Proteus Rettgeri Research Articles

Bacterial Agents Causing Chronic Suppurative Otitis Media

Background: Otitis media which is an acute or chronic inflammatory state of the middle ear may be classified as suppurative or non—suppurative.
 Methods: A total of 100 ear swabs from cases of chronic otitis media were variously collected from patients attending the ENT Clinic. Specimens were immediately transported in a transport medium to the base laboratory of the Department of Microbiology.
 Results: Out of a total number of 100 cases of chronic otitis media screened for the isolation of bacterial aetiologic agents, 8 different genera comprising 13 bacterial species were isolated. These included S. aureus (39%), Pseudomonas aeruginosa (25%), Proteus mirabilis (16%), Alcaligenes faecalis (5%) and Klebsiella aerogenes (1%). Escherichia coli, Proteus rettgeri, Staphylococcus epidermidis, and Klebsiella pneumoniae, constituted (3%), (3%), (3%) and 1% of isolates in that respective order. From the number of cases screened, it was observed that 54 (54% and 46(46%) were males and females respectively.
 Conclusion: We conclude that higher prevalence of otitis media among males than females and S. aureus has been identified as the leading pathogen in chronic otitis media.
 Keywords: Bacterial Infections, Etiology, Otitis Externa.

Assessment of the effect of suture material on the bacterial contamination of trachea

The work is devoted to assessment of bacterial contamination of trachea after circular resection with the following tracheo-tracheal anastomosis in Wistar rats. The formation of tracheo-tracheal anastomosis with the use of a monofilament, not resorptive suture material after circular resection of trachea is accompanied by the microbial growth in 83.4% of cases. The major microorganisms are conditionally pathogenic – Citrobacter freundii, Staphilococcus epidermidis, Proteus rettgeri, Escherichiae coli, they occur in 71% of cases. Pathogenic microorganisms Staphilococcus aureus, Candida fungi appeared only in microbial associations and were found in 12.5% of cases. No microbial growth was observed in 16.6%.

Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві.
 Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)).
 Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %).
 Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

Effects of Methanol Extract of Wedelia chinensis Osbeck (Asteraceae) Leaves against Pathogenic Bacteria with Emphasise on Bacillus cereus.

The antibacterial activity of the methanol extract of Wedelia chinensis leave was studied and tested against three pathogenic Gram positive bacteria (Bacillus cereus, B. subtilis and Stapylococcus aureus) and three pathogenic Gram negative bacteria (Escherichia coli, Proteus rettgeri and Pseudomonas aeruginosa) by the disk diffusion assay and broth dilution methods. The extract exhibited favourable antibacterial activity against the bacterial cells but was more potent against Gram positive bacteria with the minimum inhibition concentration of 3.12 to 6.25 mg/ml compared to the Gram negative bacteria which had minimum inhibition concentration values of 25 mg/ml. The time-kill study suggested that the extract possessed bactericidal properties at higher concentrations and eradicated the growth of bacterial cells. The major abnormalities occurred to the bacterial cells after exposed to the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The methanol extract of W. chinensis may be an effective antibacterial agent to treat bacterial infections.

Bacterial isolates associated with pelvic inflammatory disease among female patients attending some hospitals in abuja, Nigeria.

