Five papers out of 4839 titles fulfilled the inclusion criteria. Four studies were predominantly observational and one was a case report. Each demonstrated perinatal transmission. No study reported risk factors for the transmission of resistant bacteria or the impact of colonisation on neonatal outcomes. There is an absence of research into the perinatal transmission of resistant organisms despite the potential implications of such a situation. We outline objectives that need to be addressed in future research and describe a study design to ascertain the prevalence and risk factors for vertical transmission. © 2014 Royal College of Obstetricians and Gynaecologists.

  6. Resistance in bacteria of the food chain: epidemiology and control strategies

    DEFF Research Database (Denmark)

    Cavaco, Lina; Aarestrup, Frank Møller

    2013-01-01

    . The emergence and spread of resistant bacteria in the food chain is a major concern as food-producing animals may constitute a huge reservoir for antimicrobial resistance. Furthermore, food animals and food of animal origin is traded worldwide, which means that the occurrences of antimicrobial resistance...... in the food supply of one country is currently potentially a problem for all countries....

  7. Presence of antimicrobial resistance in coliform bacteria from hatching broiler eggs with emphasis on ESBL/AmpC-producing bacteria.

    Science.gov (United States)

    Mezhoud, H; Chantziaras, I; Iguer-Ouada, M; Moula, N; Garmyn, A; Martel, A; Touati, A; Smet, A; Haesebrouck, F; Boyen, F

    2016-08-01

    Antimicrobial resistance is recognized as one of the most important global health challenges. Broilers are an important reservoir of antimicrobial resistant bacteria in general and, more particularly, extended-spectrum β-lactamases (ESBL)/AmpC-producing Enterobacteriaceae. Since contamination of 1-day-old chicks is a potential risk factor for the introduction of antimicrobial resistant Enterobacteriaceae in the broiler production chain, the presence of antimicrobial resistant coliform bacteria in broiler hatching eggs was explored in the present study. Samples from 186 hatching eggs, collected from 11 broiler breeder farms, were inoculated on MacConkey agar with or without ceftiofur and investigated for the presence of antimicrobial resistant lactose-positive Enterobacteriaceae, particularly, ESBL/AmpC-producers. Escherichia coli and Enterobacter cloacae were obtained from the eggshells in 10 out of 11 (10/11) sampled farms. The majority of the isolates were recovered from crushed eggshells after external decontamination suggesting that these bacteria are concealed from the disinfectants in the egg shell pores. Antimicrobial resistance testing revealed that approximately 30% of the isolates showed resistance to ampicillin, tetracycline, trimethoprim and sulphonamides, while the majority of isolates were susceptible to amoxicillin-clavulanic acid, nitrofurantoin, aminoglycosides, florfenicol, neomycin and apramycin. Resistance to extended-spectrum cephalosporins was detected in eight Enterobacteriaceae isolates from five different broiler breeder farms. The ESBL phenotype was confirmed by the double disk synergy test and blaSHV-12, blaTEM-52 and blaACT-39 resistance genes were detected by PCR. This report is the first to present broiler hatching eggs as carriers and a potential source of ESBL/AmpC-producing Enterobacteriaceae for broiler chicks.

  8. Multidrug efflux pumps in Gram-negative bacteria and their role in antibiotic resistance.

    Science.gov (United States)

    Blair, Jessica M A; Richmond, Grace E; Piddock, Laura J V

    2014-01-01

    Gram-negative bacteria express a plethora of efflux pumps that are capable of transporting structurally varied molecules, including antibiotics, out of the bacterial cell. This efflux lowers the intracellular antibiotic concentration, allowing bacteria to survive at higher antibiotic concentrations. Overexpression of some efflux pumps can cause clinically relevant levels of antibiotic resistance in Gram-negative pathogens. This review discusses the role of efflux in resistance of clinical isolates of Gram-negative bacteria, the regulatory mechanisms that control efflux pump expression, the recent advances in our understanding of efflux pump structure and how inhibition of efflux is a promising future strategy for tackling multidrug resistance in Gram-negative pathogens.

  9. Protist-bacteria associations: Gammaproteobacteria and Alphaproteobacteria are prevalent as digestion-resistant bacteria in ciliated protozoa

    Directory of Open Access Journals (Sweden)

    Jun eGong

    2016-04-01

    Full Text Available Protistan bacterivory, a microbial process involving ingestion and digestion, is ecologically important in the microbial loop in aquatic and terrestrial ecosystems. While bacterial resistance to protistan ingestion are relatively well understood, little is known about protistan digestion in which some ingested bacteria could not be digested in cells of major protistan grazers in the natural environment. Here we report the phylogenetic identities of digestion-resistant bacteria (DRB that could survive starvation and form relatively stable associations with 11 marine and one freshwater ciliate species. Using clone library and sequencing of 16S rRNA genes, we found that the protistan predators could host a high diversity of DRB, most of which represented novel bacterial taxa that have not been cultivated. The localization inside host cells, quantity, and viability of these bacteria were checked using fluorescence in situ hybridization. The DRB were affiliated with Actinobacteria, Bacteroidetes, Firmicutes, Parcubacteria (OD1, Planctomycetes, and Proteobacteria, with Gammaproteobacteria and Alphaproteobacteria being the most frequently occurring classes. The dominance of Gamma- and Alphaproteobacteria corresponds well to a previous study of Global Ocean Sampling metagenomic data showing the widespread types of bacterial type VI and IV secretion systems (T6SS and T4SS in these two taxa, suggesting a putatively significant role of secretion systems in promoting marine protist-bacteria associations. In the DRB assemblages, opportunistic bacteria such as Alteromonadaceae, Pseudoalteromonadaceae and Vibrionaceae often presented with high proportions, indicating these bacteria could evade protistan grazing thus persist and accumulate in the community, which, however, contrasts with the well-known rarity of these bacteria in nature. This begs the question whether viral lysis is significant in killing these indigestible bacteria in microbial communities

  10. Surveillance of multidrug resistant suppurative infection causing bacteria in hospitalized patients in an Indian tertiary care hospital

    Institute of Scientific and Technical Information of China (English)

    Nabakishore Nayak; Rajesh K Lenka; Rabindra N Padhy

    2014-01-01

    Objective:To examine antibiograms of a cohort of suppurative bacteria isolated from wound-swabs from hospitalized patients of all economic groups of a typicalIndian teaching hospital. Methods:In surveillance, antibiotic resistance patterns of10 species of suppurative bacteria isolated from wound-swabs over a period of24 months were recorded.Those were subjected to antibiotic sensitivity test, using16 prescribed antibiotics of5 different groups(3 aminoglycosides, 4 beta-lactams,3 cephalosporins,4 fluoroquinolones, and2 stand-alone) in each6-month interval of the study period.Results:Of1156 samples collected,819 samples yielded pathogenic bacteria, of which,Staphylococcus aureus(S. aureus),Streptococcus pyogenes(S. pyogenes), Escherichia coli(E. coli),Pseudomonas aeruginosa(P. aeruginosa),Enterococcus faecalis(E. faecalis), Klebsiella pneumoniae(K. pneumoniae),Acinetobacter baumannii(A. baumannii),Enterobacter aerogenes(E. aerogenes),Proteus mirabilis(P. mirabilis) andProteus vulgaris(P. vulgaris) were isolated in the order of predominance.Isolated bacterial strains were floridly multidrug resistant.Strains ofE. faecalis andS. aureus were found resistant to vancomycin, one of the newly introduced antibiotics.Conclusions:Of theseS. aureus, particularly the methicillin resistant strain predominates, followed by strains ofS. pyogenes andP. aeruginosa that were in the higher proportions of multidrug resistance.

  11. The culturable soil antibiotic resistome: a community of multi-drug resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Fiona Walsh

    Full Text Available Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes. We have identified and characterized multi-drug resistance (MDR mechanisms in the culturable soil antibiotic resistome and linked the resistance profiles to bacterial species. We isolated 412 antibiotic resistant bacteria from agricultural, urban and pristine soils. All isolates were multi-drug resistant, of which greater than 80% were resistant to 16-23 antibiotics, comprising almost all classes of antibiotic. The mobile resistance genes investigated, (ESBL, bla NDM-1, and plasmid mediated quinolone resistance (PMQR resistance genes were not responsible for the respective resistance phenotypes nor were they present in the extracted soil DNA. Efflux was demonstrated to play an important role in MDR and many resistance phenotypes. Clinically relevant Burkholderia species are intrinsically resistant to ciprofloxacin but the soil Burkholderia species were not intrinsically resistant to ciprofloxacin. Using a phenotypic enzyme assay we identified the antibiotic specific inactivation of trimethoprim in 21 bacteria from different soils. The results of this study identified the importance of the efflux mechanism in the soil resistome and variations between the intrinsic resistance profiles of clinical and soil bacteria of the same family.

  12. Identification of Bacteria by Patterns Generated from Odor Spectra

    CERN Document Server

    Chang, Hung-Chih; King, Maria D; Kwan, Chiman

    2009-01-01

    We use the power density spectra obtained by fluctuation-enhanced sensing of bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) to generate new, highly distinguishable, types of patterns based on the average slope of the spectra in different frequency ranges. Such plots can be considered as "fingerprints" of bacterial odors. Three different ways of pattern generation are tested, including a simple binary version. The obtained patterns are simple enough to identify the situation by the naked eye without a pattern recognizer.

  13. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria.

    Science.gov (United States)

    Blaustein, Ryan A; Shelton, Daniel R; Van Kessel, Jo Ann S; Karns, Jeffrey S; Stocker, Matthew D; Pachepsky, Yakov A

    2016-01-01

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hot spot for proliferation and gene exchange. Pipe-based irrigation systems that utilize surface waters may contribute to the dissemination of antibiotic-resistant bacteria in a similar manner. We conducted irrigation events at a perennial stream on a weekly basis for 1 month, and the concentrations of total heterotrophic bacteria, total coliforms, and fecal coliforms, as well as the concentrations of these bacterial groups that were resistant to ampicillin and tetracycline, were monitored at the intake water. Prior to each of the latter three events, residual pipe water was sampled and 6-in. sections of pipeline (coupons) were detached from the system, and biofilm from the inner-wall was removed and analyzed for total protein content and the above bacteria. Isolates of biofilm-associated bacteria were screened for resistance to a panel of seven antibiotics, representing five antibiotic classes. All of the monitored bacteria grew substantially in the residual water between irrigation events, and the biomass of the biofilm steadily increased from week to week. The percentages of biofilm-associated isolates that were resistant to antibiotics on the panel sometimes increased between events. Multiple-drug resistance was observed for all bacterial groups, most often for fecal coliforms, and the distributions of the numbers of antibiotics that the total coliforms and fecal coliforms were resistant to were subject to change from week to week. Results from this study highlight irrigation waters as a potential source for antibiotic-resistant bacteria, which can subsequently become incorporated into and proliferate within irrigation pipe-based biofilms.

  14. Effects of immunonutrition to the pattern and resistance of bacteria isolated from complicated infections in patients with severe acute pancreatitis%免疫营养对重症急性胰腺炎细菌感染的菌谱及耐药性的影响

    Institute of Scientific and Technical Information of China (English)

    李青; 胡瑞钺

    2015-01-01

    目的:探讨免疫营养对重症急性胰腺炎(SAP)患者感染菌的菌群变化和耐药特征的影响。方法随机将68例SAP患者分为肠内免疫营养组(A组)和肠内标准营养组(B组),A组36例接受肠内免疫营养治疗,B组32例接受标准肠内营养治疗,均连续使用15d。统计上述SAP患者腹腔内胰腺与胰腺周围采集的病原菌菌群和耐药性变化。结果 A组共检出病原菌73株,革兰阴性菌57株,其中产ESBLs菌株14株,所占比率为24.6%;B组共检出病原菌75株,革兰阴性菌60株,其中产ESBLs菌株22株,所占比率为36.7%,与A组相比较其产ESBLs菌株的检出率显著增加(P<0.05)。结论重症急性胰腺炎细菌感染以革兰阴性菌为主,免疫营养可以有效降低重症急性胰腺炎细菌感染中产ESBLs菌株的分布。%Objective To investigate the effects of immunonutrition changing pattern of pathogen strains and their resistance to antimicrobial agents in patients with severe acute pancreatitis (SAP). Methods 68 SAP patients were randomly divided into enter-al immunonutrition feeding group (A group) and standard enteral nutrition group (B group). 36 patients in A group received enteral nutrition enriched with arginine and glutamine,while the other 32 patients in B group received a standard enteral nutrition. Nutri-tional support was continued for 15 days,analyzed in order to understand the changing pattern of pathogen strains and their resis-tance to antimicrobial agents. Results There were 73 pathogens be detected in A group,57 (78.1%) were gram-negative bacteria;including 14 ESBLs-positive pathogens,(24.6%). 75 pathogens be detected in B group,60 (80%) were gram-negative bacteria;in-cluding 22 ESBLs-positive pathogens(36.7%). Incidence of ESBLs-positive pathogens in A group was significant decreased than B group(P<0.05). Conclusion Gram-negative bacteria are the major pathogens of infection in SAP patients. Immunonutrition can re

  15. Bloodstream infections in intensive care unit patients: distribution and antibiotic resistance of bacteria

    Directory of Open Access Journals (Sweden)

    Russotto V

    2015-08-01

    Full Text Available Vincenzo Russotto,1 Andrea Cortegiani,1 Giorgio Graziano,2 Laura Saporito,2 Santi Maurizio Raineri,1 Caterina Mammina,2 Antonino Giarratano1 1Department of Biopathology and Medical Biotechnologies (DIBIMED, Section of Anaesthesia, Analgesia, Intensive Care and Emergency, Paolo Giaccone University Hospital, University of Palermo, Palermo, Italy; 2Department of Sciences for Health Promotion and Mother-Child Care, University of Palermo, Palermo, Italy Abstract: Bloodstream infections (BSIs are among the leading infections in critically ill patients. The case-fatality rate associated with BSIs in patients admitted to intensive care units (ICUs reaches 35%–50%. The emergence and diffusion of bacteria with resistance to antibiotics is a global health problem. Multidrug-resistant bacteria were detected in 50.7% of patients with BSIs in a recently published international observational study, with methicillin resistance detected in 48% of Staphylococcus aureus strains, carbapenem resistance detected in 69% of Acinetobacter spp., in 38% of Klebsiella pneumoniae, and in 37% of Pseudomonas spp. Prior hospitalization and antibiotic exposure have been identified as risk factors for infections caused by resistant bacteria in different studies. Patients with BSIs caused by resistant strains showed an increased risk of mortality, which may be explained by a higher incidence of inappropriate empirical therapy in different studies. The molecular genetic characterization of resistant bacteria allows the understanding of the most common mechanisms underlying their resistance and the adoption of surveillance measures. Knowledge of epidemiology, risk factors, mechanisms of resistance, and outcomes of BSIs caused by resistant bacteria may have a major influence on global management of ICU patients. The aim of this review is to provide the clinician an update on BSIs caused by resistant bacteria in ICU patients. Keywords: bloodstream infections, multidrug resistant

  16. Interfamily transfer of a plant pattern-recognition receptor confers broad-spectrum bacterial resistance.

    Science.gov (United States)

    Lacombe, Séverine; Rougon-Cardoso, Alejandra; Sherwood, Emma; Peeters, Nemo; Dahlbeck, Douglas; van Esse, H Peter; Smoker, Matthew; Rallapalli, Ghanasyam; Thomma, Bart P H J; Staskawicz, Brian; Jones, Jonathan D G; Zipfel, Cyril

    2010-04-01

    Plant diseases cause massive losses in agriculture. Increasing the natural defenses of plants may reduce the impact of phytopathogens on agricultural productivity. Pattern-recognition receptors (PRRs) detect microbes by recognizing conserved pathogen-associated molecular patterns (PAMPs). Although the overall importance of PAMP-triggered immunity for plant defense is established, it has not been used to confer disease resistance in crops. We report that activity of a PRR is retained after its transfer between two plant families. Expression of EFR (ref. 4), a PRR from the cruciferous plant Arabidopsis thaliana, confers responsiveness to bacterial elongation factor Tu in the solanaceous plants Nicotiana benthamiana and tomato (Solanum lycopersicum), making them more resistant to a range of phytopathogenic bacteria from different genera. Our results in controlled laboratory conditions suggest that heterologous expression of PAMP recognition systems could be used to engineer broad-spectrum disease resistance to important bacterial pathogens, potentially enabling more durable and sustainable resistance in the field.

  17. Surveillance of Antibiotic-Resistant Bacteria from Wastewater Effluents Across the United States

    Science.gov (United States)

    This presentation will inform the audience of the purpose and importance of the antibiotic resistant bacteria surveillances that have been conducted to date. And an overview of why the EPA is looking into this problem in wastewater effluents.

  18. Surveillance of Antibiotic-Resistant Bacteria from Wastewater Effluents Across the United States

    Science.gov (United States)

    This presentation will inform the audience of the purpose and importance of the antibiotic resistant bacteria surveillances that have been conducted to date. And an overview of why the EPA is looking into this problem in wastewater effluents.

  19. Tolerance to various toxicants by marine bacteria highly resistant to mercury

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Ramaiah, N.; Mesquita, A.; Verlecar, X.N.

    Bacteria highly resistant to mercury isolated from seawater and sediment samples were tested for growth in the presence of different heavy metals, pesticides, phenol, formaldehyde, formic acid, and trichloroethane to investigate their potential...

  20. Antimicrobial resistance of zoonotic and commensal bacteria in Europe: the missing link between consumption and resistance in veterinary medicine.

    Science.gov (United States)

    Garcia-Migura, Lourdes; Hendriksen, Rene S; Fraile, Lorenzo; Aarestrup, Frank M

    2014-05-14

    The emergence of resistance in food animals has been associated to the consumption of antimicrobials in veterinary medicine. Consequently, monitoring programs have been designed to monitor the occurrence of antimicrobial resistant bacteria. This study analyses the amount of antimicrobial agents used in nine European countries from 2005 to 2011, and compares by univariate analysis the correlations between consumptions of each of the following antimicrobial classes; tetracycline, penicillins, cephalosporins, quinolones and macrolides. An overview of resistance in zoonotic and commensal bacteria in Europe focusing on Salmonella, Escherichia coli, Campylobacter sp. and Enterococcus sp., during the same period of time based on monitoring programs is also assessed. With the exception of cephalosporins, linear regressions showed strong positive associations between the consumption of the four different antimicrobial classes. Substantial differences between countries were observed in the amount of antimicrobials used to produce 1 kg of meat. Moreover, large variations in proportions of resistant bacteria were reported by the different countries, suggesting differences in veterinary practice. Despite the withdrawn of a specific antimicrobial from "on farm" use, persistence over the years of bacteria resistant to this particular antimicrobial agent, was still observed. There were also differences in trends of resistance associated to specific animal species. In order to correlate the use of antimicrobial agents to the presence of resistance, surveillance of antimicrobial consumption by animal species should be established. Subsequently, intervention strategies could be designed to minimize the occurrence of resistance.

  1. European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

    DEFF Research Database (Denmark)

    Marques, Cátia; Gama, Luís Telo; Belas, Adriana

    2016-01-01

    of antimicrobial resistant bacteria causing urinary tract infection (UTI) in companion animals in Europe. The antimicrobial susceptibility of 22 256 bacteria isolated from dogs and cats with UTI was determined. Samples were collected between 2008 and 2013 from 16 laboratories of 14 European countries...

  2. Secular Trends in Nosocomial Bloodstream Infections : Antibiotic-Resistant Bacteria Increase the Total Burden of Infection

    NARCIS (Netherlands)

    Ammerlaan, H. S. M.; Harbarth, S.; Buiting, A. G. M.; Crook, D. W.; Fitzpatrick, F.; Hanberger, H.; Herwaldt, L. A.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Kola, A.; Kuchenbecker, R. S.; Lingaas, E.; Meessen, N.; Morris-Downes, M. M.; Pottinger, J. M.; Rohner, P.; dos Santos, R. P.; Seifert, H.; Wisplinghoff, H.; Ziesing, S.; Walker, A. S.; Bonten, M. J. M.

    2013-01-01

    Background. It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. Methods. We investigated temporal trends in annual incidence densit

  3. Endosulfan Resistance Profile of Soil Bacteria and Potential Application of Resistant Strains in Bioremediation

    Directory of Open Access Journals (Sweden)

    Chandini P.K.

    2014-05-01

    Full Text Available In the present study, bacterial strains were isolated from the soils of Wayanad District, Kerala, India and the isolates were tested for their tolerance to endosulfan and potential in bioremediation technology. Pesticide contamination in the soils, soil physico-chemical characteristics and socio-economic impacts of pesticide application were also analyzed. 28 pesticide compounds in the soil samples were analyzed and the results revealed that there was no pesticide residues in the soils. As per the survey conducted the pesticide application is very high in the study area and the level of awareness among the farmers was very poor regarding the method of application and its socio-economic and ecological impacts. A total of 9 bacterial strains were isolated with 50μg/ml of endosulfan in the isolating media and the results showed that most of the bacterial strains were highly resistance to endosulfan. Out of the 9 strains isolated 6 were highly resistant to endosulfan (500- 700μg/ml and the other 3 isolates showed the resistance of 250-500μg/ml. From the studied isolate, isolate 9 demonstrating prolific growth and high resistance was selected to check their capability to degrade endosulfan over time. Identification of the selected strain reveals that it belongs to the genus Bacillus. Results of endosulfan removal studies showed that with increase in time, the biomass of the bacterial strains increased. The complete disappearance of endosulfan from the spiked and inoculated broth during the first day of incubation (24 hour interval was observed. While the control flask showed the presence of endosulfan during the experimental period. Pesticide resistant bacteria are widely distributed in the soils of selected study area and the tolerance varied between bacteria even though they were isolated from the soils of the same area. The selected Bacillus species carry the ability to degrade endosulfan at accelerated rates and it could be useful in framing a

  4. Diversity and antibiotic resistance patterns of Sphingomonadaceae isolates from drinking water.

    Science.gov (United States)

    Vaz-Moreira, Ivone; Nunes, Olga C; Manaia, Célia M

    2011-08-15

    Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water.

  5. Diversity and Antibiotic Resistance Patterns of Sphingomonadaceae Isolates from Drinking Water▿

    Science.gov (United States)

    Vaz-Moreira, Ivone; Nunes, Olga C.; Manaia, Célia M.

    2011-01-01

    Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water. PMID:21705522

  6. Indirect resistance to several classes of antibiotics in cocultures with resistant bacteria expressing antibiotic-modifying or -degrading enzymes.

    Science.gov (United States)

    Nicoloff, Hervé; Andersson, Dan I

    2016-01-01

    Indirect resistance (IR), the ability of an antibiotic-resistant population of bacteria to protect a susceptible population, has been previously observed for β-lactamase-producing bacteria and associated with antimicrobial treatment failures. Here, we determined whether other resistance determinants could cause IR in the presence of five other classes of antibiotics. A test was designed to detect IR and 14 antibiotic resistance genes were tested in the presence of 13 antibiotics from six classes. A bioassay was used to measure the ability of resistance-causing enzymes to decrease the concentration of active antibiotics in the medium. We confirmed IR in the presence of β-lactam antibiotics (ampicillin and mecillinam) when TEM-1A was expressed. We found that bacteria expressing antibiotic-modifying or -degrading enzymes Ere(A), Tet(X2) or CatA1 caused IR in the presence of macrolides (erythromycin and clarithromycin), tetracyclines (tetracycline and tigecycline) and chloramphenicol, respectively. IR was not observed with resistance determinants that did not modify or destroy antibiotics or with enzymes modifying aminoglycosides or degrading fosfomycin. IR was dependent on the resistance enzymes decreasing the concentration of active antibiotics in the medium, hence allowing nearby susceptible bacteria to resume growth once the antibiotic concentration fell below their MIC. IR was not limited to β-lactamase-producing bacteria, but was also caused by resistant bacteria carrying cytoplasmic antibiotic-modifying or -degrading enzymes that catalyse energy-consuming reactions requiring complex cellular cofactors. Our results suggest that IR is common and further emphasizes that coinfecting agents and the human microflora can have a negative impact during antimicrobial therapy. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. [Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

    Science.gov (United States)

    Duszyńska, Wiesława

    2010-01-01

    Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

  8. Patterns of Resistance in Managing Assessment Change

    Science.gov (United States)

    Deneen, Christopher; Boud, David

    2014-01-01

    Achieving change in assessment practices in higher education is difficult. One of the reasons for this is resistance among those responsible for teaching and assessing. This paper seeks to explore this resistance through an analysis of staff dialogue during a major attempt to change the assessment practices at one institution. An institution-wide…

  9. Patterns of Resistance in Managing Assessment Change

    Science.gov (United States)

    Deneen, Christopher; Boud, David

    2014-01-01

    Achieving change in assessment practices in higher education is difficult. One of the reasons for this is resistance among those responsible for teaching and assessing. This paper seeks to explore this resistance through an analysis of staff dialogue during a major attempt to change the assessment practices at one institution. An institution-wide…

  10. Effects of ultraviolet light disinfection on tetracycline-resistant bacteria in wastewater effluents.

    Science.gov (United States)

    Childress, H; Sullivan, B; Kaur, J; Karthikeyan, R

    2014-09-01

    The ubiquitous use of antibiotics has led to an increasing number of antibiotic-resistant bacterial strains, including strains that are multidrug-resistant, pathogenic, or both. There is also evidence to suggest that antibiotic resistance genes (ARGs) spread to the environment, humans, and animals through wastewater effluents. The overall objective of this study was to investigate the effect of ultraviolet (UV) light disinfection on antibiotic-resistant bacteria. Wastewater effluent samples from a wastewater treatment plant (WWTP) in Texas were evaluated for differences in tetracycline-resistant bacteria before and after UV treatment. The effects of photoreactivation or dark repair on the reactivation of bacteria present in WWTP effluent after UV disinfection were also examined. Culture-based methods were used to characterize viable heterotrophic, tetracycline-resistant heterotrophic, Escherichia coli, and tetracycline-resistant E. coli bacteria present before and after UV treatment. UV disinfection was found to be as effective at reducing concentrations of resistant heterotrophs and E. coli, as it was at reducing total bacterial concentrations. The lowest survival ratio following UV disinfection was observed in tetracycline-resistant E. coli showing particular susceptibility to UV treatment. Photoreactivation and dark repair rates were found to be comparable to each other for all bacterial populations.

  11. Isolation and Characterization of Pb Resistant Bacteria from Cilalay Lake, Indonesia

    Directory of Open Access Journals (Sweden)

    Kesi Kurnia

    2015-12-01

    Full Text Available Pollution of water environment with heavy metals is becoming one of the most severe environmental and human health hazards. Lead (Pb is a major pollutant and highly toxic to human, animals, plants, and microbes. Toxic metals are difficult to remove from the environment, since they cannot be chemically or biologically degraded and are ultimately indestructible. Biological approaches based on metal-resistant microorganisms have received a great deal of attention as alternative remediation processes. This study aim to isolate and characterize Pb resistant of heterotrophic bacteria in Cilalay Lake, West Java, Indonesia. The water samples were collected along three points around Cilalay Lake. Water physical and chemical determination was performed using the Water Quality Checker. The bacterial isolates were screened on Triptone Glucose Yeast (TGY agar plates. Afterwards selected isolates were grown on Nutrient Agar media 50% with supplemented Pb 100 ppm by the standard disk. Population of resistant bacteria was counted. The result from metal resistant bacteria indicated that all isolates were resistant. The most abundant type of resistant bacteria to lead was Gram negative more than Gram positive. Identified have metal resistant bacteria could be useful for the bioremediation of heavy metal contaminated sewage and waste water

  12. Low nasal carriage of drug-resistant bacteria among medical students in Vienna

    Science.gov (United States)

    Gualdoni, Guido A.; Lingscheid, Tilman; Tobudic, Selma; Burgmann, Heinz

    2012-01-01

    Background: Multi-drug resistant bacteria are increasing and remain a major public health challenge worldwide. In order to understand the potential role of medical students as a reservoir for circulating pathogenic bacteria and their transmission, we analysed the nasal colonisation among 86 clinically exposed medical students of the Medical University of Vienna, which is integrated into General Hospital of Vienna. Methods: Nasal swabs obtained from 79 students were eligible for further analysis. Nasal swabs were analysed for Gram-positive and Gram-negative bacteria with special emphasis on methicillin-resistant Staphylococcus aureus. Results: 25.3% of participants were positive for Staphylococcus aureus colonization; none of the isolates showed methicillin-resistance or expression of Pantoin-Valentine-leukocidin. However, 2.5% were positive for methicillin-resistant Staphylococcus epidermidis. No participant showed Streptococcus pneumoniae colonisation. Furthermore, 10.1% of the samples displayed growth of Gram-negative bacteria, yet none showed any relevant drug-resistance. Conclusion: In conclusion, our investigation did not reveal any clinically relevant multi-drug resistant bacterial colonisation among clinically exposed medical students in Vienna. This might be explained by well-established hygienic precautions or comparably low circulation of resistant bacteria. PMID:22558038

  13. In Vitro Assessment of the Fitness of Resistant M. tuberculosis Bacteria by Competition Assay.

    Science.gov (United States)

    Gillespie, S H

    2001-01-01

    Bacteria become resistant by a number of different mechanisms, and these include mutation in chromosomal genes (1), acquisition of plasmids (2), insertion of bacteriophage, transposon or insertion sequence DNA (3-5), or gene mosaicism (6). There is a dogma that bacteria that become resistant pay a significant physiological price and that if antimicrobial prescribing is controlled it will result in the eradication of resistant organisms. There are only very few studies that investigate the physiology of resistance acquisition and these do show that a physiological price is paid for this change (7, 8). Once an organism acquires resistance through mutation, acquisition of resistance genes via plasmids, transposons and bacteriophages the initial physiological defect is compensated by the antibiotic selective pressure, which balances the physiological deficit imposed by the resistant mutation or additional DNA (8, 9).

  14. Exploring Post-Treatment Reversion of Antimicrobial Resistance in Enteric Bacteria of Food Animals as a Resistance Mitigation Strategy.

    Science.gov (United States)

    Volkova, Victoriya V; KuKanich, Butch; Riviere, Jim E

    2016-11-01

    Antimicrobial drug use in food animals is associated with an elevation in relative abundance of bacteria resistant to the drug among the animal enteric bacteria. Some of these bacteria are potential foodborne pathogens. Evidence suggests that at least in the enteric nontype-specific Escherichia coli, after treatment the resistance abundance reverts to the background pre-treatment levels, without further interventions. We hypothesize that it is possible to define the distribution of the time period after treatment within which resistance to the administered drug, and possibly other drugs in case of coselection, in fecal bacteria of the treated animals returns to the background pre-treatment levels. Furthermore, it is possible that a novel resistance mitigation strategy for microbiological food safety could be developed based on this resistance reversion phenomenon. The strategy would be conceptually similar to existing antimicrobial drug withdrawal periods, which is a well-established and accepted mitigation strategy for avoiding violative drug residues in the edible products from the treated animals. For developing resistance-relevant withdrawals, a mathematical framework can be used to join the necessary pharmacological, microbiological, and animal production components to project the distributions of the post-treatment resistance reversion periods in the production animal populations for major antimicrobial drug classes in use. The framework can also help guide design of empirical studies into the resistance-relevant withdrawal periods and development of mitigation approaches to reduce the treatment-associated elevation of resistance in animal enteric bacteria. We outline this framework, schematically and through exemplar equations, and how its components could be formulated.

  15. Analysis on the infections change and measures for the multiple drug-resistant bacteria of neurology.

    Science.gov (United States)

    Zang, Wenju

    2016-05-01

    To analyze the bacterial infection situations and the separation situations of multiple drug-resistant bacteria of the neurology of Zhengzhou People's hospital from Feb. 2012 to Dec. 2014. The patients data of neurology were retrieved by means of the doctor workstation system. The infection sites, the classification and drug-resistant feature of bacteria were classified and summarized in Excel. Finally, Compared with the infection sites, the classification and drug-resistant feature of bacteria at different year. The data obtained use SPSS 19.0 software to do statistical analysis. The infection rate of bacteria in neurology from Year 2012 to 2014 declined from 4.99% to 3.41%. But the constitution of the infection sites of bacteria had no significant changes. Staphylococcus aureus still was the majority in the infections of gram-positive bacteria, and Escherichia coli was the majority in the infections of gram-negative bacteria, and there were no significant changes in the ranking of the past three years. The separation rate of Acihetobacter baumanii and Pseudomonas aeruginosa in gram-negative bacteria gradually escalated. There were definite efficiencies in the prevention and control of the bacterial infections in neurology in the past three years. But the situation of prevention and control was still severe at the same time.

  16. Assessment of Antibiotic Resistant Commensal Bacteria in Food

    Science.gov (United States)

    2006-01-01

    to erythromycin. Block cheeses had resistant counts greater than 102 CFU/g. Raw meat products , both raw and cooked shrimps all have resistant...in 1995. Almost half of the losses came from perishable items such as dairy products and fresh fruits and vegetables (22). A number of spoilage ...fermented meats and dairy products (27,47). Several countries in the European community have tracked resistant zoonotic species using non

  17. Antibiotic Resistance Pattern and Biofilm Formation Ability of Clinically Isolates of Salmonella enterica Serotype typhimurium

    Directory of Open Access Journals (Sweden)

    Hadi Ghasemmahdi

    2015-05-01

    Full Text Available Background: The emergence of antimicrobial-resistant bacteria with biofilm formation ability may be a major threat to public health and food safety and sanitation. Objectives: The aim of this study was to determine antibiotic resistance patterns and biofilm production characteristics of Salmonella typhimurium isolated from different species of birds. Materials and Methods: The antibiotic resistance patterns of 38 pre-identified isolates were screened by standard Kirby-Bauer disc-diffusion method performed on Mueller–Hinton agar to a panel of 17 antibiotics. The extent of biofilm formation was measured by Microtiter plate (MTP-based systems. Results: The highest antimicrobial resistance was detected against nalidixic acid (97%, followed by doxycycline (86%, colistin (84%, streptomycin (84% and tetracycline (84%. All isolates were sensitive to amikacin (100% and 97% and 95% of the isolates were sensitive to ceftazidime and ceftriaxone, respectively. Twenty one different antibiotic resistance patterns were observed among S. typhimurium isolates. According to the results of the microtitre plate biofilm assay, there was a wide variation in biofilm forming ability among S. typhimurium isolates. Most of the isolates (60.52% were not capable of producing biofilm, while 26.31%, 7.89%, and 5.26% isolates were weak, strong and moderate biofilm producers, respectively. Conclusions: It was concluded that nearly all S. typhimurium isolates revealed a high multiple antibiotic resistant with low biofilm forming capabilities which proposed low association between biofilm formation and antibiotic resistance of a major food important pathogen.

  18. Evaluation of antibiotic resistance among isolated pathogenic bacteria from shrimp hatcheries in Bushehr province

    Directory of Open Access Journals (Sweden)

    Azam Moghimi

    2014-01-01

    Full Text Available Abstract Background: Rapid development of shrimp aquaculture has resulted in widespread use of antibiotics for preventing and curing diseases. In aquaculture, particularly shrimp hatcheries antibiotics are routinely used at therapeutic levels to treat disease and at sub-therapeutic levels as prophylactic agents to increase feed efficiency. Antibiotic residues in the environment are likely to lead to the development and maintenance of antibiotic resistance in microbial populations. The aim of this study was determine of antibiotic resistance to two shrimp pathogens Vibrio harveyi, V.alginolyticus, that they are agents of mortality in shrimp hatcheries. Material and Methods: After isolation and detection(by biochemical tests of two species of bacterial pathogens from three hatcheries of Bushehr province, bacterial strains were tested for sensitivity to antibiotics including erythromycin, streptomycin, oxytetracyclin, and trimetoprim by disk diffusion method. Results: Results showed that all isolated bacteria Vibrio harveyi from three hatcheries were sensitive to oxytetracyclin and trimetoprim, but to streptomycin were resistant, and to erythromycin in hatcheries A, B, C was intermediate, resistance, sensitive respectively. Bacteria Vibrio alginolyticus isolated from three hatcheries were resistant to streptomycin. But they isolated from a hatchery to the other antibiotics erythromycin, oxytetracyclin and trimetoprim were resistant, intermediate and intermediate, respectively. Also they isolated from B hatchery were resistant, sensitive and sensitive to erythromycin, oxytetracyclin and trimetoprim, respectively And from C hatchery were intermediate, sensitive and sensitive to antibiotics, respectively. Conclusion: Isolated bacteria showed the most resistance to streptomycin and erythromycin respectively. These antibiotics is used frequently in medicine and veterinary, with entrance of human and animal's bacteria resistance via waste and fluid water

  19. Sustainable control of pea bacterial blight : approaches for durable genetic resistance and biocontrol by endophytic bacteria

    NARCIS (Netherlands)

    Elvira-Recuenco, M.

    2000-01-01

    Key-words: bacterial blight, biological control, biodiversity, endophytic bacteria, L-form, pea, PDRl retrotransposon, Pisum sativum, Pisum abyssinicum, Pseudomonas syringae pv. pisi, race specific resistance, race non-specific resistance, Spanish landraces.Pea bacterial blight (Pseudom

  20. Role of shellfish hatchery as a reservoir of antimicrobial resistant bacteria.

    Science.gov (United States)

    Miranda, Claudio D; Rojas, Rodrigo; Garrido, Marcela; Geisse, Julieta; González, Gerardo

    2013-09-15

    The main aim of this study was to determine the occurrence of resistant bacteria in florfenicol-treated and untreated scallop larval cultures from a commercial hatchery and to characterize some selected florfenicol-resistant strains. Larval cultures from untreated and treated rearing tanks exhibited percentages of copiotrophic bacteria resistant to florfenicol ranging from 0.03% to 10.67% and 0.49-18.34%, respectively, whereas florfenicol resistance among oligotrophic bacteria varied from 1.44% to 35.50% and 3.62-95.71%, from untreated and treated larvae, respectively. Florfenicol resistant microbiota from reared scallop larvae mainly belonged to the Pseudomonas and Pseudoalteromonas genus and were mainly resistant to florfenicol, chloramphenicol, streptomycin and co-trimoxazole. This is the first study reporting antimicrobial resistant bacteria associated to a shellfish hatchery and the results suggest that a continuous surveillance of antimicrobial resistance even in absence of antibacterial therapy is urgently required to evaluate potential undesirable consequences on the surrounding environments.

  1. Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patientsinIndian

    Institute of Scientific and Technical Information of China (English)

    Monali Priyadarsini Mishra; Nagen Kumar Debata; Rabindra Nath Padhy

    2013-01-01

    Objective: To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months. Methods: Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer’s disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes. Results: From wards and cabins, 1 245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI. Conclusions: Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae andS. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern.

  2. Paraben resistance in bacteria from sewage treatment plant effluents in India.

    Science.gov (United States)

    Selvaraj, Krishna Kumar; Sivakumar, Senthilkumari; Sampath, Srimurali; Shanmugam, Govindaraj; Sundaresan, Umamaheswari; Ramaswamy, Babu Rajendran

    2013-01-01

    Parabens, the antimicrobial preservatives used in cosmetics, food and pharmaceuticals, are often detected in the aquatic environment. Generally, sewage treatment plants (STPs) receive community sewage containing parabens, which are ultimately released into streams/rivers. In this study, bacteria in STP effluents were evaluated for their resistance to parabens. The susceptibility was in the order of Staphylococcus aureus > Bacillus sp. >Escherichia coli > Pseudomonas aeruginosa. Gram-negative bacteria showed less susceptibility than their control and Gram-positive bacteria. Further, the bacteria were more sensitive towards butyl and ethyl parabens. Interestingly, the strains showed resistance to ≥5 mg of parabens, which is equivalent to or higher than reported environmental concentrations. The increase in paraben chain length did not enhance the susceptibility in all cases and it was understood that the activity may differ for each bacterium in the environment. This is the first profile on paraben resistance in common pathogens of Indian STPs. Paraben resistance may be developed due to continuous exposure even at sub-inhibitory and/or chronic levels in the environment and this resistance may be transferred to other pathogenic bacteria in receiving waters. Thus the study demonstrates the effectiveness of the disc diffusion method in environmental bacterial resistance assessment and addresses the risk involved in the use of parabens.

