Prevalence Of Bacterial Species Research Articles

Prevalence of thermoduric bacteria and spores in nonfat dry milk powders of Midwest origin

Samples of nonfat dry milk powder were analyzed for the presence of heat-resistant bacteria. The samples were collected from Midwest manufacturing companies and were evaluated for the presence of spores, thermoduric bacteria, and the total bacterial count. Three companies were included in this study, and results showed differences between each of the companies in the heat-resistant microbial groups tested. Company 3 had the highest levels of total spores and thermoduric bacteria: 3.6±0.14 and 3.5±0.13 log cfu/g, respectively. Interestingly, this company did not have the highest total bacterial count but rather the second lowest total bacterial count for the group, perhaps because of the higher proportion of thermophiles present in the powders from this company. The average level of total bacterial counts was 2.57±0.07 log cfu/g. Isolates obtained from the samples were identified by mass spectrometry, and all of the companies showed Bacillus licheniformis as the most prevalent bacterial species identified.

Feline urinary tract pathogens: prevalence of bacterial species and antimicrobial resistance over a 10-year period

The purpose of this retrospective study was to identify bacterial species in cats with bacterial urinary tract infections (UTIs) and to investigate their antimicrobial susceptibilities over a 10-year period. Three...

Non-fermentative gram-negative bacteria in hospital tap water and water used for haemodialysis and bronchoscope flushing: Prevalence and distribution of antibiotic resistant strains

This study provides a detailed description of the distribution of non-fermentative gram-negative bacteria (NFGNB) collected in water sources (tap water and water used for haemodialysis and bronchoscope flushing) from different wards of a tertiary care hospital. The aim is to identify risk practices for patients or to alert clinicians to the possible contamination of environment and medical devices. The resistance profile of NFGNB environmental isolates has shown that more than half (55.56%) of the strains isolated were resistant to one or more antibiotics tested in different antimicrobial categories. In particular, 38.89% of these strains were multidrug resistant (MDR) and 16.67% were extensively drug resistant (XDR). The most prevalent bacterial species recovered in water samples were Pseudomonas aeruginosa, Pseudomonas fluorescens, Ralstonia pickettii and Stenotrophomonas maltophilia. Analysis of antibiotic resistance rates has shown remarkable differences between Pseudomonadaceae (P. aeruginosa and P. fluorescens) and emerging pathogens, such as S. maltophilia and R. pickettii. Multidrug resistance can be relatively common among nosocomial isolates of P. aeruginosa, which represent the large majority of clinical isolates; moreover, our findings highlight that the emergent antibiotic resistant opportunistic pathogens, such as R. pickettii and S. maltophilia, isolated from hospital environments could be potentially more dangerous than other more known waterborne pathogens, if not subjected to surveillance to direct the decontamination procedures.

Predominance of multi-drug resistant bacterial pathogens causing surgical site infections in Muhimbili National Hospital, Tanzania.

BackgroundSurgical site infections (SSIs) remain a common and widespread problem contributing to a significant morbidity and mortality, attributed partly by the increase in antimicrobial resistance among the etiological agents. This study was done to determine the spectrum of bacterial isolates and their susceptibility patterns causing SSIs at Muhimbili National Hospital, Tanzania.MethodsThis descriptive cross sectional study was conducted between September, 2011 and February, 2012. Pus swabs or pus were cultured on blood agar (Oxoid, UK) and MacConkey agar (Oxoid, UK) and incubated aerobically at 37°C for 18–24 hours. Bacterial identification was done using API 20E and VITEK and antimicrobial susceptibility was determined by Kirby Bauer disc diffusion.ResultsOf the 100 patients, from whom wound swabs were collected, 90 (90%) had positive aerobic bacterial growth. A total of 147 pathogenic bacteria were isolated, including 114 (77.5%) gram negative and 33(22.5%) gram positive organisms. The most prevalent bacterial species were Pseudomonas aeruginosa (16.3%), followed by Staphylococcus aureus (12.2%) and Klebsiella pneumoniae (10.8%). Of the 18 S. aureus , 8 (44%) were methicillin resistant Staphylococcus aureus (MRSA) and three of them (17%) were carrying both MRSA and induced clindamycin resistance (ICR). Extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae were observed in 23 (79.3%) of the 29 isolates tested. Majority of Escherichia coli 12 (92.3%) and K. pneumoniae 11 (69%) isolates were ESBL producers. About 63% (93/147) were multiple-drug resistance (MDR) isolates, and the overall MDR among Gram positive and Gram negative bacteria was 60.6% (20/33) and 61.4%, (73/114), respectively. The prevalence of MDR for E. coli, A. baumannii and P. stuartii was 100% each. Majority (97%) of the Gram negative bacteria were resistant to more than four categories (classes) of antibiotics.ConclusionA high proportion (63%) of the isolates causing SSIs in this tertiary hospital were MDR, of which (90%) were resistant to more than four classes of antibiotics. In the light of these findings, an urgent and significant change in antibiotic prescription policy is required at this National hospital.

