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Poultry tick, Argas (Persicargas) persicus was subjected to examination and isolation of bacterial infection. All the isolates, thus obtained, were tested for virulence by inoculating the test poultry birds. Out of total isolation, 9 species viz: Salmonella gallinarum, Pseudomonas pyocyanea, Bacillus subtilis, Bacillus anthracis, Streptococcus gallinarum, Sporosarcina lutea, Aerobacter cloacae, Serratia marcescens and Flavobacterium indothelicum could reproduce the infection. In almost all of these cases, the development of the disease was latent without producing specific or prominent symptoms. However, on postmortem examination the lesions were commonly confined to liver, kidney, female genitalia and intestinal mucous membrane. The deaths mostly occurred after one month of infection except in cases of Bacillus subtilis, Salmonella gallinarum, Flavobacterium indothelicum and Pseudomanas pyocyanea which caused death after 8, 15, 22 and 24 d of inoculation respectively. The rest of test organisms including Escherichia coli, Proteus vulgaris, Proteus rettgeri, Aerobacter aerogenes, Staphylococcus aureus, Staphylococcus albus, Streptococcus zooepidemicus, Streptococcus pyogenes, Vibrio cholerae, Clostridium botulinum, Klebssiella aerogenes, and certain species of Flavobacterium viz: F. lutescens, F. capsulatum and F. devorans could not reproduce any sort of pathogenicity. Zusammenfassung Kunstliche Infektion von Geflugel mit aus der Geflugelzecke (Argas persicus) gewonnenen Bakterien Aus Geflugelzecken der Spezies A. pericus wurden Bakterien isoliert und zur Untersuchung ihrer Virulenz in Hausgeflugel injiziert. 9 der getesteten Bakterienarten: Salmonella gallinarum, Pseudomonas pyocyanea, Bacillus subtilis, Bac. anthracis, Streptococcus gallinarum, Sporosarcina lutea, Aerobacter cloacae, Serratia marcescens und Flavobacterium indothelicum riefen eine Infektion beim Geflugel hervor. In nahezu allen Fallen verlief die Entwicklung der Krankheit auserlich unsichtbar, jedoch zeigten sich nach dem Tod die Schaden an der Leber, Niere, den weiblichen Genitalien und der inneren Schleimhaute. Der Tod trat meist spater als 1 Monat nach der Infektion ein, mit Ausnahme von Bac. subtilis, Salmonella gallinarum, Flavobacterium indothelicum und Pseudomonas pyocyanea, die bereits nach 8, 15, 22 und 24 Tagen den Tod des Wirtes herbeifuhrten. Der Rest der untersuchten Bakterienarten: Escherichia coli, Proteus vulgaris, P. rettgeri, Aerobacter aerogenes, Staphylococcus aureus, St. albus, Streptococcus zooepidemicus, Str. pyogenes, Vibrio cholerae, Clostridium botulinum, Klebsiella aerogenes und gewisse Spezies von Flavobacterium, z. B. F. lutescens, F. capsulatum und F. devorans, riefen keine pathogenen Erscheinungen hervor.

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.

353 adult patients aged from 26 to 90 years with complicated urinary tract infections were investigated in a double-blind randomised multicentre trial in which 176 patients received cefetamet pivoxil (CAT) 500mg twice daily and 177 patients cefuroxime axetil (CMX) 250mg twice daily for 7 days. The groups were comparable. The bacteriological findings that were evaluated 7 to 10 days post-therapy were the main criteria for assessment of efficacy. Patients were followed up for 5 ± 1 weeks post-therapy. Bacteriological assessment was possible in 310 patients, i.e. 156 patients from the CAT group and 154 from the CMX group. Escherichia coli proved to be the predominant causative pathogen in this patient series, occurring in 68.4%. The overall bacteriological outcome was successful in 97.4% of the patients receiving CAT and 90.3% to whom CMX was given. The pathogens persisting in the CAT group were E. coli (1), Proteus rettgeri (1), and Klebsiella pneumoniae (1), while in the CMX group the pathogens were E. coli (4), Proteus spp. (2), K. pneumoniae (1), Enterobacter sp. (1), Serratia sp. (1), Levinia sp. (1) and mixed infection (1). The overall clinical outcome was successful in 137 (87.8%) of 156 assessable patients treated with CAT and in 129 (83.8%) of 154 patients to whom CMX was administered. The incidence of adverse events was 11.9% in both treatment groups. All adverse events were mild to moderate in severity and predominantly gastrointestinal. Treatment was withdrawn prematurely in 1 patient receiving CMX because of rash. Based on the presented data, we conclude that cefetamet pivoxil in the recommended dosage of 500mg twice daily is effective and well tolerated in the treatment of patients with complicated urinary tract infections.