  3. Exogenous alanine and/or glucose plus kanamycin kills antibiotic-resistant bacteria.

    Science.gov (United States)

    Peng, Bo; Su, Yu-Bin; Li, Hui; Han, Yi; Guo, Chang; Tian, Yao-Mei; Peng, Xuan-Xian

    2015-02-03

    Multidrug-resistant bacteria are an increasingly serious threat to human and animal health. However, novel drugs that can manage infections by multidrug-resistant bacteria have proved elusive. Here we show that glucose and alanine abundances are greatly suppressed in kanamycin-resistant Edwardsiella tarda by GC-MS-based metabolomics. Exogenous alanine or glucose restores susceptibility of multidrug-resistant E. tarda to killing by kanamycin, demonstrating an approach to killing multidrug-resistant bacteria. The mechanism underlying this approach is that exogenous glucose or alanine promotes the TCA cycle by substrate activation, which in turn increases production of NADH and proton motive force and stimulates uptake of antibiotic. Similar results are obtained with other Gram-negative bacteria (Vibrio parahaemolyticus, Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacterium (Staphylococcus aureus), and the results are also reproduced in a mouse model for urinary tract infection. This study establishes a functional metabolomics-based strategy to manage infection by antibiotic-resistant bacteria. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Photodynamic inactivation of antibiotic-resistant bacteria and biofilms by hematoporphyrin monomethyl ether.

    Science.gov (United States)

    Liu, Chengcheng; Hu, Min; Ma, Dandan; Lei, Jin'e; Xu, Jiru

    2016-02-01

    The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. A promising approach to killing antibiotic-resistant bacteria is photodynamic antimicrobial chemotherapy, which uses light in combination with a photosensitizer to induce a phototoxic reaction. We evaluated the photodynamic inactivation (PDI) efficiency of hematoporphyrin monomethyl ether (HMME) on antibiotic-resistant bacteria and biofilms. HMME exhibited no significant dark toxicity and provided dose-dependent inactivation of antibiotic-resistant bacteria and biofilms. After incubation with 100-μM HMME and irradiation with 72-J cm(-2) white light, 4.19-7.59 log10 reductions in survival were achieved in planktonic suspension. Antibiotic-resistant strains were as susceptible to PDI in biofilms as in planktonic suspensions, but the inactivation of bacterial cells in biofilms was attenuated. In addition, gram-positive bacterial strains and biofilms were more susceptible than gram-negative strains and biofilms to the PDI effect of HMME. Thus, HMME is a promising photosensitizer for the treatment of infectious diseases caused by antibiotic-resistant bacteria, especially gram-positive bacteria.

  5. Functional characterization of bacteria isolated from ancient arctic soil exposes diverse resistance mechanisms to modern antibiotics.

    Science.gov (United States)

    Perron, Gabriel G; Whyte, Lyle; Turnbaugh, Peter J; Goordial, Jacqueline; Hanage, William P; Dantas, Gautam; Desai, Michael M

    2015-01-01

    Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes.

  6. The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

    DEFF Research Database (Denmark)

    Guardabassi, L.; Wong, Danilo Lo Fo; Dalsgaard, A.

    2002-01-01

    The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria were investigated in two large-scale municipal treatment plants during a period of six months. Total and relative numbers of resistant bacteria were determined in raw sewage, treated sewage...... by antimicrobial susceptibility testing of Acinetobacter isolates. Based on logistic regression analysis, isolates from treated sewage and digested sludge were generally not significantly more resistant compared with isolates from raw sewage. Based on these evidences, it was concluded that tertiary wastewater...... with a genus-specific DNA probe. Independent of the different antibiotics and media used, the total numbers of resistant bacteria in treated sewage were 10-1000 times lower than in raw sewage. Based on linear regression analysis of data on bacteriological counts, the prevalences of antimicrobial...

  7. Resistance of Causing Bacteria of Bovine Mastitis in Regard to Common Antimicrobials

    Directory of Open Access Journals (Sweden)

    Darío Martínez Pacheco

    2013-05-01

    Full Text Available The bacteria develop resistence against to the common antimicrobians, which is a limitant in the control and treatment of infectious diseases. In the sistems of production of bovine milk, one problem that affects the quantity and quality of the produced milk, is the mastitis, which in most cases has a bacterian origen. Addition to correct milking routine is used many antibacterial agents that for pharmacokinetics and pharmacodynamics reasons are the first selection for this disease. Some cases the use of antibacterial agents is effective, while in other cases do not, due to the development of bacterial resistence. Recently, it has been possible to identify different mechanisms of resistence developed by bacteria. This has allowed pharmacology researchers to create new drugs or to modify existing, seeking to decrease the inefficacy caused by the mutation of the bacteria as an adaptative response mechanism. Therefore,the objective of this review is to offer an updated document on resistance mechanisms identified.

  8. Drug Resistance Mechanisms in Bacteria Causing Sexually Transmitted Diseases and Associated with Vaginosis.

    Science.gov (United States)

    Shaskolskiy, Boris; Dementieva, Ekaterina; Leinsoo, Arvo; Runina, Anastassia; Vorobyev, Denis; Plakhova, Xenia; Kubanov, Alexey; Deryabin, Dmitrii; Gryadunov, Dmitry

    2016-01-01

    Here, we review sexually transmitted diseases (STDs) caused by pathogenic bacteria and vaginal infections which result from an overgrowth of opportunistic bacterial microflora. First, we describe the STDs, the corresponding pathogens and the antimicrobials used for their treatment. In addition to the well-known diseases caused by single pathogens (i.e., syphilis, gonococcal infections, and chlamydiosis), we consider polymicrobial reproductive tract infections (especially those that are difficult to effectively clinically manage). Then, we summarize the biochemical mechanisms that lead to antimicrobial resistance and the most recent data on the emergence of drug resistance in STD pathogens and bacteria associated with vaginosis. A large amount of research performed in the last 10-15 years has shed light on the enormous diversity of mechanisms of resistance developed by bacteria. A detailed understanding of the mechanisms of antimicrobials action and the emergence of resistance is necessary to modify existing drugs and to develop new ones directed against new targets.

  9. Detection of the common resistance genes in Gram-negative bacteria using gene chip technology

    Directory of Open Access Journals (Sweden)

    C Ting

    2013-01-01

    Full Text Available Objective: To design a resistance gene detection chip that could, in parallel, detect common clinical drug resistance genes of Gram-negative bacteria. Materials and Methods: Seventy clinically significant Gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii were collected. According to the known resistance gene sequences, we designed and synthesized primers and probes, which were used to prepare resistance gene detection chips, and finally we hybridized and scanned the gene detection chips. Results: The results between the gene chip and polymerase chain reaction (PCR were compared. The rate was consistently 100% in the eight kinds of resistance genes tested (TEM, SHV, CTX-M, DHA, CIT, VIM, KPC, OXA-23. One strain of Pseudomonas aeruginosa had the IMP, but it was not found by gene chip. Conclusion: The design of Gram-negative bacteria-resistant gene detection chip had better application value.

  10. [Significance of efflux pumps in multidrug resistance of Gram-negative bacteria].

    Science.gov (United States)

    Wiercińska, Olga; Chojecka, Agnieszka; Kanclerski, Krzysztof; Rőhm-Rodowald, Ewa; Jakimiak, Bożenna

    2015-01-01

    The phenomenon of multidrug. resistance of bacteria is a serious problem of modern medicine. This resistance largely is a consequence of abuse and improper use of antibacterial substances, especially antibiotics and chemotherapeutics in hospital settings. Multidrug resistance is caused by a number of interacting mechanisms of resistance. Recent studies have indicated that efflux pumps and systems of efflux pumps are an important determinant of this phenomenon. Contribute to this particular RND efflux systems of Gram-negative bacteria, which possess a wide range of substrates such as antibiotics, dyes, detergents, toxins and active substances of disinfectants and antiseptics. These transporters are usually encoded on bacterial chromosomes. Genes encoding efflux pumps' proteins may also be carried on plasmids and other mobile genetic elements. Such pumps are usually specific to a small group of substrates, but as an additional mechanism of resistance may contribute to the multidrug resistance.

  11. Isolation and identification of cobalt- and caesium-resistant bacteria from a nuclear fuel storage pond.

    Science.gov (United States)

    Dekker, Linda; Osborne, Thomas H; Santini, Joanne M

    2014-10-01

    One of the issues facing the nuclear power industry is how to store spent nuclear fuel which is contaminated with radionuclides produced during nuclear fission, including caesium ((134)Cs(+), (135)Cs(+) and (137)Cs(+)) and cobalt ((60)Co(2+)). In this study, we have isolated Co(2+)- and Cs(+)-resistant bacteria from water collected from a nuclear fuel storage pond. The most resistant Cs(+) and Co(2+) isolates grew in the presence of 500 mM CsCl and 3 mM CoCl2. Strain Cs67-2 is resistant to fourfold more Cs(+) than Cupriavidus metallidurans str. CH34 making it the most Cs(+)-resistant strain identified to date. The Cs(+)-resistant isolates were closely related to bacteria in the Serratia and Yersinia genera, while the Co(2+)-resistant isolates were closely related to the Curvibacter and Tardiphaga genera. These new isolates could be used for bioremediation.

  12. Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria.

    Science.gov (United States)

    Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

    2017-02-28

    Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  13. A five-year antimicrobial resistance pattern observed in

    African Journals Online (AJOL)

    important public health problem, especially in developing countries, where there is substandard ... To our knowledge, no report exists regarding the antibiotic resistance pattern of Shigella species in Gondar region except one in the previous ...

  14. >From branching to nebula patterning during colonial development of the Paenibacillus alvei bacteria

    Science.gov (United States)

    Cohen, Inon; Ron, Ilan G.; Ben-Jacob, Eshel

    2000-10-01

    We present the morphology diagram (morphologies as function of peptone levels and agar concentrations) observed during colonial development of Paenibacillus alvei bacteria. These bacteria are close to Paenibacillus dendritiformis and have been studied extensively in the past. Like P. dendritiformis, P. alvei produces a layer of lubricating fluid for movement on hard surfaces. Unlike P. dendritiformis which attempts to swim on hard surfaces, P. alvei main movement on hard surfaces is swarming, like the movement of P. vortex. Under some growth conditions P. alvei and P. vortex exhibit collective migration of clusters of bacteria and formation of bacterial vortices. Under different growth conditions P. alvei develop branching patterns. P. alvei also develop new class of patterns which we coin “nebula patterns”. Modeling of the new patterns is still an open challenge.

  15. The Structure of Fitness Landscapes in Antibiotic-Resistant Bacteria

    Science.gov (United States)

    Deris, Barrett; Kim, Minsu; Zhang, Zhongge; Okano, Hiroyuki; Hermsen, Rutger; Gore, Jeff; Hwa, Terence

    2014-03-01

    To predict the emergence of antibiotic resistance, quantitative relations must be established between the fitness of drug-resistant organisms and the molecular mechanisms conferring resistance. We have investigated E. coli strains expressing resistance to translation-inhibiting antibiotics. We show that resistance expression and drug inhibition are linked in a positive feedback loop arising from an innate, global effect of drug-inhibited growth on gene expression. This feedback leads generically to plateau-shaped fitness landscapes and concomitantly, for strains expressing at least moderate degrees of drug resistance, gives rise to an abrupt drop in growth rates of cultures at threshold drug concentrations. A simple quantitative model of bacterial growth based on this innate feedback accurately predicts experimental observations without ad hoc parameter fitting. We describe how drug-inhibited growth rate and the threshold drug concentration (the minimum inhibitory concentration, or MIC) depend on the few biochemical parameters that characterize the molecular details of growth inhibition and drug resistance (e.g., the drug-target dissociation constant). And finally, we discuss how these parameters can shape fitness landscapes to determine evolutionary dynamics and evolvability.

  16. Antibiotic Resistance Pattern Of Bacterial Pathogens Isolated From Poultry Manure Used To Fertilize Fish Ponds In New Bussa, Nigeria

    Directory of Open Access Journals (Sweden)

    Funso Omojowo

    2013-02-01

    Full Text Available This study was carried out to isolate and identify antibiotic resistant bacteria from poultry manure usually used for pond fertilization. Poultry manure from 120 Chickens in National Institute for Freshwater Fisheries Research (NIFFR integrated fish farms, New-Bussa, Nigeria was collected. Five bacterial pathogens; Salmonella typhi, Escherichia coli, Shigella dysenteriae, Staphylococcus aureus and Aeromonas hydrophila were isolated. Antibiotic susceptibility testing carried out using the disk diffusion technique. Antibiotics used were; ofloxacin, amoxicillin, tetracycline, ampicillin, erythromycin, gentamicin, nalidixic acid and chloramphenicol. All the isolated organisms were 100% sensitive to ofloxacin. The multiple resistance pattern revealed that 100% were resistant to tetracycline, 84.34% resistant to ampicillin, 76.68% resistant to amoxicillin, 66% resistant to chloramphenicol, 66% resistant to gentamicin, 29% resistant to erythromycin, 28.34% resistant to nalidixic acid. The risk posed by untreated poultry manure used in fish pond fertilization and the public health implications of these results were discussed.

  17. Colonization with Multidrug-Resistant Bacteria – On the Efficiency of Local Decolonization Procedures

    Science.gov (United States)

    Münch, Julia; Hagen, Ralf Matthias; Müller, Martin; Kellert, Viktor; Wiemer, Dorothea Franziska; Hinz, Rebecca; Schwarz, Norbert Georg; Frickmann, Hagen

    2017-01-01

    The effectiveness of a disinfectant-based decolonization strategy for multidrug-resistant bacteria like extended spectrum β-lactamase (ESBL)-positive Gram-negative bacteria with or without additional fluoroquinolon and carbapenem resistance as well as vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus was assessed. Between 2011 and 2015, 25 patients from Libya, Syria, and the Ukraine with war traumata were treated at the Bundeswehr hospital Hamburg. The patients were heavily colonized and infected with multidrug-resistant bacteria, altogether comprising 371 distinct combinations of pathogens and isolation sites. Local disinfection was assessed for effectiveness regarding successful decolonization of multidrug-resistant bacteria. Altogether, 170 cases of successful decolonization were observed, comprising 95 (55.8%) such events at sampling sites that were accessible to disinfecting procedures. The remaining 75 (44.2%) decolonization events had to be considered as spontaneous. In contrast, 95 out of 172 (55.2%) colonized isolation sites that were accessible to disinfection procedures were successfully decolonized. Patient compliance with the enforced hygiene procedures was associated with decolonization success. Systemic antibiotic therapy did not relevantly affect isolation time. Disinfecting washing moderately supports local decolonization of multidrug-resistant pathogens in comparison with spontaneous decolonization rates if the patients’ compliance with the applied hygiene procedures is ensured. PMID:28690877

  18. Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

    Directory of Open Access Journals (Sweden)

    Morfin-Otero Rayo

    2012-06-01

    Full Text Available Abstract Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%, but exhibited lower rates for levofloxacin (18.2% vs 56%. Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%. This finding represents a disturbing development in a common nosocomial and community pathogen.

  19. Emergence of multi drug resistance among soil bacteria exposing to insecticides.

    Science.gov (United States)

    Rangasamy, Kirubakaran; Athiappan, Murugan; Devarajan, Natarajan; Parray, Javid A

    2017-04-01

    Impacts of pesticide exposure on the soil microbial flora and cross resistance to antibiotics have not been well documented. Development of antibiotic resistance is a common issue among soil bacteria which are exposing to pesticides continuously at sub-lethal concentration. The present study was focused to evaluate the correlation between pesticide exposures and evolution of multi drug resistance among isolates collected from soil applied with insecticides. Twenty five insecticide (Monochrotophos) degrading bacteria were isolated from contaminated agricultural soil. The bacterial isolates Bacillus Sps, Bacillus cereus, Bacillus firmus and Bacillus thuringiensis were found to be resistant against chloramphenical, monochrotophos, ampicillin, cefotaxime, streptomycin and tetracycline antibiotics used. Involvement of plasmid in drug as well as insecticide resistant was confirmed through plasmid curing among selected bacterial strains. Bacillus Sps (MK-07), Bacillus cereus (MK-11), Bacillus firmus (MK-13) and Bacillus thuringiensis (MK-24) lost their resistant against insecticides and antibiotics once after removal of plasmid by exposing to 2% sodium dodecyl sulphate. The plasmid was transformed back to bacteria which produced similar derivatives when cultured in Minimal Salt medium (pH 7.0) supplemented with 0.4% of insecticide. Homology modeling was used to prove that organophosphorus hydrolase and able to metabolize all the antibiotics showed positive interaction with high docking score. The present study revealed that persistent of insecticides in the agricultural soil may lead to increasing development of multidrug resistance among soil bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

    Science.gov (United States)

    Hacioglu, Nurcihan; Tosunoglu, Murat

    2014-01-01

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

  1. Acquisition of multidrug-resistant gram-negative bacteria: incidence and risk factors within a long-term care population.

    Science.gov (United States)

    O'Fallon, Erin; Kandel, Ruth; Kandell, Ruth; Schreiber, Robert; D'Agata, Erika M C

    2010-11-01

    An improved understanding of the transmission dynamics of multidrug-resistant (MDR) gram-negative bacteria and the mechanism of acquisition in long-term care facilities (LTCFs) could aid in the development of prevention strategies specific to LTCFs. We thus investigated the incidence of acquisition of these pathogens among an LTCF population. Prospective cohort study. Three separate wards at a 600-bed LTCF in metropolitan Boston, Massachusetts, during the period October 31, 2006, through October 22, 2007. One hundred seventy-two LTCF residents. A series of rectal samples were cultured to determine acquisition of MDR gram-negative bacteria, defined as absence of MDR gram-negative bacterial colonization at baseline and de novo recovery of MDR gram-negative bacteria from a follow-up culture. Molecular typing was performed to identify genetically linked strains. A nested matched case-control study was performed to identify risk factors associated with acquisition. Among 135 residents for whom at least 1 follow-up culture was performed, 52 (39%) acquired at least 1 MDR gram-negative organism during the study period. Thirty-two residents (62%) had not been colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture, and 20 residents (38%) were colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture. The most common coresistance pattern was resistance to extended-spectrum penicillins, ciprofloxacin, and gentamicin (57 isolates [42.5%]). Genetically related strains of MDR gram-negative bacteria were identified among multiple residents and between roommates. On conditional logistic regression analysis, antibiotic exposure during the study period was significantly associated with acquisition of MDR gram-negative bacteria (odds ratio, 5.6 [95% confidence interval, 1.1-28.7]; P = .04). Acquisition of MDR gram-negative bacteria occurred frequently through resident-to-resident transmission. Existing

  2. ANTIMICROBIAL RESISTANCE AMONG ENTERIC BACTERIA ISOLATED FROM HUMAN AND ANIMAL WASTES AND IMPACTED SURFACE WATERS: COMPARISON WITH NARMS FINDINGS

    Science.gov (United States)

    Human infection with bacteria exhibiting mono or multiple antimicrobial resistance (MAR) has been a growing problem in the US, and studies have implicated livestock as a source of MAR bacteria primarily through foodborne transmission routes. However, waterborne transmission of...

  3. Antibiotic resistance in bacteria — an emerging public

    African Journals Online (AJOL)

    Penicillin resistant pneumococci were first reported in Australia and Papua New .... to high ri1ortality. Even in developing countries not at war, political corruption and .... Stability of essential drugs in the field: results of a study conducted ...

  4. (AJST) COMPARISON OF ANTIBIOTIC RESISTANCE PATTERNS ...

    African Journals Online (AJOL)

    methods to ascertain if there is a variation due to human factors. Patients attending two ... Blood specimen was aseptically introduced into brain-heart fusion culture broth and .... this study a small sample size and limited laboratories were involved. ... Resistance: origins, evolution, selection and spread. London: Wiley (Ciba ...

  5. Zinc and copper in animal feed – development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin

    Directory of Open Access Journals (Sweden)

    Siamak Yazdankhah

    2014-09-01

    Full Text Available Farmed animals such as pig and poultry receive additional Zn and Cu in their diets due to supplementing elements in compound feed as well as medical remedies. Enteral bacteria in farmed animals are shown to develop resistance to trace elements such as Zn and Cu. Resistance to Zn is often linked with resistance to methicillin in staphylococci, and Zn supplementation to animal feed may increase the proportion of multiresistant E. coli in the gut. Resistance to Cu in bacteria, in particular enterococci, is often associated with resistance to antimicrobial drugs like macrolides and glycopeptides (e.g. vancomycin. Such resistant bacteria may be transferred from the food-producing animals to humans (farmers, veterinarians, and consumers. Data on dose-response relation for Zn/Cu exposure and resistance are lacking; however, it seems more likely that a resistance-driven effect occurs at high trace element exposure than at more basal exposure levels. There is also lack of data which could demonstrate whether Zn/Cu-resistant bacteria may acquire antibiotic resistance genes/become antibiotics resistant, or if antibiotics-resistant bacteria are more capable to become Zn/Cu resistant than antibiotics-susceptible bacteria. Further research is needed to elucidate the link between Zn/Cu and antibiotic resistance in bacteria.

  6. Identification and antimicrobial susceptibility patterns of bacteria causing otitis externa in dogs.

    Science.gov (United States)

    Zamankhan Malayeri, Hamed; Jamshidi, Shahram; Zahraei Salehi, Taghi

    2010-06-01

    Bacterial agents are considered important pathogens causing external otitis in dogs. It is essential to carry out bacterial culture and antimicrobial susceptibility test in the case of otitis externa, particularly for chronic or recurring cases. Sterile swab samples were obtained from terminal part of vertical ear canals of 74 dogs with otitis externa for cytology, bacterial culture and antimicrobial susceptibility test. Cytologic smears were stained using Gram and Giemsa staining methods. Aerobic bacterial culture performed on blood agar and MacConkey agar. Among total number of 92 isolated bacteria, 68 were Staphylococcus intermedius. Other isolated bacteria included: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Pasteurella canis, and six other species of coagulase-negative Staphylococcus. Antimicrobial susceptibility test were performed for all isolated bacteria using 14 antibiotics. Based on the results of this study, all isolated Staphylococcus spp. were sensitive to amikacin, enrofloxacin, and rifampin, and had low resistance to gentamicin, cephalothin and ceftriaxone. More than half of gram-positive isolates were resistant to penicillin and ampicillin. Generally, all isolated gram-negative bacteria, were sensitive to amikacin and enrofloxacin, and had low resistance to ceftriaxone and gentamicin. They were highly resistant to penicillin, eythromycin, and cephalothin. Regarding the results of this study, in cases of uncomplicated otitis externa, it is possible to select antimicrobial drugs merely based on cytology, but it is recommended to perform bacterial culture and antimicrobial susceptibility test. However, in complicated or refractory cases, antimicrobials should be selected based on bacterial culture and antimicrobial susceptibility test.

  7. Emerging antibiotic resistance in bacteria with special reference to India.

    Science.gov (United States)

    Raghunath, D

    2008-11-01

    The antibiotic era started in the 1940s and changed the profile of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic stress has been realized. The paper presents these subjects briefly to afford an overview. The epidemiology of antibiotic resistance is dealt with and community practices in different countries are described. The role of high antibiotic usage environments is indicated. The implication of the wide use of antibiotics in animals has been pointed out. Steadily increasing antibiotic resistance and decreasing numbers of newer antibiotics appear to point to a post-antibiotic period during which treatment of infections would become increasingly difficult. This article attempts to review the global antimicrobial resistance scene and juxtaposes it to the Indian experience. The prevalence in India of antibiotic resistance among major groups of pathogens is described. The factors that determine the prevalent high antibiotic resistance rates have been highlighted. The future research activity to ensure continued utility of antibiotics in the control of infections has been indicated.

  8. Emerging antibiotic resistance in bacteria with special reference to India

    Indian Academy of Sciences (India)

    D Raghunath

    2008-11-01

    The antibiotic era started in the 1940s and changed the profile of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic stress has been realized. The paper presents these subjects briefly to afford an overview. The epidemiology of antibiotic resistance is dealt with and community practices in different countries are described. The role of high antibiotic usage environments is indicated. The implication of the wide use of antibiotics in animals has been pointed out. Steadily increasing antibiotic resistance and decreasing numbers of newer antibiotics appear to point to a post-antibiotic period during which treatment of infections would become increasingly difficult. This article attempts to review the global antimicrobial resistance scene and juxtaposes it to the Indian experience. The prevalence in India of antibiotic resistance among major groups of pathogens is described. The factors that determine the prevalent high antibiotic resistance rates have been highlighted. The future research activity to ensure continued utility of antibiotics in the control of infections has been indicated.

  9. Antibiotic resistance in bacteria isolated from vegetables with regards to the marketing stage (farm vs. supermarket).

    Science.gov (United States)

    Schwaiger, Karin; Helmke, Katharina; Hölzel, Christina Susanne; Bauer, Johann

    2011-08-15

    The aim of this study was to elucidate whether and to what extent fresh produce from Germany plays a role as a carrier and reservoir of antibiotic resistant bacteria. For this purpose, 1001 vegetables (fruit, root, bulbous vegetables, salads and cereals) were collected from 13 farms and 11 supermarkets in Germany and examined bacteriologically. Phenotypic resistance of Enterobacter cloacae (n=172); Enterobacter gergoviae (n=92); Pantoea agglomerans (n=96); Pseudomonas aeruginosa (n=295); Pseudomonas putida (n=106) and Enterococcus faecalis (n=100) against up to 30 antibiotics was determined by using the microdilution method. Resistance to ß-lactams was most frequently expressed by P. agglomerans and E. gergoviae against cefaclor (41% and 29%). Relatively high resistance rates were also observed for doxycycline (23%), erythromycin (21%) and rifampicin (65%) in E. faecalis, for spectinomycin (28%) and mezlocillin (12%) in E. cloacae, as well as for streptomycin (19%) in P. putida. In P. aeruginosa, relatively low resistance rates were observed for the aminoglycosides amikacin, apramicin, gentamicin, neomycin, netilmicin and tobramycin (4%); 11% was resistant to streptomycin. No glycopeptide-resistant enterococci were observed. Resistance rates of bacteria isolated from farm samples were higher than those of the retail markets whenever significant differences were observed. This suggests that expressing resistance is at the expense of bacterial viability, since vegetables purchased directly at the farm are probably fresher than at the supermarket, and they have not been exposed to stress factors. However, this should not keep the customer from buying directly at the farm, since the overall resistance rates were not higher than observed in bacteria from human or animal origin. Instead, peeling or washing vegetables before eating them raw is highly recommended, since it reduces not only the risk of contact with pathogens, but also that of ingesting and spreading

  10. [Fosfomycin--its significance for treatment of diseases due to multidrug-resistant bacteria].

    Science.gov (United States)

    Stock, Ingo

    2015-01-01

    Fosfomycin is a bactericidal phosphonic acid derivative, which engages by inhibiting pyruvyltransferase at an early stage in the peptidoglycan synthesis. It shows a broad spectrum of activity that includes many multidrug-resistant gram-negative and gram-positive bacteria. Fosfomycin is active against most strains of Pseudomonas aeruginosa and several multidrug-resistant Enterobacteriaceae, e.g., Escherichia coli strains expressing extended spectrum beta-lactamases (ESBL) and Klebsiella pneumoniae strains with decreased susceptibilities to carbapenems. Most methicillin-resistant Staphylococcus aureus (MRSA) strains as well as enterococci with and without vancomycin resistance are also sensitive to fosfomycin. During the last decade, a variety of studies showed that fosfomycin is not only suitable for treating uncomplicated urinary tract diseases, but also for the treatment of many other diseases caused by bacterial pathogens with and without multidrug resistance. However, large controlled studies demonstrating the efficacy of the drug to treat diseases caused by multidrug-resistant bacteria are still missing. Considering the low number of antibacterial agents with good activity against multidrug-resistant bacteria, fosfomycin should be evaluated as an important antibiotic for the treatment of several severe illnesses due to these pathogens. However, because some multidrug-resistant bacteria are also resistant to fosfomycin, this agent should only be applied if the pathogen is sensitive to this drug. In addition, because rapid development of resistance cannot be excluded if fosfomycin will be applied alone, this drug should only be given in combination with other effective drugs for the treatment of serious systemic diseases due to multidrug-resistant bacterial pathogens.

  11. Bacteriocins active against multi-resistant gram negative bacteria implicated in nosocomial infections.

    Science.gov (United States)

    Ghodhbane, Hanen; Elaidi, Sabrine; Sabatier, Jean-Marc; Achour, Sami; Benhmida, Jeannette; Regaya, Imed

    2015-01-01

    Multiresistant Gram-negative bacteria are the prime mover of nosocomial infections. Some are naturally resistant to antibiotics, their genetic makes them insensitive to certain families of antibiotics and they transmit these resistors to their offspring. Moreover, when bacteria are subjected to antibiotics, they eventually develop resistance against drugs to which they were previously sensitive. In recent years, many bacteriocins active against gram-negative bacteria have been identified proving their efficacy in treating infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of bacteriocins acting on the most common infectious gram negative bacteria (Klebsiella, Acinetobacter, Pseudomonas aeruginosa and E. coli).

  12. Multidrug-resistant Gram-negative bacteria: a product of globalization.

    Science.gov (United States)

    Hawkey, P M

    2015-04-01

    Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use.

  13. Transfer of plasmid-mediated resistance to tetracycline in pathogenic bacteria from fish and aquaculture environments.

    Science.gov (United States)

    Guglielmetti, Elena; Korhonen, Jenni M; Heikkinen, Jouni; Morelli, Lorenzo; von Wright, Atte

    2009-04-01

    The transferability of a large plasmid that harbors a tetracycline resistance gene tet(S), to fish and human pathogens was assessed using electrotransformation and conjugation. The plasmid, originally isolated from fish intestinal Lactococcus lactis ssp. lactis KYA-7, has potent antagonistic activity against the selected recipients (Lactococcus garvieae and Listeria monocytogenes), preventing conjugation. Therefore the tetracycline resistance determinant was transferred via electroporation to L. garvieae. A transformant clone was used as the donor in conjugation experiments with three different L. monocytogenes strains. To our knowledge, this is the first study showing the transfer of an antibiotic resistance plasmid from fish-associated lactic bacteria to L. monocytogenes, even if the donor L. garvieae was not the original host of the tetracycline resistance but experimentally created by electroporation. These results demonstrate that the antibiotic resistance genes in the fish intestinal bacteria have the potential to spread both to fish and human pathogens, posing a risk to aquaculture and consumer safety.

  14. Co-occurrence of resistance to different antibiotics among aquatic bacteria

    Directory of Open Access Journals (Sweden)

    Voolaid Veiko

    2012-10-01

    Full Text Available Abstract Background Antibiotic resistance is not confined to pathogens, but is also widespread in various natural environments. In nature the microbes producing antibiotic compounds have been around for millions of years. Heavy use of antibiotics in medicine and veterinary practice may lead to the accumulation of resistance genes in microbial populations, followed by a rise in multiresistant bacteria. Results To test the extent of resistance among aquatic bacteria, we have collected 760 isolates resistant to at least one antibiotic. The phylogeny of the isolates covers a wide range of Proteobacteria, Actinobacteria and Bacteroidetes. In order to determine the extent of multiresistance, the isolates were tested on six antibiotics. As the growth rate of the different bacteria was highly variable, the classical medical resistance tests could not be used, and an alternative method considering the full growth curve was developed. In general, the overall resistances to different antibiotics could be explained by random, independent distribution. An exception to this was the resistances against tetracycline and chloramphenicol, which tended to occur in pairs. Conclusions We conclude that there is no massive spread of multiresistance determinants in the studied environment, although some specific cases can be found, awaiting for molecular characterization of the resistance mechanisms.

  15. Antibacterial activities of ethanol extracts of Philippine medicinal plants against multidrug-resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    Demetrio L Valle Jr; Jeannie I Andrade; Juliana Janet M Puzon; Esperanza C Cabrera; Windell L Rivera

    2015-01-01

    Objective:To investigate the antibacterial activities of crude ethanol extracts of 12 Philippine medicinal plants. Methods:Crude ethanol extracts from 12 Philippine medicinal plants were evaluated for their antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended spectrum β-lactamase-producing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii. Results:The leaf extracts of Psidium guajava, Phyllanthus niruri, Ehretia microphylla and Piper betle (P. betle) showed antibacterial activity against the Gram-positive methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. P. betle showed the highest antibacterial activity for these bacteria in the disk diffusion (16-33 mm inhibition diameter), minimum inhibitory concentration (19-156 μg/mL) and minimum bactericidal concentration (312μg/mL) assays. P. betle leaf extracts only showed remarkable antibacterial activity for all the Gram-negative multidrug-resistant bacteria (extended spectrumβ-lactamase-producing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing) in the disk diffusion (17-21 mm inhibition diameter), minimum inhibitory concentration (312-625μg/mL) and minimum bactericidal concentration (312-625μg/mL) assays. Conclusions:P. betle had the greatest potential value against both Gram-negative and Gram-positive multidrug-resistant bacteria. Favorable antagonistic activities were also exhibited by the ethanol extracts of Psidium guajava, Phyllanthus niruri and Ehretia microphylla.

  16. Outcome of infections due to pandrug-resistant (PDR Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Bliziotis Ioannis A

    2005-04-01

    Full Text Available Abstract Background The increasing problem of infections due to multidrug-resistant Gram-negative bacteria has led to re-use of polymyxins in several countries. However, there are already clinical isolates of Gram-negative bacteria that are resistant to all available antibiotics, including polymyxins. Methods We present a case series of patients with infections due to pathogens resistant to all antimicrobial agents tested, including polymyxins. An isolate was defined as pandrug-resistant (PDR if it exhibited resistance to all 7 anti-pseudomonal antimicrobial agents, i.e. antipseudomonal penicillins, cephalosporins, carbapenems, monobactams, quinolones, aminoglycosides, and polymyxins. Results Clinical cure of the infection due to pandrug-resistant (PDR Gram-negative bacteria, namely Pseudomonas aeruginosa or Klebsiella pneumoniae was observed in 4 out of 6 patients with combination of colistin and beta lactam antibiotics. Conclusion Colistin, in combination with beta lactam antibiotics, may be a useful agent for the management of pandrug-resistant Gram-negative bacterial infections. The re-use of polymyxins, an old class of antibiotics, should be done with caution in an attempt to delay the rate of development of pandrug-resistant Gram-negative bacterial infections.

  17. Patterns and architecture of genomic islands in marine bacteria

    Directory of Open Access Journals (Sweden)

    Fernández-Gómez Beatriz

    2012-07-01

    Full Text Available Abstract Background Genomic Islands (GIs have key roles since they modulate the structure and size of bacterial genomes displaying a diverse set of laterally transferred genes. Despite their importance, GIs in marine bacterial genomes have not been explored systematically to uncover possible trends and to analyze their putative ecological significance. Results We carried out a comprehensive analysis of GIs in 70 selected marine bacterial genomes detected with IslandViewer to explore the distribution, patterns and functional gene content in these genomic regions. We detected 438 GIs containing a total of 8152 genes. GI number per genome was strongly and positively correlated with the total GI size. In 50% of the genomes analyzed the GIs accounted for approximately 3% of the genome length, with a maximum of 12%. Interestingly, we found transposases particularly enriched within Alphaproteobacteria GIs, and site-specific recombinases in Gammaproteobacteria GIs. We described specific Homologous Recombination GIs (HR-GIs in several genera of marine Bacteroidetes and in Shewanella strains among others. In these HR-GIs, we recurrently found conserved genes such as the β-subunit of DNA-directed RNA polymerase, regulatory sigma factors, the elongation factor Tu and ribosomal protein genes typically associated with the core genome. Conclusions Our results indicate that horizontal gene transfer mediated by phages, plasmids and other mobile genetic elements, and HR by site-specific recombinases play important roles in the mobility of clusters of genes between taxa and within closely related genomes, modulating the flexible pool of the genome. Our findings suggest that GIs may increase bacterial fitness under environmental changing conditions by acquiring novel foreign genes and/or modifying gene transcription and/or transduction.

  18. Separation and Molecular Identification of Resistant Bacteria to Lead from Behbahan Bidboland Gas Refinery Wastewater (Iran

    Directory of Open Access Journals (Sweden)

    Azam Mehrbakhsh

    2016-01-01

    Full Text Available Heavy metals are one of the pollution sources in environment. The pollution due to these metals is the problem that could have negative impact on water. Human is faced with these poisons effects due to occupational reasons. The lead is regarded as heavy metal whose industrial applications cause environmental pollution in high rate.The aim of this project was Separation and Molecular Identification of Resistant Bacteria to Lead from Behbahan Bidboland Gas Refinery Wastewater (Iran. For this aim, 6 samples of water and refinery output wastewater is provided after sampling, pH, COD, BOD rates and lead metal primary concentration was determined in wastewaters, after this phase the concentration and separation of resistant bacteria was done to separate them from lead. In this phase the minimum inhibitory concentration was defined from heavy metal growth (MIC. To determine the bacteria identity first the evaluation method of bacteria morphologic and gram staining and then biochemical tests and finally colony-–PCR molecular method was used and then separated bacteria 16S rRNA gen was identified. The obtained results from this research showed that among the separated bacteria from Behbahan Bidboland gas refinery wastewater, the Providencia genous had the most resistant toward Pb. The MIC rate for this bacteria was calculated at 1140 mg/l. the result of this study showed that separated bacteria in this wastewater seemed to have high resistant toward heavy metals due to long encountering to pollution sources and hence they could be proper factor for bioremediation process of heavy metals

  19. Extreme ultraviolet resist materials for sub-7 nm patterning

    KAUST Repository

    Li, Li

    2017-06-26

    Continuous ongoing development of dense integrated circuits requires significant advancements in nanoscale patterning technology. As a key process in semiconductor high volume manufacturing (HVM), high resolution lithography is crucial in keeping with Moore\\'s law. Currently, lithography technology for the sub-7 nm node and beyond has been actively investigated approaching atomic level patterning. EUV technology is now considered to be a potential alternative to HVM for replacing in some cases ArF immersion technology combined with multi-patterning. Development of innovative resist materials will be required to improve advanced fabrication strategies. In this article, advancements in novel resist materials are reviewed to identify design criteria for establishment of a next generation resist platform. Development strategies and the challenges in next generation resist materials are summarized and discussed.

  20. Out of band radiation effects on resist patterning

    Energy Technology Data Exchange (ETDEWEB)

    George, Simi A .; Naulleau, Patrick P.

    2011-03-11

    Our previous work estimated the expected out-of-band (OOB) flare contribution at the wafer level assuming that there is a given amount of OOB at the collector focus. We found that the OOB effects are wavelength, resist, and pattern dependent. In this paper, results from rigorous patterning evaluation of multiple OOB-exposed resists using the SEMATECH Berkeley 0.3-NA MET are presented. A controlled amount of OOB is applied to the resist films before patterning is completed with the MET. LER and process performance above the resolution limit and at the resolution limits are evaluated and presented. The results typically show a negative impact on LER and process performance after the OOB exposures except in the case of single resist formulation, where resolution and performance improvement was observed.

  1. Signatures of Conformational Stability and Oxidation Resistance in Proteomes of Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Anita Vidovic

    2014-06-01

    Full Text Available Protein oxidation is known to compromise vital cellular functions. Therefore, invading pathogenic bacteria must resist damage inflicted by host defenses via reactive oxygen species. Using comparative genomics and experimental approaches, we provide multiple lines of evidence that proteins from pathogenic bacteria have acquired resistance to oxidative stress by an increased conformational stability. Representative pathogens exhibited higher survival upon HSP90 inhibition and a less-oxidation-prone proteome. A proteome signature of the 46 pathogenic bacteria encompasses 14 physicochemical features related to increasing protein conformational stability. By purifying ten representative proteins, we demonstrate in vitro that proteins with a pathogen-like signature are more resistant to oxidative stress as a consequence of their increased conformational stability. A compositional signature of the pathogens’ proteomes allowed the design of protein fragments more resilient to both unfolding and carbonylation, validating the relationship between conformational stability and oxidability with implications for synthetic biology and antimicrobial strategies.

  2. Survival and leaching of Tetracycline resistant bacteria and fecal indicators from manure in field scale experiments

    DEFF Research Database (Denmark)

    Bech, Tina; Amin, Mostofa; Lægdsmand, Mette

    The spreading of manure on agricultural land is an economic and practical solution for improving soil quality; however, animal manure frequently contains zoonotic pathogenic bacteria, such as certain Eschericia coli, Salmonella spp. and Campylobacter spp. The present experiment was conducted...... as a large multidisciplinary project. Pig manure with a natural content of Tetracycline resistant bacteria and fecal indicator organisms was followed in soil columns and a field scale experiment. In the field experiment pig manure was injected into agricultural soil. The distribution and survival of natural...... resistant bacterial species is E. coli. Drainage water from the field sites were collected weekly from one year prior to manure application, where no Tetracycline resistant bacteria were detected. For a period of 11 months following the first manure application, drainage water was sampled proportional...