Pelvic inflammatory disease refers to any infection in the female lower reproductive tract that spreads to the upper reproductive tract. The disease comprises a spectrum of inflammatory disorders of the upper female genital tract, including any combination of endometritis, salpingitis, tubo-ovarian abscess and pelvic peritonitis. PID is not a notifiable disease in most countries, so accurate statistics are not available. This situation is not in any way different here in Nigeria and more so in the Federal Capital Territory, Abuja where this research was conducted, there had never been any published report so far on PID. It therefore became pertinent that such studies be carried out to evaluate the bacterial organisms which may be associated with the disease in this part of Nigeria so that health care providers could take a better look at this affliction in women. Endocervical swabs totalling 100 were aseptically collected from patients with confirmed Pelvic Inflammatory Disease (PID), attending some hospitals in Abuja, Nigeria for detection of bacterial pathogens based on cultural and biochemical characterisation tests. Antibiogram was also conducted on the identified bacterial isolates. Out of the 100 samples analysed, 43% yielded pure cultures of bacterial isolates, 2% yielded mixed cultures while no bacterial growths were recorded from the remaining 55% samples. Organisms encountered were Staphylococcus aureus (16%), Escherichia coli (10%), Streptococcus faecalis (8%), Pseudomonas aeruginosa (4%), Streptococcus pyogenes (3%), Klebsiella pneumoniae (3%), Proteus rettgeri (2%) and Proteus mirabilis (1%). The highest percentage occurrence of pathogenic isolates was observed in polygamous married patients (90%). The age group most affected falls within the mean age 30.5 years (68%) while the least affected group falls within the mean age 40.5 years (5%). There was a significant difference in the acquisition of PID in relation to marital status (P < 0.05). However there was no significant difference in the acquisition of the disease with respect to age (P > 0.05). Antibiogram patterns of pathogenic isolates revealed varied resistance to most of the antibiotics employed. Cefotaxime (a new generation cephalosporin antibiotic) was established in this study as the best antimicrobial agent for treatment of PID due to Gram-positive and Gram-negative bacteria isolated from the women examined. In conclusion, Pelvic inflammatory disease is a major health problem in developed or developing countries of the world. PID is not a notifiable disease, as accurate statistics on disease prevalence are rarely available. There is therefore no doubt thousands of young women have salpingitis every year and their sheer number makes it an important health problem. PID hence can be said to be a very serious complication of sexually transmitted disease which should be critically and promptly handled by healthcare providers. The right type sample should be aseptically collected and be appropriately handled for laboratory investigation. Treatment of PID should be initiated as soon as the presumptive diagnosis has been made. Immediate administration of antibiotics has been effective in the long-term sequelae associated with PID, especially new generation antibiotics, such as cefotaxime as recorded in this study.

Fatty-acid composition and antibacterial activity of CHCl3 extracts of three plants of the genus Silene

A total of 84 species of the plant genus Silene (Caryophyllaceae) are indigenous to Central Asia [1]. We studied previously ecdysteroids from the aerial part of three species of Silene [2–4]. Lipids extracted by CHCl3 during isolation of the ecdysteroids were studied in order to utilize more of the raw material. Ecdysteroids were isolated by soaking the ground air-dried aerial part of the plants in MeOH at room temperature for 1 d. Then, the extract was filtered. The MeOH was distilled in a rotary evaporator. The solid was dissolved in water and treated with CHCl3. The ecdysteroids remained in the aqueous layer. The CHCl3 part of the extract was not used. We isolated the lipids from it using column chromatography over silica gel and solvent system hexane:Et2O (1:1). This isolated neutral lipids (NL). Their composition was determined using TLC and hexane:Et2O (4:1 and 1:1). The principal components of the NL were triglycerides, free fatty acids, and free sterols. Fatty acids were isolated from NL after their alkaline hydrolysis and were analyzed by GC as the methyl esters on a Chrom 5 instrument with a flame-ionization detector using a metallic column (2.5 m) packed with Chromaton N-AW with Reoplex-400 (15%). Table 1 presents the fatty-acid composition. It can be seen that the qualitative fatty-acid compositions of NL from the aerial parts of the aforementioned species of Silene were identical and consisted of 15 acids. Their quantitative compositions differed. This was evident in the content of the principal acids, the saturated one of which was palmitic acid (16:0); the unsaturated ones, two essential fatty acids -6 (18:2) and -3 (18:3). Palmitic acid dominated the NL in plants 2 and 3; the sum of linoleic and linolenic acids, in S. viridiflora. Next the antibacterial activity of these CHCl3 extracts was determined by the disk diffusion test [5]. For this, they were dissolved in DMSO. Microorganisms were grown in agar dishes at 30°C overnight in Mueller–Hinton medium (Oxoid). The suspension (100 L) contained 108 CFU/mL. Sterile filter disks (5-mm diameter) were soaked with extract solution (20 L, 5 mg/mL) and placed on the surface of the innoculated Petri dishes. The dishes were incubated at 37°C for 24 h. The antibacterial activity was estimated by measuring the inhibition zone formed around the disks. We used five disks in each Petri dish. Each test was performed in triplicate. The test cultures of microorganisms were the following: Klebsiella pneumoniae 40602; Micrococcus luteus obtained from the Microbiology Faculty, Manchester University, GB; Pseudomonas aeruginosa NCTC6749; Enterococcus faecalis NCTC775; Proteus rettgeri NCIMB9570 obtained from the National Collection of Great Britain (NCTC); bacterial strains P. agglomerans T26, B. cereus T80, and Staphylococcus saprophyticus T415 obtained from the Biology Faculty, National University of Uzbekistan. Antimicrobial activity was found by testing against several bacterial cultures. The CHCl3 extract of S. brachuica inhibited growth of three Gram-negative (E. faecalis, P. rettgeri, and P. aeruginosa) and one Gram-positive (M. luteus) bacterial strain. The CHCl3 extract of S. viridiflora was active against M. luteus, P. rettgeri, K. pneumoniae, and P. aeruginosa. The extract of S. wallichiana exhibited activity against pathogenic bacteria M. luteus and P. aeruginosa but was weaker than extracts from the other species of Silene. Thus, the microbiological studies indicated that extracts of these species of Silene exhibited antimicrobial activity against various species of bacteria.

