The MSCRAMM Family of Cell-Wall-Anchored Surface Proteins of Gram-Positive Cocci.

The microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) are a family of proteins that are defined by the presence of two adjacent IgG-like folded subdomains. These promote binding to ligands by mechanisms that involve major conformational changes exemplified by the binding to fibrinogen by the 'dock-lock-latch' mechanism or to collagen by the 'collagen hug'. Clumping factors A and B are two such MSCRAMMs that have several important roles in the pathogenesis of Staphylococcus aureus infections. MSCRAMM architecture, ligand binding, and roles in infection and colonization are examined with a focus on recent developments with clumping factors.

Characterization of a novel Gram-stain-positive anaerobic coccus isolated from the female genital tract: Genome sequence and description of Murdochiella vaginalis sp. nov.

Strain Marseille-P2341T , a nonmotile, nonspore-forming, Gram-stain-positive anaerobic coccus, was isolated in the vaginal specimen of a patient with bacterial vaginosis using culturomics. Its growth occurred at temperatures ranging from 25 to 42°C, with pH between 6.5 and 8.5, and at NaCl concentrations lower than 5%. The major fatty acids were C18:1n9 (27.7%) and C16:0 (24.4%). Its genome is 1,671,491 bp long with 49.48 mol% of G+C content. It is composed of 1,501 genes: 1,446 were protein-coding genes and 55 were RNAs. Strain Marseille-P2341T shared 97.3% of 16S rRNA gene sequence similarity with Murdochiella asaccharolytica, the phylogenetically closest species. These results enabled the classification of strain Marseille-P2341T as a new species of the genus Murdochiella for which we proposed the name Murdochiella vaginalis sp. nov. The type strain is strain Marseille-P2341T (=DSM 102237, =CSUR P2341).

Effects of intranasal steroid treatment on the presence of biofilms in non-allergic patients with chronic rhinosinusitis with nasal polyposis.

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal application of corticosteroids (INCS) is a reliable option in the management of CRSwNP. INCS medication has been suspected to influence the presence and thickness of microbial biofilms and inflammatory cell patterns in CRSwNP. Two series of identical nasal polyps obtained from non-allergic patients with CRSwNP (n = 56), who underwent endoscopic sinus surgery (ESS), were processed to hematoxylin-eosin (H.E.) and Gram staining, respectively. Patients were recruited into three groups. Group A (n = 21) consisted of patients with continuous preoperative INCS treatment. In group B (n = 17), patients were never treated by INCS, while in group C (n = 18) INCS medication was stopped at least 6 months before ESS. Biofilm positivity varied from 76.4 to 88.8% in different subject groups. These values and average thickness of biofilms did not reach statistically significant levels (Mann-Whitney's U probe, p > 0.05) in different patient groups. In contrast, microscopic pattern and numbers of predominant inflammatory cell populations displayed obvious differences according to INCS treatment (Mann-Whitney's U probe, p < 0.001). According to these observations, INCS treatment does not affect the presence and thickness of microbial biofilms in CRSwNP. In contrast, it has significant effects on the pattern of inflammatory cells infiltrating the subepithelial layer, which might result in beneficially altered extracellular matrix production and cytokine release.

How to get (a)round: mechanisms controlling growth and division of coccoid bacteria.

Bacteria come in a range of shapes, including round, rod-shaped, curved and spiral cells. This morphological diversity implies that different mechanisms exist to guide proper cell growth, division and chromosome segregation. Although the majority of studies on cell division have focused on rod-shaped cells, the development of new genetic and cell biology tools has provided mechanistic insight into the cell cycles of bacteria with different shapes, allowing us to appreciate the underlying molecular basis for their morphological diversity. In this Review, we discuss recent progress that has advanced our knowledge of the complex mechanisms for chromosome segregation and cell division in bacteria which have, deceptively, the simplest possible shape: the cocci.

Air-directed attachment of coccoid bacteria to the surface of superhydrophobic lotus-like titanium.