  3. Disinfectant-resistant bacteria in Buenos Aires city hospital wastewater Resistência bacteriana a desinfetantes em efluentes de um hospital em Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    L. Nuñez

    2007-12-01

    Full Text Available Large quantities of disinfectants are used in hospitals, externally on human skin or to eliminate microorganisms from inanimate objects. After use, residual quantities of these products reach the wastewater, exposing the bacteria that survive in hospital wastewaters to a wide range of biocides that could act as a selective pressure for the development of resistance. Increasing attention has been directed recently to the resistance of bacteria to disinfectants. The aim of this paper was to determine the disinfectant bacterial resistance pattern of the microflora released to the urban sewer system by hospital effluents. The characterization of the waste water microflora was performed by determination of the CFU of heterotrophic bacteria, fecal indicator bacteria, Pseudomonas sp. and Staphylococcus sp., in a Buenos Aires hospital effluent. The bacterial resistance to the disinfectants more frequently used in the hospital practice, glutaraldehyde, chlorhexidine and povidone-iodine, was then evaluated. Disinfectant resistant bacterial strains were isolated and typified. Between 10³ and 10(6 chlorexidine resistant bacteria/100 mL were isolated from the samples. Bacteria resistant to other disinfectants ranged between 10³ and 10(4 /100 mL. The bacterial population resistant to desinfectants to was mainly composed by Enterobacteriaceae, Staphylococcus spp, and Bacillus spp, which are highly associated to nosocomial infections. The results obtained show that the hospital effluents are of importance in the bacterial resistance selection process, particularly in the case of disinfectants.Os hospitais utilizam uma grande quantidade de desinfetantes para eliminar microorganismos tanto da pele humana como de superfícies inanimadas. Após sua utilização, esses produtos podem chegar ao esgoto em quantidades residuais. A pressão seletiva exercida pelos antimicrobianos nos efluentes hospitalares propicia a disseminação de linhagens resistentes. Além dos

  4. Laser thermal ablation of multidrug-resistant bacteria using functionalized gold nanoparticles

    Science.gov (United States)

    Mocan, Lucian; Tabaran, Flaviu A; Mocan, Teodora; Pop, Teodora; Mosteanu, Ofelia; Agoston-Coldea, Lucia; Matea, Cristian T; Gonciar, Diana; Zdrehus, Claudiu; Iancu, Cornel

    2017-01-01

    The issue of multidrug resistance (MDR) has become an increasing threat to public health. One alternative strategy against MDR bacteria would be to construct therapeutic vectors capable of physically damaging these microorganisms. Gold nanoparticles hold great promise for the development of such therapeutic agents, since the nanoparticles exhibit impressive properties, of which the most important is the ability to convert light into heat. This property has scientific significance since is exploited to develop nano-photothermal vectors to destroy bacteria at a molecular level. The present paper summarizes the latest advancements in the field of nanotargeted laser hyperthermia of MDR bacteria mediated by gold nanoparticles. PMID:28356741

  5. Antibiotic Resistant Bacteria--What Everyone Needs To Know.

    Science.gov (United States)

    Pascoe, Neil; Felkner, Marilyn; Maldonado, Maria

    2003-01-01

    Notes the overuse of antibiotics and the resulting resistant bacterial strains. Describes how to control and prevent staphylococcal infections specifically, and almost all infectious diseases generally. Specific sections address: (1) what are staph infections; (2) preventing staph infections; (3) caring for wounds; and (4) controlling staph…

  6. Photoexcited quantum dots for killing multidrug-resistant bacteria

    Science.gov (United States)

    Courtney, Colleen M.; Goodman, Samuel M.; McDaniel, Jessica A.; Madinger, Nancy E.; Chatterjee, Anushree; Nagpal, Prashant

    2016-05-01

    Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Metal nanoparticles can induce cell death, yet the toxicity effect is typically nonspecific. Here, we show that photoexcited quantum dots (QDs) can kill a wide range of multidrug-resistant bacterial clinical isolates, including methicillin-resistant Staphylococcus aureus, carbapenem-resistant Escherichia coli, and extended-spectrum β-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium. The killing effect is independent of material and controlled by the redox potentials of the photogenerated charge carriers, which selectively alter the cellular redox state. We also show that the QDs can be tailored to kill 92% of bacterial cells in a monoculture, and in a co-culture of E. coli and HEK 293T cells, while leaving the mammalian cells intact, or to increase bacterial proliferation. Photoexcited QDs could be used in the study of the effect of redox states on living systems, and lead to clinical phototherapy for the treatment of infections.

  7. Molecular tools for the characterisation of antibiotic-resistant bacteria

    NARCIS (Netherlands)

    Aarts, H.J.M.; Boumedine, K.S.; Nesme, X.; Cloeckaert, A.

    2001-01-01

    This review will discuss a number of molecular tools which are currently used as well as some innovative approaches for the characterisation of antibiotic-resistant bacterial strains. Various methods involved in the detection and characterisation of genes and mutations associated with antibiotic res

  8. Agriculture and food animals as a source of antimicrobial-resistant bacteria

    Directory of Open Access Journals (Sweden)

    Economou V

    2015-04-01

    Full Text Available Vangelis Economou,1 Panagiota Gousia2 1Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece; 2Food-Water Microbiology Unit, Department of Microbiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece Abstract: One of the major breakthroughs in the history of medicine is undoubtedly the discovery of antibiotics. Their use in animal husbandry and veterinary medicine has resulted in healthier and more productive farm animals, ensuring the welfare and health of both animals and humans. Unfortunately, from the first use of penicillin, the resistance countdown started to tick. Nowadays, the infections caused by antibiotic-resistant bacteria are increasing, and resistance to antibiotics is probably the major public health problem. Antibiotic use in farm animals has been criticized for contributing to the emergence of resistance. The use and misuse of antibiotics in farm animal settings as growth promoters or as nonspecific means of infection prevention and treatment has boosted antibiotic consumption and resistance among bacteria in the animal habitat. This reservoir of resistance can be transmitted directly or indirectly to humans through food consumption and direct or indirect contact. Resistant bacteria can cause serious health effects directly or via the transmission of the antibiotic resistance traits to pathogens, causing illnesses that are difficult to treat and that therefore have higher morbidity and mortality rates. In addition, the selection and proliferation of antibiotic-resistant strains can be disseminated to the environment via animal waste, enhancing the resistance reservoir that exists in the environmental microbiome. In this review, an effort is made to highlight the various factors that contribute to the emergence of antibiotic resistance in farm animals and to

  9. Efficacy of surface disinfectant cleaners against emerging highly resistant gram-negative bacteria.

    Science.gov (United States)

    Reichel, Mirja; Schlicht, Anastasija; Ostermeyer, Christiane; Kampf, Günter

    2014-05-28

    Worldwide, the emergence of multidrug-resistant gram-negative bacteria is a clinical problem. Surface disinfectant cleaners (SDCs) that are effective against these bacteria are needed for use in high risk areas around patients and on multi-touch surfaces. We determined the efficacy of several SDCs against clinically relevant bacterial species with and without common types of multidrug resistance. Bacteria species used were ATCC strains; clinical isolates classified as antibiotic-susceptible; and multi-resistant clinical isolates from Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens (all OXA-48 and KPC-2); Acinetobacter baumannii (OXA-23); Pseudomonas aeruginosa (VIM-1); and Achromobacter xylosoxidans (ATCC strain). Experiments were carried out according to EN 13727:2012 in quadruplicate under dirty conditions. The five evaluated SDCs were based on alcohol and an amphoteric substance (AAS), an oxygen-releaser (OR), surface-active substances (SAS), or surface-active-substances plus aldehydes (SASA; two formulations). Bactericidal concentrations of SDCs were determined at two different contact times. Efficacy was defined as a log10 ≥ 5 reduction in bacterial cell count. SDCs based on AAS, OR, and SAS were effective against all six species irrespective of the degree of multi-resistance. The SASA formulations were effective against the bacteria irrespective of degree of multi-resistance except for one of the four P. aeruginosa isolates (VIM-1). We found no general correlation between SDC efficacy and degree of antibiotic resistance. SDCs were generally effective against gram-negative bacteria with and without multidrug resistance. SDCs are therefore suitable for surface disinfection in the immediate proximity of patients. Single bacterial isolates, however, might have reduced susceptibility to selected biocidal agents.

  10. Recent investigations and updated criteria for the assessment of antibiotic resistance in food lactic acid bacteria.

    Science.gov (United States)

    Clementi, Francesca; Aquilanti, Lucia

    2011-12-01

    The worldwide use, and misuse, of antibiotics for about sixty years in the so-called antibiotic era, has been estimated in some one to ten million tons, a relevant part of which destined for non-therapeutic purposes such as growth promoting treatments for livestock or crop protection. As highly adaptable organisms, bacteria have reacted to this dramatic change in their environment by developing several well-known mechanisms of antibiotic resistance and are becoming increasingly resistant to conventional antibiotics. In recent years, commensal bacteria have become a cause of concern since they may act as reservoirs for the antibiotic resistance genes found in human pathogens. In particular, the food chain has been considered the main route for the introduction of animal and environment associated antibiotic resistant bacteria into the human gastrointestinal tract (GIT) where these genes may be transferred to pathogenic and opportunistic bacteria. As fundamental microbial communities in a large variety of fermented foods and feed, the anaerobe facultative, aerotolerant lactic acid bacteria (LAB) are likely to play a pivotal role in the resistance gene exchange occurring in the environment, food, feed and animal and human GIT. Therefore their antibiotic resistance features and their genetic basis have recently received increasing attention. The present article summarises the results of the latest studies on the most typical genera belonging to the low G + C branch of LAB. The evolution of the criteria established by European regulatory bodies to ensure a safe use of microorganisms in food and feed, including the assessment of their antibiotic resistance is also reviewed.

  11. Frequency of Bacterial Contamination and Antibiotic Resistance Patterns in Devices and in Personnel of Endoscopy and Colonoscopy Units

    Directory of Open Access Journals (Sweden)

    Torabi, P. (BSc

    2014-06-01

    Full Text Available Background and Objective: This study was aimed to determine the extent of bacterial contamination and drug resistance patterns of isolates colonized in colonoscope and endoscope and in relevant personnel. Material and Methods: A total of 107 samples were obtained from staff of endoscopy and colonoscopy units (SEU and SCU and gastroenterological imaging equipment. For isolation and identification of the bacteria, swab culture method and biochemical identification test were used, respectively. Antimicrobial resistance profiles, multi-drug resistance (MDR patterns and phenetic relatedness of these isolates were also analyzed according to standard methods. Results: Most frequent pathogenic bacteria among the SEU and gastroenterological imaging related equipments were included S. aureus (20.8 % and 0 %; Enterococcus spp. (0 % and 5.4%; Pseudomonas spp. (0% and 13.5 %, and Clostridium difficile (0% and 12.5%. Analysis of resistance phenotypes showed a high frequency of MDR phenotypes among the SEU (82.1%, and also in endoscopes, colonoscopes, and other equipments (20%, 50% and 100%, respectively. Phylotyping of S. epidermidis isolates showed the role of staff in transmission of resistance strains to medical equipments and also circulation of strains with identical resistance phenotype among the studied samples. Conclusion: High frequency of pathogenic bacteria in colonoscopes, endoscopes and in the staff of endoscopy & colonoscopy units, and also contamination of these instruments with MDR pathogens emphasize the need for proper disinfection of endoscopes and colonoscopes and also instruction of staff in these units. Key words: Bacterial Contamination; Endoscope; Colonoscope; Antimicrobial Resistance; Gastrointestinal Disease.

  12. Nisin and class IIa bacteriocin resistance among Listeria and other foodborne pathogens and spoilage bacteria.

    Science.gov (United States)

    Kaur, Gurpreet; Malik, Ravinder Kumar; Mishra, Santosh Kumar; Singh, Tejinder Pal; Bhardwaj, Arun; Singroha, Garima; Vij, Shilpa; Kumar, Naresh

    2011-06-01

    Food safety has been an important issue globally due to increasing foodborne diseases and change in food habits. To inactivate foodborne pathogens, various novel technologies such as biopreservation systems have been studied. Bacteriocins are ribosomally synthesized peptides or proteins with antimicrobial activity produced by different groups of bacteria, but the bacteriocins produced by many lactic acid bacteria offer potential applications in food preservation. The use of bacteriocins in the food industry can help reduce the addition of chemical preservatives as well as the intensity of heat treatments, resulting in foods that are more naturally preserved. However, the development of highly tolerant and/or resistant strains may decrease the efficiency of bacteriocins as biopreservatives. Several mechanisms of bacteriocin resistance development have been proposed among various foodborne pathogens. The acquiring of resistance to bacteriocins can significantly affect physiological activity profile of bacteria, alter cell-envelope lipid composition, and also modify the antibiotic susceptibility/resistance profile of bacteria. This article presents a brief review on the scientific research about the various possible mechanisms involved in the development of resistance to nisin and Class IIa bacteriocins among the foodborne pathogens.

  13. Chromium Resistant Bacteria: Impact on Plant Growth in Soil Microcosm

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    Sayel Hanane

    2014-07-01

    Full Text Available Three chromium resistant bacterial strains, Pseudomonas fluorescens PF28, Enterobacter amnigenus EA31 and Enterococcus gallinarum S34 isolated from tannery waste contaminated soil were used in this study. All strains could resist a high concentration of K2Cr2O7 that is up to 300 mg/L. The effect of these strains on clover plants (Trifolium campestre in the presence of two chromium salts CrCl3 and K2Cr2O7 was studied in soil microcosm. Application of chromium salts adversely affected seed germination, root and shoot length. Bacterial inoculation improved the growth parameters under chromate stress when compared with non inoculated respective controls. There was observed more than 50% reduction of Cr(VI in inoculated soil microcosms, as compared to the uninoculated soil under the same conditions. The results obtained in this study are significant for the bioremediation of chromate pollution.

  14. Emerging antibiotic resistance in bacteria with special reference to India

    OpenAIRE

    Raghunath, D.

    2008-01-01

    The antibiotic era started in the 1940s and changed the profi le of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic s...

  15. Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004: the ARBAO-II study

    DEFF Research Database (Denmark)

    Hendriksen, Rene S.; Mevius, Dik J; Schroeter, Andreas

    2008-01-01

    of resistance was lower. Conclusion: Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to several antimicrobial agents in different countries. The occurrence of resistance varied distinctly between isolates from healthy and diseased pigs......Background: The project "Antibiotic resistance in bacteria of animal origin - II" (ARBAO-II) was funded by the European Union (FAIR5-QLK2-2002-01146) for the period 2003-05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility......, with the isolates from healthy pigs generally showing a lower level of resistance than those from diseased pigs. The study suggests that the choice of antimicrobials used for the treatment of diseased animals should preferably be based on knowledge of the local pattern of resistance....

  16. Antimicrobial metallopolymers and their bioconjugates with conventional antibiotics against multidrug-resistant bacteria.

    Science.gov (United States)

    Zhang, Jiuyang; Chen, Yung Pin; Miller, Kristen P; Ganewatta, Mitra S; Bam, Marpe; Yan, Yi; Nagarkatti, Mitzi; Decho, Alan W; Tang, Chuanbing

    2014-04-02

    Bacteria are now becoming more resistant to most conventional antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), a complex of multidrug-resistant Gram-positive bacterial strains, has proven especially problematic in both hospital and community settings by deactivating conventional β-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, through various mechanisms, resulting in increased mortality rates and hospitalization costs. Here we introduce a class of charged metallopolymers that exhibit synergistic effects against MRSA by efficiently inhibiting activity of β-lactamase and effectively lysing bacterial cells. Various conventional β-lactam antibiotics, including penicillin-G, amoxicillin, ampicillin, and cefazolin, are protected from β-lactamase hydrolysis via the formation of unique ion-pairs between their carboxylate anions and cationic cobaltocenium moieties. These discoveries could provide a new pathway for designing macromolecular scaffolds to regenerate vitality of conventional antibiotics to kill multidrug-resistant bacteria and superbugs.

  17. Antimicrobial resistance among pathogenic bacteria from mink (Neovison vison) in Denmark

    DEFF Research Database (Denmark)

    Nikolaisen, Nanett Kvist; Lassen, Desireé Corvera Kløve; Chriél, Mariann

    2017-01-01

    of antimicrobial resistance among pathogenic bacteria isolated from Danish mink during the period 2014-2016. The aim of this investigation was to provide data on antimicrobial resistance and consumption, to serve as background knowledge for new veterinary guidelines for prudent and optimal antimicrobial usage...... of resistance to tetracycline and erythromycin. The antimicrobial consumption increased significantly during 2007-2012, and fluctuated at a high level during 2012-2016, except for a temporary drop in 2013-2014. The majority of the prescribed antimicrobials were aminopenicillins followed by tetracyclines...... and macrolides. Conclusions: The study showed that antimicrobial resistance was common in most pathogenic bacteria from mink, in particular hemolytic E. coli. There is a need of guidelines for prudent use of antimicrobials for mink....

  18. Prevalence of antibiotic-resistant bacteria in three different aquatic environments over three seasons.

    Science.gov (United States)

    Mohanta, Tandra; Goel, Sudha

    2014-08-01

    The objective of this study was to evaluate the impact of urbanization and seasonal changes on the prevalence of antibiotic-resistant bacteria in different aqueous environments. To this end, bacteria were isolated from three different water sources: the River Hooghly in Kolkata, River Kangsabati and groundwater from Kharagpur, West Bengal over three seasons: post-monsoon, winter and summer in 2012-2013. A total of 163 Gram-negative bacteria were isolated from the River Hooghly (n = 138), River Kangsabati (n = 13) and groundwater (n = 12). Antibiotic susceptibility testing was done using 12 antibiotic discs. The percentages of multiple antibiotic-resistant (MAR) bacteria at the three sampling locations were found to be 71.01 % (98/138) for River Hooghly, 15.38 % (2/13) for River Kangsabati and 8.33 % (1/12) for groundwater. Prevalence of MAR bacteria with respect to the three seasons were the following: 73.58 % in post-monsoon, 59.26 % in winter and 53.57 % in summer. Antibiotic resistance index (ARI) was calculated for each location and each season. In general, ARI values for all the River Hooghly samples were >0.2 while those for the River Kangsabati and groundwater in Kharagpur were always resistance in bacteria from the River Hooghly compared to the other two locations. In addition, percentage of MAR and ARI values followed the trend: post-monsoon > winter > summer. This may be due to the additional terrestrial resistants that get swept along with surface runoff during the monsoons.

  19. Multidrug Resistance in Quinolone-Resistant Gram-Negative Bacteria Isolated from Hospital Effluent and the Municipal Wastewater Treatment Plant.

    Science.gov (United States)

    Vaz-Moreira, Ivone; Varela, Ana Rita; Pereira, Thamiris V; Fochat, Romário C; Manaia, Célia M

    2016-03-01

    This study is aimed to assess if hospital effluents represent an important supplier of multidrug-resistant (MDR) Gram-negative bacteria that, being discharged in the municipal collector, may be disseminated in the environment and bypassed in water quality control systems. From a set of 101 non-Escherichia coli Gram-negative bacteria with reduced susceptibility to quinolones, was selected a group of isolates comprised by those with the highest indices of MDR (defined as nonsusceptibility to at least one agent in six or more antimicrobial categories, MDR ≥6) or resistance to meropenem or ceftazidime (n = 25). The isolates were identified and characterized for antibiotic resistance phenotype, plasmid-mediated quinolone resistance (PMQR) genes, and other genetic elements and conjugative capacity. The isolates with highest MDR indices were mainly from hospital effluent and comprised ubiquitous bacterial groups of the class Gammaproteobacteria, of the genera Aeromonas, Acinetobacter, Citrobacter, Enterobacter, Klebsiella, and Pseudomonas, and of the class Flavobacteriia, of the genera Chryseobacterium and Myroides. In this group of 25 strains, 19 identified as Gammaproteobacteria harbored at least one PMQR gene (aac(6')-Ib-cr, qnrB, qnrS, or oqxAB) or a class 1 integron gene cassette encoding aminoglycoside, sulfonamide, or carbapenem resistance. Most of the E. coli J53 transconjugants with acquired antibiotic resistance resulted from conjugation with Enterobacteriaceae. These transconjugants demonstrated acquired resistance to a maximum of five classes of antibiotics, one or more PMQR genes and/or a class 1 integron gene cassette. This study shows that ubiquitous bacteria, other than those monitored in water quality controls, are important vectors of antibiotic resistance and can be disseminated from hospital effluent to aquatic environments. This information is relevant to support management options aiming at the control of this public health problem.

  20. Emergence and Spread of A Plasmid-Mediated Polymyxin Resistance Mechanism, MCR-1: Are Bacteria Winning?

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2015-12-01

    regions of the world, especially in those where the use of colistin is extensive. Understanding the distribution of mcr-1 throughout the world will help us formulate good practice in the application of antibiotics. We must also closely monitor the multidrug-resistant, extensively-drug-resistant, and pandrug-resistant bacteria that acquire mcr-1. In the battle against pathogenic bacteria, antibiotics have played an essential role in saving lives. However, bacteria are sufficiently smart to develop a variety of antibiotic resistance mechanisms to protect themselves. Humans and bacteria are both severely challenged in this life-and-death struggle. The development of new strategies with which to combat pathogenic bacteria is a long-term and difficult task.

  1. Distribution Pattern of Photosynthetic Picoplankton and Heterotrophic Bacteria in the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Yu-Ming Cai; Xiu-Ren Ning; Cheng-Gang Liu; Qiang Hao

    2007-01-01

    The environmental regulation of picoplankton distribution in the northern South China Sea was examined in winter and summer of 2004. The average abundance of Synechococcus, Prochlorococcus, and heterotrophic bacteria was lower in winter (30, 21, and 780×103 cells/cm3, respectively) than in summer (53, 85, and 1 090×103 cells/cm3,respectively), but the seasonal pattern was opposite for plcoeukaryotic phytoplankton (4 500 and 3 200 cells/cm3 in winter and summer, respectively). Synechococcus, picoeukaryotes, and bacteria were most abundant in the nutrient-rich coastal zone and continental shelf, but Prochlorococcus was most abundant in the continental slope and open ocean. The vertical distribution of each photosynthetic group and heterotrophic bacteria changed between the two seasons. Synechococcus populations with apparently different phycoerythrobilln content occurred at many stations in the summer. In addition, two different populations of Prochlorococcus were found: (i) small, weakly fluorescing cells in the surface layer; and (ii) larger, strongly fluorescent cells in the deep layer. The distribution pattern of photosynthetic picoplankton and heterotrophic bacteria depends on environmental effects and their ecophysiological differences. The distribution of Synechococcus appeared to be related to nutrient availability,whereas the distribution of Prochlorococcus appeared to be limited by temperature. Synechococcus was the only picophytoplankton with a consistent strong relationship with bacteria.

  2. A Survey of the Epidemiology and Antibiotic Resistance Patterns of Enteropathogens Isolates in an Iranian Hospital

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    Mirjafari Tafti

    2016-02-01

    Full Text Available Background Infectious diarrhea is one of the most frequent diseases among children, especially in developing countries. Objectives The aim of this study was to determine the etiological agents and drug resistance patterns of common enteric pathogens isolated in an Iranian 1000-bed tertiary care hospital. Patients and Methods In a retrospective study, we analyzed the etiology and drug resistance patterns of enteric pathogens associated with diarrheal cases. The study was carried out in the Milad hospital of Tehran over two years, from April of 2012 to January of 2014. Stool specimens from patients with diarrhea (n = 7321 were examined for enteric pathogens using routine microbiological culture methods. Strains of Salmonella, Shigella, and enteric pathogenic E. coli (EPEC were serotyped and their susceptibility to commonly used antimicrobial agents was determined by a disk diffusion method, as recommended by the clinical and laboratory standards institute (CLSI guidelines. Results Enteric pathogens were isolated from 310 (4.23% of the patients. The most frequently isolated microorganisms included enteropathogenic E. coli (EPEC, Salmonella, and Shigella spp. The majority of the isolates of EPEC were resistant to commonly used antibiotics such as ampicillin (85.61%, cefixime (79.41%, and nalidixic acid. Resistance among other enteric pathogens was also prevalent. About 45.70% of the Salmonella isolates were resistant to chloramphenicol, and 87.95% were resistant to sulfamethoxazole/trimethoprim. Resistance of the Shigella isolates to nalidixic acid in comparison to the resistance recorded in previous studies was higher. Conclusions The results show that enteric bacteria, including EPEC, Salmonella spp., and Shigella spp. are the major causative agents of diarrhea in the hospital. The emergence of antimicrobial resistance among enteric pathogens is an important problem for public health. Considering the threat of emerging antimicrobial resistance

  3. Is screening patients for antibiotic-resistant bacteria justified in the Indian context?

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    S Bhattacharya

    2011-01-01

    Full Text Available Infection with multi-antibiotic-resistant bacteria is a common clinical problem in India. In some countries and centres, screening patients to detect colonisation by these organisms is used to determine specific interventions such as decolonisation treatment, prophylactic antibiotics prior to surgical interventions or for selection of empirical antibiotic therapy, and to isolate patients so that transmission of these difficult to treat organisms to other patients could be prevented. In India, there is no national guideline or recommendation for screening patients for multi-drug-resistant (MDR bacteria such as MRSA (methicillin-resistant Staphylococcus aureus, VRE (vancomycin-resistant enterococcus, ESBL (extended spectrum beta-lactamase or MBL (metallo-beta-lactamase producers. The present article discusses the relevance of screening patients for multi-antibiotic-resistant bacteria in the Indian context. Literature has been reviewed about antibiotic resistance in India, screening methodology, economic debate about screening. The percentages of strains from various hospitals in India which were reported to be MRSA was between 8 and 71%, those for ESBL between 19 and 60% and carbapenem-resistant Gram-negative bacilli between 5.3 and 59%. There exists culture-based technology for the detection of these resistant organisms from patient samples. For some pathogens, such as MRSA and VRE Polymerase chain reaction-based tests are also becoming available. Screening for MDR bacteria is an option which may be used after appraisal of the resources available, and after exploring possibility of implementing the interventions that may be required after a positive screening test result.

  4. Screening of antibiotic resistance determinants in Gram-negative bacteria isolated from environmental reservoirs

    OpenAIRE

    Carvalho, Sofia Rêgo de, 1988-

    2011-01-01

    Tese de mestrado. Biologia (Microbiologia Aplicada). Universidade de Lisboa, Faculdade de Ciências, 2011 Antibiotics are one of the most successful forms of chemotherapy and saved million of lives placing most bacterial infectious diseases under control. However, this success has been compromised the continuous selective pressure exerted by antibiotics use has resulted in multi-resistance bacteria bearing resistance mechanisms to several antibiotics. Nowadays, there is an increased recogni...

  5. Ciprofloxacin usage and bacterial resistance patterns in Crohn's disease patients with abscesses.

    Science.gov (United States)

    Park, Soo-Kyung; Kim, Kyung-Jo; Lee, Sang-Oh; Yang, Dong-Hoon; Jung, Kee Wook; Duk Ye, Byong; Byeon, Jeong-Sik; Myung, Seung-Jae; Yang, Suk-Kyun; Kim, Jin-Ho; Sik Yu, Chang

    2014-09-01

    Ciprofloxacin is the antibiotic most frequently used in the treatment of Crohn's disease (CD). We attempted to identify the microorganisms present in CD-related intra-abdominal abscesses, their ciprofloxacin resistance patterns, and the clinical impact. Microorganisms, their ciprofloxacin resistance, and clinical outcomes were retrospectively analyzed in 78 CD patients with intra-abdominal abscesses, who underwent percutaneous drainage between March 1991, and November 2011. The median time from diagnosis of CD to abscess drainage was 59.5 months (range, 1 to 178 mo). As for bacteriology, the no-growth proportion was 38.5% (n=30), and 69 microorganisms belonging to 11 genera were isolated from the other 48 (61.5%) patients. Of the 69 microorganisms, 65 were bacteria, including 30 (43.4%) gram-positive, 28 (40.6%) gram-negative aerobes, 7 (10.1%) gram-negative anaerobes, and 4 (4.1%) fungi. Streptococci spp. (25, 36.2%) were the most common bacteria, followed by Escherichia coli (18, 26.1%). Nineteen of the 28 gram-negative aerobes (67.9%) were resistant to ciprofloxacin, including 14 of 18 (77.8%) E. coli isolates. When we compared clinical characteristics and treatment outcomes in 17 patients with ciprofloxacin-resistant and 8 with ciprofloxacin-sensitive bacteria, we found that disease duration from diagnosis to drainage (97.2 vs. 50.7 mo, P=0.03) and median length of hospitalization (40 vs. 31 d, P=0.03) was significantly longer in the former. When gram-negative aerobes were isolated from abscesses in CD patients, more than two thirds were resistant to ciprofloxacin. Providers should consider this high rate of ciprofloxacin resistance when choosing first-line antibiotic treatment for CD-related intra-abdominal abscesses.

  6. Novel pollutant-resistant methylotrophic bacteria for use in bioremediation.

    Science.gov (United States)

    De Marco, Paolo; Pacheco, Catarina C; Figueiredo, Ana Rita; Moradas-Ferreira, Pedro

    2004-05-01

    Thirty one novel methylotrophic bacterial strains were isolated from a range of soil and sediment sources (both pristine and polluted) under different enrichment regimes. They were characterised physiologically and classified by their 16S rRNA gene sequence. A great taxonomical and phenotypical variety was recovered. Some of the isolates display interesting features of resistance to heavy metals, arsenate or organic pollution and four can be considered real 'super-bugs' for their ability to withstand extremely high concentrations of a variety of pollutants. A description of the 31 strains is presented in this work.

  7. Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian

    Institute of Scientific and Technical Information of China (English)

    Monali; Priyadarsini; Mishra; Nagen; Kumar; Debata; Rabindra; Nath; Padhy

    2013-01-01

    Objective:To record surveillance,antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months.Methods:Urine samples from wards and cabins were used for isolating urinary tract infection(UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests;and their antibiograms were ascertained by Kirby-Bauer’s disc diffusion method,in each 6-month interval of the study period,using 18 antibiotics of five different classes.Results:From wards and cabins,1 245 samples were collected,from which 996 strains of bacteria belonging to 11 species were isolated,during April 2011 to September2012.Two Gram-positive,Staphylococcus aureus(S.aureus)and Enterococcus faecalis(E.faecalis),and nine Gram-negative bacteria,Acinetobacter baumannii,Citrobactcr sp.,Escherichia coli,Enterobacter aerogenes,Klebsiella pneumoniae.Klebsiella oxytoca,Proteus mirabilis,Proteus vulgaris and Pseudomonas aeruginosa were isolated.Both S.aureus and E.faecalis were vancomycin resistant,and resistant-strains of all pathogens increased in each 6-month period of study.Particularly,all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole,the most preferred antibiotics of empiric therapy for UTI.Conclusions:Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied,generating the fear of precipitating fervent episodes in public health particularly with bacteria,Acinetobacter baumannii,Escherichia coli,Klebsiella pneumoniae and S.aureus.Moreover,vancomycin resistance in strains of S.aureus and E.faecalis is a matter of concern.

  8. Colonisation of antibiotic resistant bacteria in a cohort of HIV infected children in Ghana.

    Science.gov (United States)

    Sampane-Donkor, Eric; Badoe, Ebenezer Vincent; Annan, Jennifer Adoley; Nii-Trebi, Nicholas

    2017-01-01

    Antibiotic use not only selects for resistance in pathogenic bacteria, but also in commensal flora of exposed individuals. Little is known epidemiologically about antibiotic resistance in relation to people with HIV infection in sub-Saharan Africa. This study investigated the carriage of antibiotic resistant bacteria among HIV infected children at a tertiary hospital in Ghana. One hundred and eighteen HIV positive children were recruited at the Korle-Bu Teaching Hospital in Ghana and nasopharyngeal specimens were collected from them. The specimens were cultured for bacteria, and the isolates were identified by standard microbiological methods. Antibiotic susceptibility tests were carried out on selected bacterial organisms by the Kirby Bauer method. Bacteria isolated from the study subjects included Moraxella catarrhalis (39.8%), coagulase negative staphylococci (33.1%), Streptococcus pneumoniae (30.5%), diptheroids (29.7%), viridian streptococci (27.1%), Staphylococcus aureus (22.0%), Citrobacter spp. (4.2%) and Neisseria meningitidis (0.9%). Prevalence of antibiotic resistance of S. pneumoniae ranged from 5.6% (ceftriaxone) to 58.3% (cotrimoxazole), M. catarrhalis ranged from 2.1% (gentamicin) to 80.6% (ampicillin), and S. aureus ranged from 7.7% (cefoxitin) to 100% (penicillin). The prevalence of multiple drug resistance was 16.7% for S. pneumoniae, 57.4% for M. catarrhalis and 84.6% for S. aureus. HIV infected children in the study area commonly carry multi-drug resistant isolates of several pathogenic bacteria such as S. aureus and S. pneumoniae. Infections arising in these patients that are caused by S. aureus and S. pneumoniae could be treated with ceftriaxone and cefoxitin respectively.

  9. Multidrug resistant bacteria isolated from cockroaches in long-term care facilities and nursing homes.

    Science.gov (United States)

    Pai, Hsiu-Hua

    2013-01-01

    Residents in long-term care facilities and nursing homes have a relative higher risk for infections. The nocturnal and filthy habits of cockroaches may be ideal disseminators of pathogenic microorganisms in these institutions. This study was designed to determine the infestation and vector potential of cockroaches under this institutional environment. Cockroaches were collected from 69 long-term care facilities and nursing homes in Kaohsiung City. Risk factors related to cockroach infestation were determined by questionnaire survey. In addition, bacteria were isolated and identified from the alimentary tract and external surface of these insects. Antibiotic resistances of these microorganisms were then determined. Cockroach infestation was found in 45 (65.2%) institutions and 558 cockroaches (119 Periplaneta americana and 439 Blattella germanica) were collected. A significant association was found between cockroach infestation and indoor environmental sanitation. From 250 adult cockroaches, 38 species of gram-negative bacteria, 20 species of glucose non-fermenter bacilli and 6 species of gram-positive bacteria were isolated. Moreover, antibiotic resistances were found among the bacteria isolated. These findings indicate that cockroaches have the potential in transmitting pathogenic bacteria with multidrug resistances in long-term care facilities and nursing homes. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Incidence of plasmid and antibiotic resistance in psychrotrophic bacteria isolated from Antarctic sponges

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    Vivia Bruni

    2011-04-01

    Full Text Available A total of 297 bacterial strains were isolated from five Antarctic sponge species and tested by agarose gel electrophoresis for the presence of plasmid molecules. At least one kind of plasmid was carried by 69 isolates (about 23%. The disc diffusion susceptibility test was used to assay the resistance of plasmid-harbouring bacteria towards 11 antibiotics. A multiple resistance was observed for the 72% of strains, among which the 33% were resistant to only two antibiotics. Bacteria showed a high degree of resistance towards O/129 (71%, tetracycline (42% and nalidixic acid (25%, whereas any isolate showed resistance to gentamicin. The 16S rDNA sequencing revealed that plasmid-harbouring strains were mainly affiliated to the Gammaproteobacteria (81%, whereas the other detected phylogenetic groups (i.e. Firmicutes, Alphaproteobacteria, Actinobacteria and CFB group of Bacteroidetes were less abundant, each representing between 1% and 6% of the total isolates. The present study will contribute to the poor and fragmentary knowledge on plasmid incidence in natural microbial populations. In addition, monitoring antibiotic resistance in bacteria from remote areas, such as Antarctica, could also be a useful tool to evaluate the impact of anthropic pressure.

  11. [Distribution and removal of anaerobic antibiotic resistant bacteria during mesophilic anaerobic digestion of sewage sludge].

    Science.gov (United States)

    Tong, Juan; Wang, Yuan-Yue; Wei Yuan, Song

    2014-10-01

    Sewage sludge is one of the major sources that releasing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) into the environment since it contains large amount of ARB, but there is little information about the fate of the anaerobic ARB in the anaerobic digestion of sewage sludge. Therefore, the distribution, removal and seasonal changes of tetracycline and β-lactam antibiotics resistant bacteria in the mesophilic egg-shaped digesters of a municipal wastewater treatment plant were investigated for one year in this study. Results showed that there were higher amounts of ARB and higher resistance rate of β-lactam antibiotics than that of tetracycline antibiotics in the sewage sludge. All ARB could be significantly reduced during the mesophilic anaerobic digestion process by 1.48-1.64 log unit (P resistance rates were significantly increased after anaerobic digestion by 12.0% and 14.3%, respectively (P change characteristics. Except for chlorotetracycline resistant bacteria, there were more ARB in the sewage sludge in cold season than in warm season (P < 0.05).

  12. Antibacterial activities of ethanol extracts of Philippine medicinal plants against multidrug-resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    Demetrio; L.Valle; Jr.; Jeannie; I.Andrade; Juliana; Janet; M.Puzon; Esperanza; C.Cabrera; Windell; L.Rivera

    2015-01-01

    Objective: To investigate the antibacterial activities of crude ethanol extracts of 12 Philippine medicinal plants.Methods: Crude ethanol extracts from 12 Philippine medicinal plants were evaluated for their antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycinresistant Enterococcus, extended spectrum β-lactamase-producing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii. Results: The leaf extracts of Psidium guajava, Phyllanthus niruri, Ehretia microphylla and Piper betle(P. betle) showed antibacterial activity against the Gram-positive methicillinresistant Staphylococcus aureus and vancomycin-resistant Enterococcus. P. betle showed the highest antibacterial activity for these bacteria in the disk diffusion(16-33 mm inhibition diameter), minimum inhibitory concentration(19-156 μg/m L) and minimum bactericidal concentration(312 μg/m L) assays. P. betle leaf extracts only showed remarkable antibacterial activity for all the Gram-negative multidrug-resistant bacteria(extended spectrum β-lactamaseproducing, carbapenem-resistant Enterobacteriaceae and metallo-β-lactamase-producing) in the disk diffusion(17-21 mm inhibition diameter), minimum inhibitory concentration(312-625 μg/m L) and minimum bactericidal concentration(312-625 μg/m L) assays. Conclusions: P. betle had the greatest potential value against both Gram-negative and Grampositive multidrug-resistant bacteria. Favorable antagonistic activities were also exhibited by the ethanol extracts of Psidium guajava, Phyllanthus niruri and Ehretia microphylla.

  13. The role of surveillance systems in confronting the global crisis of antibiotic-resistant bacteria

    Science.gov (United States)

    Perez, Federico; Villegas, Maria Virginia

    2015-01-01

    Purpose of Review It is widely accepted that infection control, advanced diagnostics, and novel therapeutics are crucial to mitigate the impact of antibiotic-resistant bacteria. The role of global, national and regional surveillance systems as part of the response to the challenge posed by antibiotic resistance is not sufficiently highlighted. We provide an overview of contemporary surveillance programs, with emphasis on Gram-negative bacteria. Recent Findings The World Health Organization and public health agencies in Europe and the United States recently published comprehensive surveillance reports. These highlight the emergence and dissemination of carbapenem-resistant Enterobacteriaceae (CRE) and other multidrug resistant Gram-negative bacteria. In Israel, public health action to control CRE, especially Klebsiella pneumoniae carbapenemase (KPC) producing-Klebsiella pneumoniae, has advanced together with a better understanding of its epidemiology. Surveillance models adapted to the requirements and capacities of each country are in development. Summary Robust surveillance systems are essential to combat antibiotic resistance, and need to emphasize a “One Health” approach. Refinements in surveillance will come from advances in bioinformatics and genomics that permit the integration of global and local information about antibiotic consumption in humans and animals, molecular mechanisms of resistance, and bacterial genotyping. PMID:26098505

  14. New Roads Leading to Old Destinations: Efflux Pumps as Targets to Reverse Multidrug Resistance in Bacteria

    Directory of Open Access Journals (Sweden)

    Gabriella Spengler

    2017-03-01

    Full Text Available Multidrug resistance (MDR has appeared in response to selective pressures resulting from the incorrect use of antibiotics and other antimicrobials. This inappropriate application and mismanagement of antibiotics have led to serious problems in the therapy of infectious diseases. Bacteria can develop resistance by various mechanisms and one of the most important factors resulting in MDR is efflux pump-mediated resistance. Because of the importance of the efflux-related multidrug resistance the development of new therapeutic approaches aiming to inhibit bacterial efflux pumps is a promising way to combat bacteria having over-expressed MDR efflux systems. The definition of an efflux pump inhibitor (EPI includes the ability to render the bacterium increasingly more sensitive to a given antibiotic or even reverse the multidrug resistant phenotype. In the recent years numerous EPIs have been developed, although so far their clinical application has not yet been achieved due to their in vivo toxicity and side effects. In this review, we aim to give a short overview of efflux mediated resistance in bacteria, EPI compounds of plant and synthetic origin, and the possible methods to investigate and screen EPI compounds in bacterial systems.