Characterization of bacterial pathogens in rural and urban irrigation water.

The study aimed to compare the bacteriological quality of an urban and rural irrigation water source. Bacterial counts, characterization, identification and diversity of aerobic bacteria were determined. Escherichia coli isolated from both sites was subjected to antibiotic susceptibility testing, virulence gene (Stx1/Stx2 and eae) determination and (GTG)5 Rep-PCR fingerprinting. Low mean monthly counts for aerobic spore formers, anaerobic spore formers and Staphylococcus aureus were noted although occasional spikes were observed. The most prevalent bacterial species at both sites were Bacillus spp., E. coli and Enterobacter spp. In addition, E. coli and Bacillus spp. were most prevalent in winter and summer respectively. Resistance to at least one antibiotic was 84% (rural) and 83% (urban). Highest resistance at both sites was to cephalothin and ampicillin. Prevalence of E. coli possessing at least one virulence gene (Stx1/Stx2 and eae) was 15% (rural) and 42% (urban). All (rural) and 80% (urban) of E. coli possessing virulence genes showed antibiotic resistance. Complete genetic relatedness (100%) was shown by 47% of rural and 67% of urban E. coli isolates. Results from this study show that surface irrigation water sources regardless of geographical location and surrounding land-use practices can be reservoirs of similar bacterial pathogens.

Antimicrobial resistance in bacteria isolated from aquatic environments in Brazil: a systematic review

This article discusses antibiotic resistance in bacteria isolated from aquatic environments in Brazil, taking into account isolation sites, the main reported antimicrobial agents, the genes involved in resistance, the most prevalent bacterial genera and species, and the main mechanisms of resistance. This review is based upon specialized literature, consulting published scientific articles selected from the SciELO, PubMed and LILACS databases. Based upon the inclusion criteria, we selected 21 articles, most (61.6%) were from PubMed, with the highest prevalence for work done in the Southeast region (71.4%) in freshwater environments (71.4%), and the major focus on farm ponds (28.6%). Gram-negative bacteria are the most studied (71.4%) and the Aeromonas spp. was the one found most frequently (19.0%). The most frequently used antimicrobials were chloramphenicol (81.0%), gentamicin (76.2%), sulpha/trimethroprim (71.4%), ampicillin (61.9%) and tetracycline (71.4%); and the ones with higher prevalence of resistance were chloramphenicol (58.8%), sulpha/trimethroprim (78.5%) and ampicillin (84.6%). It was found that studies on resistance in other aquatic environments have not yet been conducted in Brazil, especially in the North and Northeast regions, where irregular rainfall distribution leads to the use of reservoirs as supply sources during the dry season, highlighting concerns regarding the quality, contamination and maintenance of these resources, as the water is intended for human use or for production purposes.

Quantification of bacterial species of the vaginal microbiome in different groups of women, using nucleic acid amplification tests

