Acinetobacter Anitratus Research Articles

Microbiological profile and their antibiotic sensitivity pattern in patients of chronic suppurative otitis media at eastern tertiary care center of Nepal

Chronic suppurative otitis media (CSOM) is one of the most common and an important global public health problem leading to hearing impairment and is particularly prevalent in developing countries. Even in this era of powerful antibiotics, due to increased irrational use of wide spectrum antibiotics, the resistance in the bacterial isolates is common. The objective of the study was to determine the aerobic bacterial etiology of patients with CSOM and the antimicrobial susceptibility of the bacteria isolated.A descriptive cross sectional study was carried out in 112 patients suffering from chronic discharging ear. Pus samples were cultured aerobically. Antibiotic sensitivity testing was performed with standard antibiotic discs using modified Kirby-Bauer disk diffusion method.Out of 112 patients, 70 (62.5%) were females. Among 112 swab cultures, 98 (87.5%) were positive for the growth of organism and 14 (12.5%) were sterile cultures. Among them Staphylococcus aureus (42.24%), Pseudomonas aeruginosa (28.44%), Klebsiella pneumoniae (10.34%), Acinetobacter anitratus (6.9%), Proteus mirabilis (5.17%) and E. coli (4.31%) were the common microbial isolates. Among the antibiotics commonly available as topical eardrops, Ofloxacin (91.83%)) had the highest susceptibility rate, followed by Ciprofloxacin (81.63%), Tobramycin (73.46%) and Gentamicin (63.26%).Staphylococcus aureus was the most common organism isolated followed by Pseudomonas aeruginosa. Ofloxacin had the highest susceptibility rate against the isolated organisms.

Salivary Microflora of Complete Denture Wearing Patients

Objectives of this study were to see the types of aerobic microorganisms present in the saliva of Complete Denture wearing patients and to see any change in isolation frequency and types of microorganisms at 1-week of dentures in use. Materials and Methods: Ethical clearance from the institutional ethical committee and written consent from the patients were taken. All the patients were assessed by taking a detailed history and clinical examination which were recorded in the pre-designed proforma. Standard procedures accepted in the Department of Prosthodontics and in the Department of Microbiology were performed. Each patient were examined twice, once at 24hrs of denture insertion and then at 1-week of dentures in use. A micropippet was used to collect the resting saliva from the floor of the mouth and was diluted in 1ml of normal saline in a sterile vial and was immediately taken to the microbiology lab for culture within half an hour of sample collection. Result: Microorganisms identified at 24hrs of Complete Denture insertion were Streptococcus spp. (n=35), Staphylococcus spp. (n=15), Klebsiella pneumonia (n=5), Acinetobacter anitratus (n=5), Enterobacter cloacae (n=4), Citrobacter freundii (n=4), Pseudomonas aeruginosa (n=1) and Proteus vulgaris (n=1). Two new microorganisms were isolated at 1-week, Escherichia coli (n=1) and Candida albicans (n=2). Frequency of isolation of the gram negative bacteria increased at 1-week except for Proteus vulgaris. Conclusion: Use of Complete Denture favours colonization of some microorganisms which appear in saliva of patients.

Incidence and Susceptibility of Uropathogens Isolated among the Patients at Tertiary Care Hospital in Eastern Nepal

Background Urinary Tract Infection (UTI) is one of the most common infectious diseases which affect almost all ages groups of population. Production of â-lactamases is responsible for antibacterial resistance which is frequently observed in Enterobacteriaceae isolates, particularly by E. coli and Klebsiella pneumoniae. This investigation has been carried out to determine the current status of prevalence and susceptibility of uropathogens isolated among the patients at tertiary care hospital in eastern Nepal.Material and Methods This study was done at the department of Microbiology, Nobel Medical College Teaching Hospital, Biratnagar, Nepal during May 1st 2015 to October 31st 2015. Midstream cleancatch urine was sampled from 1730 suspected urinary tract infection patients of different age and sex groups. Uropathogens were recognized in term of standard and specific microbiological techniques and antimicrobial susceptibility pattern was determined by Kirby Bauer Disc diffusion method following Clinical and Laboratory Standards Institute (CLSI) guidelines.Results Out of 1730 suspected specimens Culture resulted a total of 761 (43.98 %) positive and 969 (56.02%) negative among that significant growths of uropathogens including 700 (91.98 %) unimicrobial and 60 (7.88 %) polymicrobial growths. In term of Gender distribution 443 (25.60 %) were male and 1287 (74.40 %) were female hence the ratio is 0.34:1, respectively. E. coli was the leading isolate (66 %), followed by Klebsiella spp. (12 %), Enterococcus spp. (8 %), Pseudomonas spp. (6 %), Acinetobacter anitratus (5 %), Proteus spp. (3 %).Conclusion The high frequency of multidrug resistance in bacterial uropathogens was seen. Principally, resistance patterns were seen higher for amoxycillin, co-trimoxazole, flouroquinolones and third-generation cephalosporins, Existing uropathogens highlights the highest rate of vulnerability to nitrofurantoin, amikacin and gentamicin which provide much better antibiotic coverage and can be adapted for practical treatment of urinary tract infections. Journal of Nobel Medical College Vol.5(2) 2016; 51-55