  15. A reservoir of drug-resistant pathogenic bacteria in asymptomatic hosts.

    Directory of Open Access Journals (Sweden)

    Gabriel G Perron

    Full Text Available The population genetics of pathogenic bacteria has been intensively studied in order to understand the spread of disease and the evolution of virulence and drug resistance. However, much less attention has been paid to bacterial carriage populations, which inhabit hosts without producing disease. Since new virulent strains that cause disease can be recruited from the carriage population of bacteria, our understanding of infectious disease is seriously incomplete without knowledge on the population structure of pathogenic bacteria living in an asymptomatic host. We report the first extensive survey of the abundance and diversity of a human pathogen in asymptomatic animal hosts. We have found that asymptomatic swine from livestock productions frequently carry populations of Salmonella enterica with a broad range of drug-resistant strains and genetic diversity greatly exceeding that previously described. This study shows how agricultural practice and human intervention may lead and influence the evolution of a hidden reservoir of pathogens, with important implications for human health.

  16. Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria

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    Palloma Rodrigues Marinho

    2009-08-01

    Full Text Available Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3 isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

  17. Survival and leaching of Tetracycline resistant bacteria and fecal indicators from manure in field scale experiments

    DEFF Research Database (Denmark)

    Bech, Tina; Amin, Mostofa; Lægdsmand, Mette

    occurring indicator bacteria around a manure slurry slit in the soil was followed. During a period of two months, sections of soils with different distance to the manure string were assayed to obtain information on survival and spread of bacteriophage, faecal indicators (Enterococci, Bacterioides, E. coli......) and Tetracycline resistant bacteria. The die-off of the different organisms was quantified showing an extended survival close to the manure string. Genomic DNA from 400 Tetracycline resistant bacteria was isolated and their phylogenetic relationship was established using BOX PCR showing that the main Tetracycline...... organisms show that the upper soil and drainage water are impacted by the microorganisms natural originating from pig manure under natural conditions....

  18. A Multifunctional Subphthalocyanine Nanosphere for Targeting, Labeling, and Killing of Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Roy, Indranil; Shetty, Dinesh; Hota, Raghunandan; Baek, Kangkyun; Kim, Jeesu; Kim, Chulhong; Kappert, Sandro; Kim, Kimoon

    2015-12-01

    Developing a material that can combat antibiotic-resistant bacteria, a major global health threat, is an urgent requirement. To tackle this challenge, we synthesized a multifunctional subphthalocyanine (SubPc) polymer nanosphere that has the ability to target, label, and photoinactivate antibiotic-resistant bacteria in a single treatment with more than 99 % efficiency, even with a dose as low as 4.2 J cm(-2) and a loading concentration of 10 nM. The positively charged nanosphere shell composed of covalently linked SubPc units can increase the local concentration of photosensitizers at therapeutic sites. The nanosphere shows superior performance compared to corresponding monomers presumably because of their enhanced water dispersibility, higher efficiency of singlet-oxygen generation, and phototoxicity. In addition, this material is useful in fluorescence labeling of living cells and shows promise in photoacoustic imaging of bacteria in vivo.

  19. Colonization and resistance dynamics of gram-negative bacteria in patients during and after hospitalization.

    NARCIS (Netherlands)

    P.M.G. Filius (Margreet); I.C. Gyssens (Inge); I.M. Kershof (Irma); P.J. Roovers (Patty); A. Ott (Alewijn); A.G. Vulto (Arnold); H.A. Verbrugh (Henri); H.P. Endtz (Hubert)

    2005-01-01

    textabstractThe colonization and resistance dynamics of aerobic gram-negative bacteria in the intestinal and oropharyngeal microfloras of patients admitted to intensive care units (ICU) and general wards were investigated during and after hospitalization. A total of 3,316 specimens were obtained fro

  20. Distribution of tetracycline- and tylosin-resistance genes in bacteria from soils exposed to swine effluent

    Science.gov (United States)

    The application of animal waste from large-scale production facilities to cropland is a common means of manure disposal and nutrient recycling. In addition to the high nutrient load, antibiotic residues and antibiotic-resistant bacteria enter into the environment through this process. As yet, it i...

  1. Recycling antibiotics into GUMBOS: A new combination strategy to combat multi-drug resistant bacteria

    Science.gov (United States)

    The emergence of multi-drug resistant bacteria, coupled with the lack of new antibiotics in development, is fast evolving into a global crisis. New strategies utilizing existing antibacterial agents are urgently needed. We propose one such strategy in which four outmoded ß-lactam antibiotics (amp...

  2. Antibacterial activities of ethanol extracts of Philippine medicinal plants against multidrug-resistant bacteria

    Directory of Open Access Journals (Sweden)

    Demetrio L. Valle Jr.

    2015-07-01

    Conclusions: P. betle had the greatest potential value against both Gram-negative and Gram-positive multidrug-resistant bacteria. Favorable antagonistic activities were also exhibited by the ethanol extracts of Psidium guajava, Phyllanthus niruri and Ehretia microphylla.

  3. [Psychological impacts of being a carrier of multi-drug resistant bacteria].

    Science.gov (United States)

    Pires, Elisabete; Frange, Pierre; Henry, Benoît; Lortholary, Olivier; Reichert, Catherine

    2015-01-01

    Learning that they are a carrier of multi-drug resistant bacteria and being placed in isolation to prevent transmission has significant psychological repercussions for the patient and their families. Through therapeutic education, caregivers adapt their support to the patient's experience, raising their awareness of prevention. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Chicken Cathelicidins Display Antimicrobial Activity against Multiresistant Bacteria without Inducing Strong Resistance

    NARCIS (Netherlands)

    Veldhuizen, E.J.A.; Brouwer, E.C.; Schneider, V.A.F.; Fluit, A.C.

    2013-01-01

    The increased prevalence of multidrug-resistant (MDR) bacteria in combination with the relatively limited development of new antibiotics presents a serious threat to public health. In chicken, especially Extended-Spectrum ß-Lactamase (ESBL) carrying Enterobacteriaceae are often asymptomatically pres

  5. Trends of 9,416 multidrug-resistant Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Viviane Decicera Colombo Oliveira

    2015-06-01

    Full Text Available Summary Objective: a resistance of hospital-acquired bacteria to multiple antibiotics is a major concern worldwide. The objective of this study was to investigate multidrugresistant (MDR bacteria, clinical specimens, origin of specimen and trends, and correlate these with bacterial sensitivity and consumption of antimicrobials. Methods: 9,416 bacteria of nosocomial origin were evaluated in a tertiary hospital, from 1999 to 2008. MDR was defined for Gram-negative bacteria (GNB as resistance to two or more classes/groups of antibiotics. Results: GNB MDR increased by 3.7 times over the study period (p<0.001. Acinetobacter baumannii was the most prevalent (36.2%. Over the study period, there were significant 4.8-fold and 14.6-fold increases for A. baumannii and K. pneumoniae (p<0.001, respectively. Sixty-seven percent of isolates of MDR GNB were isolated in intensive care units. The resistance of A. baumannii to carbapenems increased from 7.4 to 57.5% during the study period and concomitant with an increased consumption. Conclusion: that decade showed prevalence of GNB and a gradual increase in MDR GNB. There was an increase in carbapenem resistance of 50.1% during the study.

  6. Spontaneous bacteriocin resistance in Listeria monocytogenes as a susceptibility screen for identifying different mechanisms of resistance and modes of action by bacteriocins of lactic acid bacteria.

    Science.gov (United States)

    Macwana, Sunita; Muriana, Peter M

    2012-01-01

    A practical system was devised for grouping bacteriocins of lactic acid bacteria (LAB) based on mode of action as determined by changes in inhibitory activity to spontaneously-acquired bacteriocin resistance (Bac(R)). Wild type Listeria monocytogenes 39-2 was sensitive to five bacteriocins produced by 3 genera of LAB: pediocin PA-1 and pediocin Bac3 (Pediococcus), lacticin FS97 and lacticin FS56 (Lactococcus), and curvaticin FS47 (Lactobacillus). A spontaneous Bac(R) derivative of L. monocytogenes 39-2 obtained by selective recovery against lacticin FS56 provided complete resistance to the bacteriocin made by Lactococcus lactis FS56. The lacticin FS56-resistant strain of L. monocyotgenes 39-2 was also cross-resistant to curvaticin FS47 and pediocin PA-1, but not to lacticin FS97 or pediocin Bac3. The same pattern of cross-resistance was also observed with Bac(R) isolates obtained with L. monocytogenes Scott A-2. A spontaneous mutation that renders a strain cross-resistant to different bacteriocins indicates that they share a common mechanism of resistance due to similar modes of action of the bacteriocins. Spontaneous resistance was acquired to other bacteriocins (in aggregate) by following the same procedure against which the Bac(R) strain was still sensitive. In subsequent challenge assays, mixtures of bacteriocins of different modes of action provided greater inhibition than mixtures of bacteriocins of the same mode of action (as determined by our screening method). This study identifies a methodical approach to classify bacteriocins into functional groups based on mechanism of resistance (i.e., mode of action) that could be used for identifying the best mixture of bacteriocins for use as biopreservatives.

  7. Antibiotic Resistance of Probiotic Strains of Lactic Acid Bacteria Isolated from Marketed Foods and Drugs

    Institute of Scientific and Technical Information of China (English)

    CHANG LIU; ZHUO-YANG ZHANG; KE DONG; JIAN-PING YUAN; XIAO-KUI GUO

    2009-01-01

    Objective To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probioties. Methods Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR. Results Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis. Conclusion Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.

  8. Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian contaminated systems.

    Science.gov (United States)

    Oyetibo, Ganiyu O; Ilori, Matthew O; Adebusoye, Sunday Adekunle; Obayori, Oluwafemi S; Amund, Olukayode O

    2010-09-01

    Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd(2+), Co(2+), Ni(2+), Cr(6+), and Hg(2+)) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd(2+), 15 mM for Co(2+) and Ni(2+), 17 mM for Cr(6+), and 10 mM for Hg(2+). Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni(2+), P. aeruginosa resisted 10 mM Co(2+). To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.

  9. Treatment of complicated intra-abdominal infections in the era of multi-drug resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Herzog T

    2010-11-01

    Full Text Available Abstract The management of severe intra-abdominal infections remains a major challenge facing surgeons and intensive care physicians, because of its association with high morbidity and mortality. Surgical management and intensive care medicine have constantly improved, but in the recent years a rapidly continuing emergence of resistant pathogens led to treatment failure secondary to infections with multi-drug resistant bacteria. In secondary peritonitis the rate of resistant germs at the initial operation is already 30%. The lack of effective antibiotics against these pathogens resulted in the development of new broad-spectrum compounds and antibiotics directed against resistant germs. But so far no "super-drug" with efficacy against all resistant bacteria exists. Even more, soon after their approval, reports on resistance against these novel drugs have been reported, or the drugs were withdrawn from the market due to severe side effects. Since pharmaceutical companies reduced their investigations on antibiotic research, only few new antimicrobial derivates are available. In abdominal surgery you may be in fear that in the future more and more patients with tertiary peritonitis secondary to multi-drug resistant species are seen with an increase of mortality after secondary peritonitis. This article reviews the current treatment modalities for complicated intra-abdominal infections with special reference to the antibiotic treatment of complicated intra-abdominal infections with multi-drug resistant species.

  10. Preparation of silver nanoparticles fabrics against multidrug-resistant bacteria

    Science.gov (United States)

    Hanh, Truong Thi; Thu, Nguyen Thi; Hien, Nguyen Quoc; An, Pham Ngoc; Loan, Truong Thi Kieu; Hoa, Phan Thi

    2016-04-01

    The silver nanoparticles (AgNPs)/peco fabrics were prepared by immobilization of AgNPs on fabrics in which AgNPs were synthesized by γ-irradiation of the 10 mM AgNO3 chitosan solution at the dose of 17.6 kGy. The AgNPs size has been estimated to be about 11 nm from TEM image. The AgNPs content onto peco fabrics was of 143±6 mg/kg at the initial AgNPs concentration of 100 ppm. The AgNPs colloidal solution was characterized by UV-vis spectroscopy and TEM image. The antibacterial activity of AgNPs/peco fabrics after 60 washings against Staphylococcus aureus and Klebsiella pneumoniae was found to be over 99%. Effects of AgNPs fabics on multidrug-resistant pathogens from the clinical specimens were also tested.

  11. Countermeasures to Antibiotics Crisis: a Global Priority List of Antibiotic-Resistant Bacteria for Research and Development of New Antibiotics

    Directory of Open Access Journals (Sweden)

    Editorial

    2017-03-01

    Full Text Available On 27 Feb., 2017, the World Health Organization (WHO announced the first list of important antibiotic-resistant bacteria (http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/, which tremendously threat human-being’s health. This list included 12 kinds of bacteria that were categorized into three priority tiers: Critical, High and Medium. In the first tier, Critical, three Gram negative bacteria were included: Acinetobacter baumannii with carbapenem-resistant, Pseudomonas aeruginosa with carbapenem-resistant; and Enterobacteriaceae with carbapenem-resistant, the third generation cephalosporin-resistant. In the second tier, High, six bacteria were suggested: Enterococcus faecium with vancomycin-resistant, Staphylococcus aureus with methicillin-resistant, vancomycin intermediate and resistant, Helicobacter pylori with clarithromycin-resistant, Campylobacter with fluoroquinolone-resistant, Salmonella spp. with fluoroquinolone-resistant, Neisseria gonorrhoeae with the third generation cephalosporin-resistant, fluoroquinolone-resistant. In the third tier, Medium, three bacteria were listed: Streptococcus pneumonia with penicillin-non-susceptible, Haemophilus influenza with ampicillin-resistant, and Shigella spp. with fluoroquinolone-resistant. This list was proposed by an expert panel, chaired by Dr. E. Tacconelli from Infectious Diseases, DZIF Center, Tübingen University, Germany and Dr. N. Magrini from EMP Department of WHO. This proposal recommended some key steps to countermeasure the challenges posed by multi-drug- and extensively drug-resistant bacteria, including research and development of new classes of antibiotics for the paediatric population, for preventing cross- and co-resistance to existing classes of antibiotics, and for oral formulations for community-acquired diseases with a high morbidity burden. This list will guide our future research and development of new antibiotics in future.

  12. Changing patterns of drug-resistant Shigella isolates in egypt.

    Science.gov (United States)

    Abd-Elmeged, Ghada M; Khairy, Rasha M; Abo-Eloyoon, Sahar M; Abdelwahab, Sayed F

    2015-06-01

    The emergence of multidrug resistance (MDR) is a serious problem in treating shigellosis. There are limited existing data examining the change in the antimicrobial resistance profile of Shigella in Egypt. We previously reported that 58% of the Shigella isolates in Egypt were resistant to at least one member of the three different antimicrobial groups. This study was performed to determine the antimicrobial resistance profile of Shigella, determine their possible mechanisms of resistance, and compare their resistance profile to those reported 20 years ago. Stool samples were collected from 500 subjects and processed for the isolation and identification of Shigella. The susceptibility of the isolates to 11 different antimicrobials was determined using the disc diffusion method. Of 500 stool cultures, 24 (4.8%) samples were positive for Shigella. There was a high percentage of resistance to ampicillin (88%), tetracycline (83%), and sulfamethoxazole-trimethoprim (75%). Also, there was a moderate percentage of resistance to chloramphenicol (46%), streptomycin (42%), ceftazidime (33%), and cefotaxime (25%). A lower percentage of resistance was recorded for amikacin, nalidixic acid (17% each), and ofloxacin (7%), while no resistance was found to ciprofloxacin (0%). Twenty-one of the isolates (88%) were resistant to at least three different antimicrobial groups (indicating MDR). The average number of antimicrobial agents to which the Shigella isolates were resistant was 4.3±1.4, while it was 3.4±1.5 in the same locality in 1994. These data demonstrate that there is a marked increase in MDR and change in the resistance patterns of Shigella over the past 20 years.

  13. Ciprofloxacin residue and antibiotic-resistant biofilm bacteria in hospital effluent.

    Science.gov (United States)

    Ory, Jérôme; Bricheux, Geneviève; Togola, Anne; Bonnet, Jean Louis; Donnadieu-Bernard, Florence; Nakusi, Laurence; Forestier, Christiane; Traore, Ousmane

    2016-07-01

    Discharge of antimicrobial residues and resistant bacteria in hospital effluents is supposed to have strong impacts on the spread of antibiotic resistant bacteria in the environment. This study aimed to characterize the effluents of the Gabriel Montpied teaching hospital, Clermont-Ferrand, France, by simultaneously measuring the concentration of ciprofloxacin and of biological indicators resistant to this molecule in biofilms formed in the hospital effluent and by comparing these data to ciprofloxacin consumption and resistant bacterial isolates of the hospital. Determination of the measured environmental concentration of ciprofloxacin by spot sampling and polar organic chemical integrative (POCIS) sampling over 2 weeks, and comparison with predicted environmental concentrations produced a hazard quotient >1, indicating a potential ecotoxicological risk. A negative impact was also observed with whole hospital effluent samples using the Tetrahymena pyriformis biological model. During the same period, biofilms were formed within the hospital effluent, and analysis of ciprofloxacin-resistant isolates indicated that Gamma-Proteobacteria were numerous, predominantly Aeromonadaceae (69.56%) and Enterobacteriaceae (22.61%). Among the 115 isolates collected, plasmid-mediated fluoroquinolone-resistant genes were detected, with mostly aac(6')-lb-cr and qnrS. In addition, 60% of the isolates were resistant to up to six antibiotics, including molecules mostly used in the hospital (aminosides and third-generation cephalosporins). In parallel, 1247 bacteria isolated from hospitalized patients and resistant to at least one of the fluoroquinolones were collected. Only 5 of the 14 species identified in the effluent biofilm were also found in the clinical isolates, but PFGE typing of the Gram-negative isolates found in both compartments showed there was no clonality among the strains. Altogether, these data confirm the role of hospital loads as sources of pollution for wastewater

  14. Factors influencing the survival and leaching of tetracycline-resistant bacteria and Escherichia coli through structured agricultural fields

    DEFF Research Database (Denmark)

    Bech, Tina Bundgaard; Rosenbom, Annette E.; Kjær, Jeanne;

    2014-01-01

    preferential transport through macropores, it was found that faecal bacteria were only leached to drainage water at Estrup. Here E. coli and tetracycline-resistant bacteria were detected at concentrations up to 3 CFU mL-1 and 130 CFU mL-1 respectively. A PCA plot revealed that leaching of faecal bacteria......Intense use of antibiotics in agricultural production may lead to the contamination of surface and groundwater by antibiotic-resistant bacteria. In the present study, the survival and leaching of E. coli and tetracycline-resistant bacteria were monitored at two well-structured agricultural fields....... Non-spiked pig slurry was injected in accordance with agricultural practice in the area. In both fields, the concentration of E. coli and tetracycline-resistant bacteria in the injected part of the plough layer decreased to the detection limit within 46–49 days. At Silstrup the decay was initiated...

  15. Quantitative relationship between antibiotic exposure and the acquisition and transmission of resistance in bacteria in the laboratory

    NARCIS (Netherlands)

    Händel, N.

    2015-01-01

    The worldwide emergence and spread of antibiotic resistant bacteria represent a major threat to human health care as the chance of therapy failure and costs for treatment increase. To curb the continuous rise of drug resistant bacteria worldwide, new strategies are urgently needed that counteract th

  16. Prevalence of plasmid-mediated multidrug resistance determinants in fluoroquinolone-resistant bacteria isolated from sewage and surface water.

    Science.gov (United States)

    Osińska, Adriana; Harnisz, Monika; Korzeniewska, Ewa

    2016-06-01

    Fluoroquinolones (FQs) are fully synthetic broad-spectrum antibacterial agents that are becoming increasingly popular in the treatment of clinical and veterinary infections. Being excreted during treatment, mostly as active compounds, their biological action is not limited to the therapeutic site, but it is moved further as resistance selection pressure into the environment. Water environment is an ideal medium for the aggregation and dissemination of antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs), which can pose a serious threat to human health. Because of this, the aim of this study was to determine the number of fluoroquinolone-resistant bacteria (FQRB) and their share in total heterotrophic plate counts (HPC) in treated wastewater (TWW), and upstream and downstream river water (URW, DRW) samples where TWW is discharged. The spread of plasmid-mediated quinolone resistance (PMQR) determinants and the presence/absence of resistance genes to other most popular antibiotic groups (against tetracyclines and beta-lactams) in selected 116 multiresistant isolates were investigated. The share of FQRB in total HPC in all samples was rather small and ranged from 0.7 % in URW samples to 7.5 % in TWW. Bacteria from Escherichia (25.0 %), Acinetobacter (25.0 %), and Aeromonas (6.9 %) genera were predominant in the FQRB group. Fluoroquinolone resistance was mostly caused by the presence of the gene aac(6')-1b-cr (91.4 %). More rarely reported was the occurrence of qnrS, qnrD, as well as oqxA, but qnrA, qnrB, qepA, and oqxB were extremely rarely or never noted in FQRB. The most prevalent bacterial genes connected with beta-lactams' resistance in FQRB were bla TEM, bla OXA, and bla CTX-M. The bla SHV was less common in the community of FQRB. The occurrence of bla genes was reported in almost 29.3 % of FQRB. The most abundant tet genes in FQRB were tet(A), tet(L), tet(K), and tet(S). The prevalence of tet genes was observed in 41.4

  17. Re-sensitizing drug-resistant bacteria to antibiotics by designing Antisense Therapeutics

    Science.gov (United States)

    Courtney, Colleen; Chatterjee, Anushree

    2014-03-01

    ``Super-bugs'' or ``multi-drug resistant organisms'' are a serious international health problem, with devastating consequences to patient health care. The Center for Disease Control has identified antibiotic resistance as one of the world's most pressing public health problems as a significant fraction of bacterial infections contracted are drug resistant. Typically, antibiotic resistance is encoded by ``resistance-genes'' which express proteins that carryout the resistance causing functions inside the bacterium. We present a RNA based therapeutic strategy for designing antimicrobials capable of re-sensitizing resistant bacteria to antibiotics by targeting labile regions of messenger RNAs encoding for resistance-causing proteins. We perform in silico RNA secondary structure modeling to identify labile target regions in an mRNA of interest. A synthetic biology approach is then used to administer antisense nucleic acids to our model system of ampicillin resistant Escherichia coli. Our results show a prolonged lag phase and decrease in viability of drug-resistant E. colitreated with antisense molecules. The antisense strategy can be applied to alter expression of other genes in antibiotic resistance pathways or other pathways of interest.

  18. New noncovalent inhibitors of penicillin-binding proteins from penicillin-resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Samo Turk

    Full Text Available BACKGROUND: Penicillin-binding proteins (PBPs are well known and validated targets for antibacterial therapy. The most important clinically used inhibitors of PBPs β-lactams inhibit transpeptidase activity of PBPs by forming a covalent penicilloyl-enzyme complex that blocks the normal transpeptidation reaction; this finally results in bacterial death. In some resistant bacteria the resistance is acquired by active-site distortion of PBPs, which lowers their acylation efficiency for β-lactams. To address this problem we focused our attention to discovery of novel noncovalent inhibitors of PBPs. METHODOLOGY/PRINCIPAL FINDINGS: Our in-house bank of compounds was screened for inhibition of three PBPs from resistant bacteria: PBP2a from Methicillin-resistant Staphylococcus aureus (MRSA, PBP2x from Streptococcus pneumoniae strain 5204, and PBP5fm from Enterococcus faecium strain D63r. Initial hit inhibitor obtained by screening was then used as a starting point for computational similarity searching for structurally related compounds and several new noncovalent inhibitors were discovered. Two compounds had promising inhibitory activities of both PBP2a and PBP2x 5204, and good in-vitro antibacterial activities against a panel of Gram-positive bacterial strains. CONCLUSIONS: We found new noncovalent inhibitors of PBPs which represent important starting points for development of more potent inhibitors of PBPs that can target penicillin-resistant bacteria.

  19. Isolation and partial characterization of actinomycetes with antimicrobial activity against multidrug resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    Smriti Singh; Pramod Kumar; N Gopalan; Bhuvnesh Shrivastava; RC Kuhad; Hotam Singh Chaudhary

    2012-01-01

    Objective: To isolate strains of Actinomycetes from different locations of Gwalior to evaluate its antimicrobial activity against multidrug resistant pathogenic strains. Method: Soil samples collected from different niche habitats of Gwalior were serially diluted and plated on selective media. Potential colonies were further purified and stored in agar slants and glycerol stocks. Isolates were biochemically characterized and purified isolates were test against pathogenic microorganisms for screening. Isolates with antagonistic properties were inoculated in production media and secondary metabolites or antimicrobial products were extracted. Result: The seven actinomycetes strains showing maximum antibacterial activity were isolated further characterized based on their colony characteristics and biochemical analyses. The isolates were screened for their secondary metabolites activity on three human pathogenic bacteria are Escherichia coli (E. coli), Methicillin-Resistant Staphylococcus aureus (S. aureus) and Vancomycin-Resistant Enterococci (VRE). Discussion: The strain MITS 1005 was found to be more active against the test bacteria.

  20. Bacteriological profile and antibiotic susceptibility patterns in neonatal septicemia in view of emerging drug resistance

    Directory of Open Access Journals (Sweden)

    Maimoona Mustafa

    2014-02-01

    Full Text Available The objective of this study was to isolate pathogenic bacteria in neo-natal septicaemia cases, and to know their antibiograms. Under aseptic precautions, blood was drawn from 140 neonates with sus-pected septicaemia and inoculated in brain heart infusion (BHI broth. Isolates obtained were identified as per standard protocol and antibi-otic susceptibility was done by Kirby Bauer disc diffusion method (as per CLSI guidelines. A total number of 62 (44.2% patients had positive blood cultures. The most common pathogens isolated were Klebsiella pneumoniae (n=22, 35% followed by Staphylococcus aureus (n=15, 24.1%, Escherichia coli (n=14, 22.5%, CONS (n=7, 11.2% and Pseudomonas aeruginosa (n=4, 6.4%. The Gram nega-tive organisms showed high resistance to commonly used antibiotics and were highly sensitive to Meropenem. The Gram positive bacteria showed high resistance to Ampicillin, Erythromycin and Amoxycillin; but they were highly susceptible to Linizolid and Vancomycin. As the Gram negative organisms were the most common isolates in neona-tal septicemia, their resistance pattern should be considered essen-tial for deciding the empirical treatment. Prompt treatment of neonatal sepsis with judicious use of appropriate antibiotics can minimize the morbidity and mortality, besides reducing the emergence of multi-drug resistant organisms in intensive care units (ICUs.

  1. Co-selection of antibiotic and heavy metal resistance in freshwater bacteria

    Directory of Open Access Journals (Sweden)

    Andrea Di Cesare

    2016-04-01

    Full Text Available Antibiotic resistant bacteria are found in most environments, especially in highly anthropized waters. A direct correlation between human activities (e.g., pollution and spread and persistence of antibiotic resistant bacteria (ARB and resistance genes (ARGs within the resident bacterial communities appears more and more obvious. Furthermore, the threat posed for human health by the presence of ARB and ARGs in these environments is enhanced by the risk of horizontal gene transfer of resistance genes to human pathogens. Although the knowledge on the spread of antibiotic resistances in waters is increasing, the understanding of the driving factors determining the selection for antibiotic resistance in the environment is still scarce. Antibiotic pollution is generally coupled with contamination by heavy metals (HMs and other chemicals, which can also promote the development of resistance mechanisms, often through co-selecting for multiple resistances. The co-selection of heavy metal resistance genes and ARGs in waters, sediments, and soils, increases the complexity of the ecological role of ARGs, and reduces the effectiveness of control actions. In this mini-review we present the state-of-the-art of the research on antibiotic- and HM-resistance and their connection in the environment, with a focus on HM pollution and aquatic environments. We review the spread and the persistence of HMs and/or ARB, and how it influences their respective gene co-selection. In the last chapter, we propose Lake Orta, a system characterized by an intensive HM pollution followed by a successful restoration of the chemistry of the water column, as a study-site to evaluate the spread and selection of HMs and antibiotic resistances in heavily disturbed environments.

  2. Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages.

    Science.gov (United States)

    Fraqueza, Maria João

    2015-11-06

    Dry-fermented sausages are meat products highly valued by many consumers. Manufacturing process involves fermentation driven by natural microbiota or intentionally added starter cultures and further drying. The most relevant fermentative microbiota is lactic acid bacteria (LAB) such as Lactobacillus, Pediococcus and Enterococcus, producing mainly lactate and contributing to product preservation. The great diversity of LAB in dry-fermented sausages is linked to manufacturing practices. Indigenous starters development is considered to be a very promising field, because it allows for high sanitary and sensorial quality of sausage production. LAB have a long history of safe use in fermented food, however, since they are present in human gastrointestinal tract, and are also intentionally added to the diet, concerns have been raised about the antimicrobial resistance in these beneficial bacteria. In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance transmission from animal to human bacterial populations. The World Health Organization 2014 report on global surveillance of antimicrobial resistance reveals that this issue is no longer a future prediction, since evidences establish a link between the antimicrobial drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the possible sources and transmission routes of antibiotic resistant LAB of dry-fermented sausages, presenting LAB antibiotic resistance profile and related genetic determinants. Whenever LAB are used as starters in dry-fermented sausages processing, safety concerns regarding antimicrobial resistance should be addressed since antibiotic resistant genes could be mobilized and transferred to other bacteria.

  3. Culture-independent detection of "TM7" bacteria in a streptomycin-resistant acidophilic nitrifying process

    Science.gov (United States)

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T.; Hiraishi, A.

    2014-02-01

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L-1 was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

  4. Induced systemic resistance of selected endophytic bacteria against Meloidogyne incognita on tomato.

    Science.gov (United States)

    Munif, A; Hallmann, J; Sikora, R A

    2001-01-01

    In previous work, the four endophytic bacteria Pantoea agglomerans MK-29, Cedeca davisae MK-30, Enterobacter spp. MK-42 and Pseudomonas putida MT-19 were shown to reduce Meloidogyne incognita on tomato when applied as a seed treatment and/or soil drench. The objective of this work was to study these bacteria for their potential to induce systemic resistance against root knot nematodes on tomato. To guarantee spatial separation between inducing agent and pathogen a split-root system was chosen and inoculated with the bacteria as a drench application on one side of the root system and 6 days later with 2000 juveniles of Meloidogyne incognita on the other side of the split-root system. The experiment was maintained in the greenhouse and repeated once. The penetration rate of juveniles as well as the total number of root-knot galls and egg masses was recorded. Treatment with all four bacteria significantly reduced juvenile penetration and the number of root-knot galls when compared with the non-treated control. Induced systemic resistance is considered a possible control mechanism of endophytic bacteria against root-knot nematodes.

  5. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods.

    Science.gov (United States)

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-07-28

    Knowledge of bacteria's heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria's heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample's thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS's performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria's thermo-tolerances.

  6. Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria.

    Science.gov (United States)

    Parkinson, Elizabeth I; Bair, Joseph S; Nakamura, Bradley A; Lee, Hyang Y; Kuttab, Hani I; Southgate, Emma H; Lezmi, Stéphane; Lau, Gee W; Hergenrother, Paul J

    2015-04-24

    Fluoroquinolones are one of the most commonly prescribed classes of antibiotics, but fluoroquinolone resistance (FQR) is widespread and increasing. Deoxynybomycin (DNM) is a natural-product antibiotic with an unusual mechanism of action, inhibiting the mutant DNA gyrase that confers FQR. Unfortunately, isolation of DNM is difficult and DNM is insoluble in aqueous solutions, making it a poor candidate for development. Here we describe a facile chemical route to produce DNM and its derivatives. These compounds possess excellent activity against FQR methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci clinical isolates and inhibit mutant DNA gyrase in-vitro. Bacteria that develop resistance to DNM are re-sensitized to fluoroquinolones, suggesting that resistance that emerges to DNM would be treatable. Using a DNM derivative, the first in-vivo efficacy of the nybomycin class is demonstrated in a mouse infection model. Overall, the data presented suggest the promise of DNM derivatives for the treatment of FQR infections.

  7. Anti-virulence approaches and novel peptidomimetics for combating resistant and biofilm associated bacteria

    DEFF Research Database (Denmark)

    Liu, Yang

    Anti-virulence approaches and novel peptidomimetics for combating resistant and biofilm associated bacteria The misuse and overuse of antibiotics has a broad impact on the environment. Antibiotic resistance has become a major threat for modern medical treatment of infectious diseases....... There are multiple mechanisms leading to antibiotic resistance such as expression of cell membrane efflux pumps and antibiotic-degrading enzymes. Moreover, bacterial biofilm communities are widely accepted as a major resistance mechanism in infection sites. Biofilms are surface-associated microbial communities...... consisting of microcolonies embedded in self-produced extracellular polymer substances (EPS). EPS can contribute to cell-cell adhesion and restrict antibiotic penetration. Biofilm cells show much greater resistance to stressful conditions than their free-living counterparts. Conventional treatment strategies...

  8. Iron metabolism and resistance to infection by invasive bacteria in the social amoeba Dictyostelium discoideum.

    Science.gov (United States)

    Bozzaro, Salvatore; Buracco, Simona; Peracino, Barbara

    2013-01-01

    Dictyostelium cells are forest soil amoebae, which feed on bacteria and proliferate as solitary cells until bacteria are consumed. Starvation triggers a change in life style, forcing cells to gather into aggregates to form multicellular organisms capable of cell differentiation and morphogenesis. As a soil amoeba and a phagocyte that grazes on bacteria as the obligate source of food, Dictyostelium could be a natural host of pathogenic bacteria. Indeed, many pathogens that occasionally infect humans are hosted for most of their time in protozoa or free-living amoebae, where evolution of their virulence traits occurs. Due to these features and its amenability to genetic manipulation, Dictyostelium has become a valuable model organism for studying strategies of both the host to resist infection and the pathogen to escape the defense mechanisms. Similarly to higher eukaryotes, iron homeostasis is crucial for Dictyostelium resistance to invasive bacteria. Iron is essential for Dictyostelium, as both iron deficiency or overload inhibit cell growth. The Dictyostelium genome shares with mammals many genes regulating iron homeostasis. Iron transporters of the Nramp (Slc11A) family are represented with two genes, encoding Nramp1 and Nramp2. Like the mammalian ortholog, Nramp1 is recruited to phagosomes and macropinosomes, whereas Nramp2 is a membrane protein of the contractile vacuole network, which regulates osmolarity. Nramp1 and Nramp2 localization in distinct compartments suggests that both proteins synergistically regulate iron homeostasis. Rather than by absorption via membrane transporters, iron is likely gained by degradation of ingested bacteria and efflux via Nramp1 from phagosomes to the cytosol. Nramp gene disruption increases Dictyostelium sensitivity to infection, enhancing intracellular growth of Legionella or Mycobacteria. Generation of mutants in other "iron genes" will help identify genes essential for iron homeostasis and resistance to pathogens.

  9. Iron metabolism and resistance to infection by invasive bacteria in the social amoeba Dictyostelium discoideum

    Directory of Open Access Journals (Sweden)

    Salvatore eBozzaro

    2013-09-01

    Full Text Available Dictyostelium cells are forest soil amoebae, which feed on bacteria and proliferate as solitary cells until bacteria are consumed. Starvation triggers a change in life style, forcing cells to gather into aggregates to form multicellular organisms capable of cell differentiation and morphogenesis. As a soil amoeba and a phagocyte that grazes on bacteria as the obligate source of food, Dictyostelium could be a natural host of pathogenic bacteria. Indeed, many pathogens that occasionally infect humans are hosted for most of their time in protozoa or free-living amoebae, where evolution of their virulence traits occurs. Due to these features and its amenability to genetic manipulation, Dictyostelium has become a valuable model organism for studying strategies of both the host to resist infection and the pathogen to escape the defence mechanisms. Similarly to higher eukaryotes, iron homeostasis is crucial for Dictyostelium resistance to invasive bacteria. Iron is essential for Dictyostelium, as both iron deficiency or overload inhibit cell growth. The Dictyostelium genome shares with mammals many genes regulating iron homeostasis. Iron transporters of the Nramp (Slc11A family are represented with two genes, encoding Nramp1 and Nramp2. Like the mammalian ortholog, Nramp1 is recruited to phagosomes and macropinosomes, whereas Nramp2 is a membrane protein of the contractile vacuole network, which regulates osmolarity. Nramp1 and Nramp2 localization in distinct compartments suggests that both proteins synergistically regulate iron homeostasis. Rather than by absorption via membrane transporters, iron is likely gained by degradation of ingested bacteria and efflux via Nramp1 from phagosomes to the cytosol. Nramp gene disruption increases Dictyostelium sensitivity to infection, enhancing intracellular growth of Legionella or Mycobacteria. Generation of mutants in other "iron genes" will help identify genes essential for iron homeostasis and resistance to

  10. Determination Pattern of Antimicrobial Resistance of Pseudomonas Isolated from Patients in a University Tertiary Hospital

    Directory of Open Access Journals (Sweden)

    Alka Hasani

    2017-07-01

    Full Text Available Introduction: Pseudomonas are ubiquitous bacteria widely present in nature. However, they have emerged as an opportunistic pathogen for humans. This bacterium is accountable for many localized and disseminated diseases, especially wounds in burn patients, respiratory infections, septicemia and bacteremia. Among all Pseudomonas species, P. aeruginosa is one of the important and most virulent species in hospital settings, while other pathogenic species include stutzeri, putida and fluorescence. The aim of this study was to assess pattern of antibiotic resistance in these bacteria isolated from a University teaching and treatment center. This cross-sectional study was conducted on 99 Pseudomonas strains (68 strains P. aeruginosa and 31 other Pseudomonas species isolated from various clinical specimens. Antimicrobial drug susceptibility test was performed using the disc agar diffusion method according to CLSI recommendations. In this study, among various clinical specimens sent to microbiology laboratory, wound (59.59% was found as a major source of Pseudomonas spp. Among various wards, Pseudomonas spp. was isolated more from patients admitted to burns ward (48.48%. Antibiotic susceptibility assay results revealed non susceptibility pattern towards most of the antibiotics; however, among all antibiotics tested, most common resistance was observed towards ceftazidime (76.76%. The results of this study shows the presence of Pseudomonas infection in the hospital setting and their developed resistance towards many conventional antibiotics, which is a concern at this treatment center. Thus, there exist a need for evaluation of careful and accurate measurement of resistance and assessment of exact drug administration policies. Therefore, to control the infection and prevent from increased prevalence of resistant strains appropriate resolution should be followed.

  11. Bioactive Compound Rich Indian Spices Suppresses the Growth of β-lactamase Produced Multidrug Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Eadlapalli Siddhartha

    2017-01-01

    Full Text Available Background: Multidrug Resistance (MDR among bacteria become a global concern due to failure of antibiotics, is drawn attention for best antimicrobials from the spices which have been using ancient days in Indian culinary and traditional medicine. Aim and Objectives: The present study was undertaken to evaluate the bioactive compounds and their antibacterial activity in routinely used culinary Indian spices against β-lactamase produced MDR bacteria. Material and Methods: Ethanolic extracts prepared from twenty spices and were evaluated for total phenolics, flavonoids, alkaloids, terpenoids, antioxidant properties, and also assayed their antibacterial activities against β-lactamase producing MDR bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. β-Lactamase and cell viability assays were performed in MDR bacteria. Results: Among twenty spices, cinnamon and clove exhibited highest levels of phenolics and terpenoids with elevated antioxidant potential and also showing greater reducing potential at lower concentrations of extract (2.3 and 4.06 µg GAE/gm, respectively. Further, the spices extracts were assessed for antimicrobial activity against β-lactamase produced tested MDR bacteria and observed higher antimicrobial activity with cinnamon, garlic, tamarind and clove at lowest concentrations of MIC and MBC at 16 - 32 µg GAE/ml, as compared to standard drug, amoxiclav (16/8 µg/ml. Spices significantly inhibited the β-lactamase activity (80–94% and also cell viability in tested MDR bacteria. Conclusion: Indian spices consist of rich bioactive profile and antioxidant activity inhibited the bacterial growth effectively by suppressing β-lactamase production in MDR bacteria. Results indicating the spices as functional foods and could be used in prevention of antibiotic resistance.