The activities in vitro of ceftazidime and of cefuroxime have been compared against 201 strains of bacteria which had been isolated either from outbreaks of nosocomial infection or were typical of strains causing such outbreaks. Ceftazidime was found to be about 1000 times more active against Pseudomonas spp. and Proteus vulgaris, and between 10 and 100 times more active against Klebsiella pneumoniae, Enterobacter spp., Citrobacter freundii, Serratia marcescens, Proteus rettgeri, Proteus morganii, Providencia stuartii, Alcaligenes faecalis and Acinetobacter spp. On the other hand, cefuroxime was more active against Staphylococcus epidermidis. An increase in inoculum size to 106 had little effect on the activity of ceftazidime, except in the case of Pr. vulgaris strains, which grew, although only to a very limited extent, even in the presence of high concentrations of ceftazidime. Anaerobic and hypercapnic conditions did not adversely affect the activity of ceftazidime. Our in-vitro results thus indicate that ceftazidime had as broad a spectrum as gentamicin, and is more intrinsically active.

Carbapenems such as imipenem and meropenem are not rapidly hydrolyzed by commonly occurring beta-lactamases. Nevertheless, it was possible, by mutagenesis and selection, to isolate mutant strains of Enterobacter cloacae and Proteus rettgeri that are highly resistant to meropenem and imipenem. Two alterations were noted in the E. cloacae mutants. First, the mutant strains appeared to be strongly derepressed in the production of beta-lactamases, which reached a very high level when the strains were grown in the presence of imipenem. Second, these mutants were deficient in the production of nonspecific porins, as judged by the pattern of outer membrane proteins as well as by reconstitution assays of permeability. As with most porin-deficient mutants, their cultures were unstable, and their cultivation in the absence of carbapenems rapidly led to an overgrowth of porin-producing revertants. Analysis of the data suggests that the synergism between the lowered outer membrane permeability and the slow but significant hydrolysis of carbapenems by the overproduced enzymes can explain the resistance phenotypes quantitatively, although the possibility of alteration of the target cannot be excluded at present. With P. rettgeri mutants, there was no indication of further derepression of beta-lactamase, but the enzyme hydrolyzed imipenem much more efficiently than the E. cloacae enzyme did. In addition, the major porin was absent in one mutant strain. These results suggest that a major factor for the carbapenem resistance of these enteric bacteria is the porin deficiency, and this conclusion forms a contrast to the situation in Pseudomonas aeruginosa, in which the most prevalent class of imipenem-resistant mutants appears to lack the specific channel protein D2 yet retains the major nonspecific porin F.

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, alpha-defensins and enzymes could explain the antimicrobial activity of HPF and its synergistic effect with certain antibiotics.

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 α-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

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.

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.

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.

The antibacterial activity of pig and calf serum and its ability to interact with gentamicin and ciprofloxacin were studied in vitro using Escherichia coli K-12, Proteus rettgeri (Sanelli) and Klebsiella pneumoniae ATCC 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 against Escherichia coli K-12 and pig serum (25%) with ciprofloxacin against Proteus rettgeri (Sanelli) and Klebsiella pneumoniae ATCC 10031. Calf serum (25%) had a synergistic effect with gentamicin against Proteus rettgeri (Sanelli) and calf serum (25%) plus ciprofloxacin against Klebsiella pneumoniae ATCC 10031. The effects of these drugs may be enhanced by pig and calf sera.

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.

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.

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.

Isozyme surveys were used to compare genetic variation within and among strains of the bacterium, Proteus rettgeri (Hadley, Elkins, and Caldwell). One strain was a standard American Type Cell Culture strain (ATCC 9250), whereas eight other strains were recovered from larva or pupa of the screwworm fly, Cochliomyia hominivorax (Coquerel), of varied geographic or animal host origins. Observations of 16 different enzyme systems of each bacterial isolate revealed extensive inter- and intrastrain variation in the numbers or positions of enzyme bands recorded among samples from different phases of culture growth or from different growth media. Similar differences were likewise noted among strains when they were sampled at the same growth phase. Hierarchical clustering and multidimensional analyses of the data produced groupings of the bacterial strains which suggested that their enzyme patterns were influenced by factors related to their geographic distribution or their animal host origins.

An evaluation of the serotyping system for Proteus rettgeri has been performed through its application to 561 human isolates of this species. Of these, 545 were typable and could be separated into 58 O serotypes. A group of isolates from one hospital, and clinically implicated in cross-infections, was found to belong the same O serotype, confirming the clinical findings. Isolates with more than one specificity of thermostable antigen, in most cases, were found to have combinations of such specificities restricted to combinations previously defined for the O-type strains. Furthermore, the use of pooled antisera was investigated and system of pooling was devised to retain the specificity of the system and to increase the facility of the typing procedure.