Bacterial Isolates from Urinary Tract Infection in Dogs in Grenada, and Their Antibiotic Susceptibility

Of 52 culture positive urine samples from dogs in Grenada for six years (2004 through 2009) 65.5% of isolates were Gram-negative bacteria, with E. coli as the predominant species, followed by Proteus mirabilis, and Pseudomonas aeruginosa. Other Gram-negative isolates included Klebsiella pneumoniae, Acinetobacter anitratus, and Serratia plymuthica. Among the Gram-positive isolates, Staphylococcus intermedius was the most common species, followed by S. aureus, coagulase-negative staphylococci, and enterococci. Sensitivity results obtained with 6 antibiotics showed least resistance to enrofloxacin, the rate being 19% for all isolates together. More than two-thirds of isolates were resistant to tetracycline. For Gram-positive isolates, resistance to cephalothin was even less than that against enrofloxacin, with a rate of only 13%. Overall resistance to amoxicillin-clavulanic acid was 36%. The most common drug used for treatment of urinary tract infections in Grenada has been amoxicillin-clavulanic acid, followed by enrofloxacin.

Colonization and infection in tracheostomized patients at tertiary care hospital in Eastern Nepal

Introduction: Tracheostomy is a life saving emergency procedure and provides many benefits for long term ventilator dependent patients. However, colonization and infection of airways after tracheostomy is one of the serious complications increasing patient morbidity and mortality. Objective: To find out the colonizing agent in the trachea of tracheostomized patients and the type and frequency of post tracheostomy infection. Methods: Study was conducted in 30 consecutive, adult patients requiring either elective or emergency tracheostomy at BPKIHS, Nepal. First and second tracheal swab was obtained immediately after tracheostomy and on the seventh day. Micro-organisms isolated from the culture of tracheal swab were noted. Patients were observed for infectious complications after tracheostomy. Results: Eighteen (60%) tracheostomies were performed electively and 12(40%) as an emergency. Sixty-eight isolates were grown from the culture of tracheal swabs. Out of 60 tracheal swabs, nine showed sterile culture. Single micro-organism was isolated from 35(58.33%) tracheal swabs and polybacterial isolation was seen in 16(26.66%) swabs. Pseudomonas aeroginosa was the commonest micro-organism isolated. After Pseudomonas, Staphylococcus aureus in the first culture and Acinetobacter anitratus in the second culture was the commonest organisms isolated. Five (16.6%) patients developed stomal infection and three (10.0%) developed pneumonia as a complication of tracheostomy. Conclusion: Trachea of the tracheostomized patients is heavily colonized by Pseudomonas aeruginosa, Acinetobacter anitratus and Staphyloccus aureus . Stomal infection and pneumonia are the infectious complication occurring within seven days of tracheostomy.Health Renaissance 2014;12(2): pp. 68-73

