The microbiological and pathomorphological characteristics of Klebsiella infection]

Biological properties of 350 strains of Klebsiella pneumoniae isolated in newborns during the outbreak of intrahospital infection have been studied. Experimental infection with isolated strains of a similar plasmid profile is simulated, interrelation between the presence of plasmids and ability of the strain to induce generalized Klebsiella infection is shown. Pathological processes in the newborns with generalized infection and in animals with the reproduced experimental Klebsiella infection are shown to be similar in principle.     

The effect of denervation on soft-tissue infection pathophysiology.

Pressure is the sine qua non in the etiology of pressure sores; however, ischemia, denervation, edema, and infection also have been implicated. The role of denervation in tissue infection was studied in an isolated in vivo ovine flap model. Twenty-six adult ewes, divided into three groups, had 29 island pedicle flaps raised on their buttocks. In group I, the cutaneous nerve remained intact, while group II had its nerve divided acutely. Group III had prolonged denervation, where the nerve was divided 7 days before flap elevation. All flaps received intradermal inoculations of 10(7) Staphylococcus aureus. Ninety-six hours later, quantitative bacteriology showed counts of 10(7), 10(7), and 10(9) colony-forming units (CFU) per gram of tissue in groups I, II, and III, respectively. Septic foci were larger in group III, and there was a significant increase in tissue edema between groups I and III. A 25-fold increase in bacterial counts seen in the prolonged denervation group may help explain why neurologically injured patients are more susceptible to infection and pressure ulcerations.     

Role of microbiological control in the choice of antibacterial therapy of respiratory infection in surgical patients during the postoperative period

The paper presents data on observation of 416 surgical patients subjected to investigation of sputum and washings from the tracheobronchial tree for estimating the role of clinico-microbiological study of respiratory tract excretions from surgical patients in choice of adequate therapy. On the basis of the obtained data and results of clinical observations a scheme of clinico-microbiological criteria was developed which would be of help for clinicians and microbiologists in difficult differential diagnosis of colonization and infection. The scheme will provide clinical microbiologists with possibility of correct interpretation of the results of studying respiratory tract excretions and presenting information containing preliminary positive or negative indications as to the presence of infection and recommendations for continuation or discontinuation of further clinico-microbiological investigations.     

Determinants of the microbiological characteristics of South Australian swimming pools

A survey of 100 swimming pools has been conducted to assess the effectiveness of disinfection practices against various microorganisms and to check compliance with recommended chlorine levels and pH. Microbiological quality was assessed from densities of total coliforms, Escherichia coli, and Pseudomonas aeruginosa, total colony counts, and the presence or absence of amoebae, including the pathogen Naegleria fowleri. Although a free chlorine residual of 1.0 mg/liter and a pH range of 7.0 to 7.6 are recommended by local health authorities, 41 pools had a lower free chlorine residual and 37 had a pH outside this range. Multiple logistic regression analysis was used to test the association of field measurements with the microbiological data. The analysis demonstrated a strong positive association of free chlorine with bacteriological quality and the absence of Naegleria spp. No other field measurement was predictive in this regard, although the absence of all amoebae was associated with a relatively low water temperature and pH. Using a mathematical model derived from this analysis, it was estimated that 99% of pools would have acceptable bacteriological quality and 94% would be free of Naegleria spp. at a free chlorine residual of 1.0 mg/liter. However, at the mean water temperature (23 degrees C) and pH (7.5) seen in this study, other amoebae would still be detectable in 500-ml samples taken from 40% of pools at this chlorine level.     

The microbiological characteristics of intestinal dysbacteriosis in children and adults in the city of Moscow

The bacteriological analysis of 302 children has revealed that dysbacteriosis with the increased content of hemolytic Escherichia in the intestine develops more frequently in the presence of the deficiency of bifido- and lactobacteria. The development of other kinds of dysbacteriosis with the increased content of different opportunistic enterobacteria, staphylococci, enterococci and fungi, as well as dysbacteriosis with the decreased content of Escherichia, does not practically depend on the deficiency of bifido- and lactobacteria. In patients with the increased content of Escherichia an increase in the content of opportunistic enterobacteria, staphylococci and fungi is observed more frequently than in patients with the low content of Escherichia.     