Literature reports disagree concerning esculin hydrolysis in the family Enterobacteriaceae. A total of 2,490 strains of the family were investigated for esculin hydrolysis by two methods, the esculin spot test and the PathoTec incubation strip, which measures constitutive enzyme, and five growth-supporting methods, which determine both constitutive and inducible enzymes. The five growth-supporting media studied were: Vaughn-Levine, the standard esculin hydrolysis medium (P. R. Edwards and W. H. Ewing, Identification of Enterobacteriaceae, 3rd ed., 1972); Vaughn-Levine without iron; Vaughn-Levine without Andrade's indicator; and bile-esculin medium. Growth media were incubated at 35 degrees C and checked every 24 h for 120 h. On growth media, 0.3% of Escherichia coli were positive in 24 h, 34% in 48 h, and 61% in 120 h. No strains were positive on the "nongrowth" tests. It appeared that the esculin hydrolysis enzyme(s) of E. coli was inducible rather than constitutive. All esculin hydrolyzers, which yielded positive tests on "constitutive tests" and 24-h tests, were limited to the genera Klebsiella, Enterobacter, and Serratia and species of Proteus vulgaris, Proteus rettgeri, and Citrobacter diversus. When used with standardized inoculum size and incubation time, the esculin hydrolysis test is very useful for differentiation within the family Enterobacteriaceae.

Between December 1, 1971, and November 30, 1972, 11 patients on a single physical rehabilitation ward in a large St. Louis, Missouri, community hospital developed Proteus rettgeri urinary tract infections; P. rettgeri isolates from each patient were indole-negative and resistant in vitro to all antibiotics tested. Infected patients were more likely to have indwelling urinary tract catheters than were matched control patients, and all had previously received systemic antibiotic therapy. Retrospective epidemiologic investigation and microbiologic samplig at the time of the investigation failed to detect a common source of infection. Infected patients appeared to be the major reservoir of the epidemic strain, and indirect-contact transmission of the organism via nursing personnel probably occurred. Data collected from a prospective study suggested that placing catheterized patients in rooms that did not contain other catheterized patients may be an effective control measure.

A total of 112 bacterial strains representing 38 species were tested for their potential to elicit food poisoning outbreaks via histamine formation in foods. Proteus morganii and Enterobacter aerogenes displayed a quantitative superiority in terms of histamine production on a trypticase-soy broth-histidine (TSBH) medium and a tuna fish infusion broth (TFIB). When bacteria were incubated under standardized conditions in TSBH medium, histamine accumulated to levels exceeding 50 nmoles/ml of media with a total of 23 strains, including 13 of 15 P. morganii strains, 3 of 3 E. aerogenes strains, 3 of 12 Hafnia alvei strains, 1 of 4 Providencia alcalifaciens strains, 1 of 5 Enterobacter cloacae strains, 1 of 1 Proteus rettgeri strains, and 1 of 1 Citrobacter diversus strains. However, only 8 of the 15 P. morganii strains and the 3 E. aerogenes strains were capable of generating histamine in excess of 200 nmoles/ml in the TSBH medium. Of the 23 strains capable of appreciable histamine production in TSBH medium, P. morganii and E. aerogenes were, by far, the most prolific histamine producers in TFIB. Of the organisms tested, only P. morganii and E. aerogenes would appear to have the capability of forming sufficient histamine in scombroid fish products to elicit food poisoning outbreaks.

Over 22-1/2 months an epidemic of at least 127 cases of nosocomial infection developed from a strain of Proteus rettgeri resistant to all antibiotics commonly tested in hospital laboratories. Although there were at least four cases of septicemia and one related death, the majority of cases consisted of asymptomatic bacteriuria or clinically mild urinary tract infection. Indwelling urinary tract devices and antibiotic therapy were important predisposing factors. Data supported an association between increasing use of gentamicin and increasing rates of resistant infection. No common source was found, and contact spread appeared more likely. Control measures included efforts to reduce unnecessary exposure to the incriminated risk factors and to improve asepsis in the management of catheterized patients. An additional 36 cases and one related death were identified in the 7-1/2 months following the investigation and institution of control measures. Nosocomial infection with extremely resistant organisms may pose a serious hazard wherever indwelling urinary tract devices and antibiotics are used together intensively.