URINARY TRACT INFECTION: ETIOLOGY AND ANTIMICROBIAL RESISTANCE WITH REFERENCE TO ADHESIVE ORGANELLES

Background: Urinary tract infection (UTI) is a serious health problem, affecting millions of people each year. Aim: The present study was undertaken to study the profile of uropathogenic bacterial flora in adult, their antibiotic resistant pattern, adherence factors of uropathogens and in vitro adherence capabilities of Uropathogens. Material and Methods: The samples were tested microbiologically by standard procedure. Antibiotic susceptibility of the isolated pathogens was tested for commonly used antibiotics by Kirby-Bauer technique according to CLSI guidelines. Adherence assay were done by hemagglutination test and Giemsa staining technique. Detection of hemolysin production was done on 5% washed sheep blood agar. Motility test was done by stabbing the isolates into SIM biochemical media. Results: Significant bacteriuria was present in 40% of samples. The most common pathogens isolated were Escherichia coli (52%), followed by Klebsiella pneumoniae (16%), Acinetobacter anitratus (11%), Proteus mirabilis (6%), Enterobacter species (5%), Citrobacter species (2%), Pseudomonas aeruginosa (2%), Morganella morganii (1%), Enterococcus species (3%) and Staphylococcus aureus (2%). The mean susceptibility of uropathogens was for amikacin (Ak-81%), nitrofurantoin (Nf-60%), cefotaxime (52%), ceftriaxone (Ci-47%), ciprofloxacin (Cf-45%), norfloxacin (Nx-33%), cotrimoxazole (Co-18%) and nalidixic acid (Na-17%). Mean adherence of pathogens to epithelial cells was 70 bacteria cell -1 . Of all, 52% isolates were hemagglutinating, 34% were alpha-hemolytic, 31% were beta-hemolytic and 68% were motile. Conclusion: Escherichia coli are the commonest cause of UTI. Adherence is one of the essential pre-requisites to establish UTI. Majority of UTI in men are mono-microbial. Most of uropathogens are susceptible to amikacin (81%) and nitrofurantoin (60%). Key words: UTI, uropathogens, adherence, antimicrobials.

Antimicrobial susceptibility pattern of Gram negative bacterial isolates from urine in tertiary care hospital of Eastern Nepal

Background:Urinary tract infections (UTIs) are themost important cause of morbidity and mortality in the world affecting all age groups. It is estimated that 150million cases ofUTI occur onaglobal basis per year. Resistance to antibiotics is highly prevalent and growingas theglobal problem inmanagementofUTI. Knowledgeof pattern of antimicrobial agents among local isolates plays a major role for selecting appropriate and effective therapy. Objectives: The present study was conducted to determine in vitro susceptibility among Gram negative organisms obtained from urineagainst commonly used antimicrobials. Methods: Urine specimens submitted to the Department of Microbiology, BP Koirala Institute of Health Sciences (BPKIHS) Hospital for culture and sensitivity over one year periodwere evaluated. Isolation, identification and determination of antimicrobial susceptibility were done by standard microbiological techniques. Results: Out of 13011 urine specimens submitted, 2131(16.3%) comprises Gram negative uropathogens, among which the most prevalentwas Escherichia coli (66.3%) followed byKlebsilla pneumoniae (11.7%), Acinetobacter anitratus (6.8%), Enterobacter aerogens (3.3%) and Pseudomonas aeruginosa (2.5%), Morganella morganii (1.3%), Proteus mirabilis (1.2%), Citrobacter frundii (0.7%), Klebsiella oxytoca (0.7%), Proteus vulgaris (0.56%). The majority (65.3%) were from femalewhile (34.7%)weremale patients.Most of theGNB isolates were found to be resistant to ampicillin (90%), norfloxacillin (60%) and ofloxacin (57.17%) where as they were susceptible to cotrimoxazole (73.2%), nitrofurantoin (69%) and amikacin (68.4%). Conclusion: Gram negative organisms remain the major cause of UTI. Various degree of antimicrobial resistance was observed among the uropathogens prevalent in our hospital. Regular monitoring of the resistance in the local isolates against the routinely used antimicrobial may have significant impact for the effective management of UTI.

PREVALENCE OF DRUG RESISTANT BACTERIA AND TOXIC CHEMICALS IN POULTRY DUST

Bacteriological investigations were carried out on air-borne and settled dust in poultry confinements. Poultry dusts were also analysed for heavy metals and toxic chemicals. Isolation of air-borne bacteria was by plate exposure, bacteria load in poultry air was carried out using air sampler and bacteria load in settled poultry dust was determined by serial dilution technique. The concentrations of nitrate, sulphate and ammonia in poultry dust was determined by the Brucine , turbidimetry and distillation methods respectively, while atomic absorption technique was used to determine the concentrations of Zn, Mn, Cu, Cd, and Pb. Bacterial load in settled dust and air in poultry confinements were found to be7-26 x 107cfu/g and 2-20 x 107cfu/m3 respectively. Isolated bacteria in poultry confinements include Escherichia coli, Klebsiella aerogenes, Salmonella enterica serovar Gallinarum, Salmonella enterica serovar Enteritidis, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Enterococcus faecalis, Proteus mirabilis, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Bacillus cereus, Bacillus mycoides, Clostridium perfringes, Citrobacter freundii, Carnobacterium piscicola, Serratia marscences and Acinetobacter anitratus. Some of these isolated bacteria were resistant to multiple drugs. Sieved poultry dust samples analyzed for their chemical compositions were found to contain the following chemicals in ?g/kg: ammonia 31.23+2.06; nitrate 7.31+0.05; sulphate 5.1+0.07; zinc 5.1+0.07; manganese 16.48+0.76; copper 0.47+0.09; cadmium 0.02+0.01 and lead 0.08+0.02. Inhalation of these drug-resistant bacteria and toxic chemicals could be of grave health consequence. Protective measures that will reduce occupational dust exposure should be in place in poultry farms