  12. Particle-associated flagellates: swimming patterns, colonization rates, and grazing on attached bacteria

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Grossart, H.P.; Ploug, H.

    2004-01-01

    Some pelagic flagellates colonize particles, such as marine snow, where they graze on bacteria and thus impact the dynamics of the attached microbial communities. Particle colonization is governed by motility. Swimming patterns of 2 particle-associated flagellates, Bodo designis and Spumella sp......., are very different, the former swimming slowly in an erratic, random pattern, and the latter faster and along smooth helixes of variable amplitude and frequency. At spatial scales exceeding ca. 50 mum, the motility of B. designis can be described as a random walk and modeled as diffusion. Spumella sp...

  13. Effect of tetracycline residues in pig manure slurry on tetracycline-resistant bacteria and resistance gene tet(M) in soil microcosms

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Wulff, Gitte; Vaclavik, Elvira;

    2006-01-01

    manure slurry and a tetracycline-resistant Enterococcus faecalis, CG I 10, containing the tetracycline resistance gene tet(m) (on the conjugative transposon, Tn916). The prevalence of both tetracycline-resistant aerobic bacteria and tetracycline-resistant enterococci declined rapidly until day 45 where...... no significant differences in the levels of tetracycline-resistant bacteria in any of the four types of microcosms could be detected. tet(M) could be detected in microcosms supplemented with either pig manure slurry and/or E. faecalis CG 110 (tet(M)) for the whole period (152 days). tet(M) could be detected...... longer than tetracycline-resistant enterococci could be isolated (limit of detection 100 CFU/g soil) probably due to viable but not culturable (VBNC) bacteria with tet(M), horizontal gene transfer of tet(M) to indigenous soil bacteria or presence of "free" DNA. The concentration of chlortetracycline...

  14. Co-occurrence of antibiotic drugs, resistant bacteria and resistance genes in runoff from cattle feedlots

    Science.gov (United States)

    Agricultural uses of antibiotics raises concerns about the development of antibiotic resistance in food animals, and the potential to transmit resistance to human clinical settings via fecal contamination of surface and ground water. Although there is broad agreement that agricultural resistance can...

  15. Presence Of Multi Drug Resistant Coliform Bacteria Isolated From Biofilm Of Sachet And Borehole Waters Sold In Abakaliki Metropolis Ebonyi State Nigeria.

    Directory of Open Access Journals (Sweden)

    Okafor Collins Onyebuchi Okeke

    2015-06-01

    Full Text Available ABSTRACT This study investigated the presence of multi drug resistant coliform bacteria from biofilm of sachet and borehole waters sold in Abakaliki metropolis in Ebonyi State Nigeria. Five hundred 500 samples of water comprising 250 each from selected brand of sachet water retailers and borehole water dispensers from seven locations were sampled for the detection of coliform bacteria from biofilm and to determine their antimicrobial susceptibility using commercially prepared antibiotic discs. Results revealed a high faecal contamination level in sachet waters as Gospel 36 72 Aqua Rapha 30 60 and Bejoy 18 36 were the highest among the sachet water brands examined with Nene and Rock Tama sachet water brands having the lowest contamination level of 612 and 1326 respectively. Borehole samples results revealed that Aboffia had 27 76.93 samples contaminated with faecal bacteria while Azugwu 11 28.5 Azuiyiokwu 18 50 Azuiyiudene 2980 Kpirikpiri 24 66.63 PrescoNtezi 1646.15 and Udensi 22 61.54. Escherichia coli Enterobacter spp and Klebsiella spp were the major contaminants of both sachet and borehole water samples. The bacteria isolates from biofilm of sachet and borehole waters were susceptible to only three of the antibiotics used namely nitrofurantoin amoxycilin and ampicillin. The bacteria were completely resistant to ciprofloxacin tetracycline norbactinnorfloxacin ofloxacin cefuroxime and gentamicin. This showed that they exhibit multi-drug resistance pattern which is a common feature of medically important biofilm bacteria. We therefore report the presence of multi-drug resistant coliform bacteria from biofilm of sachet and borehole waters sold in Abakaliki metropolis Ebonyi State Nigeria.

  16. Laboratory development of permethrin resistance and cross-resistance pattern of Culex quinquefasciatus to other insecticides.

    Science.gov (United States)

    Ramkumar, Govindaraju; Shivakumar, Muthugoundar S

    2015-07-01

    Resistance of mosquitoes to insecticides is a growing concern in India. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programs mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. In the present study, we evaluate the permethrin resistance and cross-resistance pattern of several insecticides in Culex quinquefasciatus mosquitoes. After 10 generation of selection with permethrin, the LC50 value for both larvae and adult Cx. quinquefasciatus was increased by 17.3- and 17.1-folds compared with susceptible strain. Detoxification enzyme profiles and native PAGE electrophoresis of esterase isoenzyme further revealed that esterase and CytP450 may be involved in permethrin resistance (PerRes) strain compared with susceptible strain. In addition to cross-resistance, study revealed that high resistance to cypermethrin (RR = 6.3, 8.8-folds). This study provided important information for understanding permethrin resistance and facilitating a better strategy for the management of resistance. These studies conclude that a strong foundation for further study of permethrin resistance mechanisms observed in Cx. quinquefasciatus mosquitoes.

  17. Antimicrobial resistance patterns in Danish isolates of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Bruun, Morten Sichlau; Schmidt, A.S.; Madsen, Lone

    2000-01-01

    were tested and the resulting antibiograms were used to predict the theoretical therapeutic efficacy and to evaluate if resistance had changed as a course of time. Antimicrobial agents included in this investigation were oxolinic acid (OXA), amoxicillin (AMX), potentiated sulfadiazine, oxytetracycline......The resistance pattern of Flavobacterium psychrophilum to the antimicrobial agents used in fish farming in Denmark was assessed in vitro using an agar dilution method. After identification of 387 isolates from clinical outbreaks of rainbow trout fry syndrome (RTFS) and the environment, the isolates...... (OTC) and florfenicol (FLO). We found that F. psychrophilum isolates divided in susceptible and resistant clusters reflecting the reduced efficacy in practice when using OTC and AMX. The most recent isolates were less susceptible to AMX and OXA, whereas resistance to OTC seemed stable over the last 5...

  18. [Isolation and biodiversity of copper-resistant bacteria from rhizosphere soil of Elsholtzia splendens].

    Science.gov (United States)

    Sun, Leni; He, Linyan; Zhang, Yanfeng; Zhang, Wenhui; Wang, Qi; Sheng, Xiafang

    2009-10-01

    Isolation and characterization of rhizosphere copper-resistant bacteria from a copper accumulator plant Elsholtzia splendens were investigated. Cultivable Cu-resistant bacteria were isolated by plating and screening from rhizosphere soils of Elsholtzia splendens growing on a copper mine tailing. Bacteria were characterized regarding characteristics that may be relevant for a beneficial plant-microbe interaction--Cu tolerance, phosphate-solubilizing, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophore and indoleacetic acid production, and further classified by restriction analysis of 16S rDNA (ARDRA). Strains that produced ACC deaminase were identified by 16S rDNA sequence analysis. Twenty-seven Cu-resistant strains were isolated from rhizosphere soil of Elsholtzia splendens and classified by ARDRA in 7 different taxonomic groups at the similarity level of 60% . All strains produced IAA or their derivatives, 44.4% of the strains produced a very high level of siderophores, and five strains were able to grow on ACC as the sole nitrogen source. Strains 2EBS12, 2EBS13, 2EBS15 and 3EBS11 were identified as Acinetobacter, strain 2EBS14 was essentially consistent Alcaligenes. Cu-resistant rhizobacteria isolated from Elsholtzia splendens have abundant characteristics relative to promoting plant growth and genetic diversity, rhizobacteria Acinetobacter sp. and Alcaligenes sp. contained ACC deaminase activity.

  19. [Inactivation of the chlorine-resistant bacteria isolated from the drinking water distribution system].

    Science.gov (United States)

    Chen, Yu-Qiao; Duan, Xiao-Di; Lu, Pin-Pin; Wang, Qian; Zhang, Xiao-Jian; Chen, Chao

    2012-01-01

    Inactivation experiments of seven strains of chlorine-resistant bacteria, isolated from a drinking water distribution system, were conducted with four kinds of disinfectants. All the bacteria showed high resistance to chlorine, especially for Mycobacterium mucogenicum. The CT value of 99.9% inactivation for M. mucogenicum, Sphingomonas sanguinis and Methylobacterium were 120 mg x (L x min)(-1), 7 mg x (L x min)(-1) and 4 mg x (L x min)(-1), respectively. The results of inactivation experiments showed that chlorine dioxide and potassium monopersulfate could inactive 5 lg of M. mucogenicum within 30 min, which showed significantly higher efficiency than free chlorine and monochloramine. Free chlorine was less effective because the disinfectant decayed very quickly. Chloramination needed higher concentration to meet the disinfection requirements. The verified dosage of disinfectants, which could effectively inactivate 99.9% of the highly chlorine-resistant M. mucogenicum within 1 h, were 3.0 mg/L monochloramine, 1.0 mg/L chlorine dioxide (as Cl2), and 1.0 mg/L potassium monopersulfate (as Cl2). It was suggested that the water treatment plants increase the concentration of monochloramine or apply chlorine dioxide intermittently to control the disinfectant-resistant bacteria.

  20. Nontoxic colloidal particles impede antibiotic resistance of swarming bacteria by disrupting collective motion and speed

    Science.gov (United States)

    Lu, Shengtao; Liu, Fang; Xing, Bengang; Yeow, Edwin K. L.

    2015-12-01

    A monolayer of swarming B. subtilis on semisolid agar is shown to display enhanced resistance against antibacterial drugs due to their collective behavior and motility. The dynamics of swarming motion, visualized in real time using time-lapse microscopy, prevents the bacteria from prolonged exposure to lethal drug concentrations. The elevated drug resistance is significantly reduced when the collective motion of bacteria is judiciously disrupted using nontoxic polystyrene colloidal particles immobilized on the agar surface. The colloidal particles block and hinder the motion of the cells, and force large swarming rafts to break up into smaller packs in order to maneuver across narrow spaces between densely packed particles. In this manner, cohesive rafts rapidly lose their collectivity, speed, and group dynamics, and the cells become vulnerable to the drugs. The antibiotic resistance capability of swarming B. subtilis is experimentally observed to be negatively correlated with the number density of colloidal particles on the engineered surface. This relationship is further tested using an improved self-propelled particle model that takes into account interparticle alignment and hard-core repulsion. This work has pertinent implications on the design of optimal methods to treat drug resistant bacteria commonly found in swarming colonies.

  1. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria.

    Science.gov (United States)

    Li, Xian-Zhi; Plésiat, Patrick; Nikaido, Hiroshi

    2015-04-01

    The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.

  2. The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

    Science.gov (United States)

    Plésiat, Patrick

    2015-01-01

    SUMMARY The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps. PMID:25788514

  3. Resistance to antibiotics in Gram-negative bacteria isolated from broiler carcasses

    Directory of Open Access Journals (Sweden)

    Moreira M.A.S.

    2002-01-01

    Full Text Available One hundred and ninety-seven isolates of Gram-negative bacteria, comprising 10 genera, were isolated from poultry carcasses at a processing plant in order to investigate resistance to low levels of antibiotics. The samples were taken just after evisceration and before inspection. Most of the isolates were of Samonella and Escherichia. Other genera present were Enterobacter, Serratia, Klebsiella, Kluyvera, Erwinia, Citrobacter, Pseudomonas and Aeromonas. Distinct profiles of antibiotic resistance were detected. Resistance to more than two antibiotics predominated and spanned several classes of antibiotics. Salmonellae and escherichiae were mainly resistant to the aminoglycosides, followed by tetracycline, nitrofuran, sulpha, macrolide, chloramphenicol, quinolones and beta-lactams. Most isolates were sensitive to 30mug/ml olaquindox, the growth promoter in use at the time of sampling. However, many were resistant to a level of 10mug/ml and 13mug/ml olaquindox, levels present in the gut due to the dilution in the feed. The results suggest a possible role of low level administration of antibiotics to broilers in selecting multi-resistant bacteria in vivo.

  4. Antisense RNA regulation and application in the development of novel antibiotics to combat multidrug resistant bacteria.

    Science.gov (United States)

    Ji, Yinduo; Lei, Ting

    2013-01-01

    Despite the availability of antibiotics and vaccines, infectious diseases remain one of most dangerous threats to humans and animals. The overuse and misuse of antibacterial agents have led to the emergence of multidrug resistant bacterial pathogens. Bacterial cells are often resilient enough to survive in even the most extreme environments. To do so, the organisms have evolved different mechanisms, including a variety of two-component signal transduction systems, which allow the bacteria to sense the surrounding environment and regulate gene expression in order to adapt and respond to environmental stimuli. In addition, some bacteria evolve resistance to antibacterial agents while many bacterial cells are able to acquire resistance genes from other bacterial species to enable them to survive in the presence of toxic antimicrobial agents. The crisis of antimicrobial resistance is an unremitting menace to human health and a burden on public health. The rapid increase in antimicrobial resistant organisms and limited options for development of new classes of antibiotics heighten the urgent need to develop novel potent antibacterial therapeutics in order to combat multidrug resistant infections. In this review, we introduce the regulatory mechanisms of antisense RNA and significant applications of regulated antisense RNA interference technology in early drug discovery. This includes the identification and evaluation of drug targets in vitro and in vivo, the determination of mode of action for antibiotics and new antibacterial agents, as well as the development of peptide-nucleic acid conjugates as novel antibacterials.

  5. Emergence of Pan-drug resistance amongst gram negative bacteria! The First case series from India

    Directory of Open Access Journals (Sweden)

    Abdul Ghafur

    2014-09-01

    Full Text Available Objective: Increasing prevalence of carbapenem resistant Gram negative bacteria is a serious clinical and public health challenge. Bacteria resistant to all available antibiotics (Pan Drug Resistance herald the onset of post antibiotics era. We hereby report clinical profile of 13 patients with pan drug resistant gram negative isolates. Methods:Retrospective analysis of 13 patients with pan drug resistant gram negative isolates over the last 18 months was done by medical records review. Identification of the isolates and susceptibility testing was done using VITEK auto analyzer in concordance with the corresponding CLSI guidelines. Results:Out of four patients with bacteremic isolates, three patients received colistin based combination therapy. Though two of these patients had microbiologic clearance, all the three died. Out of the 9 patients with non bacteremic isolates, 4 had infection and 5 had colonization. Three (out of four were treated with combination therapy including colistin and one patient received colistin monotherapy. All four patients had microbiological clearance. Three patients had clinical cure and were discharged. One patient later developed bacteremia and died. Conclusion:Infections, particularly blood stream with pan drug resistant organisms has a higher mortality. Urgent studies to reevaluate existing therapeutic options and research into new antibiotic molecules are the need of the hour. J Microbiol Infect Dis 2014; 4(3: 86-91

  6. [Surveillance report of drug-resistant bacteria from 2007 to 2012 in Saga Prefecture, Japan (the second report)].

    Science.gov (United States)

    Kiyosuke, Makiko; Nagasawa, Zenzo; Hotta, Taeko; Utsumi, Takashi; Kang, Dongchon; Miyamoto, Hiroshi

    2014-06-01

    Drug-resistant bacteria are a problematic issue in Japan. Surveillance of drug-resistant bacteria is important because the frequency of isolation and kinds of such bacteria vary between hospitals and local areas. This study summarizes the results of detection of drug-resistant bacteria in Saga Prefecture from July 2007 to June 2012. Data presented in this study were collected through questionnaire survey that was conducted in 12 hospitals. Frequency of drug-resistant bacteria are as follows: 62.5% of Staphylococcus aureus was methicillin-resistant S. aureus (MRSA); 62.2% of Streptococcus pneumoniae was penicillin-intermediate S. pneumoniae (PISP) or penicillin-resistant S. pneumoniae (PRSP); 26.4% of Haemophilus influenzae was beta-lactamase negative ampicillin-resistant H. influenzae (BLNAR); 0.5% of Pseudomonas aeruginosa was metallo-beta-lactamase (MBL) P. aeruginosa; 0.5% of P. aeruginosa was multi-drug resistant P. aeruginosa (MDRP); 12.9% and 5.1% of Escherichia coli and Klebsiella pneumoniae, respectively, were extended-spectrum beta-lactamase (ESBL) producing organisms. While the isolation frequencies of MRSA and PISP/PRSP were unchanged, those of BLNAR, ESBL producing E. coli and ESBL producing K. pneumoniae raised from 15.4% to 34.2%, from 5.7% to 18.4% and from 2.6% to 8.2%, respectively, over the past 5 years. The frequencies of isolation of MDRP and two drug resistant P. aeruginosa declined. This study revealed that the overall trend in the long-term changes of isolation frequency of drug-resistant bacteria in Saga Prefecture is similar to the trend in the national data. It also showed that the frequency and kinds of drug-resistant bacteria are variable between hospitals and local areas. Further study, such as examination of the usage and MIC value of antimicrobial drugs, will enable us to gain more detailed information on the drug-resistant bacteria.

  7. Survey of antimicrobial susceptibility patterns of the bacteria of the Bacteroides fragilis group isolated from the intestinal tract of children

    Directory of Open Access Journals (Sweden)

    Viviane Nakano

    2004-05-01

    Full Text Available The bacteria of the Bacteroides fragilis group are considered important clinical pathogens and they are the most common anaerobes isolated from human endogenous infections. In this study, the susceptibility patterns to antibiotics and metals of 114 species of the B. fragilis group isolated from children with and without diarrhea were determined. Susceptibility was assayed by using an agar dilution method with Wilkins-Chalgren agar. All B. fragilis strains were resistant to lead and nickel, but susceptible to metronidazole and imipenem. beta-lactamase production was detected by using biological and nitrocefin methods, respectively, in 50% and 90.6% of the isolates of children with diarrhea and in 60% and 90% of the isolates of children without diarrhea. Our results show an increase of antibiotics and metals resistance in this microbial group, and a periodic evaluation of the antimicrobial susceptibility is needed. In Brazil, the contamination for antibiotics or metal ions is often observed, and it is suggested an increase the antimicrobial resistance surveillance of this microbial group, mainly those isolated from children's diarrhea.

  8. Antimicrobial susceptibility patterns among bacteria isolated from intensive care units of the largest teaching hospital at the northwest of Iran

    Directory of Open Access Journals (Sweden)

    Hadi Hamishehkar

    Full Text Available ABSTRACT This study was conducted to determine the antimicrobial susceptibility patterns among common pathogens in the intensive care units (ICUs of a university hospital in northwestern Iran. A retrospective study was done on laboratory records of patients with nosocomial infection who were admitted to five ICUs of Imam Reza Hospital during a 21-month period from March 2010 to January, 2012. A total number of 556 isolates from 328 patients were evaluated. The most common sites of infections included respiratory (51.7%, urinary (24.8%, and blood (10.4%. The most frequently isolated microorganisms were Enterobacter aerogenes (50.6% followed by Escherichia coli (16.7% and Pseudomonas aeruginosa (7.5%. Staphylococcus aureus was the most frequent pathogen among gram-positives (39.7%. The rate of methicillin-resistant Staphylococcus aureus (MRSA was 87.5%. Multidrug-resistant (MDR gram-negative bacteria were documented in 25.8% of Acinetobacter, 20% of Klebsiella, and 16.6% of Pseudomonas. The most active antimicrobials were vancomycin (93.5% followed by amikacin (71.5% and gentamicin (46%. The overall antibiotic susceptibility was as follows: 36% ciprofloxacin, 19% imipenem, 20% trimethoprim-sulfamethoxazole, 20.5% ceftazidime, and 12% ceftriaxone. Due to the high rate of antimicrobial resistance in the ICU setting, more surveillance and control of the use of antimicrobials is needed to combat infections.

  9. Associations of erythrocyte fatty acid patterns with insulin resistance.

    Science.gov (United States)

    Bigornia, Sherman J; Lichtenstein, Alice H; Harris, William S; Tucker, Katherine L

    2016-03-01

    Synergistic or additive effects or both on cardiometabolic risk may be missed by examining individual fatty acids (FAs). A pattern analysis may be a more useful approach. In addition, it remains unclear whether erythrocyte FA composition relates to insulin resistance among Hispanics/Latinos. We derived erythrocyte FA patterns for a Puerto Rican cohort and examined their association with diet and insulin resistance in cross-sectional and prospective analyses. At baseline, principal components analysis was used to derive factor patterns with the use of 24 erythrocyte FAs from 1157 participants of the Boston Puerto Rican Health Study (aged 45-75 y). Dietary intake was assessed with a validated semiquantitative food-frequency questionnaire. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated at baseline and at the 2-y follow-up. Relations between FA patterns and HOMA-IR were analyzed in a sample of 922 participants with available data. Five FA patterns were derived, differentiated by 1) relatively high de novo lipogenesis (DNL) FAs and low n-6 (ω-6) FAs, 2) high very-long-chain saturated FAs, 3) high n-3 (ω-3) FAs, 4) high linoleic acid and low arachidonic acid, and 5) high trans FAs. The DNL pattern was positively correlated with sugar and inversely with n-6 and monounsaturated FA intakes. Only the DNL pattern was positively related to baseline HOMA-IR [adjusted geometric means (95% CIs) for quartiles 1 and 4: 1.72 (1.58, 1.87) and 2.20 (2.02, 2.39); P-trend insulin sensitivity in a Hispanic/Latino cohort. © 2016 American Society for Nutrition.

  10. Analysis on Antimicrobial Resistance of Clinical Bacteria Isolated from County Hospitals and a Teaching Hospital

    Institute of Scientific and Technical Information of China (English)

    SUN Ziyong; LI Li; ZHU Xuhui; MA Yue; LI Jingyun; SHEN Zhengyi; JIN Shaohong

    2006-01-01

    The distinction of antimicrobial resistance of clinical bacteria isolated from county hospitals and a teaching hospital was investigated. Disc diffusion test was used to study the antimicrobial resistance of isolates collected from county hospitals and a teaching hospital. The data was analyzed by WHONET5 and SPSS statistic software. A total of 655 strains and 1682 strains were collected from county hospitals and a teaching hospital, respectively, in the year of 2003. The top ten pathogens were Coagulase negative staphylococci (CNS), E. coli, Klebsiella spp. , S. areus, P. aeruginosa, Enterococcus spp. , Enterobacter spp. , otherwise Salmonella spp. , Proteus spp. , Shigella spp. in county hospitals and Streptococcus spp. , Acinetobacter spp. , X. maltophilia in the teaching hospital. The prevalence of multi-drug resistant bacteria was 5% (4/86) of methicillin-resistant S. areus (MRSA), 12% (16/133) and 15.8 % (9/57) of extended-spectrum β-lactamases producing strains of E. coli and Klebsiella spp. , respectively, in county hospitals. All of the three rates were lower than that in the teaching hospital and the difference was statistically significant (P<0.01). However, the incidence of methicillin-resistant CNS (MRCNS) reached to 70 % (109/156) in the two classes of hospitals. Generally, the antimicrobial resistant rates in the county hospitals were lower than those in the teaching hospital, except the resistant rates of ciprofloxacin, erythromycin, clindamycin, SMZco which were similar in the two classes of hospitals. There were differences between county hospitals and the teaching hospital in the distribution of clinical isolates and prevalence of antimicrobial resistance. It was the basis of rational use of antimicrobial agents to monitor antimicrobial resistance by each hospital.

  11. Conjugation between quinolone-susceptible bacteria can generate mutations in the quinolone resistance-determining region, inducing quinolone resistance.

    Science.gov (United States)

    Pitondo-Silva, André; Martins, Vinicius Vicente; Silva, Carolina Fávero da; Stehling, Eliana Guedes

    2015-02-01

    Quinolones are an important group of antibacterial agents that can inhibit DNA gyrase and topoisomerase IV activity. DNA gyrase is responsible for maintaining bacteria in a negatively supercoiled state, being composed of subunits A and B. Topoisomerase IV is a homologue of DNA gyrase and consists of two subunits codified by the parC and parE genes. Mutations in gyrA and gyrB of DNA gyrase may confer resistance to quinolones, and the majority of resistant strains show mutations between positions 67 and 106 of gyrA, a region denoted the quinolone resistance-determining region (QRDR). The most frequent substitutions occur at positions 83 and 87, but little is known about the mechanisms promoting appearance of mutations in the QRDR. The present study proposes that some mutations in the QRDR could be generated as a result of the natural mechanism of conjugation between bacteria in their natural habitat. This event was observed following conjugation in vitro of two different isolates of quinolone-susceptible Pseudomonas aeruginosa, which transferred plasmids of different molecular weights to a recipient strain of Escherichia coli (HB101), also quinolone-susceptible, generating two different transconjugants that presented mutations in DNA gyrase and acquisition of resistance to all quinolones tested.

  12. Antimicrobial activity of medicinal plants used by aborigines of Kalahandi, Orissa, India against multidrug resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    Debasmita Dubey; Mahesh C Sahu; Shakti Rath; Bimoch Projna Paty; Nagen K Debata; Rabindra N Padhy

    2012-01-01

    Objective: To evaluate the antimicrobial potency of 20 non-edible and/or poisonous plants used by an aborigine tribe (Kandha) of Kalahandi district for infectious diseases. Methods: Over a period of 5 months from two hospitals, 10 pathogenic bacteria (Staphylococcus aureus (S. aureus), Acinetobacter sp., Citrobacter freundii (C. freundii), Chromobacterium violeceum (C. violeceum),Escherichia coli (E. coli), Klebsiella sp., Proteus sp., Pseudomonas aeruginosa (P. aeruginosa) Salmonella typhi (S. typhi) and Vibrio cholerae (V. cholerae) were isolated to pure axenic cultures from clinical samples. Water and ethanolic extracts of leaves and barks were concentrated before monitoring antimicrobial activity by agar-well diffusion method. Results: All bacterial strains isolated were multidrug resistant. Ethanolic extract of most plants had effective antimicrobial activity against all the isolated multidrug resistant bacteria. Plants, Anthocephalus cadamba (A. cadamba) and Pterocarpus santalinus (P. santalinus) had antibacterial effect on all used bacteria. Water extract of several plants too had effective antimicrobial activity for all bacteria used. Effective in vitro control of MDR strains of Acinetobacter sp., C. freundii, Proteus sp. and P. aeruginosa, the most potential urinary tract infection causing organisms by plant extracts of all major plant used herein is recorded. MDR C. violaceum isolated from skin lesions was found to be resistant to imipenem, piperacillin-tazobactam and amoxyclav and was found sensitive to 13 plant extracts. Conclusion: Effective in vitro control of MDR strains of Acinetobacter sp.,C. freundii, Proteus sp. and P. aeruginosa; enteropathogenic bacteria, E. coli, S. typhi, Klebsiella sp. and V. cholerae were found to be well controlled by all plant extracts used.

  13. Sewage sludge and liquid pig manure as possible sources of antibiotic resistant bacteria.

    Science.gov (United States)

    Hölzel, Christina S; Schwaiger, Karin; Harms, Katrin; Küchenhoff, Helmut; Kunz, Anne; Meyer, Karsten; Müller, Christa; Bauer, Johann

    2010-05-01

    Within the last decades, the environmental spread of antibiotic resistant bacteria has become a topic of concern. In this study, liquid pig manure (n=305) and sewage sludge (n=111) - used as agricultural fertilizers between 2002 and 2005 - were investigated for the presence of Escherichia coli, Enterococcus faecalis and Enterococcus faecium. Bacteria were tested for their resistance against 40 chemotherapeutics including several "reserve drugs". E. coli (n=613) from pig manure were at a significantly higher degree resistant to streptomycin, doxycycline, spectinomycin, cotrimoxazole, and chloramphenicol than E. coli (n=116) from sewage sludge. Enterococci (Ent. faecalis, n=387, and Ent. faecium, n=183) from pig manure were significantly more often resistant to high levels of doxycycline, rifampicin, erythromycin, and streptomycin than Ent. faecalis (n=44) and Ent. faecium (n=125) from sewage sludge. Significant differences in enterococcal resistance were also seen for tylosin, chloramphenicol, gentamicin high level, fosfomycin, clindamicin, enrofloxacin, moxifloxacin, nitrofurantoin, and quinupristin/dalfopristin. By contrast, aminopenicillins were more effective in enterococci from pig manure, and mean MIC-values of piperacillin+tazobactam and third generation cefalosporines were significantly lower in E. coli from pig manure than in E. coli from sewage sludge. 13.4% (E. coli) to 25.3% (Ent. faecium) of pig manure isolates were high-level multiresistant to substances from more than three different classes of antimicrobial agents. In sewage sludge, high-level-multiresistance reached from 0% (Ent. faecalis) to 16% (Ent. faecium). High rates of (multi-) resistant bacteria in pig manure emphasize the need for a prudent - cautious - use of antibiotics in farm animals.

  14. Level and transport pattern of faecal coliform bacteria from tropical urban catchments.

    Science.gov (United States)

    Chow, M F; Yusop, Z; Toriman, M E

    2013-01-01

    Urbanization and frequent storms play important roles in increasing faecal bacteria pollution, especially for tropical urban catchments. However, only little information on the faecal bacteria levels from different land use types and the factors that influence bacteria concentrations is available. Thus, the objectives of this study were to quantify the levels and transport mechanism of faecal coliforms (FCs) from residential and commercial catchments. Stormwaters were sampled and the runoff flow rates were measured from both catchments during four storm events in Skudai, Malaysia. The samples were then analysed for FC, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS) and ammoniacal-nitrogen (NH3-N) concentrations. Intra-storm and inter-storm characteristics of FC bacteria were investigated in order to identify the level and transport pattern of FC. The commercial catchment showed significantly higher event mean concentration (EMC) of FC than the residential catchment. For the residential catchment, the highest bacterial concentrations occurred during the early part of stormwater runoff with peak concentrations usually preceding the peak flow. First flush effect was more prevalent at the residential catchment.

  15. Synergistic effects of antimicrobial peptide DP7 combined with antibiotics against multidrug-resistant bacteria

    Science.gov (United States)

    Wu, Xiaozhe; Li, Zhan; Li, Xiaolu; Tian, Yaomei; Fan, Yingzi; Yu, Chaoheng; Zhou, Bailing; Liu, Yi; Xiang, Rong; Yang, Li

    2017-01-01

    Antibiotic-resistant bacteria present a great threat to public health. In this study, the synergistic effects of antimicrobial peptides (AMPs) and antibiotics on several multidrug-resistant bacterial strains were studied, and their synergistic effects on azithromycin (AZT)-resistance genes were analyzed to determine the relationships between antimicrobial resistance and these synergistic effects. A checkerboard method was used to evaluate the synergistic effects of AMPs (DP7 and CLS001) and several antibiotics (gentamicin, vancomycin [VAN], AZT, and amoxicillin) on clinical bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli). The AZT-resistance genes (ermA, ermB, ermC, mefA, and msrA) were identified in the resistant strains using quantitative polymerase chain reaction. For all the clinical isolates tested that were resistant to different antibiotics, DP7 had high antimicrobial activity (≤32 mg/L). When DP7 was combined with VAN or AZT, the effect was most frequently synergistic. When we studied the resistance genes of the AZT-resistant isolates, the synergistic effect of DP7–AZT occurred most frequently in highly resistant strains or strains carrying more than two AZT-resistance genes. A transmission electron microscopic analysis of the S. aureus strain synergistically affected by DP7–AZT showed no noteworthy morphological changes, suggesting that a molecular-level mechanism plays an important role in the synergistic action of DP7–AZT. AMP DP7 plus the antibiotic AZT or VAN is more effective, especially against highly antibiotic-resistant strains. PMID:28356719

  16. Suppression of Emergence of Resistance in Pathogenic Bacteria: Keeping Our Powder Dry, Part 1.

    Science.gov (United States)

    Drusano, G L; Louie, Arnold; MacGowan, Alasdair; Hope, William

    2015-12-28

    We are in a crisis of bacterial resistance. For economic reasons, most pharmaceutical companies are abandoning antimicrobial discovery efforts, while, in health care itself, infection control and antibiotic stewardship programs have generally failed to prevent the spread of drug-resistant bacteria. At this point, what can be done? The first step has been taken. Governments and international bodies have declared there is a worldwide crisis in antibiotic drug resistance. As discovery efforts begin anew, what more can be done to protect newly developing agents and improve the use of new drugs to suppress resistance emergence? A neglected path has been the use of recent knowledge regarding antibiotic dosing as single agents and in combination to minimize resistance emergence, while also providing sufficient early bacterial kill. In this review, we look at the data for resistance suppression. Approaches include increasing the intensity of therapy to suppress resistant subpopulations; developing concepts of clinical breakpoints to include issues surrounding suppression of resistance; and paying attention to the duration of therapy, which is another important issue for resistance suppression. New understanding of optimizing combination therapy is of interest for difficult-to-treat pathogens like Pseudomonas aeruginosa, Acinetobacter spp., and multidrug-resistant (MDR) Enterobacteriaceae. These lessons need to be applied to our old drugs to preserve them as well and need to be put into national and international antibiotic resistance strategies. As importantly, from a regulatory perspective, new chemical entities should have a corresponding resistance suppression plan at the time of regulatory review. In this way, we can make the best of our current situation and improve future prospects.

  17. Fluoroquinolone-resistant enteric bacteria in sub-Saharan Africa: Clones, Implications and Research needs

    Directory of Open Access Journals (Sweden)

    Marie Anne Chattaway

    2016-04-01

    Full Text Available Fluoroquinolones came into widespread use in African countries in the early 2000s, after patents for the first generation of these drugs expired. By that time, quinolone antibacterial agents had been used intensively worldwide and resistant lineages of many bacterial species had evolved. We sought to understand which Gram negative enteric pandemic lineages have been reported from Africa, as well as the nature and transmission of any indigenous resistant clones. A systematic review of articles indexed in the Medline and AJOL literature databases was conducted. We report on the findings of 43 eligible studies documenting local or pandemic fluoroquinolone-resistant enteric clones in sub-Sahara African countries. Most reports are of invasive non-typhoidal Salmonella and Escherichia coli lineages and there have been three reports of cholera outbreaks caused by fluoroquinolone-resistant Vibrio cholerae O1. Fluoroquinolone-resistant clones have also been reported from commensals and animal isolates but there are few data for non-Enterobacteriaceae and almost none for difficult-to-culture Campylobacter spp. Fluoroquinolone-resistant lineages identified in African countries were universally resistant to multiple other classes of antibacterial agents. Although as many as 972 non-duplicate articles refer to fluoroquinolone resistance in enteric bacteria from Africa, most do not report on subtypes and therefore information on the epidemiology of fluoroquinolone-resistant clones is available from only a handful of countries in the subcontinent. When resistance is reported, resistance mechanisms and lineage information is rarely investigated. Insufficient attention has been given to molecular and sequence-based methods necessary for identifying and tracking resistant clones in Africa and more research is needed in this area.

  18. In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador.

    Science.gov (United States)

    Eisenberg, Joseph N S; Goldstick, Jason; Cevallos, William; Trueba, Gabriel; Levy, Karen; Scott, James; Percha, Bethany; Segovia, Rosana; Ponce, Karina; Hubbard, Alan; Marrs, Carl; Foxman, Betsy; Smith, David L; Trostle, James

    2012-05-07

    The evolution of antibiotic resistance (AR) increases treatment cost and probability of failure, threatening human health worldwide. The relative importance of individual antibiotic use, environmental transmission and rates of introduction of resistant bacteria in explaining community AR patterns is poorly understood. Evaluating their relative importance requires studying a region where they vary. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to study how changes in the social and natural environment affect the epidemiology of resistant Escherichia coli. We conducted seven bi-annual 15 day surveys of AR between 2003 and 2008 in 21 villages. Resistance to both ampicillin and sulphamethoxazole was the most frequently observed profile, based on antibiogram tests of seven antibiotics from 2210 samples. The prevalence of enteric bacteria with this resistance pair in the less remote communities was 80 per cent higher than in more remote communities (OR = 1.8 [1.3, 2.3]). This pattern could not be explained with data on individual antibiotic use. We used a transmission model to help explain this observed discrepancy. The model analysis suggests that both transmission and the rate of introduction of resistant bacteria into communities may contribute to the observed regional scale AR patterns, and that village-level antibiotic use rate determines which of these two factors predominate. While usually conceived as a main effect on individual risk, antibiotic use rate is revealed in this analysis as an effect modifier with regard to community-level risk of resistance.

  19. Screening of metal-resistant coal mine bacteria for biofabrication of elemental silver nanoparticle

    Indian Academy of Sciences (India)

    SUBHASMITA PANDA; KANTI KUSUM YADAV; PARTH SARTHI NAYAK; MANORANJAN ARAKHA; SUMAN JHA

    2016-04-01

    Green synthesis approaches for nanoparticle synthesis are considered as nontoxic, eco-friendly and cost-effective approaches than other physical and chemical approaches. Here, we report green synthesis of silver nanoparticle using the bacteria from the habitat of relatively metal-rich coal mine dust. The bacteria showed resistance to significant concentration of anti-microbial Ag(I) ion. The nanoparticle was synthesized at minimum inhibitory concentration (MIC) of Ag(I) using only two isolates. The synthesis of silver nanoparticle was confirmed from the surface plasmon resonance property of the nanoparticle, whereas morphological features were studied using field emission scanning electron microscope. The hydrodynamic size analysis showed the presence ofmicroparticles along with the nanoparticles. Additionally, IR study provided information about the bacterial proteins involved in either reduction of Ag(I) into silver nanoparticle or capping of reduced silver nanocrystal or both.Thus, majority of the bacteria found in the coal mines have the resistance against the antimicrobial metal ion, and the potential to reduce the ion into nano- or micro-particles. Hence, the bacteria can be used as a single cell factoryfor production of silver nanomaterial.

  20. Laser thermal ablation of multidrug-resistant bacteria using functionalized gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Mocan L

    2017-03-01

    Full Text Available Lucian Mocan,1,2 Flaviu A Tabaran,3 Teodora Mocan,2,4 Teodora Pop,5 Ofelia Mosteanu,5 Lucia Agoston-Coldea,6 Cristian T Matea,2 Diana Gonciar,2 Claudiu Zdrehus,1,2 Cornel Iancu1 13rd Department of General Surgery, “Iuliu Hatieganu” University of Medicine and Pharmacy, 2Department of Nanomedicine, “Octavian Fodor” Gastroenterology Institute, 3Department of Pathology, University of Agricultural Sciences and Veterinary Medicine, Faculty of Veterinary Medicine, 4Department of Physiology, 53rd Gastroenterology Department, 6Department of Internal Medicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania Abstract: The issue of multidrug resistance (MDR has become an increasing threat to public health. One alternative strategy against MDR bacteria would be to construct therapeutic vectors capable of physically damaging these microorganisms. Gold nanoparticles hold great promise for the development of such therapeutic agents, since the nanoparticles exhibit impressive properties, of which the most important is the ability to convert light into heat. This property has scientific significance since is exploited to develop nano-photothermal vectors to destroy bacteria at a molecular level. The present paper summarizes the latest advancements in the field of nanotargeted laser hyperthermia of MDR bacteria mediated by gold nanoparticles. Keywords: bacteria, photo-thermal ablation, gold nanoparticles, antibiotic resistance

  1. Resistance in bacteria of the food chain: epidemiology and control strategies

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Wegener, Henrik Caspar; Collignon, P.

    2008-01-01

    licensing, removing financial incentives, banning or restricting the use of certain drugs, altering prescribers behavior, improving animal health, improving hygiene and implementing microbial criteria for certain types of resistant pathogens for use in the control of trade of both food animals and food....... quantification of the transmission difficult. The exposure of humans to antimicrobial resistance from food animals can be controlled by either limiting the selective pressure from antimicrobial usage or by limiting the spread of the bacteria/genes. A number of control options are reviewed, including drug...