Crystalline tryptophanase prepared from the cells of Proteus rettgeri is inactive in the absence of added pyridoxal phosphate. Half-maximal enzyme activity is obtained at a concentration of 1.81 µm. Binding of pyridoxal phosphate to the apoenzyme is accompanied by pronounced increase in absorbance at 340 and 420 nm. Holotryptophanase requires K+ or for its maximal activity, but Na+ is inactive. No appreciable spectral change was observed on changing the ionic environments.The amount of pyridoxal phosphate bound to the enzyme was determined by equilibrium dialysis and spectrophotometric titration to be 4 moles per mole of enzyme. Reduction of holoenzyme with sodium borohydride results in a shift of the absorption peak at 420 to 336 nm. ɛ-Pyridoxyllysine was isolated from the acid hydrolyzate of the reduced holoenzyme by paper chromatography and electrophoresis.Addition of the substrate, l-tryptophan, or the competitive inhibitor, l-alanine, to the holoenzyme causes appearance of a new peak near 500 nm whic...

A Proteus-typing method based on proticin production and proticin susceptibility (c.f. Senior, 1977) has been modified to increase its sensitivity. Proticins were prepared in fluid medium and applied to agar-plates shortly before seeding the plates with indicator bacteria. A given 10 proticin producer strains, which are responsible for the susceptibility patterns of the indicator-bacteria (S-types), form the foundation for this typing method. Using this producer-set an indicator-set (28 strains) was selected which was suitable for the typing of strains with different proticin activities (P-types). Standardization of the temperature for proticin production proved to be necessary. The degree of similarity between proticins was further elaborated by testing all indicator strains for susceptibility to proticin titrations. In the group of 148 clinical Proteus-isolates (four species) used for the development of the typing system 28 S-types and 34 P-types were observed. By combining the S- and P-type parameters 86 S-P-types were obtained for the 4 species combined. Seven strains were not typable. A separate group of 100 clinical Proteus-isolates was tested in order to prove the usefulness of the method. 39 new S-P-types were found. Repeated isolations from the same patients yielded the same patterns. Proteus S-P-typing is a useful method for the typing of Proteux vulgaris and Proteus mirabilis, but proves inadequate for the typing of Proteus rettgeri and Proteus morganii.

The R-B system and the Enterotube were compared for accuracy and speed in identifying Enterobacteriaceae. Two hundred isolates were studied. Accuracy was evaluated by two criteria, correct identification of the isolate and correct results of the individual tests. The numbers of errors resulting from the use of the Enterotube and the R-B system were found to be about the same. The Enterotube was more successful in identifying isolates without the use of further tests, mainly because the inclusion of urea enabled the differentiation of Proteus rettgeri from Providencia. The Enterotube was found to be more satisfactory for our use, because there were many Proteus and Providencia isolates in our laboratories.

Incidence of β-lactamase production (using the Nitrocefin test and isoelectric focusing) was evaluated on 284 strains of ampicillin-resistant Enterobacteriaceae. Production of the various β-lactamases was correlated with the resistance to different β-lactam antibiotics. No obvious correlation between the β-lactamase production and the resistance pattern was found. The most striking result was the lack of β-lactamase production in 42.6% of the strains. About 50% or more of the Proteus morganii, Proteus vulgaris, Serratia and Enterobacter strains produced no β-lactamases, in contrast to E. coli, Klebsiella, and Proteus rettgeri strains which produced β-lactamases extensively. The predominant enzyme was TEM 1, while TEM 2 enzyme was extremely common in Proteus mirabilis and Proteus rettgeri. Finally, it can be concluded from our results that the production of β-lactamases can be regarded as an important but not the sole determinant of resistance of β-lactam antibiotics.

The 181 bacteria classified as Proteus rettgeri biovar 5 considered to be a group intermediate to P. rettgeri and Providencia stuartii were found, in all cases, to possess O-specificities characteristic of Providencia O-serovars. Isolates of the intermediate group showed biochemical reactions characteristic of Prov. stuartii except for positive reactions in tests for urea hydrolysis. The reassignment of the intermediate strains (P. rettgeri biovar 5) to Prov. stuartii is advocated.

1. 1. Arylsulphatase in Proteus rettgeri was separated into four fractions by DEAE-cellulose chromatography. 2. 2. Fractions 2, 3 and 4 were shown by polyacrylamide-gel electrophoresis and/or sucrose density gradient centrifugation to contain more than one form of the enzyme. Some forms differed in substrate specificity. 3. 3. Arylsulphatase present in fraction 1 was previously shown to be homogeneous by paper electrophoresis and some properties of this enzyme have been determined. These include a substratedependent activation by PO43− and a shift in optimum pH in the presence of CN−.