BackgroundThe vaginal microbiome plays an important role in urogenital health. Quantitative real time Polymerase Chain Reaction (qPCR) assays for the most prevalent vaginal Lactobacillus species and bacterial vaginosis species G. vaginalis and A. vaginae exist, but qPCR information regarding variation over time is still very limited. We set up qPCR assays for a selection of seven species and defined the temporal variation over three menstrual cycles in a healthy Caucasian population with a normal Nugent score. We also explored differences in qPCR data between these healthy women and an ‘at risk’ clinic population of Caucasian, African and Asian women with and without bacterial vaginosis (BV), as defined by the Nugent score.ResultsTemporal stability of the Lactobacillus species counts was high with L. crispatus counts of 108 copies/mL and L. vaginalis counts of 106 copies/mL. We identified 2 types of ‘normal flora’ and one ‘BV type flora’ with latent class analysis on the combined data of all women. The first group was particularly common in women with a normal Nugent score and was characterized by a high frequency of L. crispatus, L. iners, L. jensenii, and L. vaginalis and a correspondingly low frequency of L. gasseri and A. vaginae. The second group was characterized by the predominance of L. gasseri and L. vaginalis and was found most commonly in healthy Caucasian women. The third group was commonest in women with a high Nugent score but was also seen in a subset of African and Asian women with a low Nugent score and was characterized by the absence of Lactobacillus species (except for L. iners) but the presence of G. vaginalis and A. vaginae.ConclusionsWe have shown that the quantification of specific bacteria by qPCR contributes to a better description of the non-BV vaginal microbiome, but we also demonstrated that differences in populations such as risk and ethnicity also have to be taken into account. We believe that our selection of indicator organisms represents a feasible strategy for the assessment of the vaginal microbiome and could be useful for monitoring the microbiome in safety trials of vaginal products.

Adherence to Streptococci Facilitates Fusobacterium nucleatum Integration into an Oral Microbial Community

The development of multispecies oral microbial communities involves complex intra- and interspecies interactions at various levels. The ability to adhere to the resident bacteria or the biofilm matrix and overcome community resistance are among the key factors that determine whether a bacterium can integrate into a community. Fusobacterium nucleatum is a prevalent Gram-negative oral bacterial species that is able to adhere to a variety of oral microbes and has been implicated in playing an important role in the establishment of multispecies oral microbial community. However, the majority of experiments thus far has focused on the physical adherence between two species as measured by in vitro co-aggregation assays, while the community-based effects on the integration of F. nucleatum into multispecies microbial community remains to be investigated. In this study, we focus on community integration of F. nucleatum. We demonstrated using an established in vitro mice oral microbiota (O-mix) that the viability of F. nucleatum was significantly reduced upon addition to the O-mix due to cell contact-dependent induction of hydrogen peroxide (H(2)O(2)) production by oral community. Interestingly, this inhibitory effect was significantly alleviated when F. nucleatum was allowed to adhere to its known interacting partner species (such as Streptococcus sanguinis) prior to addition. Furthermore, this aggregate formation-dependent protection was absent in the F. nucleatum mutant strain ΔFn1526 that is unable to bind to a number of Gram-positive species. More importantly, this protective effect was also observed during integration of F. nucleatum into a human salivary microbial community (S-mix). These results suggest that by adhering to other oral microbes, F. nucleatum is able to mask the surface components that are recognized by H(2)O(2) producing oral community members. This evasion strategy prevents detection by antagonistic oral bacteria and allows integration into the developing oral microbial community.

The human gut microbiome: are we our enterotypes?

Blood groups, finger prints, iris scans and DNA bar codes are several ways to distinguish or identify individual humans. According to Arumugam and colleagues (2011) we can now also be distinguished by the microbial communities in our faeces, our ‘enterotypes’. The human gut is one of the most densely populated ecosystems known, and although this ecosystem contains members of the three domains of life – bacteria, archaea and eucarya (Finegold et al., 1983) – it is dominated by bacteria. They are essential in digesting the food we eat and in keeping us healthy by stimulating our immune system and fighting off pathogenic bacteria. It is estimated that 1013–1014 microbes inhabit our gastrointestinal tract (GIT), with the greatest number residing in the distal gut, where they synthesize essential vitamins and process otherwise indigestible components of our diet such as plant polysaccharides (Backhed et al., 2005). Early studies used 16S ribosomal DNA (rDNA) analysis to type and enumerate the distal gut and faecal microbiota. More than 90% of the bacterial phylotypes present in the intestinal microbiota in healthy humans are members of only three bacterial divisions: the Bacteroidetes, the Firmicutes and the Actinobacteria (Zoetendal et al., 2006). Nevertheless, each healthy adult's gut appears to have a unique and relatively stable microbiota (Zoetendal et al., 1998; Turnbaugh et al., 2007), which is a reflection of the numerous different phylogenetic clusters among the Firmicutes, Clostridium clusters IV, IX and XIVa, including the predominant genera Clostridium, Eubacterium, Roseburia and Ruminococcus. Furthermore, the Actinobacteria that encompass mainly the genera Bifidobacterium and Atopobium also represent important members of the gut microbial community (Harmsen et al., 2002; Turroni et al., 2008). Notably, recent estimates of the diversity of the human gut microbial ecosystem indicate it may encompass more than 1000 species and a multitude of strains (Backhed et al., 2005; Blaut and Clavel, 2007; Rajilic‐Stojanovic et al., 2007). Microbiota composition studies in humans have discovered that aberrations in the microbiome composition is present in obese individuals (Ley et al., 2006; Turnbaugh et al., 2009) as well as in individuals with a variety of other diseases (Zoetendal et al., 2008). Since the largest part (∼80%) of gut microbes remains uncultured, metagenomics analysis has become fashionable in the past 5 years to estimate the types, relative abundance and genome content of microbes in various parts of the GIT. The first metagenomics analysis from just two faecal samples (Gill et al., 2006) led to early insight into enrichment of genes encoding specific metabolic pathways, including metabolism associated with glycans, amino acids and xenobiotics, but also methanogenesis and biosynthesis of vitamins and isoprenoids. However, this early study provided only a very fragmented view due to limitations in sample size, sequencing technology, number of bases sequenced and availability of suitable reference genomes of gut inhabitants.