The epidemiological characteristics of HIV infection in Turkmenistan

In the presence of the low spread of HIV infection a sharp increase in sexually transmitted diseases is noted. Nevertheless, taking into account a rise in STD, the reality of the potential risk of the spread of HIV is emphasized. Thus, in 1996 morbidity is syphilis was found to grow 7.2 times in comparison with 1992, amounting to 37.5 cases per 100,000 of the population; morbidity in gonorrhea amounted to 32.4 cases per 100,000 of the population with the proportion coming to medical institutions not exceeding 30%. A high proportion of hepatitis B virus carriers was also established (from 15% to 30% of healthy persons), while morbidity in virus hepatitides rose twofold for the period of 1994-1995. During recent years the service for the prophylaxis of AIDS was noted to considerably decrease measures on mass screening. At the same time the article attracts attention to the necessity of increasing the work on the dissemination of information and education on HIV/AIDS drug among addicts, prostitutes and homosexuals. The Draft National Program of the Prophylaxis of HIV infection and STD for 1998-2002 has been worked out. Great importance of methodological and financial assistance rendered since 1994 by international organizations, including WHO, UNFPA, etc., have been emphasized.     

Antibiotic prophylaxis, antibiotic therapy and microbiological situation in surgical unit]

The clinical and economic efficacies of antibiotic prophylaxis in the surgical unit of the Hospital were confirmed by the results of the analysis of 1313 case records of the patients operated during a year for acute appendicitis and acute cholecystitis. At the same time it was shown advisable to use antibiotic therapy in the patients with various pathological processes. The dynamics of the microbial dissemination in the surgical unit and some other units of the Hospital, as well as the dynamics of antibiotic resistance of the microflora, its interrelation with the volume of the antibacterials used and their rotation are described.     

Determinants of the microbiological characteristics of South Australian swimming pools.

A survey of 100 swimming pools has been conducted to assess the effectiveness of disinfection practices against various microorganisms and to check compliance with recommended chlorine levels and pH. Microbiological quality was assessed from densities of total coliforms, Escherichia coli, and Pseudomonas aeruginosa, total colony counts, and the presence or absence of amoebae, including the pathogen Naegleria fowleri. Although a free chlorine residual of 1.0 mg/liter and a pH range of 7.0 to 7.6 are recommended by local health authorities, 41 pools had a lower free chlorine residual and 37 had a pH outside this range. Multiple logistic regression analysis was used to test the association of field measurements with the microbiological data. The analysis demonstrated a strong positive association of free chlorine with bacteriological quality and the absence of Naegleria spp. No other field measurement was predictive in this regard, although the absence of all amoebae was associated with a relatively low water temperature and pH. Using a mathematical model derived from this analysis, it was estimated that 99% of pools would have acceptable bacteriological quality and 94% would be free of Naegleria spp. at a free chlorine residual of 1.0 mg/liter. However, at the mean water temperature (23 degrees C) and pH (7.5) seen in this study, other amoebae would still be detectable in 500-ml samples taken from 40% of pools at this chlorine level.     

Dromedary milk lactic acid fermentation: microbiological and rheological characteristics

The ability of dromedary skim milk to form an acid curd during a lactic acid starter fermentation was investigated. The activity of the starter in dromedary milk was characterized by a longer lag phase (∼5 vs. ∼1 h) and by an earlier decline phase. This suggests the presence of inhibiting factors. The maximum buffering capacity of dromedary milk as well as its minimum apparent viscosity were obtained at lower pH values. Similarly, its elastic modulus appeared later (pH 5.7 vs. 6.3). Because these rheological and biochemical events took place at lower pH values, dromedary skim milk seems to present a higher physical stability toward the increase of acidity. Determination of the rheological and microscopic characteristics of the dromedary milk coagulum (pH 4.4) did not reveal curd formation but indicated a fragile and heterogeneous structure. This coagulum, which is very different from that of cows' milk, seems to be made up of dispersed casein flakes. Journal of Industrial Microbiology & Biotechnology (2001) 26, 263–270. Received 01 May 2000/ Accepted in revised form 26 January 2001     