A serotyping system for Proteus rettgeri on the basis of 72 O antigens has been developed in a study of 324 strains obtained from widely distributed sources. In the investigation of the interrelations among the 72 O-type strains by cross-titration of each of the 72 anti-O sera with antigen of each of the O-type strains, both reciprocal and nonreciprocal (unilateral) reactions were observed. The presence of the Kunin common enterobacterial antigen (CA) was noted in each strain of P. rettgeri examined, and the unilateral reactions of two antisera were shown to be due to antibody present against CA. This indicated that CA was in the immunogenic state in two strains of this species. A second common antigen resembling CA in some respects but differing in specificity and in its agglutinability was shown to be the cause of unilateral reactions in a third antiserum. In other cases, unilateral reactive antibodies appeared to be directed against antigens that remained undefined. Each reciprocal reaction was investigated to determine the nature of the interrelations between interacting strains, and the definition of these led to the development of procedures for the production of absorbed anti-O sera with greater specificity. The serotyping scheme has increased the number of strains that may be typed through their O antigens, and its application in epidemiological investigations of infections due to P. rettgeri is indicated.

Determination of the minimal inhibitory concentration of fosfomycin in the agar dilution test on Mueller-Hinton agar showed that the addition of glucose-6-phosphate to the nutrient medium potentiates the action of fosfomycin against Escherichia coli, Klebsiella, Enterobacter, Citrobacter and Staphylococcus aureus, sometimes by as much as 256-fold. Such a potentiation of action was not detectable with Serratia marcescens, the individual Proteus species, Pseudomonas aeruginosa or enterococci. Fosfomycin is very effective against most medically important bacterial species on Mueller-Hinton agar containing 25 micrograms/ml glucose-6-phosphate. Over 90% of the cultures of E. coli, Citrobacter, Enterobacter, S. marcescens,Proteus mirabilis, Proteus vulgaris, Proteus rettgeri, P. aeruginosa, S. aureus and enterococci examined were inhibited by less than or equal to 64 micrograms/ml fosfomycin.

Measuring the specific enzyme activity in cells of Proteus rettgeri it was shown that urease formation is controlled by repression through ammonia. Derepressed synthesis of the enzyme, as initiated by the absence of ammonia, required an external nitrogen source, which may not only be urea, but also nitrate, glutamate or nutrient broth. In contradiction to earlier reports the observations indicated that urea is not required for the synthesis of this enzyme, and that, therefore, urease is not an inducible enzyme in this microorganism.

The new aminoglycoside antibiotic, amikacin (formerly called BB-K8), was used to treat 12 episodes of urinary tract infection caused by hospital-acquired Proteus rettgeri strains. These bacteria were resistant in vitro to kanamycin and gentamicin, and infection persisted in most of the patients in spite of therapy with one of these agents. In all cases, the urinary tract infection was controlled or eradicated by therapy, although relapse or reinfection was frequently encountered in these patients with complicated urological problems. No toxicities attributable to the drug were encountered in the small group of patients.

The minimal inhibitory concentrations of clindamycin and gentamicin alone and in combinations were determined by a microdilution method for 163 aerobic, facultative, and anaerobic clinical isolates. All 77 strains of Staphylococcus aureus, Diplococcus pneumoniae, Streptococcus pyogenes , and anaerobic bacteria (except for three strains of Clostridium ) were inhibited by 1.6 μg or less of clindamycin per ml. Gentamicin did not interfere with the activity of clindamycin within the range of concentrations tested (0.1 to 100 μg/ml); for some strains combinations were synergistic. Sixty-two (94%) of 66 strains of Enterobacteriaceae and Pseudomonas aeruginosa were inhibited by 6.2 μg or less of gentamicin per ml. Combinations of clindamycin and gentamicin were indifferent for 29 strains and synergistic for 33 strains. All 20 strains of enterococcus, three strains of Clostridium , three strains of Escherichia coli , and one strain of Proteus rettgeri were resistant to both clindamycin (minimal inhibitory concentration greater than 3.1 μg/ml) and gentamicin (minimal inhibitory concentration greater than 6.2 μg/ml). Combinations of clindamycin and gentamicin were indifferent for 16 and synergistic for 11 of the resistant strains. Except for clindamycin-sensitive isolates, synergy was usually observed only at concentrations of one or both drugs which are not readily obtainable in vivo. Antagonism was never observed.