Viral-bacterial associations in acute apical abscesses

Viral-bacterial and bacterial synergism have been suggested to contribute to the pathogenesis of several human diseases. This study sought to investigate the possible associations between 9 candidate endodontic bacterial pathogens and 9 human viruses in samples from acute apical abscesses. DNA extracts from purulent exudate aspirates of 33 cases of acute apical abscess were surveyed for the presence of 9 selected bacterial species using a 16S ribosomal RNA gene-based nested polymerase chain reaction (PCR) approach. Single or nested PCR assays were used for detection of the human papillomavirus (HPV) and herpesviruses types 1 to 8. Two-thirds of the abscess samples were positive for at least one of the target viruses. Specifically, the most frequently detected viruses were HHV-8 (54.5%); HPV (9%); and varicella zoster virus (VZV), Epstein-Barr virus (EBV), and HHV-6 (6%). Bacterial DNA was present in all cases and the most prevalent bacterial species were Treponema denticola (70%), Tannerella forsythia (67%), Porphyromonas endodontalis (67%), Dialister invisus (61%), and Dialister pneumosintes (57.5%). HHV-8 was positively associated with 7 of the target bacterial species and HPV with 4, but all these associations were weak. Several bacterial pairs showed a moderate positive association. Viral coinfection was found in 6 abscess cases, but no significant viral association could be determined. Findings demonstrated that bacterial and viral DNA occurred concomitantly in two-thirds of the samples from endodontic abscesses. Although this may suggest a role for viruses in the etiology of apical abscesses, the possibility also exists that the presence of viruses in abscess samples is merely a consequence of the bacterially induced disease process. Further studies are necessary to clarify the role of these viral-bacterial interactions, if any, in the pathogenesis of acute apical abscesses.

Genome Sequence of Lactobacillus farciminis KCTC 3681

Lactobacillus farciminis is one of the most prevalent lactic acid bacterial species present during the manufacturing process of kimchi, the best-known traditional Korean dish. Here, we present the draft genome sequence of the type strain Lactobacillus farciminis KCTC 3681 (2,498,309 bp, with a G+C content of 36.4%), which consists of 5 scaffolds.

Comparison of beta-lactamase genes in clinical and food bacterial isolates in India