  2. Role of Mn2+ and Compatible Solutes in the Radiation Resistance of Thermophilic Bacteria and Archaea

    Directory of Open Access Journals (Sweden)

    Kimberly M. Webb

    2012-01-01

    Full Text Available Radiation-resistant bacteria have garnered a great deal of attention from scientists seeking to expose the mechanisms underlying their incredible survival abilities. Recent analyses showed that the resistance to ionizing radiation (IR in the archaeon Halobacterium salinarum is dependent upon Mn-antioxidant complexes responsible for the scavenging of reactive oxygen species (ROS generated by radiation. Here we examined the role of the compatible solutes trehalose, mannosylglycerate, and di-myo-inositol phosphate in the radiation resistance of aerobic and anaerobic thermophiles. We found that the IR resistance of the thermophilic bacteria Rubrobacter xylanophilus and Rubrobacter radiotolerans was highly correlated to the accumulation of high intracellular concentration of trehalose in association with Mn, supporting the model of Mn2+-dependent ROS scavenging in the aerobes. In contrast, the hyperthermophilic archaea Thermococcus gammatolerans and Pyrococcus furiosus did not contain significant amounts of intracellular Mn, and we found no significant antioxidant activity from mannosylglycerate and di-myo-inositol phosphate in vitro. We therefore propose that the low levels of IR-generated ROS under anaerobic conditions combined with highly constitutively expressed detoxification systems in these anaerobes are key to their radiation resistance and circumvent the need for the accumulation of Mn-antioxidant complexes in the cell.

  3. Multiple metal resistant transferable phenotypes in bacteria as indicators of soil contamination with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.P.; Ryan, D.J.; Dowling, D.N. [Dept. of Science and Health, Inst. of Tech. Carlow, Carlow (Ireland)

    2005-07-01

    Environmental contamination by heavy metals affects microbial communities. The number of single and multiple heavy metal resistant bacteria may be an indicator of the level of contamination. This paper details the isolation and characterisation of metal resistant microorganisms isolated from rhizosphere/soil samples obtained from an abandoned zinc, lead and copper mine and a local unaffected site. This data was compared to the level of heavy metal in the soils to establish the effect of metals on the microbial community and to determine the relationship between pollutant levels and resistant strains. This paper outlines the diversity of transferable resistance determinants between both sites and details the levels of heavy metal resistant bacteria and those expressing transferable multiple heavy metal tolerance. Methods. The sample sites were located in Co. Galway, Ireland. The first sample site (site A) was a former lead, zinc and copper mine, which was closed in 1961 due to exhaustion of ore. The second site (site B) was located two and a half kilometres from the mining site and was not affected by the mining operations. Composite soil samples were characterised for general soil matrix composition, organic content, pH and general chemical parameters. The soil was also enumerated for the total viable heterotrophic counts and tested on Pseudomonas selective agar (PSA) for total Pseudomonas counts and Sucrose Asparagine (SA), which is semi-selective for fluorescent Pseudomonas. (orig.)

  4. Antimicrobial resistance of coagulase-negative staphylococci and lactic acid bacteria from industrially produced dairy products

    Directory of Open Access Journals (Sweden)

    Nevijo Zdolec

    2013-03-01

    Full Text Available In this research, the susceptibility to clindamycin, tetracycline, amikacin, amoxicillin + clavulanic acid, enrofloxacine, vancomycin, trimethoprim + sulphametoxazol, tobramycin, chloramphenicol, ciprofloxacin, erythromycin, penicillin and trimethoprim was tested in coagulase-negative staphylococci (n=78 and lactic acid bacteria (n=30 by means of disk diffusion test and E-test. The isolates were collected from soft and hard cheeses, butter and brine. All isolates of coagulase-negative staphylococci were susceptible to clindamycin, amikacin, amoxicillin + clavulanic acid, enrofloxacine, vancomycin, chloramphenicol and ciprofloxacin according to CLSI breakpoints. A total of 30 staphylococci isolates (38.46 % were resistant to erythromycin, 18 to penicillin (23.07 %, 4 to tetracycline (5.12 %, and one isolate to trimethoprim, tobramicin and trimethoprim + sulphametoxazol (1.28 %. Among 78 tested staphylococci, 35 of them were resistant to at least one antimicrobial substance (44.87 %. The rate of resistant isolates of different soft cheese types ranged from 22 to 70 %, while resistant staphylococci were absent in hard cheese and brine. The growth of lactic acid bacteria was not influenced by trimethoprim + sulphametoxazol (n=29, vancomycin (n=29, trimethoprim (n=28, amikacin (n=10 and tobramycin (n=10. The results show that significant part of apathogenic microbiota in different dairy products is phenotypically resistant to antimicrobial agents.

  5. Antibacterial activity of some natural products against bacteria expressing a multidrug-resistant phenotype

    OpenAIRE

    2011-01-01

    Abstract The present study assessed the antimicrobial activities of various natural products belonging to the terpenoids, alkaloids and phenolics against a collection of Gram-negative multidrug-resistant (MDR) bacteria. The results demonstrated that most of the compounds were extruded by bacterial efflux pumps. In the presence of the efflux pump inhibitor phenylalanine arginine ?-naphthylamide (PA?N), the activities of laurentixanthone B (xanthone), plumbagin (naphthoquinone), 4-hy...

  6. Colistin and tigecycline resistance in carbapenemase-producing Gram-negative bacteria: emerging resistance mechanisms and detection methods.

    Science.gov (United States)

    Osei Sekyere, J; Govinden, U; Bester, L A; Essack, S Y

    2016-09-01

    A literature review was undertaken to ascertain the molecular basis for tigecycline and colistin resistance mechanisms and the experimental basis for the detection and delineation of this resistance particularly in carbapenemase-producing Gram-negative bacteria. Pubmed, Google Scholar and Science Direct were searched with the keywords colistin, tigecycline, resistance mechanisms and detection methods. Trans-complementation and comparative MIC studies, mass spectrometry, chromatography, spectrofluorometry, PCR, qRT-PCR and whole genome sequencing (WGS) were commonly used to determine tigecycline and colistin resistance mechanisms, specifically modifications in the structural and regulatory efflux (acrAB, OqxAB, kpgABC adeABC-FGH-IJK, mexAB-XY-oprJM and soxS, rarA robA, ramRAB marRABC, adeLRS, mexRZ and nfxb) and lipid A (pmrHFIJFKLM, lpxA, lpxC lpxD and mgrB, pmrAB, phoPQ,) genes respectively. Mutations in the ribosomal 16S rRNA operon rrnBC, also yielded resistance to tigecycline through target site modifications. The mcr-1 gene conferring resistance to colistin was identified via WGS, trans-complementation and a murine thigh infection model studies. Common detection methods are mainly antibiotic sensitivity testing with broth microdilution while molecular identification tools are mostly PCR and WGS. Spectrofluorometry, MALDI-TOF MS, micro-array and real-time multiplex PCR hold much promise for the future as new detection tools.

  7. ANTIMICROBIAL RESISTANCE PATTERN OF STAPHYLOCOCCUS AUREUS ISOLATES FROM DAKSHINA KANNADA

    Directory of Open Access Journals (Sweden)

    Rao Venkatakrishna

    2011-03-01

    Full Text Available Methicillin resistant Staphylococcus aureus (MRSA is an important cause of infections in hospitals and pose a great challenge to the treating clinicians; even emergence of vancomycin resistance has been reported. Therefore the knowledge of prevalence of MRSA and their antimicrobial profile becomes necessary. This study is aimed to determine prevalence of MRSA and their antimicrobial sensitivity pattern in Dakshina Kannada.Clinical specimens and carrier samples were cultured as per standard methods. The isolates were identified by using catalase test, coagulase tube test, mannitol fermentation and DNAase test. Antimicrobial susceptibility test was done for the isolates as per Kirby-Bauer disc diffusion method; the isolates were also tested for methicillin resistance using oxacillin and cefoxitin discs.A total of 250 isolates were tested (200 clinical isolates and 50 from carriers and 67 MRSA isolates were obtained (52 clinical samples and 15 from carriers. The degree of resistance to penicillin, ampicillin, ciprofloxacin, clindamycin and erythromycin were 100%, 100%, 53-56%, 14-16 % and 45-48% respectively. Resistance to vancomycin was not found. As the degree of resistance of MRSA towards antibiotics varies from region to region, in vitro susceptibility testing of every isolate of MRSA in clinical laboratories is inevitable.

  8. Cultivation of hard-to-culture subsurface mercury-resistant bacteria and discovery of new merA gene sequences

    DEFF Research Database (Denmark)

    Rasmussen, L D; Zawadsky, C; Binnerup, S J

    2008-01-01

    was increased up to 2,800 times and numbers of mCFU were similar to the total number of mercury-resistant bacteria in the soils. Denaturing gradient gel electrophoresis analysis of DNA extracted from membranes suggested stimulation of growth of hard-to-culture bacteria during the preincubation. A total of 25......Mercury-resistant bacteria may be important players in mercury biogeochemistry. To assess the potential for mercury reduction by two subsurface microbial communities, resistant subpopulations and their merA genes were characterized by a combined molecular and cultivation-dependent approach...

  9. Transmission dynamics of resistant bacteria in a predator-prey system.

    Science.gov (United States)

    Gao, Xubin; Pan, Qiuhui; He, Mingfeng

    2015-01-01

    This paper discusses the impact on human health caused by the addition of antibiotics in the feed of food animals. We use the established transmission rule of resistant bacteria and combine it with a predator-prey system to determine a differential equations model. The equations have three steady equilibrium points corresponding to three population dynamics states under the influence of resistant bacteria. In order to quantitatively analyze the stability of the equilibrium points, we focused on the basic reproduction numbers. Then, both the local and global stability of the equilibrium points were quantitatively analyzed by using essential mathematical methods. Numerical results are provided to relate our model properties to some interesting biological cases. Finally, we discuss the effect of the two main parameters of the model, the proportion of antibiotics added to feed and the predation rate, and estimate the human health impacts related to the amount of feed antibiotics used. We further propose an approach for the prevention of the large-scale spread of resistant bacteria and illustrate the necessity of controlling the amount of in-feed antibiotics used.

  10. Synergistic antimicrobial activity of Camellia sinensis and Juglans regia against multidrug-resistant bacteria.

    Science.gov (United States)

    Farooqui, Amber; Khan, Adnan; Borghetto, Ilaria; Kazmi, Shahana U; Rubino, Salvatore; Paglietti, Bianca

    2015-01-01

    Synergistic combinations of antimicrobial agents with different mechanisms of action have been introduced as more successful strategies to combat infections involving multidrug resistant (MDR) bacteria. In this study, we investigated synergistic antimicrobial activity of Camellia sinensis and Juglans regia which are commonly used plants with different antimicrobial agents. Antimicrobial susceptibility of 350 Gram-positive and Gram-negative strains belonging to 10 different bacterial species, was tested against Camellia sinensis and Juglans regia extracts. Minimum inhibitory concentrations (MICs) were determined by agar dilution and microbroth dilution assays. Plant extracts were tested for synergistic antimicrobial activity with different antimicrobial agents by checkerboard titration, Etest/agar incorporation assays, and time kill kinetics. Extract treated and untreated bacteria were subjected to transmission electron microscopy to see the effect on bacterial cell morphology. Camellia sinensis extract showed higher antibacterial activity against MDR S. Typhi, alone and in combination with nalidixic acid, than to susceptible isolates." We further explore anti-staphylococcal activity of Juglans regia that lead to the changes in bacterial cell morphology indicating the cell wall of Gram-positive bacteria as possible target of action. The synergistic combination of Juglans regia and oxacillin reverted oxacillin resistance of methicillin resistant Staphylococcus aureus (MRSA) strains in vitro. This study provides novel information about antimicrobial and synergistic activity of Camellia sinensis and Juglans regia against MDR pathogens.

  11. Synergistic antimicrobial activity of Camellia sinensis and Juglans regia against multidrug-resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Amber Farooqui

    Full Text Available Synergistic combinations of antimicrobial agents with different mechanisms of action have been introduced as more successful strategies to combat infections involving multidrug resistant (MDR bacteria. In this study, we investigated synergistic antimicrobial activity of Camellia sinensis and Juglans regia which are commonly used plants with different antimicrobial agents. Antimicrobial susceptibility of 350 Gram-positive and Gram-negative strains belonging to 10 different bacterial species, was tested against Camellia sinensis and Juglans regia extracts. Minimum inhibitory concentrations (MICs were determined by agar dilution and microbroth dilution assays. Plant extracts were tested for synergistic antimicrobial activity with different antimicrobial agents by checkerboard titration, Etest/agar incorporation assays, and time kill kinetics. Extract treated and untreated bacteria were subjected to transmission electron microscopy to see the effect on bacterial cell morphology. Camellia sinensis extract showed higher antibacterial activity against MDR S. Typhi, alone and in combination with nalidixic acid, than to susceptible isolates." We further explore anti-staphylococcal activity of Juglans regia that lead to the changes in bacterial cell morphology indicating the cell wall of Gram-positive bacteria as possible target of action. The synergistic combination of Juglans regia and oxacillin reverted oxacillin resistance of methicillin resistant Staphylococcus aureus (MRSA strains in vitro. This study provides novel information about antimicrobial and synergistic activity of Camellia sinensis and Juglans regia against MDR pathogens.

  12. Azithromycin, fluoroquinolone and chloramphenicol resistance of non-chlamydia conjunctival bacteria in rural community of Ethiopia

    Directory of Open Access Journals (Sweden)

    Bayeh Abera

    2014-01-01

    Full Text Available Aim: To determine profiles of non-chlamydia conjunctival bacteria and their antimicrobial susceptibility from adults who underwent trachomatous trichiasis surgery in rural areas of Ethiopia. Materials and Methods: A cross-sectional study was conducted in rural districts in West Gojjam administrative zone. Conjunctival swabs were collected during surgery and transported using Stuart transport broth (Oxoid, UK. Antibiotic susceptibility of conjunctival isolates was determined using the Kirby-Bauer disc-diffusion method. Results: Non-chlamydia pathogenic bacteria were recovered from conjunctiva of 438 (31% participants before treatment. The isolated conjunctival bacteria were Staphylococcus aureus, coagulase-negative Staphylococci, Streptococcus group (A, C, F and G, Enterococci, Streptococcus pneumoniae, Moraxella spp., Escherichia coli, Citrobacter spp., Proteus spp., Klebsiella spp., Pseudomonas spp. and Enterobacter spp. Overall, resistance rates of 57.8% to azithromycin and 68.5% to chloramphenicol were found. However, 86-94.4% sensitivity was demonstrated to ciprofloxacin and norfloxacin. Moderate sensitivity rates (61.8-78.4% were observed to ceftriaxone, tetracycline and cotrimoxazole. Conclusion: Fluoroquinolones that have activity against the majority of bacterial isolates were potent at in vitro. However, unacceptably high levels of resistance to azithromycin and chloramphenicol in rural community indicated a need for further study and antimicrobial resistance surveillance.

  13. Photodynamic inactivation of multidrug-resistant bacteria in hospital wastewaters: influence of residual antibiotics.

    Science.gov (United States)

    Almeida, Joana; Tomé, João P C; Neves, Maria G P M S; Tomé, Augusto C; Cavaleiro, José A S; Cunha, Ângela; Costa, Liliana; Faustino, Maria A F; Almeida, Adelaide

    2014-04-01

    One environmental concern related to hospital effluents is discharge of them without preliminary treatment. Antimicrobial photodynamic inactivation (PDI) may represent an alternative to the traditional expensive, unsafe and not always effective disinfection methods. The main goal of this work was to assess the efficiency of PDI on clinical multidrug-resistant (MDR) bacteria in hospital wastewaters in order to evaluate its potential use in treating hospital effluents. The efficiency of PDI was assessed using a cationic porphyrin as the photosensitizer (PS), four MDR bacteria either in phosphate buffered saline or in filtrated hospital wastewaters. The synergistic effect of PDI and antibiotics (ampicillin and chloramphenicol) was also evaluated, as well as the effect of the surfactant sodium dodecyl sulfate (SDS). The results show the efficient inactivation of MDR bacteria in PBS (reduction of 6-8 log after 270 min of irradiation at 40 W m(-2) with 5.0 μM of PS). In wastewater, the inactivation of the four MDR bacteria was again efficient and the decrease in bacterial survival starts even sooner. A faster decrease in bacterial survival occurred when PDI was combined with the addition of antibiotics, at sub-inhibitory and inhibitory concentrations, but the SDS did not affect the PDI efficiency. It can be concluded that PDI has potential to be an effective alternative for the inactivation of MDR bacteria in hospital wastewaters and that the presence of antibiotics may enhance its effectiveness.

  14. Multiple Antibiotic Resistance and Heavy Metal Resistance Profile of Bacteria Isolated from Giant Freshwater Prawn (Macrobrachium rosenbergii) Hatchery

    Institute of Scientific and Technical Information of China (English)

    S W Lee; M Najiah; W Wendy; A Zahrol; M Nadirah

    2009-01-01

    In this article,antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn (Macrobrachium rosenbergii) hatchery in Malaysia are described.Although giant freshwater prawn was introduced into Malaysia since the 1980s,there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn (M.rosenbergii) hatchery in Malaysia.Therefore,this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M.rosenbergii hatchery.The results can provide valuable information for local M.rosenbergii post-larval producer.Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows:oxolinic acid (2 μg),ampicillin (10 μg),erythromycin (15 μg),furazolidone (15 μg),lincomycin (15 μg),amoxicillin (25 μg),col istin sulphate (25 μg),doxycycline (30 μg),florfenicol (30 μg),flumequine (30 μg),nalidixic acid (30 μg),tetracycline (30 μg),oleandomyein (15 μg),fosfomycin (50 μg),and spiramycin (100 μg),whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique.In this study,5 types of bacteria were successfully isolated;they were Aeromonas spp.(n= 77),Escherichia coil (n = 73),Edwardsiella spp.(n = 62),Salmonella spp.(n= 75),and Vibrio spp.(n = 43).The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study,approximately 89.7% of the bacterial isolates were sensitive to this antibiotic.Multiple antibiotic resistance (MAR) index indicated that the hatchery water source and M.rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic.Furthermore,all the tested heavy metals (Cd2+,Cr6+ Hg2+,and Cu2+) failed to inhibit the growth of the bacterial isolates.Therefore,it indicated that the water source of the hatchery is

  15. Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria.

    Science.gov (United States)

    Palaniappan, Kavitha; Holley, Richard A

    2010-06-15

    Plant-derived antibacterial compounds may be of value as a novel means for controlling antibiotic resistant zoonotic pathogens which contaminate food animals and their products. Individual activity of natural antimicrobials (eugenol, thymol, carvacrol, cinnamaldehyde, allyl isothiocyanate (AIT)) and activity when paired with an antibiotic was studied using broth microdilution and checkerboard methods. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interactions between the inhibitors. Bacteria tested were chosen because of their resistance to at least one antibiotic which had a known genetic basis. Substantial susceptibility of these bacteria toward the natural antimicrobials and a considerable reduction in the minimum inhibitory concentrations (MIC's) of the antibiotics were noted when paired combinations of antimicrobial and antibiotic were used. In the interaction study, thymol and carvacrol were found to be highly effective in reducing the resistance of Salmonella Typhimurium SGI 1 (tet A) to ampicillin, tetracycline, penicillin, bacitracin, erythromycin and novobiocin (FIC<0.4) and resistance of Streptococcus pyogenes ermB to erythromycin (FIC<0.5). With Escherichia coli N00 666, thymol and cinnamaldehyde were found to have a similar effect (FIC<0.4) in reducing the MIC's of ampicillin, tetracycline, penicillin, erythromycin and novobiocin. Carvacrol, thymol (FIC<0.3) and cinnamaldehyde (FIC<0.4) were effective against Staphylococcus aureus blaZ and in reducing the MIC's of ampicillin, penicillin and bacitracin. Allyl isothiocyanate (AIT) was effective in reducing the MIC of erythromycin (FIC<0.3) when tested against S. pyogenes. Fewer combinations were found to be synergistic when the decrease in viable population (log DP) was calculated. Together, fractional inhibitory concentrations < or = 0.5 and log DP<-1 indicated synergistic action between four natural antimicrobials and as many as three antibiotics

  16. Epidemiology and molecular characterization of multidrug-resistant Gram-negative bacteria in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Nuntra Suwantarat

    2016-05-01

    Full Text Available Abstract Background Multidrug-resistant Gram-negative bacteria (MDRGN, including extended-spectrum β-lactamases (ESBLs and multidrug-resistant glucose-nonfermenting Gram-negative bacilli (nonfermenters, have emerged and spread throughout Southeast Asia. Methods We reviewed and summarized current critical knowledge on the epidemiology and molecular characterization of MDRGN in Southeast Asia by PubMed searches for publications prior to 10 March 2016 with the term related to “MDRGN definition” combined with specific Southeast Asian country names (Thailand, Singapore, Malaysia, Vietnam, Indonesia, Philippines, Laos, Cambodia, Myanmar, Brunei. Results There were a total of 175 publications from the following countries: Thailand (77, Singapore (35, Malaysia (32, Vietnam (23, Indonesia (6, Philippines (1, Laos (1, and Brunei (1. We did not find any publications on MDRGN from Myanmar and Cambodia. We did not include publications related to Shigella spp., Salmonella spp., and Vibrio spp. and non-human related studies in our review. English language articles and abstracts were included for analysis. After the abstracts were reviewed, data on MDRGN in Southeast Asia from 54 publications were further reviewed and included in this study. Conclusions MDRGNs are a major contributor of antimicrobial-resistant bacteria in Southeast Asia. The high prevalence of ESBLs has been a major problem since 2005 and is possibly related to the development of carbapenem resistant organisms in this region due to the overuse of carbapenem therapy. Carbapenem–resistant Acinetobacter baumannii is the most common pathogen associated with nosocomial infections in this region followed by carbapenem-resistant Pseudomonas aeruginosa. Although Southeast Asia is not an endemic area for carbapenem-resistant Enterobacteriaceae (CRE, recently, the rate of CRE detection has been increasing. Limited infection control measures, lack of antimicrobial control, such as the presence of

  17. Antibiotic Resistance Pattern of Extended-Spectrum Beta-Lactamases-Producing Klebsiella pneumoniae Clinical Isolates from Zahedan, Southeast Iran

    Directory of Open Access Journals (Sweden)

    Shahram Shahraki-Zahedani

    2016-10-01

    Full Text Available Background Resistance to various classes of antibiotics is common among extended-spectrum beta-lactamases (ESBLs-producing bacteria. Objectives To determine the antibiotic resistance pattern of ESBLs-producing K. pneumoniae clinical isolates from Zahedan. Methods In this sectional-descriptive study, susceptibility of 51 ESBLs-producing K. pneumoniae isolates to 18 antimicrobial agents was determined. Results All isolates were resistant to cefotaxime, cefpodoxime and amoxicillin as well as susceptible to colistin sulfate. Also, most isolates were resistant to trimethoprim/sulfamethoxazole and aztreonam. Conclusions Our findings demonstrated that the rate of resistance to beta-lactams, sulfonamides, tetracyclines, aminoglycosides and fluoroquinolones in ESBLs-producing K. pneumoniae isolates is high in Zahedan.

  18. ANTIBIOTIC RESISTANCE IN LACTIC ACID BACTERIA ISOLATED FROM FERMENTED DAIRY PRODUCTS AND BOZA

    Directory of Open Access Journals (Sweden)

    Gamze Başbülbül

    2015-06-01

    Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.

  19. Study of frequency of bacteria isolated from blood culture and their antibiotic susceptibility pattern in a university hospital in Tehran

    OpenAIRE

    Hoorieh Saderi; Ali akbar Karimi; Marzieh Loni

    2009-01-01

    Introduction: Determining frequency of bacteria, isolated from blood culture and their antibiotic susceptibility patterns, has epidemiological significance and can help in selecting empirical therapy. This study was aimed to assess, the frequency of bacteria isolated from blood culture of patients suspected to bacteremia and their antibiotic susceptibility patterns. Methods: Culture of blood and determination of antibiotic susceptibility was done by standard methods. In this study, a variety ...

  20. Enumeration and characterization of antimicrobial-resistant Escherichia coli bacteria in effluent from municipal, hospital, and secondary treatment facility sources.

    Science.gov (United States)

    Galvin, Sandra; Boyle, Fiona; Hickey, Paul; Vellinga, Akke; Morris, Dearbháile; Cormican, Martin

    2010-07-01

    We describe a modification of the most probable number (MPN) method for rapid enumeration of antimicrobial-resistant Escherichia coli bacteria in aqueous environmental samples. E. coli (total and antimicrobial-resistant) bacteria were enumerated in effluent samples from a hospital (n = 17) and municipal sewers upstream (n = 5) and downstream (n = 5) from the hospital, effluent samples from throughout the treatment process (n = 4), and treated effluent samples (n = 13). Effluent downstream from the hospital contained a higher proportion of antimicrobial-resistant E. coli than that upstream from the hospital. Wastewater treatment reduced the numbers of E. coli bacteria (total and antimicrobial resistant); however, antimicrobial-resistant E. coli was not eliminated, and E. coli resistant to cefotaxime (including extended-spectrum beta-lactamase [ESBL] producers), ciprofloxacin, and cefoxitin was present in treated effluent samples.

  1. Antibiotic resistance profiles among mesophilic aerobic bacteria in Nigerian chicken litter and associated antibiotic resistance genes1.

    Science.gov (United States)

    Olonitola, Olayeni Stephen; Fahrenfeld, Nicole; Pruden, Amy

    2015-05-01

    The effect of global antibiotic use practices in livestock on the emergence of antibiotic resistant pathogens is poorly understood. There is a paucity of data among African nations, which suffer from high rates of antibiotic resistant infections among the human population. Escherichia (29.5%), Staphylococcus (15.8%), and Proteus (15.79%) were the dominant bacterial genera isolated from chicken litter from four different farms in Zaria, Nigeria, all of which contain human pathogenic members. Escherichia isolates were uniformly susceptible to augmentin and cefuroxime, but resistant to sulfamethoxazole (54.5%), ampicillin (22.7%), ciprofloxacin (18.2%), cephalothin (13.6%) and gentamicin (13.6%). Staphylococcus isolates were susceptible to ciprofloxacin, gentamicin, and sulfamethoxazole, but resistant to tetracycline (86.7%), erythromycin (80%), clindamycin (60%), and penicillin (33.3%). Many of the isolates (65.4%) were resistant to multiple antibiotics, with a multiple antibiotic resistance index (MARI) ≥ 0.2. sul1, sul2, and vanA were the most commonly detected antibiotic resistance genes among the isolates. Chicken litter associated with antibiotic use and farming practices in Nigeria could be a public health concern given that the antibiotic resistant patterns among genera containing pathogens indicate the potential for antibiotic treatment failure. However, the MARI values were generally lower than reported for Escherichia coli from intensive poultry operations in industrial nations.

  2. Occurrence of antimicrobial resistance among bacterial pathogens and indicator bacteria in pigs in different European countries from year 2002 – 2004: the ARBAO-II study

    Directory of Open Access Journals (Sweden)

    Hendriksen Rene S

    2008-06-01

    Full Text Available Abstract Background The project "Antibiotic resistance in bacteria of animal origin – II" (ARBAO-II was funded by the European Union (FAIR5-QLK2-2002-01146 for the period 2003–05. The aim of this project was to establish a program for the continuous monitoring of antimicrobial susceptibility of pathogenic and indicator bacteria from food animals using validated and harmonised methodologies. In this report the first data on the occurrence of antimicrobial resistance among bacteria causing infections in pigs are reported. Methods Susceptibility data from 17,642 isolates of pathogens and indicator bacteria including Actinobacillus pleuropneumoniae, Streptococcus suis and Escherichia coli isolated from pigs were collected from fifteen European countries in 2002–2004. Results Data for A. pleuropneumoniae from infected pigs were submitted from five countries. Most of the isolates from Denmark were susceptible to all drugs tested with the exceptions of a low frequency of resistance to tetracycline and trimethoprim – sulphonamide. Data for S. suis were obtained from six countries. In general, a high level of resistance to tetracycline (48.0 – 92.0% and erythromycin (29.1 – 75.0% was observed in all countries whereas the level of resistance to ciprofloxacin and penicillin differed between the reporting countries. Isolates from England (and Wales, France and The Netherlands were all susceptible to penicillin. In contrast the proportion of strains resistant to ciprofloxacin ranged from 12.6 to 79.0% (2004 and to penicillin from 8.1 – 13.0% (2004 in Poland and Portugal. Data for E. coli from infected and healthy pigs were obtained from eleven countries. The data reveal a high level of resistance to tetracyclines, streptomycin and ampicillin among infected pigs whereas in healthy pigs the frequency of resistance was lower. Conclusion Bacterial resistance to some antimicrobials was frequent with different levels of resistance being observed to

  3. In vitro antibacterial activity of Quercus infectoria gall extracts against multidrug resistant bacteria.

    Science.gov (United States)

    Wan Nor Amilah, W A W; Masrah, M; Hasmah, A; Noor Izani, N J

    2014-12-01

    Antimicrobial activities of plants have long been evaluated for their promising use as antimicrobial agent and in minimizing the unwanted resistance effects of microorganisms. The study was conducted to evaluate the antibacterial activity of Quercus infectoria gall crude extracts against multidrug resistant (MDR) bacteria in vitro. The screening test was determined by disc diffusion technique using sterile filter paper discs impregnated with 1 mg/ disc (50 mg/ml) aqueous and ethanol extracts of Q. infectoria galls tested on five selected MDR bacterial strains. The minimum inhibitory concentration (MIC) was determined using the twofold serial micro dilution technique at concentration ranging from 5.00 mg/ml to 0.01 mg/ml. The minimum bactericidal concentration (MBC) was determined by sub culturing the microtitre wells showing no turbidity on the agar plate to obtain the MBC value. Both extracts showed substantial inhibitory effects against methicillin resistant coagulase negative Staphylococcus (MRCoNS) and methicillin resistant Staphylococcus aureus (MRSA). A slightly reduced inhibitory zone diameter was observed with MDR Acinetobacter sp. while no inhibitory effect was displayed among the extended spectrum beta lactamases (ESBL) K. pneumoniae and ESBL E. coli isolates. A significant difference in the zone sizes between both extracts was only observed in MRSA (p antibacterial activities and may be considered as a potentially good source of antimicrobial agent especially against MDR Gram positive bacteria.

  4. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

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    R Andreazza

    2011-03-01

    Full Text Available Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária experimental station, Bento Gonçalves, RS, Brazil (29º09'53.92''S and 51º31'39.40''W and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30º29'43.48''S and 53'32'37.87W. Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L-1 in 24 h. Contrarily isolate N11 (Bacillus pumilus displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h. GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  5. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption.

    Science.gov (United States)

    Andreazza, R; Pieniz, S; Okeke, B C; Camargo, F A O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09'53.92″S and 51°31'39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29'43.48″S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L(-1) in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

  6. Characterization of antibiotic resistance in commensal bacteria from an aquaculture ecosystem

    Directory of Open Access Journals (Sweden)

    Ying eHuang

    2015-09-01

    Full Text Available The objective of the study was to improve understanding of antibiotic resistance (AR ecology through characterization of antibiotic resistant commensal isolates associated with an aquaculture production system. A total of 4767 isolates non-susceptible to sulfamethoxazole/trimethoprim, tetracycline, erythromycin, or cefotaxime, originated from fish, feed, and environmental samples of an aquaculture farm with no known history of antibiotic applications were examined. Close to 80% of the isolates exhibited multi-drug resistance in media containing the corresponding antibiotics, and representative AR genes were detected in various isolates by PCR, with feed isolates had the highest positive rate detected. Identified AR gene carriers involve 18 bacterial genera. Selected AR genes led to acquired resistance in other bacteria by transformation. The AR traits in many isolates were stable in the absence of selective pressure. AR-rich feed and possibly environmental factors may contribute to AR in the aquaculture ecosystem. For Minimum Inhibitory Concentration test, Brain Heart Infusion medium was found more suitable for majority of the bacteria examined than cation-adjusted Mueller Hinton broth, with latter being the recommended medium for clinical isolates by standard protocol. The data indicated a need to update the methodology due to genetic diversity of microbiota for better understanding of the AR ecology.

  7. Investigated of ampC in Carbapenem Resistant Gram-Negative Bacteria Isolated from Burned Patients

    Directory of Open Access Journals (Sweden)

    Leila Azimi

    2015-10-01

    Full Text Available Background: Gram-Negative bacteria are the most cause of nosocomial infection especially in burned patients. Carbapenem resistant strains can limit seriously the choice of antibiotic therapy. AmpC can make resistance to carbapenem and detection of that can be useful for identification ofcarbapenem resistant. The aim of this study was identification of ampC in most prevalent cause of nosocomial infection.Methods: boronic acid combined with meropenem in combination disc method was used for phenotypic method and PCR was used for molecular identification of ampC.Results: Fifty one strains showed positive results in phenotypic method but 119 strains were harbored ampC gene. Combination disc method with meropenem and boronic acid showed 34.4% sensitivity and 78.5% specificity according to the results of this study.Conclusions: the results of this study were indicated the more prevalent of ampC in carbapenem resistant Gram-Negative bacteria. On the other hand use of boronic acid combined with meropenem showed low sensitivity for detection of ampC.

  8. Coevolution of antibiotic production and counter-resistance in soil bacteria.

    Science.gov (United States)

    Laskaris, Paris; Tolba, Sahar; Calvo-Bado, Leo; Wellington, Elizabeth M; Wellington, Liz

    2010-03-01

    We present evidence for the coexistence and coevolution of antibiotic resistance and biosynthesis genes in soil bacteria. The distribution of the streptomycin (strA) and viomycin (vph) resistance genes was examined in Streptomyces isolates. strA and vph were found either within a biosynthetic gene cluster or independently. Streptomyces griseus strains possessing the streptomycin cluster formed part of a clonal complex. All S. griseus strains possessing solely strA belonged to two clades; both were closely related to the streptomycin producers. Other more distantly related S. griseus strains did not contain strA. S. griseus strains with only vph also formed two clades, but they were more distantly related to the producers and to one another. The expression of the strA gene was constitutive in a resistance-only strain whereas streptomycin producers showed peak strA expression in late log phase that correlates with the switch on of streptomycin biosynthesis. While there is evidence that antibiotics have diverse roles in nature, our data clearly support the coevolution of resistance in the presence of antibiotic biosynthetic capability within closely related soil dwelling bacteria. This reinforces the view that, for some antibiotics at least, the primary role is one of antibiosis during competition in soil for resources.

  9. Distribution of antimicrobial-resistant lactic acid bacteria in natural cheese in Japan.

    Science.gov (United States)

    Ishihara, Kanako; Nakajima, Kumiko; Kishimoto, Satoko; Atarashi, Fumiaki; Muramatsu, Yasukazu; Hotta, Akitoyo; Ishii, Satomi; Takeda, Yasuyuki; Kikuchi, Masanori; Tamura, Yutaka

    2013-10-01

    To determine and compare the extent of contamination caused by antimicrobial-resistant lactic acid bacteria (LAB) in imported and domestic natural cheeses on the Japanese market, LAB were isolated using deMan, Rogosa and Sharpe (MRS) agar and MRS agar supplemented with six antimicrobials. From 38 imported and 24 Japanese cheeses, 409 LAB isolates were obtained and their antimicrobial resistance was tested. The percentage of LAB resistant to dihydrostreptomycin, erythromycin, and/or oxytetracycline isolated from imported cheeses (42.1%) was significantly higher than that of LAB resistant to dihydrostreptomycin or oxytetracycline from cheeses produced in Japan (16.7%; P=0.04). Antimicrobial resistance genes were detected in Enterococcus faecalis (tetL, tetM, and ermB; tetL and ermB; tetM) E. faecium (tetM), Lactococcus lactis (tetS), Lactobacillus (Lb.), casei/paracasei (tetM or tetW), and Lb. rhamnosus (ermB) isolated from seven imported cheeses. Moreover, these E. faecalis isolates were able to transfer antimicrobial resistance gene(s). Although antimicrobial resistance genes were not detected in any LAB isolates from Japanese cheeses, Lb. casei/paracasei and Lb. coryniformis isolates from a Japanese farm-made cheese were resistant to oxytetracycline (minimal inhibitory concentration [MIC], 32 µg/mL). Leuconostoc isolates from three Japanese farm-made cheeses were also resistant to dihydrostreptomycin (MIC, 32 to >512 µg/mL). In conclusion, the present study demonstrated contamination with antimicrobial-resistant LAB in imported and Japanese farm-made cheeses on the Japanese market, but not in Japanese commercial cheeses.

  10. Quantifying Cost-Effectiveness of Controlling Nosocomial Spread of Antibiotic-Resistant Bacteria : The Case of MRSA

    NARCIS (Netherlands)

    Wassenberg, Marjan W. M.; de Wit, G. Ardine; van Hout, Ben A.; Bonten, Marc J. M.

    2010-01-01

    Background: The costs and benefits of controlling nosocomial spread of antibiotic-resistant bacteria are unknown. Methods: We developed a mathematical algorithm to determine cost-effectiveness of infection control programs and explored the dynamical interactions between different epidemiological var

  11. Occurrence and distribution of multiple antibiotic-resistant bacteria of Enterobacteriaceae family in waters of Veraval coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Maloo, A.; Borade, S.; Dhawde, R.; Gajbhiye, S.N.; Dastager, S.G.

    commonly used for treating human infections. Antibiotic resistance of bacteria was determined by the disc diffusion method. Of 235 isolates, 99 fecal coliforms, 30 Escherichia coli, 43 Enterobacter spp., 56 Klebsiella spp., and seven Salmonella spp. were...

  12. Association between the consumption of antimicrobial agents in animal husbandry and the occurrence of resistant bacteria among food animals

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller

    1999-01-01

    Antimicrobial agents are used in food animals for therapy and prophylaxis of bacterial infections and in feed to promote growth. The use of antimicrobial agents for food animals may cause problems in the therapy of infections by selecting for resistance among bacteria pathogenic for animals...... animals, the quantitative impact of the use of different antimicrobial agents on selection for resistance and the most appropriate treatment regimens to limit the development of resistance is incomplete. Surveillance programmes monitoring the occurrence and development of resistance and consumption...... or humans. The emergence of resistant bacteria and resistance genes following the use of antimicrobial agents is relatively well documented and it seems evident that all antimicrobial agents will select for resistance. However, current knowledge regarding the occurrence of antimicrobial resistance in food...

  13. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture

    DEFF Research Database (Denmark)

    Noor Uddin, Gazi Md; Larsen, Marianne Halberg; Christensen, Henrik

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance...... in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic....... used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have...

  14. Detection,isolation,and identification of cadmium-resistant bacteria based on PCR-DGGE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study focused on the screening of cadmium-resistant bacterial strains from Pb-Zn tailing.We investigated the diversity of microbial community inhabiting Dong-san-cha Pb-Zn tailing in Beijing,China,by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene of bacterial strain,and found two dominant strains in the DGGE profile.Using special culture media,We isolated two strong cadmium-resistant bacterial strains.On the basis of morphological,physiological,and biochemical characteristics,BIOLOG,and 16S rDNA sequencing,the two strains were identified as Bacillus cereus and Enterobaeter cloacae.Minimal inhibitory concentrations (MICs) of heavy metals for the bacteria were determined.E.cloacae showed higher MIC values for heavy metals and a larger range of antibiotic resistance than B.cereus.

  15. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture

    DEFF Research Database (Denmark)

    Noor Uddin, Gazi Md; Larsen, Marianne Halberg; Christensen, Henrik;

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance...... in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic....... used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have...

  16. Multi-antibiotic resistant bacteria in frozen food (ready to cook food) of animal origin sold in Dhaka, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Fouzia Sultana; Kamrunnahar; Hafsa Afroz; Afroz Jahan; Md Fakruddin; Suvamoy Datta

    2014-01-01

    Objective: To investigate the bacterial load and antibiotic resistance pattern of bacterial isolates obtained from (ready to cook) frozen food samples of animal origin in Dhaka, Bangladesh. Methods: A total of 20 samples of frozen ready to cook food of animal origin were purchased from different separate grocery stores in Dhaka, Bangladesh. Bacteria were isolated and identified based on the basis of biochemical properties. Results: A total of 57 isolates has been isolated from 20 samples, of them 35.08% were Gram positive and 64.92% were Gram negative organisms. Highest percentages of isolated organisms were Staphylococcocus spp. (24.56%), Alcaligene spp. (17.54%), Klebshiella spp. (12.28%) and the lowest percentages of organisms were Enterococcus spp., Actinobacillus spp. and Proteus spp. Antibiogram results clearly showed that levofloxacin and imipenem were the most effective drug against the isolates. The less effective antibiotics were chloramphenicol and nalidixic acid and resistance was highest against ciprofloxacin. The most contaminated food was chicken nuggets. Conclusions: This type of frozen food contaminated with multi-antibiotic resistant microorganisms can be potential vehicles for transmitting food-borne diseases.