SCE-963 {7β-[2-(2-aminothiazol-4-yl)acetamido]-3-[({1-(2-dimethylaminoethyl)- 1H-tetrazol-5-yl}thio)methyl]-ceph-3-em-4-carboxylic acid}, a new semisynthetic cephalosporin, showed excellent antibacterial activity against gram-positive and gram-negative bacteria, including Haemophilus influenzae , indole-positive Proteus, Enterobacter species, and Citrobacter freundii . The minimum inhibitory concentrations of SCE-963 against most strains of clinically isolated Escherichia coli, Klebsiella pneumoniae, H. influenzae , and Proteus mirabilis were within the range of 0.2 to 0.78 μg/ml. These activities were about 10 times more potent than those of cefazolin, cephaloridine, and cephalothin. Variations in pH, addition of horse serum, and type of growth medium had no significant effect on the activity of the cephalosporin, but the inoculum size elicited a considerable effect on the activity of β-lactamase-producing strains of bacteria. SCE-963 exerted bactericidal and bacteriolytic effects on Staphylococcus aureus and E. coli . The pronounced in vitro activity was reflected in the remarkable protection in mice infected with a wide range of gram-negative bacteria, such as E. coli, K. pneumoniae, P. mirabilis, Proteus vulgaris, Proteus morganii , and Proteus rettgeri . The protective effects of SCE-963 in mice infected with E. coli, K. pneumoniae , and P. vulgaris varied according to the challenge dose. The activity of SCE-963 was far more potent when the drug was administered parenterally rather than orally.

One hundred and six strains from the Proteus-Providence group and 27 other strains from the rest of the Enterobacteriaceae were subjected to 178 morphological. physiological and biochemical tests and the results analysed by computer. Most of the Proteus-Providence strains grouped into six main clusters; (1) Proteus mirabilis, (2) Proteus vulgaris, (3) Proteus morganii, (4) Providencia alcalifaciens, Shigella dysenteriae, (5) Proteus rettgeri, (6) Providencia stuartii. On the basis of these groupings a scheme has been drawn up for distinguishing between the different taxa in the Proteus-Providence group.

Norfloxacin is a quinolinecarboxylic acid compound. We examined the in vitro activity of this compound against gram-positive and -negative species, including anaerobic species. It inhibited 90% (MIC90) of strains of Escherichia coli at 0.05 microgram/ml, Klebsiella sp. at 0.4 microgram/ml, Salmonella and Shigella spp. at 0.1 microgram/ml, Citrobacter sp. at 0.4 microgram/ml, Enterobacter cloacae at 0.2 microgram/ml, Enterobacter aerogenes at 0.4 microgram/ml, and Enterobacter agglomerans at 0.2 microgram/ml. The MICs of Proteus mirabilis, Morganella sp., Proteus vulgaris, Proteus rettgeri, and Providencia sp. were 0.1, 0.2, 0.8, 0.3, and 1.6 micrograms/ml, respectively. The MIC90 of Serratia sp. was 1.6 micrograms/ml, and that of Acinetobacter sp. was 6.3 micrograms/ml. For Pseudomonas aeruginosa the MIC50, the MIC75, and the MIC90 were 0.8, 1.6, and 3.1 micrograms/ml, respectively. The MIC50 of Pseudomonas maltophilia was 3.1 micrograms/ml, and the MIC90 was 12.5 micrograms/ml. Yersinia, Arizona, and Aeromonas all were inhibited at concentrations below 1 microgram/ml, as was Campylobacter. The activity of the compound against gram-positive species was less impressive: the MIC90s of Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus faecalis were 1.6, 6.3, 3.1, and 12.5 micrograms/ml, respectively. All Listeria strains were inhibited by 3.1 micrograms/ml. The activity of norfloxacine was not affected by the type of medium, pH, or inoculum size. There was no major difference between MIC and minimum bactericidal concentration values. Norfloxacin inhibited bacteria in every species which was resistant to ampicillin, carbenicillin, cephalexin, gentamicin, and trimethoprim at concentrations lower than those of aminothiazolyl cephalosporins, moxalactam, and aminoglycosides.

FR-31564, a new phosphonic acid antibiotic, was active against most Gram-negative bacteria except Serratia marcescens and glucose-nonfermenting Gram-negative rods excluding Pseudomonas aeruginosa. The antibacterial activity in vitro of FR-31564 was stronger than that of fosfomycin especially against Escherichia coli, Klebsiella pneumoniae, Enterobacter species and P. aeruginosa. FR-31564 also was active against Gram-negative bacteria resistant to beta-lactam antibiotics and against gentamicin-resistant strains of P. aeruginosa. The antibacterial activity in vitro of FR-31564, like that of fosfomycin, was enhanced when 10% rabbit blood was added to the nutrient agar. The therapeutic efficacy of FR-31564 in experimental infections in mice was superior to that of fosfomycin in infections due to most Gram-negative bacteria used, and was similar to that of gentamicin in infections due to Citrobacter freundii, Proteus rettgeri and Proteus inconstans B. The protective effect of FR-31564, particularly in the P. aeruginosa infection, was superior to that of other control drugs including gentamicin.