Meningitis bacteriana por bacilos gramnegativos en adultos

Gram-negative bacilli are causative agents of bacterial meningitis in the neonatal period but rarely cause meningitis in adults without risk factors. To report on meningitis due to gram-negative bacilli (MGNB) in adults diagnosed in a hospital over a 25-year period. We reviewed the medical records of all patients with an age > or = 14 years who had been diagnosed with MGNB between 1982 and 2006. Fifteen cases of MGNB are included (10.5% of the cases of bacterial meningitis with an identified aetiology), with a mean age of 48 years (14-79). Twelve (80%) were post-operative: recent neurosurgery (9 cases, 75%) and having a neurosurgical device (8 cases, 67%) were risk factors. Three (20%) were spontaneous: two were of a urinary origin and one had an undetermined origin. The aetiology was: Pseudomonas aeruginosa (3 cases), Escherichia coli (3 cases), Enterobacter aerogenes (2 cases), Pseudomonas fluorescens (1 case), Klebsiella pneumoniae (1 case), Morganella morganii (1 case), Acinetobacter anitratus (1 case), Acinetobacter iwoffii (1 case) and Flavobacterium brevis (1 case); in one patient with Gram positive staining for gram-negative bacilli, the culture was negative, and three of them (20%) were mixed infections (Staphylococcus spp.). Three patients (20%) died. In adults, gram-negative bacilli rarely cause spontaneous meningitis, but are a common causation of post-neurosurgical meningitis and in those with neurosurgical devices. The mortality rate of MGNB is high.

Trends in antimicrobial susceptibility of Gram-negative bacteria isolated from blood in Jakarta from 2002 to 2008

This study examined the susceptibility of Gram-negative bacteria in the bloodstream to antimicrobials with the aim of providing information relevant to the guidance of therapy. Blood specimens received by the Laboratory of Clinical Microbiology, Faculty of Medicine, University of Indonesia, from 2002 to 2008, were analyzed for the presence of Gram-negative bacteria and their susceptibility to four antibiotic groups frequently administered in hospitals and community settings. During the seven-year period leading up to 2008, approximately 68% of Gram-negative bacteria were identified among all positive isolates from blood specimens. The eight most frequent species found were Acinetobacter anitratus (25.8%), Pseudomonas aeruginosa (19.5%), Klebsiella pneumoniae subsp. pneumoniae (14.5%), Enterobacter aerogenes (8%), Salmonella Typhi (7.5%), Escherichia coli (6.2%), Alcaligenes faecalis (5.6%) and Klebsiella oxytoca (3.2%). At 80% susceptibility or greater, Ceftriaxone and Cefotaxime were active only on E. coli and S. Typhi. Cefepime demonstrated activity on all eight species tested except K. pneumonia while Amikacin showed activity against five species, A. faecalis, E. aerogenes, E. coli, K. pneumoniae subsp. pneumoniae and S. Typhi. Gentamycin was active against three species: E. aerogenes, K. oxytoca and S. Typhi. Ciprofloxacin and Levofloxacin significantly differed in their spectrum: while Ciprofloxacin was active against four of the eight species tested (E. aerogenes, E. coli, K. oxytoca, and S. Typhi ), Levofloxacin was similar to Cefepime and was active against all eight species except K. pneumoniae subsp. pneumonia. Since antimicrobials are broadly used in Jakarta, it is important that the information captured in this study be disseminated.