Incidence of Proteus species in wound infections and their sensitivity pattern in the University of Benin Teaching Hospital

Proteus species are frequently recovered from infected wounds. They contaminate wounds and thus cause infections. This study was carried out at the University of Benin Teaching Hospital (UBTH) to determine the involvement of Proteus species as one of the major causative organisms in wound infections. The study also determined the sensitivity pattern of the Proteus isolates. This was a prospective and cross-sectional study. Wound swabs and aspirates from various parts of the body and consisting of accidental, pathological and post-operative wounds were collected from patients who attended the clinics at the UBTH and examined by standard bacteriological methods. All isolates were tested for sensitivity against ciprofloxacin 5 µg, gentamycin 10 µg, streptomycin 10 µg, ofloxacin 5 mg/µg, chloramohenicol 10 µg, erythromycin 10 µg and tetracycline 10 µg. Of the 400 wound samples from various parts of the body 390 (97.5%) yielded growths and produced 560 isolates. Ten samples (2.5%) yielded no growths. Proteus species accounted for 150 (26.8%) of the isolates. Proteus mirabilis was the Proteus species most commonly isolated, 97 (17.3%), Proteus vulgaris 40 (7.1%), Proteus rettgeri 8 (1.40%), and Proteus morgagni 5 (0.9%). All the isolates were sensitive to ciprofoxacin, ofloxacin and gentamycin while all were resistant to tetracycline and erythromycin. Knowledge of the microbial flora of an environment and the sensitivity pattern are important tools in the management of wound infections especially those caused by Proteus species, and are also useful in formulating rational antibiotic policy.

Incidence of Proteus species in wound infections and their sensitivity pattern in the University of Benin Teaching Hospital

Proteus species are frequently recovered from infected wounds. They contaminate wounds and thus cause infections. This study was carried out at the University of Benin Teaching Hospital (UBTH) to determine the involvement of Proteus species as one of the major causative organisms in wound infections. The study also determined the sensitivity pattern of the Proteus isolates. This was a prospective and cross-sectional study. Wound swabs and aspirates from various parts of the body and consisting of accidental, pathological and post-operative wounds were collected from patients who attended the clinics at the UBTH and examined by standard bacteriological methods. All isolates were tested for sensitivity against ciprofloxacin 5 µg, gentamycin 10 µg, streptomycin 10 µg, ofloxacin 5 mg/µg, chloramohenicol 10 µg, erythromycin 10 µg and tetracycline 10 µg. Of the 400 wound samples from various parts of the body 390 (97.5%) yielded growths and produced 560 isolates. Ten samples (2.5%) yielded no growths. Proteus species accounted for 150 (26.8%) of the isolates. Proteus mirabilis was the Proteus species most commonly isolated, 97 (17.3%), Proteus vulgaris 40 (7.1%), Proteus rettgeri 8 (1.40%), and Proteus morgagni 5 (0.9%). All the isolates were sensitive to ciprofoxacin, ofloxacin and gentamycin while all were resistant to tetracycline and erythromycin. Knowledge of the microbial flora of an environment and the sensitivity pattern are important tools in the management of wound infections especially those caused by Proteus species, and are also useful in formulating rational antibiotic policy.

Isolation, purification, characterization, and physiological behavior of drinking water-borne pathogenic bacteria.