Mass mortalities in silver carp were related to infection of handling lesions with Proteus rettgeri, a gram negative bacterium normally found in the gut of poultry. Poultry faeces are used extensively to fertilize carp ponds and experimental infections showed that the condition could be reproduced by scarification and exposure to the micro-organism or by its inoculation.

A blood culture bottle from a patient with bacteremia contained both Proteus rettgeri biogroup 5 and Providencia stuartii (described in Bergey's Manual of Determinative Bactiology [8th ed., 1974] as Proteus inconstans), which had the same unusual antibiotic resistance pattern. Single colonies of this P. rettgeri biogroup 5 isolate were shown to produce urea- clones. If current taxonomy is used, the strain changed from P. rettgeri to P. stuartii in the laboratory and probably also in the patient. Urea- clones were also found in three of six other strains of P. rettgeri biogroup 5. No urea-negative clones were found in two isolates each of P. rettgeri biogroups 1 and 3. Previous data from deoxyribonucleic acid-deoxyribonucleic acid hybridization, biochemical reactions, and serological cross-reactions all have indicated that the taxon now called P. rettgeri biogroup 5 should be classified as P. stuartii urea+. We propose that this taxonomic change be made. Urease production is probably plasmid mediated in P. stuartii urea+ and can easily be lost, as shown in our case report and in three stock cultures. Urea hydrolysis will no longer be the key test for differentiating P. rettgeri from P. stuartii. Rather, acid production from trehalose, D-arabitol, adonitol, and D-mannitol will be the key tests. Whereas P. rettgeri is usually trehalose-, D-arabitol+, adonitol+, and D-mannitol+, P. stuartii has the opposite reactions.

The name Providencia rustigianii sp. nov. is proposed for a group of organisms previously known as Providencia alcalifaciens biogroup 3. By DNA hybridization, strains of P. rustigianii were 81 to 99% related to each other at 60 degrees C, but only 44 to 49% related to P. alcalifaciens biogroups 1 and 2 and 26 to 33% related to Providencia stuartii. P. rustigianii could be differentiated from P. alcalifaciens and P. stuartii by simple biochemical tests. P. rustigianii produced acid from D-galactose but not from trehalose; P. stuartii produced acid from both; and P. alcalifaciens produced acid from neither. P. rustigianii could be distinguished from Providencia rettgeri (formerly Proteus rettgeri) by urea hydrolysis and acid production from D-arabitol; P. rustigianii was negative for these two tests, but P. rettgeri was positive. Strains of P. rustiganii were 32 to 34% related to strains of P. rettgeri. Three of the 11 strains of P. rustigianii were isolated from stools, but the sources of the other isolates are unknown. Three strains (27%) were sensitive to colistin, and 82 to 100% were sensitive to ampicillin, carbenicillin, cephalothin, gentamicin, kanamycin, nalidixic acid, streptomycin, and tetracycline. Strain ATCC 33673 (CDC no. 0132-68) is the type strain for this species.

Amikacin was used in the treatment of 56 serious gram-negative infections in 54 patients of whom 47 survived. In six of the seven nonsurvivors, the infections were under control at the time of death. The clinical isolates were multiple drug-resistant gram-negative organisms, with Proteus rettgeri being most common. Forty-five (80 per cent) of these infections were nosocomial in origin, and the genitourinary tract was the source in 39 (70 per cent). Complications directly related to amikacin therapy were few and suggested renal or otologic toxicity. In this series of patients, amikacin appeared to be of therapeutic benefit in the treatment of serious gram-negative infections.

The effect of cefsulodin in combination with mecillinam was examined against a wide range of bacterial species. The antibacterial spectrum was widened by the combination of cefsulodin and mecillinam in the ratio of 5: 1 and 10: 1. In overall observations, in the in vitro test, a synergistic effect against clinical isolates was found on Klebsiella pneumoniae, Citrobacter freundii, Enterobacter cloacae, Serratia marcesscens, Proteus mirabilis and Proteus vulgaris, and an additive effect was found on Staphylococcus aureus, Escherichia coli, Proteus morganii, Proteus rettgeri, Proteus inconstans and Pseudomonas aeruginosa. In in vivo tests, a synergistic effect was observed on S. marcescens TN 66 and K. pneumoniae DT infections and an additive effect was observed on S. aureus 308 A-1, E. coli O-111 and T-7, C. freundii TN 518, E. cloacae TN 603, P. vulgaris GN 4712, P. morganii TN 373 and P. aeruginosa U 31 infections.