Isolation of environmental microorganisms from clinical specimens: A report of the occurrence of Acinetobacter anitratus in blood of hospitalized patients in Jakarta in a 7 year period

Aim To report the presence of environmental microorganisms, A. anitratus, in blood of hospitalized patients in Jakarta from 2002 to 2008 and their susceptibility to antibiotics. Methods A Retrospective study was performed on all blood specimens that were received in Clinical Microbiology Laboratory (CML) Faculty of Medicine University of Indonesia during 2002-2008. Culture and antimicrobial susceptibility examination were carried out according to up to date standard practice in CML and Clinical Laboratory Standard Institute, recpectively. Data was collected by WHONET 5.4 program. All Gram-negative microorganisms that were isolated from blood specimens were tabulated, and so the antibiotics susceptibility of A. anitratus. The origin of the specimens in term of institutions where the specimens came from was also analyzed. Results In a 7 year period up to 2008, A. anitratus was found in blood specimens, and these invironmental bacteria were in fact the most predominant isolated Gram negative microorganisms. Together with another environmental microorganism, Pseudomonas aeruginosa, it composed nearly 50%. Antimicrobial susceptibility test of this microorganism showed some degree of resistance to all tested antibiotics. The origin of those blood specimens which yielded A. anitratus were mainly from government-owned hospitals, that was 88 specimens (74%), followed by private hospitals (18 specimens, 15%), individuals (3 specimens, 3%), and unknown source (10 specimens, 8%). Conclusion Persistent occurrence of A. anitratus in blood specimens of hospitalized patients in hospitals in Jakarta was observed. In the near future, a study to fi nd risk factors for the acquisition of A. anitratus bacteremia is needed to reduce potential hospital associated infection. Moreover, genotyping is advised in order to determine the relationship of hospital and patient derived strains. (Med J Indones 2009; 18:227-32)

Effectiveness of chlorination and ozonation methods on pure cultures of floc-forming micro-organisms and activated sludge: A comparative study

Chlorination is a very useful control method of filamentous bulking in activated sludge systems; however, it favours formation of undesirable compounds such as trihalomethanes. Other oxidants, such as ozone, could be used for bulking control. In view of the fact that chlorine and ozone are both non-selective chemical agents affecting filamentous and floc-forming micro-organisms, the determination of optimum dosage conditions becomes essential to minimise the impact produced on the activated sludge process. In this work, the effects of chlorine and ozone on the biomass concentration of activated sludge and on different parameters that characterise the microbial metabolic activity were compared. The following techniques were applied: Respirometry (oxygen uptake rate); and INT-dehydrogenase activity test carried out both by spectrophotometry (DHAa) and image analysis (DHAi). The respirometric technique and the DHAa test quantified oxidants action on the total respiratory activity of flocs; the image DHAi test was applied to evaluate the specific action of the oxidants on filamentous micro-organisms. Additionally, plate count technique, respirometry and DHAa test were correlated using chlorine and ozone experiments on pure cultures of a floc-forming micro-organism (Acinetobacter anitratus) to compare the effect of the oxidising agents on the metabolic activity and the viability of the micro-organisms. Ozone was found to have more intense antimicrobial action. In activated sludge, ozone reduced total biomass concentration by oxidising various components and causing cell lysis. An equation was proposed to estimate biomass concentration of activated sludge as a function of time and ozone dose rate; in contrast, at the doses applied, chlorine did not reduce the concentration of activated sludge biomass. In activated sludge, adequate conditions for both oxidants were identified under which the respiratory activity of filamentous micro-organisms could be considerably inhibited, causing the lowest possible impact on whole floc metabolic activity. An initial chlorine dose of 7.9 mgCl2·gVSS-1 for a contact time of 5 min (initial pulse= 6.0 mgCl2·l-1), and a total ozone dose of 66.0 mgO3·gVSS-1 (ozone dose rate of 3.3 mgO3·gVSS-1·min-1 for a contact time of 20 min) were the most suitable conditions to control filamentous bulking. Water SA Vol.32 (4) 2006: pp.585-595

Inhibitory Effect of a Surfactant on Pure Cultures of a Filamentous and a Floc Forming Micro-Organism