The present study aimed to determine the occurrence of human disease-causing enteric bacteria on raw vegetables, fruits, meats, and milk products sold in Indian markets. The study further aimed to analyze antibiotic resistance rates and the presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC. Twenty-three food-borne and 23 clinical isolates were compared for antibiotic resistance rates and the presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC. Swabs were taken from unwashed and washed food items, as well as from some chopped food specimens, and inoculated on appropriate culture medium. Bacterial isolates were identified, antibiotic susceptibility was performed, and bla genes were detected by PCR. Thirty-eight bacterial isolates were obtained from the food specimens, of which 36 (94.7%) were Gram-negative and two (5.3%) were Gram-positive bacterial species. Klebsiella pneumoniae was the most prevalent (52.6%; 20/38) bacterial species isolated, followed by Citrobacter koseri (18.4%; 7/38). In food isolates, the majority of the isolates were resistant to gentamicin (33.3%) followed by amikacin (11.1%). Resistance to a third-generation cephalosporin was noticed in only 5.6% isolates. However, in clinical isolates, maximal resistance was noticed against third-generation cephalosporins followed by ofloxacin in 91.3% and 86.9% isolates, respectively, and resistance to gentamicin and amikacin was noticed in 78.3% and 52.2% isolates, respectively. The presence of blaCTX-M, blaTEM, blaSHV, and blaAmpC in clinical isolates was noticed in 52.2%, 60.9%, 21.7%, and 43.5%, respectively. None of the isolates from food showed the presence of any of the above-cited genes. Probably bla genes have not yet disseminated to raw-food vegetation in India.

Invasion of human coronary artery endothelial cells by Streptococcus mutans OMZ175

Dissemination of oral bacteria into the bloodstream has been associated with eating, oral hygiene, and dental procedures; including tooth extraction, endodontic treatment, and periodontal surgery. Recently, studies identified Streptococcus mutans, the primary etiological agent of dental caries, as the most prevalent bacterial species found in clinical samples from patients who underwent heart valve and atheromatous plaque surgery. By using antibiotic protection assays, we tested the capacity of 14 strains of S. mutans to invade primary human coronary artery endothelial cells (HCAEC). Serotype e strain B14 and serotype f strain OMZ175 of S. mutans were able to efficiently invade HCAEC. Among the tested strains, serotype f S. mutans OMZ175 was the most invasive, whereas strains of serotype c S. mutans, the most prevalent serotype in dental plaque, were not invasive. Based on its high invasion rate, we further investigated the invasive properties of serotype f OMZ175. Using transmission electron microscopy and antibiotic protection assays we demonstrate that S. mutans OMZ175 is capable of attaching to the HCAEC surface, entering the cells and surviving in HCAEC for at least 29 h. Our findings highlight a potential role for S. mutans in the pathogenesis of certain cardiovascular diseases.

Bacteria of dental caries in primary and permanent teeth in children and young adults.

Although Streptococcus mutans has been implicated as a major etiological agent of dental caries, our cross-sectional preliminary study indicated that 10% of subjects with rampant caries in permanent teeth do not have detectable levels of S. mutans. Our aims were to use molecular methods to detect all bacterial species associated with caries in primary and permanent teeth and to determine the bacterial profiles associated with different disease states. Plaque was collected from 39 healthy controls and from intact enamel and white-spot lesions, dentin lesions, and deep-dentin lesions in each of 51 subjects with severe caries. 16S rRNA genes were PCR amplified, cloned, and sequenced to determine species identities. In a reverse-capture checkerboard assay, 243 samples were analyzed for 110 prevalent bacterial species. A sequencing analysis of 1,285 16S rRNA clones detected 197 bacterial species/phylotypes, of which 50% were not cultivable. Twenty-two new phylotypes were identified. PROC MIXED tests revealed health- and disease-associated species. In subjects with S. mutans, additional species, e.g., species of the genera Atopobium, Propionibacterium, and Lactobacillus, were present at significantly higher levels than those of S. mutans. Lactobacillus spp., Bifidobacterium dentium, and low-pH non-S. mutans streptococci were predominant in subjects with no detectable S. mutans. Actinomyces spp. and non-S. mutans streptococci were predominant in white-spot lesions, while known acid producers were found at their highest levels later in disease. Bacterial profiles change with disease states and differ between primary and secondary dentitions. Bacterial species other than S. mutans, e.g., species of the genera Veillonella, Lactobacillus, Bifidobacterium, and Propionibacterium, low-pH non-S. mutans streptococci, Actinomyces spp., and Atopobium spp., likely play important roles in caries progression.