An inducible tryptophanase was crystallized from the cell extract of Proteus rettgeri grown in a medium containing l-tryptophan. The purification procedure included ammonium sulfate fractionation, heat treatment, DEAE-Sephadex and hydroxylapatite column chromatographies. Crystals were obtained from solutions of the purified enzyme by the addition of ammonium sulfate.The crystalline enzyme preparation was homogeneous by the criteria of ultracentrifugation and zone electrophoresis. The molecular weight was determined to be approximately 210,000.The crystalline enzyme catalyzed the degradation of l-tryptophan into indole, pyruvate and ammonia in the presence of added pyridoxal phosphate. The enzyme also catalyzed pyruvate formation from 5-hydroxy-l-tryptophan, 5-methyl-l-tryptophan, S-methyl-l-cysteine and l- cysteine. l-, d-Alanine, l-phenylalanine and indole inhibited pyruvate formation from these substrates.

Enteric bacteria, including stocked strains of pathogenic species and organisms naturally present in the stream, were capable of growth in a chemostat with autoclaved river water taken 750 m below a sewage outfall. Maximal specific growth rates for all organisms occurred at 30 C, whereas culture generation times ranged between 33.3 and 116 hr. Of the six laboratory strains of enteric species used, Escherichia coli and Enterobacter aerogenes grew at generation times of 34.5 and 33.3 hr, respectively, while the remaining Proteus, Arizona, Salmonella , and Shigella spp. reproduced at a rate two to three times slower than the coliforms. Little or no growth occurred in the water at incubation temperatures of 20 and 5 C, and death was observed for Salmonella senftenberg at 20 and 5 C and for E. aerogenes and Proteus rettgeri at 5 C. When enteric bacteria naturally present in the river water were employed in similar experiments, coliform bacteria demonstrated a generation time of approximately 116 hr, whereas fecal coliforms failed to grow. Growth of the bacteria from the river demonstrated a periodicity of approximately 100 hr, which suggests that much of the growth of these organisms in the chemostat may be on the glass surfaces. This phenomenon, however, was not observed with any of the stocked enteric species. Neither the stock cultures nor the aquatic strains were capable of growth in autoclaved river water taken above the sewage outfall at the three temperatures tested.

SummaryPlate dilution tests with 8 antibiotics and 13 combinations of antibiotics performed on 82 strains of Proteus gave evidence of synergism between Colimycine and sulfonamides. Tube dilution tests on 54 strains showed the same synergism for all Proteus species except for Proteus rettgeri.

The transfer of an R-factor from Proteus Rettgeri to Escherichia coli W 677 was strongly inhibited by levallorphan at concentrations which do not affect growth of either the donor or the recipient cells. The effect is not due to the transfer of the episom itself but to inhibition of mating-pair formation.

Majority (80%) of the 40 strains of Proteus rettgeri isolated from clinical specimens were resistant to seven drugs: [chloramphenicol (CM), tetracycline (TC), dihydrostreptomycin (SM), sulfanilamide (SA), kanamycin (KM), ampicillin (APC), and cephaloridine (CER)], followed by those resistant to six drugs (15%), single TC-resistance (2.5%) and non-resistant strains (2.5%), in decreasing orders. Ninety-five percent of the 39 multiple drug-resistant strains conjugally transferred some of their resistance markers and 92% of the R+ P. rettgeri were found to be in a hetero-R state. The R factor conferring single KM-resistance was isolated most frequently but TC resistance was never transferable. Detailed analysis of two strains of P. rettgeri in a hetero-R state, GN3162 and GN3163, using two recipients, Escherichia coli ML1410 and P. rettgeri GN3195, disclosed that resistance patterns of conjugants obtained from the same donor strain were almost identical in both recipients of the different species. When strain ML1410, which had received the whole pattern of multiple resistance of the original isolate, was used as a secondary donor, separate transfer of R factors was again observed. The component of R factors in the hetero-R strains was determined by transduction experiments as R (KM), R (APC), R (CM. KM) and R (SM. SA). All of these R factors were fi–. Reconstruction of the original hetero-R state was carried out by superinfection either in E. coli or P. rettgeri, and one of the original strains was observed to be carrying three kinds of R factors, viz., (CM. KM), (SM. SA), and (KM).

Multiple electrophoretic species of arylsulfatase were demonstrated in sonicates of Proteus rettgeri by paper electrophoresis. Subsequent treatment of the sonicates with streptomycin sulfate and DEAE-cellulose chromatography resolved enzyme activity into four fractions. Electrophoretic examination of each chromatographic fraction revealed sulfatase heterogeneity comparable to that of the initial extract. These electrophoretic components differed in their general response to a number of arylsulfatase inhibitors. The results are discussed in relation to the finding of multiple species of arylsulfatase in other biological systems.