Activated sludge is the most widely used biological process for wastewater treatment. Inorganic and organic compounds are removed by a biotic community in the aeration basin. Problems of these systems are loss of settleability and poor sludge compaction due to excessive growth of filamentous micro-organisms. The filamentous bulking can be controlled by the addition of chemical agents. Strong oxidants, such as chlorine, are utilized to eliminate filamentous bacteria; however, these substances also tend to attack floc-forming bacteria and to cause process breakdown. Besides, chlorine may become hazardous owing to the formation of chemical products as chloramines. Surfactant addition constitutes an interesting alternative for the control of filamentous bulking. In this work the effect of a surfactant Triton X-100 (octylphenol ethoxylate), on the respiratory activity (RA) of pure cultures of a filamentous (Sphaerotilus natans) and a floc-former micro-organism (Acinetobacter anitratus) was evaluated. In the concentration range tested (60-220 mg l−1), the surfactant was observed to exhibit high RA specific inhibition of the filamentous micro-organism with no significant effect on the floc-forming bacteria. Light microscopy observations showed that the surfactant induced cell lysis, leaving only empty sheaths in the case of filamentous micro-organisms. A kinetic equation to predict the microbial RA fraction of a S. natans pure culture as a function of surfactant concentration and contact time was proposed. The effect of Triton X-100 on the inactivation of pure cultures of both micro-organisms was compared to that of chlorine. Triton X-100 results were adequate to eliminate filamentous bacteria emerging as an alternative for filamentous bulking treatment.

Preliminary studies of cellulase production by Acinetobacter anitratus and Branhamella sp.

Two Bacteria species, Acinetobacter anitratus and Branhamella sp., were isolated from the haemolymph of the giant African snail, Archachatina marginata. The endocellulase activity of the culture broth was determined during bacterial growth by measuring the release of reducing sugar from carboxymethyl cellulose (CMC). The peak of enzyme production occurred at the late logarithm phase for each bacterial species. The kinetics of CMC and celloboise hydrolysis was found to be the Michaelis-Menten type. The KM values of CMC substrate were found to be 4.97 and 7.90 mg/ml for A. anitratus and Branhamella sp., respectively. The KM values for cellobiose as substrate were 0.32 and 2.50 mM for A. anitratus and Branhamella sp., respectively. A multiplicity of cellulase complexes in the haemolymph of A. marginata is indicated.

Effect of Ozone on Filamentous Bulking in a Laboratory Scale Activated Sludge Reactor Using Respirometry and INT-Dehydrogenase Activity

Filamentous bulking can be controlled by the addition of oxidant chemical agents such as ozone. To evaluate the ozone effect on activated sludge from a laboratory scale reactor, different techniques were applied: Settleability test, respirometry (oxygen uptake rate), and the INT-dehydrogenase activity test carried out both by spectrophotometry ( DHAa ) and image analysis ( DHAi ) . In activated sludge, the respirometric technique and the spectrophotometric DHAa quantified ozone action on the total respiratory activity of flocs; in contrast, the image DHAi test was applied to evaluate the specific action of ozone on filamentous microorganisms. The conditions for application of the INT-dehydrogenase activity test were standardized using pure cultures of a filamentous microorganism (Sphaerotilus natans) and a floc-forming bacterium (Acinetobacter anitratus). For activated sludge with filamentous bulking, ozone doses and treatment times necessary to improve settleability were established. Ozone dose levels an...

Growth study on chrysene degraders isolated from polycyclic aromatic hydrocarbon polluted soils in Nigeria

Acinetobacter anitratus, Alcaligenes faecalis, Acinetobacter mallei and Micrococcus varians were isolated from polycyclic aromatic hydrocarbon polluted soils by enrichment culture using chrysene as sole carbon and energy source. Physiochemical evaluation revealed that these isolates grew well at a temperature range of 20 - 40°C, pH 6.0-8.0 but less tolerable to various salt concentrations except Micrococcus varians which grew at 1.0 to 7.5% NaCl. These organisms utilized chrysene, anthracene, naphthalene, crude oil, kerosene, diesel and engine oil as sole carbon source. None could utilize benzene, hexane, xylene, phenol and toluene as carbon sources. Growth study of the isolates on 0.1% (w/v) chrysene resulted in highest cell density of 8.8x10 7 , 7.9x10 7 , 6.3x10 6 , 6.3x10 6 cfu/ml for A. anitratus, Alc. faecalis, A. mallei and M. varians, respectively. There was statistical significant difference (P< 0.05) in the growth of these organisms on chrysene as sole carbon and energy source when compared with non-chrysene control. This study indicates the potential of these hitherto unreported tropical bacterial strains as chrysene degraders and their use in biodegradation processes involving petrochemical products.

