Growth Of Potential Pathogens Research Articles

The effect of synbiotic preparations on the intestinal microbiota and her metabolism in broiler chickens

The aim of the research was to determine the effect of newly elaborated synbiotic preparations on the count of dominant intestinal microorganisms, on the profile of fatty acids (short chain – SCFA and branched chain – BCFA), the lactic acid produced and the performance of chickens. The studies determined the composition of the dominant intestinal microbiota with use of the culture method. The fatty acid profile was also determined using the high-performance liquid chromatography method (HPLC). Moreover, the performance of chickens was determined such as the daily cumulative mortality rate, the feed conversion ratio (FCR) and the European Production Efficiency Factor (EPEF). It was found that synbiotics had a beneficial effect on parameters of the performance of chickens, and also resulted in increase in the count of beneficial bacteria and to the restriction in growth of potential pathogens in the gastrointestinal tract. Synbiotics caused an increase in the concentration of lactic acid and SCFA and a decrease in the concentration of BCFA in the broiler’s excreta. These results showed a beneficial effect of the tested synbiotics on the intestinal microbiota, their metabolism and the performance of broiler chickens. The elaborated synbiotics can be successfully used as feed additives for broiler chickens.

Influence of dietary components on development of the microbiota in single-stomached species

After birth, development of a normal microbial community occurs gradually, and is affected by factors such as the composition of the maternal gut microbiota, the environment, and the host genome. Diet also has a direct influence, both on composition and activity of this community. This influence begins with the milk, when specific components exert their growth-promoting effect on a beneficial microbiota, thereby suppressing potential pathogens. For example, breast-fed infants compared with formula-fed babies usually have a microbial community dominated by bifidobacteria. When solid food is introduced (weaning), dramatic changes in microbial composition occur, so pathogens can gain access to the disturbed gastrointestinal (GI) ecosystem. However, use of specific dietary components can alter the composition and activity of the microbiota positively. Of all dietary components, fermentable carbohydrates seem to be most promising in terms of promoting proliferation of beneficial bacterial species. Carbohydrate fermentation results in the production of SCFA which are known for their trophic and health-promoting effects. Fermentation of proteins, on the other hand, is often associated with growth of potential pathogens, and results in production of detrimental substances including NH3 and amines. In terms of the GI microbiota, lipids are often associated with the antimicrobial activity of medium-chain fatty acids and their derivatives. The present review aims to provide deeper insights into the composition and development of the neonatal GI microbiota, how this microbiota can be influenced by certain dietary components, and how this might ultimately lead to improvements in host health.

Chronic sinusitis in children and adults: Role of bacteria and antimicrobial management

The nasopharynx serves as the reservoir for anaerobic bacteria as well as pathogenic bacteria that can cause respiratory infections including sinusitis. Some of these organisms possess the ability to interfere with the growth of potential pathogens and may play a role in preventing infections. Anaerobic bacteria emerge as pathogens as the infection becomes chronic. This may result from the selective pressure of antimicrobial agents that enable resistant anaerobic organisms to survive, and from the development of conditions appropriate for anaerobic growth, which include the reduction in oxygen tension and an increase in acidity within the sinus. Anaerobes were identified in chronic sinusitis in adults and children whenever techniques for their cultivation were employed. The predominant isolates were pigmented Prevotella, Fusobacterium, and Peptostreptococcus spp. The choice of antimicrobial agent in chronic sinusitis should provide coverage for the usual pathogens in acute sinusitis as well as beta-lactamase-producing aerobic and anaerobic organisms.

Effects of antimicrobial therapy on the microbial flora of the adenoids.