Superhydrophobic titanium surfaces fabricated by femtosecond laser ablation to mimic the structure of lotus leaves were assessed for their ability to retain coccoid bacteria. Staphylococcus aureus CIP 65.8T, S. aureus ATCC 25923, S. epidermidis ATCC 14990T and Planococcus maritimus KMM 3738 were retained by the surface, to varying degrees. However, each strain was found to preferentially attach to the crevices located between the microscale surface features. The upper regions of the microscale features remained essentially cell-free. It was hypothesised that air entrapped by the topographical features inhibited contact between the cells and the titanium substratum. Synchrotron SAXS revealed that even after immersion for 50 min, nano-sized air bubbles covered 45% of the titanium surface. After 1 h the number of cells of S. aureus CIP 65.8T attached to the lotus-like titanium increased to 1.27×10(5) mm(-2), coinciding with the replacement of trapped air by the incubation medium.

Genome sequence of Peptoniphilus rhinitidis 1-13T, an anaerobic coccus strain isolated from clinical specimens.

A new Peptoniphilus species has been isolated from samples from a patient who was scheduled for endoscopic sinus surgery for chronic rhinosinusitis. The isolate, Peptoniphilus rhinitidis 1-13(T) (KCTC 5985(T)), can use peptone as a sole carbon source and produce butyrate as a metabolic end product. This is the first report of the draft genome sequence of a novel species in the genus Peptoniphilus within the group of Gram-positive anaerobic cocci.

[Systematic review of antimicrobial resistance among Gram positive cocci in hospitals in Colombia]. / Revisión sistemática de la resistencia antimicrobiana en cocos Gram positivos intrahospitalarios en Colombia.

INTRODUCTION: Bacterial resistance is a public health problem worldwide whose proper management requires knowledge of its presence and its behavior in each region and country. OBJECTIVES: A survey of the medical literature was conducted to identify levels of resistance to antibiotic markers in Gram positive bacterial isolates from Colombian hospitals. MATERIALS AND METHODS: A systematic review of the literature included articles indexed in MEDLINE and LILACS. A manual search was made of Colombian scientific journals and other infectious disease literature not available electronically. RESULTS: A total of 34 observational studies were located, including a series of consecutive reports initiated in 2001. Most of the reports came from the city of Bogota. The rate of methicillin resistance for Staphylococcus aureus and coagulase-negative staphylococci in non intensive care unit isolates ranged between 35%-50% and 72%-76%, respectively. Resistance in intensive care unit isolates had a range between 35%-71% and 74%-83%, respectively. The rate of vancomycin-resistant Enterococcus faecium averaged less than 20% over the years but with large annual variation . CONCLUSIONS: Resistance markers appeared in high frequency among Gram positive isolates identified in hospitals in major Colombian cities.

Filifactor alocis has virulence attributes that can enhance its persistence under oxidative stress conditions and mediate invasion of epithelial cells by porphyromonas gingivalis.

Filifactor alocis, a Gram-positive anaerobic rod, is one of the most abundant bacteria identified in the periodontal pockets of periodontitis patients. There is a gap in our understanding of its pathogenicity and ability to interact with other periodontal pathogens. To evaluate the virulence potential of F. alocis and its ability to interact with Porphyromonas gingivalis W83, several clinical isolates of F. alocis were characterized. F. alocis showed nongingipain protease and sialidase activities. In silico analysis revealed the molecular relatedness of several virulence factors from F. alocis and P. gingivalis. In contrast to P. gingivalis, F. alocis was relatively resistant to oxidative stress and its growth was stimulated under those conditions. Biofilm formation was significantly increased in coculture. There was an increase in adherence and invasion of epithelial cells in coculture compared with P. gingivalis or F. alocis monocultures. In those epithelial cells, endocytic vesicle-mediated internalization was observed only during coculture. The F. alocis clinical isolate had an increased invasive capacity in coculture with P. gingivalis compared to the ATCC 35896 strain. In addition, there was variation in the proteomes of the clinical isolates compared to the ATCC 35896 strain. Hypothetical proteins and those known to be important virulence factors in other bacteria were identified. These results indicate that F. alocis has virulence properties that may enhance its ability to survive and persist in the periodontal pocket and may play an important role in infection-induced periodontal disease.

Aspects of eukaryotic-like signaling in Gram-positive cocci: a focus on virulence.