One‐year bacterial colonization patterns of Staphylococcus aureus and other bacteria at implants and adjacent teeth

(i) To assess the pattern of early bacterial colonization on titanium oral implants after installation, at 12 weeks and at 12 months, (ii) to compare the microbiota at submucosal implant sites and adjacent subgingival tooth sites and (iii) to assess whether or not early colonization was predictive of 12-month colonization patterns. Submucosal/subgingival plaque samples from 17 titanium oral implants and adjacent teeth were analyzed by checkerboard DNA-DNA hybridization 30 min, 12 weeks and 12 months after implant installation. At 12 months, none of the inserted implants had been lost or presented with signs of peri-implantitis. The distribution of sites at implants and teeth with bleeding on probing varied between 2% and 11%. Probing pocket depths < or =3 mm were found at 75% of implant sites. At 12 months, the sum of the bacterial counts of 40 species was statistically significantly higher at tooth compared with implant sites (mean difference: 34.4 x 10(5), 95% confidence interval -0.4 to 69.4, P<0.05). At 12 months, higher individual bacterial counts at tooth sites were found for 7/40 species compared with implant sites. Detection or lack of detection of Staphylococcus aureus at implant sites at 12 weeks resulted in the highest positive (e.g. 80%) and negative (e.g. 90%) predictive values, respectively. Between 12 weeks and 12 months, the prevalence of Tannerella forsythia increased statistically significantly at implant sites (P<0.05). Lack of detection of Porphyromonas gingivalis at 12 weeks yielded a negative predictive value of 93.1% of this microorganism being undetectable at implant sites at 12 months. Within the limits of this study, the findings showed (i) a few differences in the prevalence of bacterial species between implant and adjacent tooth sites at 12 months and (ii) high positive and negative predictive values for selected bacterial species.

Prevalence of bacterial species in cats with clinical signs of lower urinary tract disease: Recognition of Staphylococcus felis as a possible feline urinary tract pathogen

This study investigated the prevalence of bacterial pathogens of the urinary tract in Australian cats. Urine was collected by cystocentesis and subjected to urinalysis, bacterial culture and susceptibility testing. A total of 126 isolates were obtained from 107 culture-positive cats. Escherichia coli was most commonly isolated (37.3% of isolates) with the majority of isolates showing susceptibility to the 14 antimicrobials tested. Just over a quarter of isolates (27.0%) were Enterococcus faecalis, which showed resistance to cephalosporins and clindamycin. Staphylococcus felis, a previously unreported feline urinary tract pathogen which was susceptible to all antimicrobial agents tested, comprised 19.8% of the isolates. S. felis was significantly associated with urine that had a higher specific gravity ( p = 0.011) and pH ( p = 0.006) and was more likely to contain crystals ( p = 0.002) than urine from which other bacterial species were isolated. This is the first published study that associates the isolation of S. felis with clinical signs of lower urinary tract disease in cats.

Identification, molecular biotyping and ultrastructural studies of bacterial communities isolated from two damaged frescoes of St Damian's Monastery in Assisi.

To investigate the composition of the microbial community in biodeterioration of two frescoes in St Damian's Monastery in Assisi. A total of 1292 colonies were isolated from the most deteriorated parts, analysed by microbiological, biomolecular and ultrastructural techniques, and taxonomically classified. Molecular biotyping of Staphylococcus cohnii colonies, one of the most prevalent bacterial species, showed a very restricted genome diversity while Bacillus licheniformis were very homogeneous by RFLP, tDNA-PCR and random-amplified polymorphic DNA. Electron microscopy confirmed heterogeneity of the bacterial population in the different sampling areas. Several of the identified species are widespread in the soil or saprophytes of human skin. Although unable to demonstrate that they are involved in biodeterioration, they may represent trophic elements contributing to fungi-related chromatic alterations when adequate environmental conditions occur. Deterioration may in part be prevented or controlled by adequate air filtering or conditioning of the room.

Comparison of Systemic Flurithromycin Therapy and Clinical Procedures in the Treatment of Periodontal Diseases

The purpose of the present investigation was to evaluate, in 20 periodontal patients, the microbial and clinical effects of flurithromycin therapy plus scaling and root planning (SRP) in comparison with SRP alone. Clinical assessments of plaque, bleeding on probing and pocket depth were made prior to SRP alone and SRP plus flurithromycin therapy (375 mg twice daily for 5 days) and after both treatments. Subgingival plaque samples (n. 180) were taken prior to and after both treatments and analyzed by conventional bacteriological procedures. Differences in pocket depth and prevalence of bacterial species were analyzed pre- and post-therapies using statistical analyses. A significant decrease (p<0.001) was seen for pocket depth post SRP alone and post SRP plus flurithromycin. After two treatments, Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Prevotella melaninogenica were eradicated from all tested sites. If we compare the preva-lence of the species isolated after SRP alone and after SRP plus flurithromycin sta-tistically significant differences were detected for P. gingivalis and for Fusobacterium nucleatum (p<0.05 and p<0.01, respectively).Flurithromycin can be considered a useful adjunct to mechanical periodontal treatment since it is more efficient in eliminating periodontal pathogens.