The core of the adenoids contains polymicrobial aerobic and anaerobic flora and also includes potential respiratory pathogens. Similar flora, although in higher numbers and with a higher frequency of pathogens, are found in inflamed or hypertrophic adenoids and many of these bacteria are resistant to antimicrobial agents. Exposure to antimicrobial therapy can alter the colonization patterns and select for resistant organisms. Production of beta-lactamase is one of the major mechanisms of resistance of these organisms. The adenoids of healthy individuals, in contrast to those with recurrent respiratory tract infections, are generally colonized by aerobic and anaerobic organisms that are capable of interfering with the growth of potential pathogens. Maintaining the beneficial effects of normal flora by avoiding unnecessary exposure to antimicrobial therapy may be a useful tool in preventing colonization of the adenoids by potential pathogens. This review discusses the unique microbiology of the adenoids in individuals with a variety of pathological conditions, the interactions between the various organisms and the effects of antimicrobial therapy on the microbial flora of the adenoids.

Dynamics of nasopharyngitis in children

Purpose: Our goal was to characterize the dynamics and bacterial interaction of the aerobic and anaerobic flora of nasal discharge of children at different stages of uncomplicated nasopharyngitis. Methods And Patients: Serial semiquantitative nasopharyngeal (NP) and quantitative nasal discharge (ND) cultures were taken every 3 to 5 days from 20 children in whom purulent discharge eventually developed (group 1), and a single culture was obtained from a group of 20 who had only clear discharge (group 2). Results: Aerobic and anaerobic bacteria were isolated from all NP cultures. Bacterial growth was present in 8 (40%) NDs of group 2. Only 7 (35%) of the clear NDs of group 1 showed bacterial growth; the number increased to 14 (70%) at the mucoid stage and 20 (100%) at the purulent stage. It declined to 6 (30%) at the final clear stage. The number of species and total number of organisms increased in the NDs of group 1. Group 1 patients had higher recovery rates of Streptococcus pneumoniae and Haemophilus influenzae in their NP cultures than group 2 patients ( P < 0.05). During the purulent stage, Peptostreptococcus species were isolated in 15 (75%), Fusobacterium species in 10 (50%), Prevotella species in 9 (45%), H influenzae in 8 (40%), S pneumoniae in 6 (30%), and β-hemolytic streptococci in 5 (25%) of group 1 NDs. This was higher than their recovery in the clear stages of both groups and the mucoid stage of group 1. A total of 8 organisms capable of interfering with the growth of potential pathogens were isolated from the NPs of group 1, as compared with 35 from group 2 ( P < 0.001). Conclusions: The development of purulent nasopharyngitis is associated with the pre-existing presence of potential pathogens and the absence of interfering organisms. (Otolaryngol Head Neck Surg 2000;122:696-700.)

Dynamics of nasopharyngitis in children.

Our goal was to characterize the dynamics and bacterial interaction of the aerobic and anaerobic flora of nasal discharge of children at different stages of uncomplicated nasopharyngitis. Serial semiquantitative nasopharyngeal (NP) and quantitative nasal discharge (ND) cultures were taken every 3 to 5 days from 20 children in whom purulent discharge eventually developed (group 1), and a single culture was obtained from a group of 20 who had only clear discharge (group 2). Aerobic and anaerobic bacteria were isolated from all NP cultures. Bacterial growth was present in 8 (40%) NDs of group 2. Only 7 (35%) of the clear NDs of group 1 showed bacterial growth; the number increased to 14 (70%) at the mucoid stage and 20 (100%) at the purulent stage. It declined to 6 (30%) at the final clear stage. The number of species and total number of organisms increased in the NDs of group 1. Group 1 patients had higher recovery rates of Streptococcus pneumoniae and Haemophilus influenzae in their NP cultures than group 2 patients (P < 0.05). During the purulent stage, Peptostreptococcus species were isolated in 15 (75%), Fusobacterium species in 10 (50%), Prevotella species in 9 (45%), H influenzae in 8 (40%), S pneumoniae in 6 (30%), and beta-hemolytic streptococci in 5 (25%) of group 1 NDs. This was higher than their recovery in the clear stages of both groups and the mucoid stage of group 1. A total of 8 organisms capable of interfering with the growth of potential pathogens were isolated from the NPs of group 1, as compared with 35 from group 2 (P < 0.001). The development of purulent nasopharyngitis is associated with the pre-existing presence of potential pathogens and the absence of interfering organisms.