Storage of oil field-produced waters alters their chemical and microbiological characteristics

Many oil fields are in remote locations, and the time required for shipment of produced water samples for microbiological examination may be lengthy. No studies have reported on how storage of oil field waters can change their characteristics. Produced water samples from three Alberta oil fields were collected in sterile, industry-approved 4-l epoxy-lined steel cans, sealed with minimal headspace and stored under anoxic conditions for 14 days at either 4°C or room temperature (ca. 21°C). Storage resulted in significant changes in water chemistry, microbial number estimates and/or community response to amendment with nitrate. During room-temperature storage, activity and growth of sulfate-reducing bacteria (and, to a lesser extent, fermenters and methanogens) in the samples led to significant changes in sulfide, acetate and propionate concentrations as well as a significant increase in most probable number estimates, particularly of sulfate-reducing bacteria. Sulfide production during room-temperature storage was likely to be responsible for the altered response to nitrate amendment observed in microcosms containing sulfidogenic samples. Refrigerated storage suppressed sulfate reduction and growth of sulfate-reducing bacteria. However, declines in sulfide concentrations were observed in two of the three samples stored at 4°C, suggesting abiotic losses of sulfide. In one of the samples stored at room temperature, nitrate amendment led to ammonification. These results demonstrate that storage of oil field water samples for 14 days, such as might occur because of lengthy transport times or delays before analysis in the laboratory, can affect microbial numbers and activity as well as water sample chemistry.     

The epidemiological characteristics of meningococcal infection in the USSR

The epidemiological analysis of morbidity in meningococcal infection in the USSR in the period of 1969-1987 showed that the second rise of the morbidity level occurred in 1984 and was followed by its decrease in most of the regions of the USSR. This study also revealed that the characteristic feature of the second rise of morbidity in meningococcal infection was a considerable involvement of young children (aged up to 3 years), as well as the increased etiological role of group B meningococci in cases of meningococcal infection and the circulation of these microorganisms among the population. Besides, the preservation of the etiological importance of group A meningococci in many regions of the USSR, especially among adults, was noted. In this connection, the use of Soviet group A meningococcal polysaccharide vaccine on epidemiological indications was considered to be epidemiologically substantiated.     

Mineralogical characteristics of residues produced in microbiological treatment of acidic mine drainages

Inorganic residues produced on the disks of rotating biological contactor (RBC) wastewater treatment units during microbiological oxidation of the ferrous iron in both natural and synthetic acidic mine drainages were analyzed using x‐ray energy‐dispersive microanalysis, x‐ray diffraction, and scanning electron microscopy. The predominant mineral forms were x‐ray amorphous ferric hydroxysulfates. In addition, jarosites were detected in RBC units which treated natural mine drainages, and magnetite was detected in solids generated during treatment of a synthetic acidic mine drainage. Bacteria were observed on the surface of the inorganic residues and in gelatinous films seen microscopically following chemical dissolution of the iron crust.     

温带草原退化对土壤剖面微生物学特征的影响

【目的】草地退化已成为我国草原当前面临的最主要问题。土壤微生物量和土壤酶活性是反映土壤养分和土壤环境质量的重要指标。揭示退化程度对温带草原土壤剖面微生物学特征的影响规律。【方法】以内蒙古温带草原为研究对象,选取成熟自然草地以及中、重度退化草地和极度退化草地4种典型不同退化程度的草地,按不同土壤深度分层采样并进行土壤微生物量和土壤微生物酶活性的测定。【结果】表层土壤微生物生物量及其酶活性在不同退化样地中呈现出一致的趋势:成熟自然样地中度退化样地重度退化样地极度退化样地;10-20 cm土层土壤微生物学特征与表层的差异随着退化程度的加深逐渐减少,甚至在极度退化样地中10-20 cm层土壤微生物指标高于表层。【结论】表层土壤微生物生物量及其酶活性随着退化程度的加深而减少。同时,退化程度越严重,表层与10–20 cm土层之间土壤微生物学特征的差异越小。这一结果为评价草地退化程度提供了新思路,为温带草原的恢复和重建提供了重要的理论依据。