  17. Nosocomial Infections in Intensive Care Unit: Pattern of Antibiotic-resistance in Iranian Community.

    Science.gov (United States)

    Esfahani, Bahram Nasr; Basiri, Rozita; Mirhosseini, Seyed Mohammad Mahdy; Moghim, Sharareh; Dolatkhah, Shahaboddin

    2017-01-01

    Bacterial infections are responsible for great number of mortality in Intensive Care Unit (ICU). Knowledge about prevalence of bacterial infections and their antibiotic-resistance pattern would be a great step for their treatment and management. Data about nosocomial infections in ICUs of Alzahra Hospital (referral hospital in Isfahan, center of Iran) were gathered during the years 2007-2010. A questionnaire was fulfilled for any specific patient with nosocomial infection containing demographic data of patient and also characteristics of the infection. Out of all patients, 707 individuals (65.6%) were male and 370 (34.4%) were female. Our data revealed that Pseudomonas aeruginosa (13.9%), Klebsiella (11%), and Escherichia coli (6.4%) were the most prevalent bacterial infections. The most common sites of nosocomial infections in the ICU were respiratory system (399 cases, 37%), urinary system (230 cases, 21.4%), and blood (102 cases, 9.5%). The antibiotic-resistance of each bacteria in ICU ward was assessed and data were categorized in a table. There were less documentary about bacterial cultures in the year 2007 when compared with the next years. We found some differences (such as bacterial prevalence in ICU wards which caused nosocomial infections) in our local prevalence of nosocomial infections and also in their resistance pattern compared to other centers. Knowing about our data will help physicians to administer the most suitable antibiotics for treatment of nosocomial infections in our area.

  18. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria.

    Science.gov (United States)

    Tängdén, Thomas

    2014-05-01

    Combination antibiotic therapy for Gram-negative sepsis is controversial. The present review provides a brief summary of the existing knowledge on combination therapy for severe infections with multidrug-resistant Pseudomonas spp., Acinetobacter spp., and Enterobacteriaceae. Empirical combination antibiotic therapy is recommended for severe sepsis and septic shock to reduce mortality related to inappropriate antibiotic treatment. Because definitive combination therapy has not been proven superior to monotherapy in meta-analyses, it is generally advised to de-escalate antibiotic therapy when the antibiotic susceptibility profile is known, although it cannot be excluded that some subgroups of patients might still benefit from continued combination therapy. Definitive combination therapy is recommended for carbapenemase-producing Enterobacteriaceae and should also be considered for severe infections with Pseudomonas and Acinetobacter spp. when beta-lactams cannot be used. Because resistance to broad-spectrum beta-lactams is increasing in Gram-negative bacteria and because no new antibiotics are expected to become available in the near future, the antibacterial potential of combination therapy should be further explored. In vitro data suggest that combinations can be effective even if the bacteria are resistant to the individual antibiotics, although existing evidence is insufficient to support the choice of combinations and explain the synergistic effects observed. In vitro models can be used to screen for effective combinations that can later be validated in animal or clinical studies. Further, in the absence of clinical evidence, in vitro data might be useful in supporting therapeutic decisions for severe infections with multidrug-resistant Gram-negative bacteria.

  19. Multidrug-Resistant Gram-Negative Bacteria Colonization of Healthy US Military Personnel in the US and Afghanistan

    Science.gov (United States)

    2013-02-05

    Randrianirina F, Ratovoson R, et al: Rectal carriage of extended- spectrum beta-lactamase-producing gram - negative bacilli in community settings in...FEB 2013 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Multidrug-resistant gram - negative bacteria colonization of healthy US...98) Prescribed by ANSI Std Z39-18 Multidrug-resistant gram - negative bacteria colonization of healthy US military personnel in the US and

  20. Bacteria associated with highly drought resistant Pistacia terebinthus: the key to reduce drought stress in other plant species?

    OpenAIRE

    Van de Weyer, Inge

    2013-01-01

    Plant-associated bacteria can not only stimulate plant growth, but also play an important role in the adaptation of their host plant to stress-inducing environmental conditions such as extreme drought. In this project, the effect of inoculation with selected endophytic bacteria isolated from the highly drought resistant tree Pistacia terebinthus on the drought resistance of four different plant species was evaluated. The results show that drought had a strong negative impact on all plant spec...

  1. Extended-spectrum beta-lactamase-producing bacteria in a tertiary care hospital in Madrid: epidemiology, risk factors and antimicrobial susceptibility patterns

    Directory of Open Access Journals (Sweden)

    Ines Rubio-Perez

    2012-07-01

    Full Text Available Introduction: Extended-spectrum beta-lactamase (ESBL producing bacteria have been increasingly reported as causal agents of nosocomial infection worldwide. Resistance patterns vary internationally, and even locally, from one institution to the other. We investigated the clinical isolates positive for ESBL-producing bacteria in our institution, a tertiary care hospital in Madrid (Spain, during a 2-year period (2007–2008. Methods: Clinical and microbiological data were retrospectively reviewed. Two hundred and nineteen patients were included in the study. Results: Advanced age, diabetes, use of catheters, previous hospitalization and previous antibiotic treatment were some of the risk factors found among patients. Escherichia coli was the most frequent isolate, and urinary tract the most common site of isolation. Internal Medicine, Intensive Care Unit (ICU and General Surgery presented the highest number of isolates. There were no outbreaks during the study period. Antibiotic patterns showed high resistance rates to quinolones in all isolates. There was 100% sensitivity to carbapenems. Conclusion: Carbapenems continue to be the treatment of choice for ESBL-producing bacteria. Infection control measures are of great importance to avoid the spread of these nosocomial infections.

  2. RESISTANCE OF KARST CAVERNS NITROGEN-FIXING BACTERIA TO EXTREME FACTORS

    Directory of Open Access Journals (Sweden)

    Tashyrev O. B.

    2014-10-01

    Full Text Available To determine the studied bacteria resistance quantitative parameters of extreme factors such as toxic metals (Cu2+, organic xenobiotics (p-nitrochlorobenzene and UV-irradiation were the aim of the research. Six strains of nitrogen-fixing bacteria isolated from clays of two caverns Mushkarova Yama (Podolia, Ukraine and Kuybyshevskaya (Western Caucasus, Abkhazia and Azotobacter vinelandii УКМ В-6017 as a reference strain have been tested. For this purpose the maximum permissible concentration of Cu2+ and p-nitrochlorobenzene in the concentration gradient and lethal doses of UV by the survival caverns have been determined. Maximum permissible concentrations for strains were as 10 ppm Cu2+, 70–120 ppm of p-nitrochlorobenzene. The maximum doses of UV-irradiation varied in the range of 55–85 J/m2 (LD99.99. It is shown that three classes of extreme factors resistance parameters of karst caverns strains are similar to the strain of terrestrial soil ecosystems. The most active studied strains reduce the concentration of p-nitrochlorobenzene in the medium in 13 times. The ability of nitrogen-fixing bacteria to degrade p-nitrochlorobenzene could be used in creation new environmental biotechnology for industrial wastewater treatment from nitrochloroaromatic xenobiotics. Isolated strains could be used as destructors for soils bioremediation in agrobiotechnologies and to optimize plants nitrogen nutrition in terrestrial ecosystems.

  3. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  4. Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems

    Directory of Open Access Journals (Sweden)

    J. Lienard

    2017-01-01

    Full Text Available A growing number of human infections incriminate environmental bacteria that have evolved virulent mechanisms to resist amoebae and use them as a replicative niche. These bacteria are designated amoeba-resisting bacteria (ARB. Despite the isolation of these ARB in various human clinical samples, the possible source of infection remains undetermined in most cases. However, it is known that the ARB Legionella pneumophila, for instance, causes a respiratory infection in susceptible hosts after inhalation of contaminated water aerosols from various sources. The Chlamydiales order contains many ARB, such as Parachlamydia acanthamoebae or Simkania negevensis, previously implicated in human respiratory infections with no identified contamination sources. We thus investigated whether domestic water systems are a potential source of transmission of these Chlamydiales to humans by using amoebal culture and molecular methods. Other important ARB such as mycobacteria and Legionella were also investigated, as were their possible amoebal hosts. This work reports for the first time a very high prevalence and diversity of Chlamydiales in drinking water, being detected in 35 (72.9% of 48 investigated domestic water systems, with members of the Parachlamydiaceae family being dominantly detected. Furthermore, various Legionella and mycobacteria species were also recovered, some species of which are known to be causal agents of human infections.

  5. Antimicrobial Action of Water-Soluble β-Chitosan against Clinical Multi-Drug Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Seong-Cheol Park

    2015-04-01

    Full Text Available Recently, the number of patients infected by drug-resistant pathogenic microbes has increased remarkably worldwide, and a number of studies have reported new antibiotics from natural sources. Among them, chitosan, with a high molecular weight and α-conformation, exhibits potent antimicrobial activity, but useful applications as an antibiotic are limited by its cytotoxicity and insolubility at physiological pH. In the present study, the antibacterial activity of low molecular weight water-soluble (LMWS α-chitosan (α1k, α5k, and α10k with molecular masses of 1, 5, and 10 kDa, respectively and β-chitosan (β1k, β5k, and β10k was compared using a range of pathogenic bacteria containing drug-resistant bacteria isolated from patients at different pH. Interestingly, β5k and β10k exhibited potent antibacterial activity, even at pH 7.4, whereas only α10k was effective at pH 7.4. The active target of β-chitosan is the bacterial membrane, where the leakage of calcein is induced in artificial PE/PG vesicles, bacterial mimetic membrane. Moreover, scanning electron microscopy showed that they caused significant morphological changes on the bacterial surfaces. An in vivo study utilizing a bacteria-infected mouse model found that LMWS β-chitosan could be used as a candidate in anti-infective or wound healing therapeutic applications.

  6. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture.

    Directory of Open Access Journals (Sweden)

    Gazi Md Noor Uddin

    Full Text Available Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic antimicrobial resistance and associated transferable resistance genes. The bacterial species was established by 16S rRNA sequence analysis of 125 representative bacterial isolates. MIC testing was done for a range of antimicrobials and whole genome sequencing of six multiple antimicrobial resistant Bacillus spp. used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have missed a few bacterial species present in the tested products this would represent minor bias, but future studies may apply culture independent identification methods like pyro sequencing. Only 6/60 isolates were resistant to more than four antimicrobials and whole genome sequencing showed that they contained macrolide (ermD, tetracycline (tetL, phenicol (fexA and trimethoprim (dfrD, dfrG and dfrK resistance genes, but not known structures associated with horizontal gene transfer. Probiotic bacterial strains used in Vietnamese shrimp culture seem to contribute with very limited types and numbers of resistance genes compared to the naturally occurring bacterial species in aquaculture environments. Approval procedures of probiotic products must be

  7. Identification and Antimicrobial Resistance of Bacteria Isolated from Probiotic Products Used in Shrimp Culture.

    Science.gov (United States)

    Noor Uddin, Gazi Md; Larsen, Marianne Halberg; Christensen, Henrik; Aarestrup, Frank M; Phu, Tran Minh; Dalsgaard, Anders

    2015-01-01

    Probiotics are increasingly used in aquaculture to control diseases and improve feed digestion and pond water quality; however, little is known about the antimicrobial resistance properties of such probiotic bacteria and to what extent they may contribute to the development of bacterial resistance in aquaculture ponds. Concerns have been raised that the declared information on probiotic product labels are incorrect and information on bacterial composition are often missing. We therefore evaluated seven probiotics commonly used in Vietnamese shrimp culture for their bacterial species content, phenotypic antimicrobial resistance and associated transferable resistance genes. The bacterial species was established by 16S rRNA sequence analysis of 125 representative bacterial isolates. MIC testing was done for a range of antimicrobials and whole genome sequencing of six multiple antimicrobial resistant Bacillus spp. used to identify resistance genes and genetic elements associated with horizontal gene transfer. Thirteen bacterial species declared on the probiotic products could not be identified and 11 non-declared Bacillus spp. were identified. Although our culture-based isolation and identification may have missed a few bacterial species present in the tested products this would represent minor bias, but future studies may apply culture independent identification methods like pyro sequencing. Only 6/60 isolates were resistant to more than four antimicrobials and whole genome sequencing showed that they contained macrolide (ermD), tetracycline (tetL), phenicol (fexA) and trimethoprim (dfrD, dfrG and dfrK) resistance genes, but not known structures associated with horizontal gene transfer. Probiotic bacterial strains used in Vietnamese shrimp culture seem to contribute with very limited types and numbers of resistance genes compared to the naturally occurring bacterial species in aquaculture environments. Approval procedures of probiotic products must be strengthened

  8. Preliminary survey of antibiotic-resistant fecal indicator bacteria and pathogenic Escherichia coli from river-water samples collected in Oakland County, Michigan, 2003

    Science.gov (United States)

    Fogarty, Lisa R.; Duris, Joseph W.; Aichele, Stephen S.

    2005-01-01

    A preliminary study was done in Oakland County, Michigan, to determine the concentration of fecal indicator bacteria (fecal coliform bacteria and enterococci), antibiotic resistance patterns of these two groups, and the presence of potentially pathogenic Escherichia coli (E. coli). For selected sites, specific members of these groups [E. coli, Enterococcus faecium (E. faecium) and Enterococcus faecalis (E. faecalis)] were isolated and tested for levels of resistance to specific antibiotics used to treat human infections by pathogens in these groups and for their potential to transfer these resistances. In addition, water samples from all sites were tested for indicators of potentially pathogenic E. coli by three assays: a growth-based assay for sorbitol-negative E. coli, an immunological assay for E. coli O157, and a molecular assay for three virulence and two serotype genes. Samples were also collected from two non-urbanized sites outside of Oakland County. Results from the urbanized Oakland County area were compared to those from these two non-urbanized sites. Fecal indicator bacteria concentrations exceeded State of Michigan recreational water-quality standards and (or) recommended U.S. Environmental Protection Agency (USEPA) standards in samples from all but two Oakland County sites. Multiple-antibiotic-resistant fecal coliform bacteria were found at all sites, including two reference sites from outside the county. Two sites (Stony Creek and Paint Creek) yielded fecal coliform isolates resistant to all tested antibiotics. Patterns indicative of extended-spectrum-β-lactamase (ESBL)- producing fecal coliform bacteria were found at eight sites in Oakland County and E. coli resistant to clinically significant antibiotics were recovered from the River Rouge, Clinton River, and Paint Creek. Vancomycin-resistant presumptive enterococci were found at six sites in Oakland County and were not found at the reference sites. Evidence of acquired antibiotic resistances was

  9. Detection of tetracycline resistance determinant tetA gene and antimicrobial resistance pattern in Escherichia coli isolates recovered from healthy layer chickens

    Directory of Open Access Journals (Sweden)

    A. Balasubramaniam

    2014-09-01

    Full Text Available Aim: The aim was to study the occurrence of tetracycline resistance determinant tetA gene, and antibacterial resistance pattern in commensal Escherichia coli recovered from healthy non-clinical layer chickens. Materials and Methods: Twenty-four cloacal swabs were obtained from 15 flocks in five different layer farms located at around Namakkal, which is a place of high-intensity layer chicken rearing in south India. Identification of E. coli was carried out by performing cultural and biochemical tests. Antimicrobial resistance test was carried out using disc diffusion method. The polymerase chain reaction employing tetAC forward and tetAC reverse primers were carried out to detect tetA gene conferring resistance to tetracycline. Result: All the collected cloacal swabs yielded E. coli. Twenty-one isolates (88% were resistant to tetracycline antibiotic in disc diffusion method. All the isolates showed resistance to more than six antibiotics, which implied existence of multidrug resistant microbiota in intestine of poultry. Only seven (29% isolates showed the presence of tetA gene indicating the involvement of either other one or more efflux gene(s, namely tetB, tetC and tetD or ribosomal protection encoded by tetM, tetO, tetQ and tetS genes than tetA gene. Conclusion: Based on the presence of tetA gene among tetracycline-resistant bacteria in healthy non-clinical food-producing animals such as layer chickens, it can be significant in human medicine as tetA gene could easily be spread to other bacteria. This kind of phenomenon can be extrapolated in transfer of resistance for other antibacterial essential for treating bacterial infections in human. We conclude that preventing the spread of antimicrobial resistance through direct or indirect contact, consumed food/feed and through the environment is empirical in reduction of failures while treating bacterial infections.

  10. Emergence of ciprofloxacin-resistant extended-spectrum β-lactamase-producing enteric bacteria in hospital wastewater and clinical sources.

    Science.gov (United States)

    Maheshwari, Meenu; Yaser, Nawar Hadi; Naz, Suraiya; Fatima, Mansha; Ahmad, Iqbal

    2016-06-01

    This study aimed to evaluate the incidence of ciprofloxacin-resistant extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and clinical sources. Enteric bacteria, mainly Escherichia coli, were isolated from clinical sources (urinary tract and gastrointestinal tract infections; 80 isolates) and hospital wastewater (103 isolates). The antibiotic resistance profile and ESBL production of the isolates were investigated by disc diffusion assay and combined disc diffusion test, respectively. Plasmid profiling was performed by agarose gel electrophoresis, and elimination of resistance markers was performed by a plasmid curing experiment. Antibiotic susceptibility testing revealed a high incidence of β-lactam resistance, being highest to ampicillin (88.0%) followed by amoxicillin, ceftriaxone, cefpodoxime, cefotaxime, aztreonam, cefepime and ceftazidime. Among the non-β-lactam antibiotics, the highest resistance was recorded to nalidixic acid (85.7%). Moreover, 50.8% of enteric bacteria showed resistance to ciprofloxacin. Among 183 total enteric bacteria, 150 (82.0%) exhibited multidrug resistance. ESBL production was detected in 78 isolates (42.6%). A significantly higher incidence of ciprofloxacin resistance was observed among ESBL-producing enteric bacteria both in clinical (P=0.0015) and environmental isolates (P=0.012), clearly demonstrating a close association between ESBL production and ciprofloxacin resistance. Plasmid profiling of selected ESBL-positive strains indicated the presence of one or more plasmids of varying sizes. Plasmid curing resulted in loss of ciprofloxacin and cefotaxime resistance markers simultaneously from selected ESBL-positive isolates, indicating the close relationship of these markers. This study revealed a common occurrence of ciprofloxacin-resistant ESBL-producing enteric bacteria both in hospital wastewater and clinical sources, indicating a potential public health threat.

  11. Pigments from UV-resistant Antarctic bacteria as photosensitizers in Dye Sensitized Solar Cells.

    Science.gov (United States)

    Órdenes-Aenishanslins, N; Anziani-Ostuni, G; Vargas-Reyes, M; Alarcón, J; Tello, A; Pérez-Donoso, J M

    2016-09-01

    Here we report the use of pigments produced by UV-resistant Antarctic bacteria as photosensitizers in Dye Sensitized Solar Cells (DSSCs). Pigments were obtained from red and yellow colored psychrotolerant bacteria isolated from soils of King George Island, Antarctica. Based on metabolic characteristics and 16s DNA sequence, pigmented bacteria were identified as Hymenobacter sp. (red) and Chryseobacterium sp. (yellow). Pigments produced by these microorganisms were extracted and classified as carotenoids based on their spectroscopic and structural characteristics, determined by UV-Vis spectrophotometry and infrared spectroscopy (FTIR), respectively. With the purpose of develop green solar cells based on bacterial pigments, the photostability and capacity of these molecules as light harvesters in DSSCs were determined. Absorbance decay assays determined that bacterial carotenoids present high photostability. In addition, solar cells based on these photosensitizers exhibit an open circuit voltage (VOC) of 435.0 [mV] and a short circuit current density (ISC) of 0.2 [mA·cm(-2)] for the red pigment, and a VOC of 548.8 [mV] and a ISC of 0.13 [mA·cm(-2)] for the yellow pigment. This work constitutes the first approximation of the use of pigments produced by non-photosynthetic bacteria as photosensitizers in DSSCs. Determined photochemical characteristics of bacterial pigments, summed to their easy obtention and low costs, validates its application as photosensitizers in next-generation biological solar cells.

  12. Molecular basis of active copper resistance mechanisms in Gram-negative bacteria.

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    Bondarczuk, Kinga; Piotrowska-Seget, Zofia

    2013-12-01

    Copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. The dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. This challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. Such mechanisms have been found in both eukaryotic and prokaryotic cells. In bacteria a number of different systems such as extra- and intracellular sequestration, enzymatic detoxification, and metal removal from the cell enabling them to survive in the presence of high concentration of copper have been identified. Gram-negative bacteria, due to their additional compartment, need to deal with both cytoplasmic and periplasmic copper. Therefore, these bacteria have evolved intricate and precisely regulated systems which interact with each other. In this review the active mechanisms of copper resistance at their molecular level are discussed.

  13. Identification of Enterococcus faecalis bacteria resistant to heavy metals and antibiotics in surface waters of the Mololoa River in Tepic, Nayarit, Mexico.

    Science.gov (United States)

    Mondragón, Verónica Alejandra; Llamas-Pérez, Dámaris F; González-Guzmán, Gladis E; Márquez-González, Antonio R; Padilla-Noriega, Roberto; Durán-Avelar, Ma de Jesús; Franco, Bernardo

    2011-12-01

    Heavy metal and antibiotic resistance have been shown to have a strong correlation in nature, and their inter-relation is an important subject of study. We report an analysis of surface waters of the Mololoa River in the municipality of Tepic, state of Nayarit, Mexico. This river has two distinctive sources of contamination: sewage waters and trash confinements. Our findings demonstrate a correlation between the river flow pattern and resistance to heavy metals or to heavy metals and antibiotics in isolated bacteria of the genus Enterococcus, specifically Enterococcus faecalis. The Mololoa River provides a model to study the relationship between water flow and generation of biodiversity, and more importantly, it constitutes a model for studying genetic diversity of bacteria affecting human health.

  14. Incidence and behaviour of Tn916-like elements within tetracycline-resistant bacteria isolated from root canals.

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    Rossi-Fedele, G; Scott, W; Spratt, D; Gulabivala, K; Roberts, A P

    2006-08-01

    Tetracycline resistance is commonly found in endodontic bacteria. One of the most common tetracycline-resistance genes is tet(M), which is often encoded on the broad-host-range conjugative transposon Tn916. This study aimed to determine whether tet(M) was present in bacteria isolated from endodontic patients at the Eastman Dental Institute and whether this gene was carried on the transferable conjugative transposon Tn916. The cultivable microflora isolated from 15 endodontic patients was screened for resistance to tetracycline. Polymerase chain reactions for tet(M) and for unique regions of Tn916 were carried out on the DNA of all tetracycline-resistant bacteria. Filter-mating experiments were used to see if transfer of any Tn916-like elements could occur. Eight out of 15 tetracycline-resistant bacteria isolated were shown to possess tet(M). Furthermore, four of these eight were shown to possess the Tn916-unique regions linked to the tet(M) gene. Transfer experiments demonstrated that a Neisseria sp. donor could transfer an extremely unstable Tn916-like element to Enterococcus faecalis. The tet(M) gene is present in the majority of tetracycline-resistant bacteria isolated in this study and the conjugative transposon Tn916 has been shown to be responsible for the support and transfer of this gene in some of the bacteria isolated.

  15. Cockroaches (periplaneta americana and blattella germanica: reservoirs of multi drug resistant (MDR bacteria in Uyo, Akwa Ibom State

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    E.P. Udoinyang

    2012-08-01

    Full Text Available Bacteriological examination of external surfaces and internal guts of Periplaneta americana and Blattela germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using disc diffusion methods. Of the 317 bacteria isolated from the external surfaces and internal guts of P. americana, 275 (86.8% were Gram-negative bacilli, while 42 (13.2% were Gram-positive bacteria. Of the 204 bacterial isolates from B. germanica, 175 (85.8% were Gram negative, while 29 (14.2% were Gram positive bacteria. The bacteria isolated were Salmonella spp, Shigella spp, Staphylococcus aureus, coagulase negative Staphylococcus spp, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter freundii, Morganella morganii, Proteus vulgaris, Proteus mirabilis, Enterobacter cloacae and Providencia spp. Among the Gram positive bacteria, only 75.8% S. aureus and 76.5% B. cereus were sensitive to Streptomycin and Gentamycin, while their resistance profiles to antibiotics in decreasing order were as follows: Chloramphenicol (41.7%, Amoxicillin (40.3%, Streptomycin (36.1%, Tetracycline (36.0%, Erythromycin (35.5%, Gentamicin (34.0%, Penicillin (34.6%, Cephalothin (27.8%, Sulfamethoxazole (23.4%, Ciprofloxacin (18.4% and Levofloxacin (17.7%. Less than 50% of E. cloacae and Providencia spp were resistant to Streptomycin, while ˂ 40% of P. vulgaris, K. pneumoniae, and P. aeruginosa were resistant to Chloramphenicol. Of the 353 (67.8% multi drug resistant bacteria, 121 (23.2% were resistant to 3 antibiotics, 232 (65.7% were resistant to 4-10 antibiotics. The antibiotic resistant Salmonella spp. and P. mirabilis had Multiple Antibiotic Resistance (MAR indexes ranging from 0.27 to 0.82. These findings suggest cockroaches in Uyo as potential vectors of medically important multiple drug-resistant bacteria.

  16. Isolation and Genetic Analysis of Multidrug Resistant Bacteria from Diabetic Foot Ulcers.

    Science.gov (United States)

    Shahi, Shailesh K; Kumar, Ashok

    2015-01-01

    Severe diabetic foot ulcers (DFUs) patients visiting Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, were selected for this study. Bacteria were isolated from swab and deep tissue of 42 patients, for examining their prevalence and antibiotic sensitivity. DFUs of majority of the patients were found infected with Enterococcus spp. (47.61%), Escherichia coli (35.71%), Staphylococcus spp. (33.33%), Alcaligenes spp. (30.95%), Pseudomonas spp. (30.95%), and Stenotrophomonas spp. (30.95%). Antibiotic susceptibility assay of 142 bacteria with 16 antibiotics belonging to eight classes showed the presence of 38 (26.76%) isolates with multidrug resistance (MDR) phenotypes. MDR character appeared to be governed by integrons as class 1 integrons were detected in 26 (68.42%) isolates. Altogether six different arrays of genes (aadA1, aadB, aadAV, dhfrV, dhfrXII, and dhfrXVII) were found within class 1 integron. Gene cassette dhfrAXVII-aadAV (1.6 kb) was present in 12 (3 Gram positive and 9 Gram negative) isolates and was conserved across all the isolates as evident from RFLP analysis. In addition to the presence of class 1 integron, six β-lactamase resistance encoding genes namely bla TEM, bla SHV, bla OXA, bla CTX-M-gp1, bla CTX-M-gp2, and bla CTX-M-gp9 and two methicillin resistance genes namely mecA and femA and vancomycin resistance encoding genes (vanA and vanB) were identified in different isolates. Majority of the MDR isolates were positive for bla TEM (89.47%), bla OXA (52.63%), and bla CTX-M-gp1 (34.21%). To our knowledge, this is the first report of molecular characterization of antibiotic resistance in bacteria isolated from DFUs from North India. In conclusion, findings of this study suggest that class-1 integrons and β-lactamase genes contributed to the MDR in above bacteria.

  17. Isolation and genetic analysis of multidrug resistant bacteria from diabetic foot ulcers

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    Shailesh Kumar Shahi

    2016-01-01

    Full Text Available Severe diabetic foot ulcers (DFUs patients visiting Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, were selected for this study. Bacteria were isolated from swab and deep tissue of 42 patients, for examining their prevalence and antibiotic sensitivity. DFUs of majority of the patients were found infected with Enterococcus spp. (47.61%, Escherichia coli (35.71%, Staphylococcus spp. (33.33%, Alcaligenes spp. (30.95%, Pseudomonas spp. (30.95% and Stenotrophomonas spp. (30.95%. Antibiotic susceptibility assay of 142 bacteria with 16 antibiotics belonging to eight classes showed the presence of 38 (26.76% isolates with multidrug resistance (MDR phenotypes. MDR character appeared to be governed by integrons as class 1 integrons were detected in 26 (68.42% isolates. Altogether six different arrays of genes (aadA1, aadB, aadAV, dhfrV, dhfrXII and dhfrXVII were found within class 1 integron. Gene cassette dhfrAXVII-aadAV (1.6 kb was present in 12 (3 Gram positive and 9 Gram negative isolates and was conserved across all the isolates as evident from RFLP analysis. In addition to the presence of class 1 integron, six β-lactamase resistance encoding genes namely blaTEM, blaSHV, blaOXA, blaCTX-M-gp1, blaCTX-M-gp2 and blaCTX-M-gp9 and two methicillin resistance genes namely mecA and femA and vancomycin resistance encoding genes (vanA and vanB were identified in different isolates. Majority of the MDR isolates were positive for blaTEM (89.47%, blaOXA (52.63% and blaCTX-M-gp1 (34.21%. To our knowledge, this is the first report of molecular characterization of antibiotic resistance in bacteria isolated from DFUs from North India. In conclusion, findings of this study suggest that class-1 integrons and β-lactamase genes contributed to the MDR in above bacteria.

  18. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

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    Kailong Huang

    2014-06-01

    Full Text Available In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB and antibiotic resistance genes (ARGs in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP sludge.

  19. Prevalence of uropathogen and their antibiotic resistance pattern among diabetic patients

    Science.gov (United States)

    Nigussie, Demiss; Amsalu, Anteneh

    2017-01-01

    Objective Diabetes mellitus (DM) and antibiotic resistance is an emerging public health problem in Ethiopia. Urinary tract infections (UTIs) are common and occasionally life-threatening condition among diabetic patients. Despite, all these problems, antibiotics are prescribed empirically which may adversely affect antibiotic resistance so far. Therefore the aim of this study was to identify the etiologic agents of UTI and their antibiotic resistance pattern among diabetic patients attending diabetic clinic of Hawassa University Referral Hospital. Material and methods A cross-sectional study was conducted in a total of 240 diabetic patients from June to October, 2014. After obtaining an informed written consent, socio-demographic and clinical data were collected using pre-structured questionnaire. Clean catch mid-stream urine samples were collected and processed for identification of uropathogen through culture using standard microbiologic procedure. Antibiotic susceptibility test was carried out using Kirby-Bauer disc diffusion method. Results The overall prevalence of diabetic UTI was 13.8%. Out of the total number of patients, 11.2% and 23.1% had asymptomatic and symptomatic bacteriuria respectively. DM patients with no previous history of UTI [AOR=3.55; 95% CI=1.186–10.611] and illiterate [AOR=2.5; 95% CI=1.052–5.989] had higher odds of UTI compared with their counterparts. E. coli was the commonest isolated uropathogen followed by coagulase-negative Staphylococci. All the isolated bacteria were resistant to ampicillin but sensitive to nitrofurantoin. Gram-negative isolates demonstrated high level of resistance to trimethoprim-sulphamethoxazole in 9 (81.8%), gentamicin in 8 (72.7%) and ceftriaxone in 7 (63.6%) patients. Gram-positive bacteria showed resistance to penicillin in 14 (87.5%), norfloxacin in 10 (62.5%) and ciprofloxacin in 8 (50.0%) patients. Multidrug resistance was observed in 93.9% of the isolated uropathogens. Conclusion Illiterate DM

  20. Target recognition, resistance, immunity and genome mining of class II bacteriocins from Gram-positive bacteria.

    Science.gov (United States)

    Kjos, Morten; Borrero, Juan; Opsata, Mona; Birri, Dagim J; Holo, Helge; Cintas, Luis M; Snipen, Lars; Hernández, Pablo E; Nes, Ingolf F; Diep, Dzung B

    2011-12-01

    Due to their very potent antimicrobial activity against diverse food-spoiling bacteria and pathogens and their favourable biochemical properties, peptide bacteriocins from Gram-positive bacteria have long been considered promising for applications in food preservation or medical treatment. To take advantage of bacteriocins in different applications, it is crucial to have detailed knowledge on the molecular mechanisms by which these peptides recognize and kill target cells, how producer cells protect themselves from their own bacteriocin (self-immunity) and how target cells may develop resistance. In this review we discuss some important recent progress in these areas for the non-lantibiotic (class II) bacteriocins. We also discuss some examples of how the current wealth of genome sequences provides an invaluable source in the search for novel class II bacteriocins.

  1. Recycling antibiotics into GUMBOS: a new combination strategy to combat multi-drug-resistant bacteria.

    Science.gov (United States)

    Cole, Marsha R; Hobden, Jeffery A; Warner, Isiah M

    2015-04-10

    The emergence of multi-drug-resistant bacteria, coupled with the lack of new antibiotics in development, is fast evolving into a global crisis. New strategies utilizing existing antibacterial agents are urgently needed. We propose one such strategy in which four outmoded β-lactam antibiotics (ampicillin, carbenicillin, cephalothin and oxacillin) and a well-known antiseptic (chlorhexidine di-acetate) were fashioned into a group of uniform materials based on organic salts (GUMBOS) as an alternative to conventional combination drug dosing strategies. The antibacterial activity of precursor ions (e.g., chlorhexidine diacetate and β-lactam antibiotics), GUMBOS and their unreacted mixtures were studied with 25 clinical isolates with varying antibiotic resistance using a micro-broth dilution method. Acute cytotoxicity and therapeutic indices were determined using fibroblasts, endothelial and cervical cell lines. Intestinal permeability was predicted using a parallel artificial membrane permeability assay. GUMBOS formed from ineffective β-lactam antibiotics and cytotoxic chlorhexidine diacetate exhibited unique pharmacological properties and profound antibacterial activity at lower concentrations than the unreacted mixture of precursor ions at equivalent stoichiometry. Reduced cytotoxicity to invasive cell types commonly found in superficial and chronic wounds was also observed using GUMBOS. GUMBOS show promise as an alternative combination drug strategy for treating wound infections caused by drug-resistant bacteria.

  2. Ecological study on antimicrobial-resistant zoonotic bacteria transmitted by flies in cattle farms.

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    Mohammed, Asmaa N; Abdel-Latef, Gihan K; Abdel-Azeem, Naglaa M; El-Dakhly, Khaled Mohamed

    2016-10-01

    Flies were qualitatively and quantitatively monitored on both livestock animals and the surrounding environment to investigate their role as a potential carrier for antimicrobial-resistant bacteria of zoonotic importance in cattle farms. This was done by the use of visual observations and animal photography; meanwhile, in the surrounding environment, flies were collected using sticky cards and then microscopically identified. Representative fly samples were cultured for bacterial isolation, biochemical identification, and then tested against common 12 antibiotics. The total average of dipterous flies in examined farms was 400.42 ± 6.2. Culicoides biting midges were the most common existing species (70.01 %) followed by house flies, stable flies, and mosquitoes (18.31, 7.74, and 3.91 %, respectively) at X (2) = 9.0, P house flies could be considered as a potential carrier for multi-drug-resistant bacteria of zoonotic importance. Furthermore, cows' environment has an essential role in propagation and wide spread of antimicrobial-resistant bacterial pathogens.

  3. Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.

    Science.gov (United States)

    El Salabi, Allaaeddin; Walsh, Timothey R; Chouchani, Chedly

    2013-05-01

    Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.

  4. Establishment of Experimental Murine Peritonitis Model with Hog Gastric Mucin for Carbapenem-Resistant Gram-Negative Bacteria

    Science.gov (United States)

    Park, Chulmin; Chun, Hye-Sun; Byun, Ji-Hyun; Cho, Sung-Yeon

    2017-01-01

    Animal models are essential to studies of infectious diseases. The use of mice to test bacterial infection has been extensively reported. However, methods applied to clinical isolates, particularly for carbapenem-resistant bacteria, must be tailored according to the infection models and bacteria used. In this study, we infected 6-week-old female BALB/c mice intraperitoneally with different strains of resistant bacteria plus 3% hog gastric mucin. This method was found to be efficient and readily applicable for investigation of carbapenem-resisant Gram-negative pathogens (e.g., Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) detected in Korea.

  5. Heavy metal resistance strategies of acidophilic bacteria and their acquisition: importance for biomining and bioremediation.

    Science.gov (United States)

    Navarro, Claudio A; von Bernath, Diego; Jerez, Carlos A

    2013-01-01

    Microbial solubilizing of metals in acid environments is successfully used in industrial bioleaching of ores or biomining to extract metals such as copper, gold, uranium and others. This is done mainly by acidophilic and other microorganisms that mobilize metals and generate acid mine drainage or AMD, causing serious environmental problems. However, bioremediation or removal of the toxic metals from contaminated soils can be achieved by using the specific properties of the acidophilic microorganisms interacting with these elements. These bacteria resist high levels of metals by using a few "canonical" systems such as active efflux or trapping of the metal ions by metal chaperones. Nonetheless, gene duplications, the presence of genomic islands, the existence of additional mechanisms such as passive instruments for pH and cation homeostasis in acidophiles and an inorganic polyphosphate-driven metal resistance mechanism have also been proposed. Horizontal gene transfer in environmental microorganisms present in natural ecosystems is considered to be an important mechanism in their adaptive evolution. This process is carried out by different mobile genetic elements, including genomic islands (GI), which increase the adaptability and versatility of the microorganism. This mini-review also describes the possible role of GIs in metal resistance of some environmental microorganisms of importance in biomining and bioremediation of metal polluted environments such as Thiomonas arsenitoxydans, a moderate acidophilic microorganism, Acidithiobacillus caldus and Acidithiobacillus ferrooxidans strains ATCC 23270 and ATCC 53993, all extreme acidophiles able to tolerate exceptionally high levels of heavy metals. Some of these bacteria contain variable numbers of GIs, most of which code for high numbers of genes related to metal resistance. In some cases there is an apparent correlation between the number of metal resistance genes and the metal tolerance of each of these

  6. Rapid evolution of symbiotic bacteria populations in spirotetramat-resistant Aphis gossypii glover revealed by pyrosequencing.

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    Zhang, Juhong; Pan, Yiou; Zheng, Chao; Gao, Xiwu; Wei, Xiang; Xi, Jinghui; Peng, Tianfei; Shang, Qingli

    2016-12-01

    Aphis gossypii is one of the most economically important insect pests for agriculture worldwide. Aphids have developed symbiotic associations with bacterial species, which has led to morphological and molecular differences, such as body color and insecticide resistance. Adults and 3rd instar nymphs of a laboratory-selected spirotetramat-resistant strain of cotton aphid presented 579-fold and 15-fold higher resistance to spirotetramat, respectively, than a susceptible strain (Pan et al., 2015; Peng et al., 2016). In this study, we found that antibiotics, especially ampicillin and tetracycline, increased spirotetramat toxicity in resistant aphids. We also characterized all of the bacterial endosymbionts in these two clones by sequencing the 16S rRNA genes of the endosymbiont. The total reads could be clustered into 3534 operational taxonomic units (OTUs) that showed 97% similarity and belonged to six abundant phyla. Proteobacteria and Firmicutes dominated in the two strains, and the most abundant families were Enterobacteriaceae, Lactobacillaceae and Rhodobiaceae. The genera Arsenophonus, Anderseniella, Buchnera and Lactobacillus were most abundant in the susceptible strain, whereas a significant decrease in abundance of Anderseniella and a great increase in abundance of Arsenophonus and Lactobacillus were observed in the resistant strain. Certain identified species had low sequence similarity to the reported species, which indicates the possibility of novel taxa. The type and abundance of different bacterial groups varied significantly between the two strains. The insecticide selection pressure could be the reason for the observed shift in the bacteria groups. These results increase our understanding of the symbiotic relationships between bacteria and their hosts under insecticide stress and provide clues for the development of potential control techniques against this cotton aphid. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Antimicrobial resistance in bacteria isolated from aquatic environments in Brazil: a systematic review

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    Ermeton Duarte do Nascimento

    2014-04-01

    Full Text Available This article discusses antibiotic resistance in bacteria isolated from aquatic environments in Brazil, taking into account isolation sites, the main reported antimicrobial agents, the genes involved in resistance, the most prevalent bacterial genera and species, and the main mechanisms of resistance. This review is based upon specialized literature, consulting published scientific articles selected from the SciELO, PubMed and LILACS databases. Based upon the inclusion criteria, we selected 21 articles, most (61.6% were from PubMed, with the highest prevalence for work done in the Southeast region (71.4% in freshwater environments (71.4%, and the major focus on farm ponds (28.6%. Gram-negative bacteria are the most studied (71.4% and the Aeromonas spp. was the one found most frequently (19.0%. The most frequently used antimicrobials were chloramphenicol (81.0%, gentamicin (76.2%, sulpha/trimethroprim (71.4%, ampicillin (61.9% and tetracycline (71.4%; and the ones with higher prevalence of resistance were chloramphenicol (58.8%, sulpha/trimethroprim (78.5% and ampicillin (84.6%. It was found that studies on resistance in other aquatic environments have not yet been conducted in Brazil, especially in the North and Northeast regions, where irregular rainfall distribution leads to the use of reservoirs as supply sources during the dry season, highlighting concerns regarding the quality, contamination and maintenance of these resources, as the water is intended for human use or for production purposes.