Assessment of the California mastitis test usage in smallholder dairy herds and risk of violative antimicrobial residues

This study evaluated how predictive the California Mastitis Test (CMT) is for sub-clinical mastitis under tropical smallholder dairy production conditions in Kenya. It intended to establish whether the CMT usage could be contributing to misdiagnosis and consequent mistreatment with animal drugs resulting in residue problems. Milk samples (n = 239) were aseptically collected from lactating cows in the Rift Valley of Kenya and tested using the CMT, somatic cell counts (SCC) and bacterial culture. The samples were also screened for violative drug residues using the commercial delvo test and compared to the milks mastitic status for possible association. There was a numerical but non-significant (p > 0.05) difference evident in the frequencies observed using the three different mastitis indicators. The prevalent bacterial species isolated from mammary glands with subclinical mastitis were Staphylococcus aureus (45.6%), coagulase-negative Staphylococci (13.0%), Streptococci (11.7%) and Escherichia coli 5.9%. There was an overall poor but significant (p < 0.05) correlation between the CMT and the violative antimicrobial residues in samples from all quarters, infected and non-infected respectively. The results suggest that the CMT use amongst the smallholder dairy sector as a mastitic indicator may not be a risk factor in violative antimicrobial residues problems in milk.

Surveillance for antimicrobial susceptibility among clinical isolates of Pseudomonas aeruginosa and Acinetobacter baumannii from hospitalized patients in the United States, 1998 to 2001.

Pseudomonas aeruginosa and Acinetobacter baumannii are the most prevalent nonfermentative bacterial species isolated from clinical specimens of hospitalized patients. A surveillance study of 65 laboratories in the United States from 1998 to 2001 found >90% of isolates of P. aeruginosa from hospitalized patients to be susceptible to amikacin and piperacillin-tazobactam; 80 to 90% of isolates to be susceptible to cefepime, ceftazidime, imipenem, and meropenem; and 70 to 80% of isolates to be susceptible to ciprofloxacin, gentamicin, levofloxacin, and ticarcillin-clavulanate. From 1998 to 2001, decreases in antimicrobial susceptibility (percents) among non-intensive-care-unit (non-ICU) inpatients and ICU patients, respectively, were greatest for ciprofloxacin (6.1 and 6.5), levofloxacin (6.6 and 3.5), and ceftazidime (4.8 and 3.3). Combined 1998 to 2001 results for A. baumannii isolated from non-ICU inpatients and ICU patients, respectively, demonstrated that >90% of isolates tested were susceptible to imipenem (96.5 and 96.6%) and meropenem (91.6 and 91.7%); fewer isolates from both non-ICU inpatients and ICU patients were susceptible to amikacin and ticarcillin-clavulanate (70 to 80% susceptible); and <60% of isolates were susceptible to ceftazidime, ciprofloxacin, gentamicin, or levofloxacin. From 1998 to 2001, rates of multidrug resistance (resistance to at least three of the drugs ceftazidime, ciprofloxacin, gentamicin, and imipenem) showed small increases among P. aeruginosa strains isolated from non-ICU inpatients (5.5 to 7.0%) and ICU patients (7.4 to 9.1%). From 1998 to 2001, rates of multidrug resistance among A. baumannii strains isolated from non-ICU inpatients (27.6 to 32.5%) and ICU patients (11.6 to 24.2%) were higher and more variable than those observed for P. aeruginosa. Isolates concurrently susceptible, intermediate, or resistant to both imipenem and meropenem accounted for 89.8 and 91.2% of P. aeruginosa and A. baumannii isolates, respectively, studied from 1998 to 2001. In conclusion, for aminoglycosides and most beta-lactams susceptibility rates for P. aeruginosa and A. baumannii were constant or decreased only marginally (</=3%) from 1998 to 2001. Greater decreases in susceptibility rates were, however, observed for fluoroquinolones and ceftazidime among P. aeruginosa isolates.