The present work was devoted for isolation, characterization, and studying physiological behavior of drinking water borne pathogenic bacteria isolated from tap and cooling water. Total of 171 bacterial isolates were isolated from twenty nine different localities on eight common and specific agar media (Nutrient, Salmonella & Shigella, Desoxycholate citrate, Eosin–methylene blue, Thioglycollate, Mannitol salt, MacConkey and Clostridium) agar media. All bacterial isolates were purified and characterized on the basis of morphological, physiological, and biochemical tests. These lead to the following suggested names: Bacillus cereus (8); B. badius (1); B. macerans (1); B. brevis (6); B. circulans (4); B. coagulans (3); B. firmus (4); B. globisporus (2); B. megaterium (10); B. mycoides (3); B. pantotheniticus (9); B .pasteurii (1); B. pumilus (1); Staphylococcus gallinarum (1); Staph. epidermidis (6); Staph. haemolyticus (1); Staph. sciuri (2); Enterobacter aerogenes (1); Micrococcus halobius (2); M. sedentarius (1); M. varians (1); Pseudomonas aeruginosa (6); Klebsiella oxytoca (2); K. pneumonia (3); Enterobacter agglomerans (3); Edwardsiella ictalluri (4); Citrobacter freundii (1); Salmonella typhi (3); S. pullorum (1); Shigella dysenteriae (2); Sh. flexneri (2); Proteus mirabilis (13); Providencia stuartii (1); Pro. Rettgeri (2); Proteus rettgeri (1) and Escherichia coli (2).Thirty six characterized bacterial strains were selected and studying some physiological characteristics and evaluating of their five extracellular enzymes potencies including &#945;-amylase, cellulase, lipase, pectinase, and protease with percentage of 41.66, 41.66, 33.33, 11.11, & 94.44 % respectively among all selected bacterial strains. The selected water borne pathogenic bacterial strains were growing at different pH values covering a relatively wide range of pH (4-12). Minimum, maximum, and optimum pH values for their growth were determined as 4, 12, and 7 respectively. Selected isolates showed abundant growth within the temperature range of 10-55ºC. Bacterial strains succeeded to grow in sodium chloride free medium and also containing sodium chloride up to 12.5 % (w/v). Recorded data emphasized that tested drinking water samples were polluted with different waterborne pathogenic bacteria and by investigating its physiological behavior, the virulence of the 36 bacterial strains was controllable. New Egyptian Journal of Microbiology Vol. 17 (2) 2007: pp. 105-120

Studies on bacterial flora and biological control agent of Cydia pomonella L. (Lepidoptera: Tortricidae)

In the present study, in order to find a more effective and safe biological control agent against Cydia pomonella, we investigated the bacterial flora and tested them for insecticidal effects on this insect. According to morphological, physiological and biochemical tests, bacterial flora were identified as Proteus rettgeri (Cp1), Eschericia coli (Cp2), Pseudomonas stutzeri (Cp3), Pseudomonas aeroginosa (Cp4), Bacillus laterosporus (Cp5), Micrococcus sp. (Cp6), Proteus vulgaris (Cp7) and Deinococcus sp. (Cp8). Insecticidal effects of bacterial isolates were performed on larvae C. pomonella. The highest insecticidal effect determined was 65 % by Bacillus laterosporus within eight days. The insecticidal effects of the other isolates (Cp1, Cp2, Cp3, Cp4, Cp6, Cp7 and Cp8 ) we determined as 22, 19, 25, 60, 20, 57 and 17% within the same period, respectively. No mortality was detected on control groups.

Influence of Human Ascitic Fluid on the In Vitro Antibacterial Activity of Moxifloxacin

We investigated the in vitro influence of HAF on the antibacterial activity of moxifloxacin against Escherichia coli ATCC 10798, Escherichia coli K-12, Proteus rettgeri (Sanelli), Staphylococcus aureus ATCC 25923 Staphylococcus aureus NCTC 1808 and Staphylococcus epidermidis ATCC 12228. Human ascitic fluid was obtained from 6 cirrhotic patients by paracentesis. The interaction effect was evaluated by the checkerboard technique. Our results indicate the ability of human ascitic fluid to reduce minimum inhibitory concentrations of moxifloxacin against Gram-negative bacteria, but not against Gram-positives.