  8. Multidrug-resistant Gram-negative bacteria-resistant infections: epidemiology, clinical issues and therapeutic options

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    Matteo Bassetti

    2016-12-01

    Full Text Available In the last decade, we have witnessed a dramatic increase in the number of multidrug resistant Gram-negative (MDRGN bacterial pathogens, both in Italy and worldwide, with Enterobacteriacae (mostly Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii being the major threats in clinical practice. Inadequate empirical antimicrobial therapy of severe infections caused by MDR Enterobacteriacae has been associated with an increased morbidity and mortality. However, a careful selection of patients who may receive empirical treatment covering MDR Enterobacteriacae is important to avoid the overuse of broad-spectrum antibiotics. The aim of this review is to describe the mechanism of resistance, epidemiology, risk factors, clinical issues, and therapeutic options for MDRGN pathogens.

  9. Bacteria isolated from a sugarcane agroecosystem: their potential production of polyhydroxyalcanoates and resistance to antibiotics

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    Lima Teresa Cristina S. de

    1999-01-01

    Full Text Available In this investigation, a sugarcane agroecosystem at a coastal tableland, in the northeast of Brazil, was screened to obtain bacteria strains able to synthesize poly-b-hydroxyalkanoates (PHA, using sucrose as the main carbon source. The potential to synthesize PHA was tested qualitatively by Sudan Black staining of colonies growing in different carbon sources: sucrose, glucose, fructose, propionate and cellulose. In a typical sugarcane crop management system, the plantation is burned before harvesting and vinasse, a byproduct of alcohol production, is used in a fertirrigation system causing, probably, selective pressures on the microbiota of natural environments. Eightytwo bacteria strains, belonging to 16 different genera and 35 different species, were isolated. The data showed that 11 strains (ca 13%, nine of which belonging to the genus Pseudomonas, presented a strong Sudan Black staining in several carbon sources tested and, simultaneously, showed multiple resistance to antibiotics. Resistance to antibiotics is an advantageous feature for the biotechnological production of PHAs. The total number of isolates with multiple resistance to antibiotics was 73, and 38% of them belong to the genus Pseudomonas. Among the isolates, ca 86% and 43% grew in the presence of 10-100 U/ml of penicillin and/or 100-300 mg/ml of virginiamycin, respectively. These antibiotics are utilized in the alcohol distillery we investigated. The results suggest that some agroecosystem environments could be considered as habitats where bacteria are submitted to nutritional unbalanced conditions, resulting in strains with potential ability to produce PHAs, and also, to an increase in the microbial diversity.

  10. In Vitro Biofilm Formation by Uropathogenic Bacteria and their Antibiotic Susceptibility Pattern

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    Somya Verma

    2016-07-01

    Full Text Available Background: Uropathogens have an ability to form biofilm in urinary tract. Microorganisms growing in biofilm are associated with chronic and recurrent UTI. They are highly resistant to a variety of antimicrobial agents. There are different phenotypic methods to detect biofilm production like Tube Adherence Method (TAM, Congo Red Agar Method (CRAM, Tissue Culture Plate Method (TCPM, etc. Aim and Objectives: The purpose of the study was to observe biofilm formation by uropathogens, their antibiotic resistance pattern and to correlate biofilm formation with drug resistance. Material and Methods: Total 168 isolates were collected from urine over six months. They were subjected to AST by Kirby Bauer disc diffusion method. Detection of biofilm production was done by TAM, CRAM, and TCPM. Results: Escherichia coli was the commonest isolate. Of the 68 clinical isolates, 54% were positive for biofilm production by TAM, 58% by CRAM, and 66% by TCPM. Compared to non-biofilm producers higher antibiotic resistance was observed among biofilm producers. TCPM was found to be more accurate. Conclusion: E. coli was the most frequent isolate. Biofilm producers were found to be resistant for multiple drugs. TCPM was found to be more quantitative and reliable

  11. Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

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    Meirelles-Pereira Frederico de

    2002-01-01

    Full Text Available In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc., the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteristics of three coastal lagoons, comparing the results with those from hospital sewage. Of the lagoons evaluated, two (Geribá and Imboassica receive domestic sewage discharge, and the other (Cabiúnas is still in a natural state. We isolated in a culture medium containing 32 ¼ µg/ml of Cephalothin, fecal coliforms (E. coli, non-fecal coliforms (Klebsiella, Enterobacter, Serratia, and Citrobacter, non-glucose-fermenting Gram-negative bacilli, and Aeromonas sp. In cultures from the hospital drain we found strains showing numerous markers for resistance to most of the 11 antimicrobials tested. On the other hand, in cultures from Cabiúnas and Imboassica lagoons, we found strains showing resistance only to antibiotics frequently observed in non-selective situations (considered as "common" markers. The capacity for dilution in the ecosystem, and salinity appeared related with the occurrence of multi-resistant bacterial strains. The intensity of recent fecal contamination was not shown to be associated with the numbers and types of markers found.

  12. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

    Directory of Open Access Journals (Sweden)

    Gamal Fadl M. Gad

    2014-01-01

    Full Text Available A total of 244 lactic acid bacteria (LAB strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7% followed by Streptococcus spp. (65, 36.1% and Lactococcus spp. (27, 15%. Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus,8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M and/or erm(B]. PCR assays shows that some resistant strains harbor tet(M and/or erm(B resistance genes.

  13. Diversity of heavy metal resistant bacteria from Kalimas Surabaya: A phylogenetic taxonomy approach

    Science.gov (United States)

    Zulaika, Enny; Utomo, Andry Prio; Prima, Adisya; Alami, Nur Hidayatul; Kuswytasari, Nengah Dwianita; Shovitri, Maya; Sembiring, Langkah

    2017-06-01

    Bacterial resistance to heavy metal is a genetic and physiological adaptation to the environment which contaminated by heavy metal. Kalimas is an important river in Surabaya that is contaminated by some heavy metals and probably as a habitat for heavy metal resistance bacteria. Bacterial resistance to heavy metals are different for each species, and their diversity can be studied by phylogenetic taxonomy approach. Isolates screening was done using nutrient agar which contained 1 mg/L HgCl2, CdCl2 and K2Cr2O7. Bacterial viability were observed by nutrient broth which contained 10 mg/L HgCl2, 30 mg/L CdCl2 and 50 mg/L K2Cr2O7. Isolates that resistant to heavy metal and viable after exposure to heavy metal were identified using 16S rRNA gene marker by Polymerase Chain Reaction (PCR). Phylogenetic tree reconstruction was done by the neighbor-joining algorithm. Genetic assignment showed isolates that resist and viable after exposure of Hg, Cd and Cr are Bacillus S1, SS19 and DA11. Based on BLAST analysis from NCBI gene bank, 16S rRNA sequences, those isolates were similar with the member of Bacillus cereus. Depend on 16S rRNA nucleotide alignment by the neighbor-joining algorithm, Bacillus S1, SS19 and DA11 were belong to Bacillus cereus sensu-lato group.

  14. [Distribution and antibiotics resistance related to nosocomial pathogenic bacteria infection in patients after cardiac surgery].

    Science.gov (United States)

    Dang, Hai-ming; Song, Yue; Cao, Jian; Wu, Li-song; Dong, Ran

    2013-05-01

    To investigate the clinical distribution and antibiotics resistance of nosocomial infection caused pathogenic bacteria in patients after cardiac surgery. Clinical data from 612 patients after cardiac surgery under microbiologically documented nosocomial infection was retrospectively analyzed from January 2007 to December 2012. Identification on related bacterial was performed in an automatic ATB Expression system while antimicrobial susceptibility was tested by Kirby-Bauer method. were analyzed by WHONET5.4. There were 697 strains of clinical pathogenic bacilli isolates identified and 421 (60.4%) of them were isolated from sputum while 185 (26.5%) were from blood. Acinetobacter spp. (124 strains, 17.8%), Pseudomonas aeruginosa (85 strains, 12.2%) and Klebsiella pneumoniae (50 strains, 7.2%) were the predominant Gram-negative bacilli while S. epidermidis (75 strains, 10.8%) was the predominant Gram-positive cocci. The predominant eumycete was Candida albicans (43 strains, 6.2%). from the susceptibility test showed that carbapenems, cefoperazone/sulbactam and piperacillin/tazobactam were the most active antibiotics. The detection of meticillin-resistant Staphylococcus (MRS) were 82.9% in S aureus and 95.9% in coagulase negative Staphylococcus. There was no Staphylococcus strains resistant to vancomycin found. Non-fermenting Gram-negative bacilli and Staphylococcus appeared the important pathogens in patients after cardiac surgery. Drug resistance to antibiotics was quite common. Prevention on nosocomial infection and rational use of antibiotics remained very important in reducing the amount of drug resistant strains.

  15. Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram‐Negative Bacteria

    Science.gov (United States)

    Borselli, Diane; Blanchet, Marine; Bolla, Jean‐Michel; Muth, Aaron; Skruber, Kristen

    2017-01-01

    Abstract Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram‐negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU‐N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer‐membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de‐energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance. PMID:28098416

  16. 'Trade-off' in Antarctic bacteria: limnetic psychrotrophs concede multiple enzyme expressions for multiple metal resistance

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; LokaBharathi, P.A.; Nair, S.; Chandramohan, D.

    January 2007 C211 Springer Science+Business Media B.V. 2006 Abstract The present study examines the metal and antibiotic resistant bacteria in ice and water from lakes east and west of the Indian base camp (Maitri) in Antarctica. The isolates from western...) Effects of cadmium and lead on growth, respiration and enzyme activity of the marine bacterium Pseudomonas marina. Chemo- sphere 17: 597–607 De Flora S, Bennicelli C, Bagnasco M (1994) Genotoxicity of mercury compounds: a review. Mut Res 317: 57–79 De...

  17. Coupling of radiofrequency with magnetic nanoparticles treatment as an alternative physical antibacterial strategy against multiple drug resistant bacteria

    Science.gov (United States)

    Chaurasia, Akhilesh K.; Thorat, Nanasaheb D.; Tandon, Anshula; Kim, Jin-Hahn; Park, Sung Ha; Kim, Kyeong Kyu

    2016-09-01

    Antibiotic resistant bacteria not only affect human health and but also threatens the safety in hospitals and among communities. However, the emergence of drug resistant bacteria is inevitable due to evolutionary selection as a consequence of indiscriminate antibiotic usage. Therefore, it is necessary to develop a novel strategy by which pathogenic bacteria can be eliminated without triggering resistance. We propose a novel magnetic nanoparticle-based physical treatment against pathogenic bacteria, which blocks biofilm formation and kills bacteria. In this approach, multiple drug resistant Staphylococcus aureus USA300 and uropathogenic Escherichia coli CFT073 are trapped to the positively charged magnetic core-shell nanoparticles (MCSNPs) by electrostatic interaction. All the trapped bacteria can be completely killed within 30 min owing to the loss of membrane potential and dysfunction of membrane-associated complexes when exposed to the radiofrequency current. These results indicate that MCSNP-based physical treatment can be an alternative antibacterial strategy without leading to antibiotic resistance, and can be used for many purposes including environmental and therapeutic applications.

  18. Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu.

    Science.gov (United States)

    Nachimuthu, Ramesh; Subramani, Ramkumar; Maray, Suresh; Gothandam, K M; Sivamangala, Karthikeyan; Manohar, Prasanth; Bozdogan, Bülent

    2016-10-01

    Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were 128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E

  19. Method of lift-off patterning thin films in situ employing phase change resists

    Science.gov (United States)

    Bahlke, Matthias Erhard; Baldo, Marc A; Mendoza, Hiroshi Antonio

    2014-09-23

    Method for making a patterned thin film of an organic semiconductor. The method includes condensing a resist gas into a solid film onto a substrate cooled to a temperature below the condensation point of the resist gas. The condensed solid film is heated selectively with a patterned stamp to cause local direct sublimation from solid to vapor of selected portions of the solid film thereby creating a patterned resist film. An organic semiconductor film is coated on the patterned resist film and the patterned resist film is heated to cause it to sublime away and to lift off because of the phase change.

  20. Neonatal bacteriemia isolates and their antibiotic resistance pattern in neonatal insensitive care unit (NICU at Beasat Hospital, Sanandaj, Iran.

    Directory of Open Access Journals (Sweden)

    Parvin Mohammadi

    2014-05-01

    Full Text Available Bacteremia continues to result in significant morbidity and mortality, particularly among neonates. There is scarce data on neonatal bacteremia in among Iranian neonates. In this study, we determined neonatal bacteremia isolates and their antibiotic resistance pattern in neonatal insensitive care unit at Beasat hospital, Sanandaj, Iran. During one year, all neonates admitted to the NICU were evaluated. Staphylococcal isolates were subjected to determine the prevalence of MRS and mecA gene. A total of 355 blood cultures from suspected cases of sepsis were processed, of which 27 (7.6% were positive for bacterial growth. Of the 27 isolates, 20 (74% were Staphylococcus spp as the leading cause of bacteremia. The incidence of Gram negative bacteria was 04 (14.8%. The isolated bacteria were resistant to commonly used antibiotics. Maximum resistance among Staphylococcus spp was against Penicillin, and Ampicillin. In our study, the isolated bacteria were 7.5 % Vancomycin and Ciprofloxacin sensitive. Oxacillin disk diffusion and PCR screened 35% and 30% mec a positive Staphylococcus spp. The spectrum of neonatal bacteremia as seen in NICU at Beasat hospital confirmed the importance of pathogens such as Staphylococcus spp. Penicillin, Ampicillin and Cotrimoxazol resistance was high in theses isolates with high mecA gene carriage, probably due to antibiotic selection.

  1. Antimicrobial resistance of enteric bacteria among ceftiofur treated and non-antimicrobial treated co-mingled pasture beef cows

    Science.gov (United States)

    Concerns have been raised that antimicrobial use in food animal production considerably increases antimicrobial resistance in bacteria. Due to their longevity, pasture beef cows are likely to be exposed to different antimicrobials that may create favorable conditions for antimicrobial resistant bact...

  2. 革兰阴性菌耐药%Drug resistance of Gram-negative bacterias

    Institute of Scientific and Technical Information of China (English)

    赵长安

    2016-01-01

    随着抗生素滥用状况的日趋严峻、使用监管的日渐复杂和发现新的尤其是针对革兰阴性菌(GNB)抗生素技术难度的日益增加,GNB 的耐药问题日趋严峻。现主要讨论临床上常见的 GNB 耐药的相关问题。%Along with the condition of antibiotic abuse,the regulatory hurdles to new antibiotics which have be-come increasingly complex and the technical difficulty of discovering new antibiotics,especially those able to penetrate Gram -negative bacteria(GNB),drug -resistant of GNB has become increasingly serious.This review focuses on com-mon clinical GNB drug resistance related issues.

  3. Term-seq reveals abundant ribo-regulation of antibiotics resistance in bacteria.

    Science.gov (United States)

    Dar, Daniel; Shamir, Maya; Mellin, J R; Koutero, Mikael; Stern-Ginossar, Noam; Cossart, Pascale; Sorek, Rotem

    2016-04-01

    Riboswitches and attenuators are cis-regulatory RNA elements, most of which control bacterial gene expression via metabolite-mediated, premature transcription termination. We developed an unbiased experimental approach for genome-wide discovery of such ribo-regulators in bacteria. We also devised an experimental platform that quantitatively measures the in vivo activity of all such regulators in parallel and enables rapid screening for ribo-regulators that respond to metabolites of choice. Using this approach, we detected numerous antibiotic-responsive ribo-regulators that control antibiotic resistance genes in pathogens and in the human microbiome. Studying one such regulator in Listeria monocytogenes revealed an attenuation mechanism mediated by antibiotic-stalled ribosomes. Our results expose broad roles for conditional termination in regulating antibiotic resistance and provide a tool for discovering riboswitches and attenuators that respond to previously unknown ligands.

  4. Changes in diversity of cultured bacteria resistant to erythromycin and tetracycline in swine manure during simulated composting and lagoon storage.

    Science.gov (United States)

    Wang, L; Gutek, A; Grewal, S; Michel, F C; Yu, Z

    2015-09-01

    This study investigated the impact of composting and lagoon storage on survival and change in diversity of tetracycline-resistant (Tc(r) ) and erythromycin-resistant (Em(r) ) bacteria and the resistance genes they carry in swine manure. Treatments were arranged as a 2 × 2 factorial design: composting vs lagoon storage and 0 vs 1% Surround WP Crop Protectant (a clay product) in three replicates. After 48 days of treatments, resistant bacteria were enumerated by selective plating and identified by 16S rRNA gene sequencing. The erm and the tet gene(s) carried by the resistant isolates were screened using class-specific PCR assays. The plate counts of Tc(r) and Em(r) bacteria decreased by 4-7 logs by composting, but only by 1-2 logs by the lagoon treatment. During the treatments, Acinetobacter gave way to Pseudomonas and Providencia as the largest resistant genera. The clay product had little effect on survival or diversity of resistant bacteria. Of six classes of erm and seven classes of tet genes tested, changes in prevalence were also noted. The results indicate that composting can dramatically shift Tc(r) and Em(r) bacterial populations, and composting can be an effective and practical approach to decrease dissemination of antibiotic resistance from swine farms to the environment. The presented research provided evidence that composting is much more effective than lagoon storage in dramatically decreasing culturable bacteria resistant to erythromycin and tetracycline in swine manure. Considerable diversity changes of resistant bacteria were also demonstrated during composting or lagoon storage. Overall, Acinetobacter was the major resistant genus in untreated swine manure, but pseudomonads and Providencia became the major resistant genera after the treatments. This is the first study that investigated diversity changes of cultured bacteria resistant to these two antibiotics during composting and lagoon storage of swine manure. New genes encoding resistance to

  5. Control of multidrug resistant bacteria in a tertiary care hospital in India

    Directory of Open Access Journals (Sweden)

    Jaggi Namita

    2012-06-01

    Full Text Available Abstract Background The objective of this study was to assess the impact of antimicrobial stewardship programs on the multidrug resistance patterns of bacterial isolates. The study comprised an initial retrospective analysis of multidrug resistance in bacterial isolates for one year (July 2007-June 2008 followed by prospective evaluation of the impact of Antimicrobial Stewardship programs on resistance for two years and nine months (July 2008-March 2011. Setting A 300-bed tertiary care private hospital in Gurgaon, Haryana (India Findings Methods Study Design • July 2007 to June 2008: Resistance patterns of bacterial isolates were studied. • July 2008: Phase I intervention programme Implementation of an antibiotic policy in the hospital. • July 2008 to June 2010: Assessment of the impact of the Phase I intervention programme. • July 2010 to March 2011: Phase II intervention programme: Formation and effective functioning of the antimicrobial stewardship committee. Statistical correlation of the Defined daily dose (DDD for prescribed drugs with the antimicrobial resistance of Gram negatives. Results Phase I intervention programme (July 2008 resulted in a decrease of 4.47% in ESBLs (E.coli and Klebsiella and a significant decrease of 40.8% in carbapenem-resistant Pseudomonas. Phase II intervention (July 2010 brought a significant reduction (24.7% in carbapenem-resistant Pseudomonas. However, the resistance in the other Gram negatives (E.coli, Klebsiella, and Acinetobacter rose and then stabilized. A positive correlation was observed in Pseudomonas and Acinetobacter with carbapenems and cefoperazone-sulbactam. Piperacillin-tazobactam showed a positive correlation with Acinetobacter only. E.coli and Klebsiella showed positive correlation with cefoparazone-sulbactam and piperacillin-tazobactam. Conclusion An antimicrobial stewardship programme with sustained and multifaceted efforts is essential to promote the judicious use of antibiotics.

  6. Evaluation of antimicrobial resistance pattern of nosocomial and community bacterial pathogens at a teaching hospital in Tehran,Iran.

    Directory of Open Access Journals (Sweden)

    Samin Zamani

    2014-03-01

    Full Text Available Antimicrobial resistance in pathogens not only in hospitals but also in the community has become an important public health problem. The aim of this study was to determine the antimicrobial resistance patterns of predominant pathogens from hospitalized and outpatients in a university hospital in Tehran, Iran. A total of 820 samples of common Gram-negative and Gram-positive bacteria were collected from a major referral and teaching hospital affiliated to Tehran University of Medical Sciences in Iran during April 2010 to February 2011. The pattern of antibiotic resistance was determined by disk diffusion test as recommended by the Clinical Laboratory and Standards Institute (CLSI. Gram-negative bacilli were the most isolated pathogens. Acinetobacter spp. and Pseudomonas aeruginosa (P. aeruginosa was the most antibiotic-resistant pathogens. Imipenem and piperacillin/tazobactam were the most active antimicrobials against gram-negative bacilli whereas vancomycin was the antimicrobial agent most consistently active against the Gram-positive cocci. Community-acquired organisms were more susceptible to antimicrobial drugs tested than nosocomial isolates. The rates of antibiotic resistance among isolated pathogens in this study were approximately similar to other studies. However, high rates of antibiotic resistance among Acinetobacter spp and P. aeruginosa, the most isolated pathogens, indicating that antibiotic policy is urgently needed to prevent the resistance development ago.

  7. Evaluation of antimicrobial resistance pattern of nosocomial and community bacterial pathogens at a teaching hospital in Tehran,Iran.

    Science.gov (United States)

    Zamani, Samin; Nasiri, Mohammad Javad; Khoshgnab, Behshad Noorazar; Ashrafi, Abbas; Abdollahi, Alireza

    2014-01-01

    Antimicrobial resistance in pathogens not only in hospitals but also in the community has become an important public health problem. The aim of this study was to determine the antimicrobial resistance patterns of predominant pathogens from hospitalized and outpatients in a university hospital in Tehran, Iran. A total of 820 samples of common Gram-negative and Gram-positive bacteria were collected from a major referral and teaching hospital affiliated to Tehran University of Medical Sciences in Iran during April 2010 to February 2011. The pattern of antibiotic resistance was determined by disk diffusion test as recommended by the Clinical Laboratory and Standards Institute (CLSI). Gram-negative bacilli were the most isolated pathogens. Acinetobacter spp. and Pseudomonas aeruginosa (P. aeruginosa) was the most antibiotic-resistant pathogens. Imipenem and piperacillin/tazobactam were the most active antimicrobials against gram-negative bacilli whereas vancomycin was the antimicrobial agent most consistently active against the Gram-positive cocci. Community-acquired organisms were more susceptible to antimicrobial drugs tested than nosocomial isolates. The rates of antibiotic resistance among isolated pathogens in this study were approximately similar to other studies. However, high rates of antibiotic resistance among Acinetobacter spp and P. aeruginosa, the most isolated pathogens, indicating that antibiotic policy is urgently needed to prevent the resistance development ago.

  8. Identification and Antibacterial Activity of Bacteria Isolated from Marine Sponge Haliclona (Reniera) sp. against Multi-Drug Resistant Human Pathogen

    Science.gov (United States)

    Ardhanu Asagabaldan, Meezan; Ayuningrum, D.; Kristiana, R.; Sabdono, A.; Radjasa, O. K.; Trianto, A.

    2017-02-01

    The marine sponge Haliclona (Reniera) sp. was a potential source of natural bioactive compounds. This sponge widely distributed along the coast of Panjang Island, Jepara, Indonesia. The aims of this research were to isolate the associated bacteria with Haliclona (Reniera) sp. and to screen the antibacterial activity against Multi-Drug Resistant (MDR) bacteria. Amount five bacteria were isolated using media selective for bacteria. The antibacterial activities of bacteria were performed by overlay methods. The bacteria strain PSP. 39-04 had the best activity against Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, and Enterobacter cloaceae. Based on colony morphology and phylogenetic characterization using 16S rRNA gene sequencing, PSP 39-04 was closely related with Chromohalobacter salixigens strain DSM3043.

  9. Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

    Science.gov (United States)

    Andreazza, R.; Pieniz, S.; Okeke, B.C.; Camargo, F.A.O

    2011-01-01

    Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09′53.92″S and 51°31′39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29′43.48″S and 53′32′37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L−1 in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration. PMID:24031606

  10. Isolation and molecular characterization of multidrug-resistant Gram-negative bacteria from imported flamingos in Japan

    Directory of Open Access Journals (Sweden)

    Fukumoto Yukio

    2009-11-01

    Full Text Available Abstract Imported animals, especially those from developing countries, may constitute a potential hazard to native animals and to public health. In this study, a new flock of lesser flamingos imported from Tanzania to Hiroshima Zoological Park were screened for multidrug-resistant Gram-negative bacteria, integrons and antimicrobial resistance genes. Thirty-seven Gram-negative bacterial isolates were obtained from the flamingos. Seven isolates (18.9% showed multidrug resistance phenotypes, the most common being against: ampicillin, streptomycin, tetracycline, trimethoprim/sulfamethoxazole and nalidixic acid. Molecular analyses identified class 1 and class 2 integrons, β-lactamase-encoding genes, blaTEM-1 and blaCTX-M-2 and the plasmid-mediated quinolone resistance genes, qnrS and qnrB. This study highlights the role of animal importation in the dissemination of multidrug-resistant bacteria, integrons and antimicrobial resistance genes from one country to another.

  11. Directly patternable high refractive index ferroelectric sol–gel resist

    Energy Technology Data Exchange (ETDEWEB)

    Garoli, D., E-mail: denis.garoli@iit.it [Istituto Italiano di Tecnologia, Via Morego 16, 16136 Genova (Italy); Della Giustina, G. [Industrial Engineering Department, University of Padova and INSTM, Via Marzolo 9, 35131 Padova (Italy)

    2015-08-15

    The development of a ferroelectric negative tone sol–gel resist for Ultraviolet (UV) and Electron Beam (EB) lithography is presented. A new system based on Lead Zirconate Titanate (PZT, with formula PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}) was synthesized by sol–gel method. The lithographic performances were investigated and several structures spanning from the micron range down to less than 50 nm have been achieved by UV and EB lithography. The system interaction with UV light and Electron beam was thoroughly characterized by FT-IT spectroscopy. The exposed PZT was annealed at high temperatures in order to study the crystalline phase evolution, the optical constants values and stability of patterned structures. After exposure and annealing, the refractive index of the material can vary from 1.68 up to 2.33 (@400 nm), while the ferroelectric behaviour seems to be maintained after high temperature annealing. These results suggest a possible application of PZT resist not only as ferroelectric but also as nanopatternable high refractive index material. Moreover, direct nanopatterning by means of Focused Ion Beam (FIB) lithography was verified and the potentiality for the preparation of high aspect ratio hollow nanostructures will be presented. - Highlights: • A new formula directly patternable PZT high refractive index resist is presented. • The gel is sensitive to both UV and electron beam exposure. • The refractive index can vary from 1.68 up to 2.33 (@400 nm). • Direct nanopatterning by means of Focused Ion Beam (FIB) lithography was verified. • High aspect ratio hollow nanostructures will be presented.

  12. Monitoring of Water Spectral Pattern Reveals Differences in Probiotics Growth When Used for Rapid Bacteria Selection.

    Directory of Open Access Journals (Sweden)

    Aleksandar Slavchev

    Full Text Available Development of efficient screening method coupled with cell functionality evaluation is highly needed in contemporary microbiology. The presented novel concept and fast non-destructive method brings in to play the water spectral pattern of the solution as a molecular fingerprint of the cell culture system. To elucidate the concept, NIR spectroscopy with Aquaphotomics were applied to monitor the growth of sixteen Lactobacillus bulgaricus one Lactobacillus pentosus and one Lactobacillus gasseri bacteria strains. Their growth rate, maximal optical density, low pH and bile tolerances were measured and further used as a reference data for analysis of the simultaneously acquired spectral data. The acquired spectral data in the region of 1100-1850nm was subjected to various multivariate data analyses - PCA, OPLS-DA, PLSR. The results showed high accuracy of bacteria strains classification according to their probiotic strength. Most informative spectral fingerprints covered the first overtone of water, emphasizing the relation of water molecular system to cell functionality.

  13. Bacterial urinary tract infection in renal transplant recipients and their antibiotic resistance pattern: A four-year study.

    Directory of Open Access Journals (Sweden)

    Azar Dokht Khosravi

    2014-04-01

    Full Text Available Urinary tract infections (UTIs are the most common infections in renal transplant recipients and are considered a potential cause of bacteremia, sepsis, and affects graft outcomes. The aim of the present study was to determine the incidence of UTI among renal transplant recipients and investigation of antimicrobial susceptibility pattern of causative agents.In total, 1165 patients from March 2009 to December 2012, in transplant center of Golestan Hospital, Ahvaz, Iran, were investigated. Qualitative urine cultures were performed for all cases, causative microorganisms were identified and colony count was performed according to the standard protocol. Antibiotic susceptibility testing was then performed to determine the susceptibility pattern of recovered bacteria from confirmed UTIs.UTI was diagnosed in 391 patients(33.56%. Gram-negative bacteria were the most prevalent isolated microorganisms with E. coli (43.53%, followed by Enterobacter spp. (35.37% as the major organisms. Among Gram positives, Coagulase-negative Staphylococci was isolated from 6.8% of cases. The rate of resistance to all tested antibiotics was highest in Enterobacter spp., however the most common resistance were seen against cefixime, cephalotin, and cotrimoxazole in all tested gram negatives.the rate of UTIs among renal transplant recipients was noticeable in this study with high antibiotic resistance. Multi-resistant bacterial infections are potentially life-threatening emerging problem in renal transplantation. Prophylactic measures must be applied to patients at greater risk.

  14. Isolation, structural elucidation and in vitro activity of 2-acetyl-2-decarboxamido-oxytetracycline against environmental relevant bacteria, including tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Lykkeberg, Anne Kruse; Sengeløv, Gitte; Cornett, Claus;

    2004-01-01

    2-Acetyl-2-decarboxamido-oxytetracycline (ADOTC) is a major impurity of oxytetracycline (OTC) produced as a side product during fermentation. ADOTC was isolated from OTC and other impurities using preparative HPLC. The preparative column was an Xterra MS. C-18 chromatographic column (100 mm x 19 ...... sludge bacteria was deter-mined giving a potency of only 3% of that of OTC. With tetracycline-resistant bacteria, no anti-microbial activity was observed, indicating a mode of action similar to that of OTC....

  15. Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter

    DEFF Research Database (Denmark)

    Li, Lili; Olsen, Rikke Heidemann; Ye, Lei

    2016-01-01

    oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6...... resistance genes were found in new carriers: bla TEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; bla CMY-2 in Lactococcus lactis, Klebsiella...

  16. UV-Resistant Non-Spore-Forming Bacteria From Spacecraft-Assembly Facilities

    Science.gov (United States)

    Venkateswaran, Kasthuri

    2008-01-01

    Four species of non-spore-forming bacteria collected from clean-room surfaces in spacecraft-assembly facilities could survive doses of ultraviolet (UV) radiation that would suffice to kill most known cultivable bacterial species. In a previous study, high UV resistance was found in spores of the SAFR-032 strain of Bacillus pumilus, as reported in "Ultraviolet- Resistant Bacterial Spores," NASA Tech Briefs, Vol. 31, No. 9 (September 2007), page 94. These studies are parts of a continuing effort to understand the survival of hardy species of bacteria under harsh conditions, and develop means of sterilizing spacecraft to prevent biocontamination of Mars that could in turn interfere with future life detection missions. The four species investigated were Arthrobacter sp. KSC_Ak2i, Microbacterium schleiferi LMA_AkK1, Brevundimonas diminuta KSC_Ak3a, and Sphingomonas trueperi JSC_Ak7-3. In the study, cells of these species were mixed into Atacama Desert soil (to elucidate the shadowing effect of soil particles) and the resulting mixtures were tested both in solution and in a desiccated state under simulated Martian atmospheric and UV conditions. The UV-survival indices of Arthrobacter sp. and Microbacterium schleiferi were found to be comparable to those of Bacillus pumilus spores.

  17. Antibiotic resistance and assessment of food-borne pathogenic bacteria in frozen foods.

    Science.gov (United States)

    Baek, Eunhye; Lee, Dokyung; Jang, Seok; An, Hyangmi; Kim, Mijin; Kim, Kyungjae; Lee, Kangoh; Ha, Namjoo

    2009-12-01

    One hundred ninety-three frozen food samples collected in Korea various public bazaars from October 2006 to September 2007. Staphylococci were detected in 21.8% of frozen food samples. Staphylococcus aureus was isolated from 17 (8.8%) samples. Other staphylococci isolates were identified as S. warneri (7.8%), S. epidermidis (2.1%), S. xylosus (1.6%), S. eguorum (1%), and S. vitulinus (0.5%). Additionally, the antimicrobial susceptibility of 42 staphylococcal isolates to ten different antimicrobial agents was determined. The staphylococcal isolates demonstrated antimicrobial resistance to mupirocin (31%) oxacillin (14.3%), gentamicin (9.5%), teicoplanin (7.1%) and ciprofloxacin (7.1%). Most of the staphylococcal isolates showed high-level resistance to mupirocin (MIC(90), >128 microg/mL). Fortunately, most of the isolates were susceptible to vancomycin. The total bacteria and Escherichia coli count were tested to investigate the microbiological quality of frozen foods. From 193 frozen food samples, 43 (22.3%), 34 (17.6%) and 19 (9.8%) samples were shown to be of unacceptable quality due to total bacteria, coliform and E. coli counts, respectively.

  18. Ciprofloxacin Residues in Municipal Biosolid Compost Do Not Selectively Enrich Populations of Resistant Bacteria

    Science.gov (United States)

    Youngquist, Caitlin P.; Liu, Jinxin; Orfe, Lisa H.; Jones, Stephen S.

    2014-01-01

    Biosolids and livestock manure are valuable high-carbon soil amendments, but they commonly contain antibiotic residues that might persist after land application. While composting reduces the concentration of extractable antibiotics in these materials, if the starting concentration is sufficiently high then remaining residues could impact microbial communities in the compost and soil to which these materials are applied. To examine this issue, ciprofloxacin was added to biosolid compost feedstock to achieve a total concentration of 19 ppm, approximately 5-fold higher than that normally detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (1 to 3.5 ppm). This feedstock was placed into mesh bags that were buried in aerated compost bays. Once a week, a set of bags was removed and analyzed (treated and untreated, three replicates of each; 4 weeks). Addition of ciprofloxacin had no effect on the recovery of resistant bacteria at any time point (P = 0.86), and a separate bioassay showed that aqueous extractions from materials with an estimated 59 ppm ciprofloxacin had no effect on the growth of a susceptible strain of Escherichia coli (P = 0.28). Regression analysis showed that growth of the susceptible strain of E. coli can be reduced given a sufficiently high concentration of ciprofloxacin (P ciprofloxacin in the materials tested here, the culture-based methods were consistent with the materials having sufficient adsorptive capacity to prevent typical concentrations of ciprofloxacin residues from selectively enriching populations of resistant bacteria. PMID:25261519

  19. Drug efflux pump deficiency and drug target resistance masking in growing bacteria

    Science.gov (United States)

    Fange, David; Nilsson, Karin; Tenson, Tanel; Ehrenberg, Måns

    2009-01-01

    Recent experiments have shown that drug efflux pump deficiency not only increases the susceptibility of pathogens to antibiotics, but also seems to “mask” the effects of mutations, that decrease the affinities of drugs to their intracellular targets, on the growth rates of drug-exposed bacteria. That is, in the presence of drugs, the growth rates of drug-exposed WT and target mutated strains are the same in a drug efflux pump deficient background, but the mutants grow faster than WT in a drug efflux pump proficient background. Here, we explain the mechanism of target resistance masking and show that it occurs in response to drug efflux pump inhibition among pathogens with high-affinity drug binding targets, low cell-membrane drug-permeability and insignificant intracellular drug degradation. We demonstrate that target resistance masking is fundamentally linked to growth-bistability, i.e., the existence of 2 different steady state growth rates for one and the same drug concentration in the growth medium. We speculate that target resistance masking provides a hitherto unknown mechanism for slowing down the evolution of target resistance among pathogens. PMID:19416855

  20. Effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth.

    Science.gov (United States)

    Li, Kefeng; Ramakrishna, Wusirika

    2011-05-15

    Naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. This study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant Pseudomonas strains previously isolated from Torch Lake sediment. These strains showed variable susceptibility to different antibiotics. Furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. Bacterial strains TLC 3-3.5-1 and TLC 6-6.5-1 showed high bioaccumulation ability of Zn (up to 15.9 mg/g dry cell) and Pb (80.7 mg/g dry cell), respectively. All the strains produced plant growth promoting indole-3-acetic acid (IAA), iron chelating siderophore and solubilized mineral phosphate and metals. The effect of bacterial inoculation on plant growth and copper uptake by maize (Zea mays) and sunflower (Helianthus annuus) was investigated using one of the isolates (Pseudomonas sp. TLC 6-6.5-4) with higher IAA production and phosphate and metal solubilization, which resulted in a significant increase in copper accumulation in maize and sunflower, and an increase in the total biomass of maize. The multiple metal-resistant bacterial isolates characterized in our study have potential applications for remediation of metal contaminated soils in combination with plants and metal contaminated water.

  1. Effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kefeng [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Ramakrishna, Wusirika, E-mail: wusirika@mtu.edu [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)

    2011-05-15

    Naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. This study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant Pseudomonas strains previously isolated from Torch Lake sediment. These strains showed variable susceptibility to different antibiotics. Furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. Bacterial strains TLC 3-3.5-1 and TLC 6-6.5-1 showed high bioaccumulation ability of Zn (up to 15.9 mg/g dry cell) and Pb (80.7 mg/g dry cell), respectively. All the strains produced plant growth promoting indole-3-acetic acid (IAA), iron chelating siderophore and solubilized mineral phosphate and metals. The effect of bacterial inoculation on plant growth and copper uptake by maize (Zea mays) and sunflower (Helianthus annuus) was investigated using one of the isolates (Pseudomonas sp. TLC 6-6.5-4) with higher IAA production and phosphate and metal soubilization, which resulted in a significant increase in copper accumulation in maize and sunflower, and an increase in the total biomass of maize. The multiple metal-resistant bacterial isolates characterized in our study have potential applications for remediation of metal contaminated soils in combination with plants and metal contaminated water.

  2. Plasmid-Mediated Quinolone Resistance (PMQR) Genes and Class 1 Integrons in Quinolone-Resistant Marine Bacteria and Clinical Isolates of Escherichia coli from an Aquacultural Area.

    Science.gov (United States)

    Tomova, Alexandra; Ivanova, Larisa; Buschmann, Alejandro H; Godfrey, Henry P; Cabello, Felipe C

    2017-06-23

    Antimicrobial usage in aquaculture selects for antimicrobial-resistant microorganisms in the marine environment. The relevance of this selection to terrestrial animal and human health is unclear. Quinolone-resistance genes qnrA, qnrB, and qnrS were chromosomally located in four randomly chosen quinolone-resistant marine bacteria isolated from an aquacultural area with heavy quinolone usage. In quinolone-resistant uropathogenic clinical isolates of Escherichia coli from a coastal area bordering the same aquacultural region, qnrA was chromosomally located in two E. coli isolates, while qnrB and qnrS were located in small molecular weight plasmids in two other E. coli isolates. Three quinolone-resistant marine bacteria and three quinolone-resistant E. coli contained class 1 integrons but without physical association with PMQR genes. In both marine bacteria and uropathogenic E. coli, class 1 integrons had similar co-linear structures, identical gene cassettes, and similarities in their flanking regions. In a Marinobacter sp. marine isolate and in one E. coli clinical isolate, sequences immediately upstream of the qnrS gene were homologous to comparable sequences of numerous plasmid-located qnrS genes while downstream sequences were different. The observed commonality of quinolone resistance genes and integrons suggests that aquacultural use of antimicrobials might facilita