Living organisms adapt to the dynamic external environment for their survival. Environmental adaptation in prokaryotes is thought to be primarily accomplished by signaling events mediated by two-component systems, consisting of histidine kinases and response regulators. However, eukaryotic-like serine/threonine kinases (STKs) have recently been described to regulate growth, antibiotic resistance and virulence of pathogenic bacteria. This article summarizes the role of STKs and their cognate phosphatases (STPs) in Gram-positive cocci that cause invasive infections in humans. Given that a large number of inhibitors to eukaryotic STKs are approved for use in humans, understanding how serine/threonine phosphorylation regulates virulence and antibiotic resistance will be beneficial for the development of novel therapeutic strategies against bacterial infections.

Resistance to antibiotics in urinopathogenic bacteria isolated in patients attending Kenyatta University Health Clinic, Nairobi.

OBJECTIVE: To determine the aetiological bacterial agents of urinary tract infections, within communities in Kenyatta University, and current resistance levels to commonly available therapeutic agents. DESIGN: Cross-sectional survey research design. SETTING: Kenyatta University Health Services Clinic, Nairobi. SUBJECTS: Outpatients with symptoms of urinary tract infection within the six months study duration were observed. RESULTS: Females were particularly prone to have confirmed cases of UTI. Escherichia coli were the principle aetiological agent accounting for 61.7% of the isolates. Other bacterial agents were Enterobacter agglomerans (18.7%), Citrobacter diversus (4%), Klebsiella pneumoniae (3.3%), Proteus spp. (2.1%), Pseudomonas spp. (0.1%), Staphylococcus saprophyticus (9.3%), and Streptococcus feacalis (0.7%). Over 60% of the Gram negative bacterial isolates were resistant to cotrimoxazole and ampicillin, 39% resistant to augmentin and 25% were resistant to nalidixic acid. The ceftazidime was the most efficacious antimicrobial with an Escherichia coli resistance level of 2.2% (P=0.05). Resistance to nitrofuraintoin, gentamicin, cefuroxime, norfloxacin and ciprofloxacin was demonstrated in less than 15% of the bacterial isolates. CONCLUSION: The cephalosporins, fluoroquinolones, nitrofurantoin and gentamicin have good efficacy against the uropathogenic bacteria and may be good therapeutic choices when culture results are unavailable. High resistance levels exist against cotrimoxazole, ampicillin, augmentin, and nalidixic acid. These later antibiotics should therefore be used against the uropathogenic bacteria with caution.

Analysis of adherence, biofilm formation and cytotoxicity suggests a greater virulence potential of Gardnerella vaginalis relative to other bacterial-vaginosis-associated anaerobes.

Worldwide, bacterial vaginosis (BV) is the most common vaginal disorder in women of childbearing age. BV is characterized by a dramatic shift in the vaginal microflora, involving a relative decrease in lactobacilli, and a proliferation of anaerobes. In most cases of BV, the predominant bacterial species found is Gardnerella vaginalis. However, pure cultures of G. vaginalis do not always result in BV, and asymptomatic women are sometimes colonized with low numbers of G. vaginalis. Thus, there is controversy about whether G. vaginalis is an opportunistic pathogen and the causative agent of many cases of BV, or whether BV is a polymicrobial condition caused by the collective effects of an altered microbial flora. Recent studies of the biofilm-forming potential and cytotoxic activity of G. vaginalis have renewed interest in the virulence potential of this organism. In an effort to tease apart the aetiology of this disorder, we utilized in vitro assays to compare three virulence properties of G. vaginalis relative to other BV-associated anaerobes. We designed a viable assay to analyse bacterial adherence to vaginal epithelial cells, we compared biofilm-producing capacities, and we assessed cytotoxic activity. Of the BV-associated anaerobes tested, only G. vaginalis demonstrated all three virulence properties combined. This study suggests that G. vaginalis is more virulent than other BV-associated anaerobes, and that many of the bacterial species frequently isolated from BV may be relatively avirulent opportunists that colonize the vagina after G. vaginalis has initiated an infection.

Murdochiella asaccharolytica gen. nov., sp. nov., a Gram-stain-positive, anaerobic coccus isolated from human wound specimens.