Fluorogenic Assay for Penicillin G Acylase Activity

A simple, highly sensitive, and rapid assay for high-throughput screening of penicillin G acylase-producing bacteria is presented. The method is based on the specific release of fluorescent 7-amino-4-methyl-coumarin through cleavage of phenylacetyl-4-methyl-coumaryl-7-amide by penicillin G acylase. The present method is suitable for screening pure enzymes as well as various penicillin G acylases like those from Escherichia coli, Proteus rettgeri, and Kluyvera citrophila in cell extracts. In addition, the new substrate was used for rapid assay of amidase activity in nondenaturing polyacrylamide gels.

ANTIBACTERIAL ACTIVITY OF GENTAMICIN AND CIPROFLOXACIN AGAINST GRAM-NEGATIVE BACTERIA: INTERACTIONS WITH PIG AND CALF SERA

The antibacterial activity of pig and calf serum and its ability to interact with gentamicin and ciprofloxacin were studiedin vitrousingEscherichia coliK-12,Proteus rettgeri(Sanelli) andKlebsiella pneumoniaeATCC 10031. The antimicrobial activity of the above drugs, alone or in combination with serum, was investigated by the checkerboard method and expressed as the minimal inhibitory concentration (μg ml−1). Pig serum (25%) with gentamicin had a synergistic antibacterial effect againstEscherichia coliK-12 and pig serum (25%) with ciprofloxacin againstProteus rettgeri(Sanelli) andKlebsiella pneumoniaeATCC 10031. Calf serum (25%) had a synergistic effect with gentamicin againstProteus rettgeri(Sanelli) and calf serum (25%) plus ciprofloxacin againstKlebsiella pneumoniaeATCC 10031. The effects of these drugs may be enhanced by pig and calf sera.

Antibacterial activity of human pleural fluid: alone and in combination with antibiotics.

This study investigated the antibacterial activity of human pleural fluid (HPF) and its interaction with gentamicin (GM), meropenem (MRPM), ciprofloxacin (CPFX) and clarithromycin (CLTM) against Escherichia coli K-12, Proteus rettgeri (Sanelli) and Staphylococcus aureus. Minimal inhibitory concentrations or volumes, expressed as MIC or volume percentage (MIV, V/V%), were measured using a micro-dilution technique in microtiter plates. The antimicrobial activity of HPF combinations with antimicrobial drugs was evaluated by the chequerboard method calculating the fractional inhibitory concentration index (FIC) values. HPF MIVs (%) were: 37.54; 19.85; 1.74 for E. coli, P. rettgeri and S. aureus, respectively. FIC values indicated a synergistic effect with GM, MRPM and CPFX against E. coli and P. rettgeri and an additive effect for the combination HPF plus CLTM or indifference with HPF plus GM and CPFX against S. aureus. The presence of antibodies, complement factors, lysozyme, α-defensins and enzymes could explain the antimicrobial activity of HPF and its synergistic effect with certain antibiotics.

Antibacterial Activity of Peritoneal Exudate in Patients Treated with2 g Cefotiam for Surgical Anti-Microbial Prophylaxis

The objective of this study was to investigate the presence of antibacterial activity in peritoneal exudate (PE) of patients treated with cefotiam (CFT). CFT (2 g) was administered as a ‘single-shot’ antimicrobial prophylaxis to 6 patients at the beginning of colorectal resection. Samples of PE were collected from each patient on days 1, 2 and 3 after surgery. CFT was detectable in the samples of day 1 for 5 of the 6 patients. The influence of PE on antibacterial activity of the antimicrobial drug was evaluated carrying out the MICs of CFT against Escherichia coli K-12, E. coli (ATCC 10798), Klebsiella pneumoniae (ATCC 1003), Proteus rettgeri (Sanelli) and Staphylococcus aureus (ATCC 29213) with and without the addition of PE. The presence of PE enhanced the antimicrobial activity of CFT against gram-negative strains, but not against S. aureus (ATCC 29213). These results suggest the presence of substances in PE that possess endogenous antibacterial activity. Thus, antimicrobial activity in PE cannot be predicted by evaluating pathogen sensitivity in vitro only.