Aerobic Bacterial Flora of Semen and Stallion Reproductive Tract and its Relation to Fertility Under Field Conditions

This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was found in almost all samples from fresh semen (total 115 samples). P. aeruginosa was isolated from 46/115 (40%) of the samples and from 12 of the 16 stallions. K. pneumoniae was isolated from the semen of one stallion. Samples taken from the distal urethra after ejaculation contained fewer microorganisms than samples from fresh semen. No bacteria were found in 51% of the extended semen samples. Most of the stallions had an acceptable sperm morphology, and very few of the ejaculates contained inflammatory cells. Pregnancy results among the stallions varied, but were acceptable for most of them. There was no correlation between the frequency of samples testing positive for P. aeruginosa in raw semen and pregnancy results.

Growth of potential pathogens in denture-soaking solution of myelosuppressed cancer patients

M yelosupprcssion that results in markedly decreased numbers of circulating granulocytes and mucosal damage sustained during antineoplastic chemotherapy may predispose cancer patients to infection.‘.’ The more profound the myelosuppression, the higher the risk of infection, with a significantly higher probability of infection when granulocyte levels fall to less than 1 OO/&‘~ * Most of the infections are caused by opportunistic gram-negative bacilli, especially Pseudomonas aeruginosa, and several species of fungi.“-” Many of the organisms, which are thought to be acquired nosocomially or succeed to predominance after admission to the hospital, effect a change in the patient’s normal flora.‘~‘~ I2 As the organisms are generally not present in the pharynx of a normal population, such factors as hospital treatment modalities, serious systemic disease, and debilitation are thought to select for these pathogens.‘3-‘S Most infections in this population result from microorganisms that have colonized the patient’s alimentary canal, including the oral cavity.‘0,‘P.20 Exogenous sources of infection include food, water, shower stalls, humidifiers, ice machines, respirators, intravenous catheters, and members of the hospital staff.” In one investigation, dentures and denture-soaking containers used by myelosuppressed hospital patients were found to be contaminated heavily with pathogens, especially gram-negative bacilli. 2’ Under these conditions dentures could serve as reservoirs for pathogens in the hospital environment and as a source of infection and cross-contamination. The objective of this investigation was to determine if denture-borne pathogens would

INCREASING SHELF LIFE BY CARBON DIOXIDE TREATMENT AND LOW TEMPERATURE STORAGE OF BULK PACK FRESH CHICKENS PACKAGED IN NYLON/SURLYN FILM

ABSTRACTSimulated commercial bulk pack, whole chickens were subjected to conventional ice pack and three modified atmospheric, vacuum and two levels of CO2 within a Nylon/Surlyn film, storage environments. Pathogenic and nonpathogenic microbial growth, void space gas composition (except ice pack) and off‐odor development were monitored on samples stored at 1.1°C. Polynomial regression analysis of aerobic growth curves revealed that the lag phase was extended to 8‐10 days by using a CO2 addition rate of 3.61 × 10‐4 and 7.22 × 10‐4 m3/kg, respectively. The transition from lag to log phase appeared when the residual level of CO, in the void space reached 15‐55%. Following initial replacement of the air in the pouch with 95% CO2, the growth of anaerobic microorganisms was limited by the presence of CO2. The growth of potential pathogens, salmonella, coliforms, Staphylococcus aureus and Clostridium perfringens in the presence or absence of CO2 was negligible at 1.1°C. Off‐odor development can be detected when the colony forming units (CFU) numbers reach 106/g of body weight. Carbon dioxide restricts the growth of most objectionable putrefactive off‐odor bacteria; lactic acid organisms are encouraged by its presence on the surface of the sample and in the pouch void space. A recommended usage rate of 7.22 × 10‐4 m3 CO2/kg of body weight extends shelf life quality to 27 days at 1.1°C.