Detection of Paragonimus heterotremus Eggs in Experimentally Infected Cats by a Polymerase Chain Reaction–Based Method

A polymerase chain reaction (PCR) procedure for the detection of Paragonimus heterotremus eggs in stool samples was developed and compared with Stoll's egg count method. The primers were designed on the basis of a previously constructed pPH-13-specific DNA probe, which produced an approximate 0.5-kb amplified product. This PCR method could detect as few as 5 eggs in 0.6 g of artificially inoculated feces of a healthy control cat or as little as 1 x 10(-4) ng of P. heterotremus genomic DNA. The assay had 100% sensitivity in all infected cats. The method did not yield an approximate 0.5-kb product with DNA from other parasites such as Gnathostoma spinigerum, Trichinella spiralis, Fasciola gigantica, Echinostoma malayanum, Opisthorchis viverrini, Dirofilaria immitis, and Taenia saginata; exceptions were Paragonimus siamensis and Paragonimus westermani. In addition, no genomic DNA from Escherichia coli, Burkholderia pseudomallei, Acinetobacter anitratus, Mycobacterium tuberculosis, Staphylococcus aureus, beta-Streptococcus grA, and Proteus mirabilis or from the vertebrate and invertebrate hosts of P. heterotremus was amplified in the PCR assay. This assay has great potential for application in clinical epidemiological studies.

An optimization study of solid-state fermentation: xanthophylls extraction from marigold flowers.

Marigold flowers are the main natural source of xanthophylls, and marigold saponified extract is used as an additive in several food and pharmaceutical industries. In this work, the use of a solid-state fermentation (ensilage) process for increasing the yield of xanthophylls extracted from fermented marigold flowers was examined. The process consisted of a mixed culture of three microorganisms (Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans), part of the normal microbiota associated with the marigold flower. These microorganisms had been previously isolated, and were identified as relevant for the ensilage process due to their capacity to produce cellulolytic enzymes. Based on experimental design strategies, optimum operation values were determined for aeration, moisture, agitation, and marigold-to-inoculum ratio in the proposed solid-state fermentation equipment, leading to a xanthophylls yield of 17.8-g/kg dry weight. The optimum achieved represents a 65% increase with respect to the control. HPLC analysis indicated conservation of extracted oleoresin. Based on the experimental results, interactions were identified that could be associated with the heat and mass-transfer reactions taking place within the bioreactor. The insight gained allows conditions that limit growth and metabolic activity to be avoided.

Improving xanthophyll extraction from marigold flower using cellulolytic enzymes.

In this work is studied the effect of a noncommercial enzyme preparation on xanthophyll extraction from marigold flower (Tagetes erecta). The enzymatic extract was synthesized by endogenous microorganisms previously isolated and identified as Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans. The results show that the extraction yield depends directly on the extent of the enzymatic hydrolysis of cell walls in the flower petals and that it is possible to reach yields in excess of those previously reported for treatments with commercially available enzymes (29.3 g/kg of dry weight). HPLC analysis of the product indicates that the original xanthophyll profile is not altered. The enhanced extraction system appears to be very competitive when compared to the traditional process and current alternatives.

Ventilator-associated pneumonia at a tertiary-care center in a developing country: incidence, microbiology, and susceptibility patterns of isolated microorganisms.

Ventilator-associated pneumonia (VAP) complicates the course of up to 24% of intubated patients. Data from the Middle East are scarce. The objective of this study was to evaluate the incidence, microbiology, and antimicrobial susceptibility patterns of isolated microorganisms in VAP in a developing country. Prospective observational cohort study. The American University of Beirut Medical Center, a tertiary-care center that serves as a major referral center for Lebanon and neighboring countries. All patients admitted to the intensive care and respiratory care units from March to September 2001, and who had been receiving mechanical ventilation for at least 48 hours, were included in the study. Results of samples submitted for culture were recorded and antimicrobial susceptibility testing of isolated pathogens was performed. Seventy patients were entered into the study. The incidence of VAP was 47%. Gram-negative bacilli accounted for 83% of all isolates. The most commonly identified organism was Acinetobacter anitratus, followed by Pseudomonas aeruginosa. Fifty percent of all gram-negative bacterial isolates were classified as antibiotic resistant. Compared with patients without VAP, patients with VAP remained intubated for a longer period and stayed in the intensive care unit longer. VAP was not associated with an increased mortality rate. Compared with other studies, the results from this referral center in Lebanon indicate a higher incidence of VAP and a high prevalence of resistant organisms. These data are relevant because they direct the choice of empiric antibiotic therapy for VAP.