INFECTIONS IN THE BITE SITE AFTER ENVENOMING BY SNAKES OF THE Bothrops GENUS

Envenomation caused by snakes of the Bothrops genus produces a lesion in the bite site and can result in extensive necrosis. The dead tissue can be secondarily infected by bacteria that come from the snake, and the bacteria can be inoculated at the moment of the bite. The bacteria that most commonly cause infection are the enterobacteria, mainly Morganella morganii, Proteus rettgeri, Enterobacter sp., and Escherichia coli. Group D streptococci including here Enterococcus sp. and the Bacteroides sp. are also involved. Based on a study of the sensibility of these bacteria, it has been suggested that this infection must be treated with chloramphenicol, as a sole antimicrobial agent, or with the combinations of benzylpenicillin or ampicillin with aminoglycoside or trimethoprim/sulfamethoxazole. Although Governmental Health Services do not recommend the prophylactic use of antimicrobial drugs, it is not yet clear that such a procedure would not be useful in cases with a high probability of infection.

Microbiology of activated sludge treating wastewater containing Ni(II) and Cr(VI)

The species of microorganisms dominating a laboratory-scale once-through activated sludge unit treating simulated wastewater with different influent strengths (650 and 1300 mgl−1 COD) and containing 5 to 10 mgl−1 Ni(II) and 1 to 50 mgl−1 Cr(VI) were identified by standard biochemical tests. Within this framework, combinations of metals and influent COD concentrations were tried. Organisms, namely Proteus rettgeri, Acinetobacter sp., Flavobacterium lutescens, Bacillus cereus var. albolactis, Klebsiella sp., Arthrobacter simplex, and Pseudomonas mendocina, were identified at different stages of the experiments.

Microbiology of activated sludge treating wastewater containing Ni(II) and Cr(VI)

The species of microorganisms dominating a laboratory-scale once-through activated sludge unit treating simulated wastewater with different influent strengths (650 and 1300 mgl−1 COD) and containing 5 to 10 mgl−1 Ni(II) and 1 to 50 mgl−1 Cr(VI) were identified by standard biochemical tests. Within this framework, combinations of metals and influent COD concentrations were tried. Organisms, namely Proteus rettgeri, Acinetobacter sp., Flavobacterium lutescens. Bacillus cereus var. albolactis, Klebsiella sp., Arthrobacter simplex, and Pseudomonas mendocina, were identified at different stages of the experiments.

Different biological conditions influencing bacterial adherence assay.

Adherence of bacteria to animal cells is considered the first step in the pathogenesis of many infectious diseases. The most suitable techniques developed in vitro to check the capacity of bacteria to adhere to different tissues use monolayers of established cell lines. We studied the influence of incubation time (1, 2, 3 hours), cell substrates (Hep-2, H-407) and the number of bacteria per cell (1, 10, 100, 1000) on the adherence index (number of adherent bacteria per cell determined by microscopic count) of the fimbriated Escherichia coli 454 strain, Proteus rettgeri 25 and Enterobacter cloacae 10. The data were analyzed with different statistical methods and the results evidenced that all the conditions considered affect either the end-point of the test or the adherence index. Our observations indicate that the different methods used make it impracticable to compare many data from the literature and suggest the need to search for more homogeneity in this type of assay.

Rapid emergence of quinolone resistance in cirrhotic patients treated with norfloxacin to prevent spontaneous bacterial peritonitis

We carried out quantitative culturing of stools from 31 hospitalized alcoholic patients with cirrhosis and ascites, before treatment with 400 mg of norfloxacin per day, weekly for the first month, and then every 2 weeks thereafter for 15 to 229 days (median, 54 days). Members of the family Enterobacteriaceae virtually disappeared from the stools (< 10(2)/g), but treatment had little effect on enterococci. No selection of resistant organisms occurred in 15 patients, but the remaining 16 patients developed fecal organisms resistant to fluoroquinolones between days 14 and 43 of treatment (median, 25 days). Staphylococcus aureus was isolated four times, coagulase-negative Staphylococcus spp. were isolated six times, Citrobacter freundii was isolated four times, Enterobacter cloacae was isolated three times, Klebsiella oxytoca was isolated twice, Proteus rettgeri was isolated once, and untypeable streptococci were isolated six times. Some isolates persisted, while others were transient (one to seven consecutively positive cultures). The MICs of four quinolones (nalidixic acid, norfloxacin, ofloxacin, and ciprofloxacin) were determined by use of experimental microwell strips (ATB CMI; Biomerieux S.A.). All the strains isolated before treatment were susceptible to the four quinolones, with low MICs, whereas those isolated during norfloxacin treatment were highly resistant. Long-term norfloxacin administration thus carries a risk of disturbing the bacterial ecology in these patients, suggesting that digestive decontamination should no longer be prescribed routinely to cirrhotic patients with ascites.