Two strains of previously unknown Gram-stain-positive, anaerobic, coccus-shaped bacteria from human wound specimens were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies and distinguishable biochemical characteristics demonstrated that these two unknown strains, WAL 1855C(T) and WAL 2038E, are genotypically homogeneous and constitute a novel lineage within Clostridium cluster XIII. There was 13-14 % 16S rRNA gene sequence divergence between the novel strains and the most closely related species, Parvimonas micra, Finegoldia magna and species of Helcococcus. Based on the phenotypic and phylogenetic findings, a novel genus and species, Murdochiella asaccharolytica gen. nov., sp. nov., are proposed. Strain WAL 1855C(T) (=ATCC BAA-1631(T) =CCUG 55976(T)) is the type strain of Murdochiella asaccharolytica.

Fosfomycin for the treatment of infections caused by Gram-positive cocci with advanced antimicrobial drug resistance: a review of microbiological, animal and clinical studies.

BACKGROUND: The advancing antimicrobial drug resistance in Gram-positive cocci complicates the selection of appropriate therapy. The re-evaluation of older antibiotics may prove useful in expanding relevant therapeutic options. OBJECTIVE: We sought to evaluate fosfomycin for the treatment of infections caused by methicillin-resistant staphylococci, vancomycin-resistant enterococci, and penicillin-non-susceptible pneumococci. METHODS: We searched in PubMed, Scopus, and the Cochrane Library for studies evaluating the antimicrobial activity of fosfomycin against the above-mentioned pathogens, or the in vivo or clinical effectiveness of fosfomycin for the treatment of infections caused by these pathogens. RESULTS/CONCLUSIONS: As reported in the identified studies, the susceptibility rate of methicillin-resistant Staphylococcus aureus to fosfomycin was > or = 90% in 12/22, and 50-90% in 7/22 studies; the cumulative susceptibility rate was 87.9% (4240/4892 isolates). The cumulative susceptibility rate of vancomycin-resistant enterococci to fosfomycin was 30.3% (183/604 isolates), and that of penicillin-non-susceptible pneumococci was 87.2% (191/219 isolates). Clinical data show that fosfomycin, primarily in combination regimens, has been associated with clinical success in 28/29 (96.6%) cases of infection (mainly pneumonia, bacteremia, and meningitis) by fosfomycin-susceptible isolates of methicillin-resistant S. aureus. The above data support further research on the role of fosfomycin against infections caused by Gram-positive cocci with advanced antimicrobial drug resistance.

SufA - a bacterial enzyme that cleaves fibrinogen and blocks fibrin network formation.

Finegoldia magna is a member of the normal human bacterial flora on the skin and other non-sterile body surfaces, but this anaerobic coccus is also an important opportunistic pathogen. SufA was the first F. magna proteinase to be isolated and characterized. Many bacterial pathogens interfere with different steps of blood coagulation, and here we describe how purified SufA efficiently and specifically cleaves fibrinogen in human plasma. SufA is both secreted by F. magna and associated with the bacterial surface. Successful gene targeting has previously not been performed in anaerobic cocci, but in order to study the role of the SufA that is present at the bacterial surface, we constructed an F. magna mutant that expresses a truncated SufA lacking proteolytic activity. In contrast to wild-type bacteria that delayed the coagulation of human plasma, mutant bacteria had no such effect. Wild-type and mutant bacteria adhered to keratinocytes equally well, but in a plasma environment only wild-type bacteria blocked the formation of fibrin networks surrounding adherent bacteria. The effective cleavage of fibrinogen by SufA suggests that the interference with fibrin network formation represents an adaptive mechanism of F. magna with potential implications also for pathogenicity.

Crustin expression following bacterial injection and temperature change in the shore crab, Carcinus maenas.

The expression of carcinin, a crustin-type antimicrobial protein, in the crab, Carcinus maenas, was studied following in vivo challenge with Planococcus citreus, a Gram-positive bacterium known to be killed by the encoded protein. Real-time PCR analyses reveal that injection of P. citreus failed to elicit any significant changes in expression at 0-24h post-injection although there was a small, but significant, down-regulation at 84h in crabs held at 15 degrees C but not those at 5 or 20 degrees C. By contrast, un-injected crabs held at various temperatures between 5 and 20 degrees C, showed significantly up-regulated expression at 5 and at 20 but not 10 degrees C compared with controls at 15 degrees C. Thus expression of carcinin seems to be affected by temperature, especially when the animal is close to the edges of its physiologically tolerated thermal range.

Survival kinetics of faecal bacterial indicators in spent broiler litter composting.

AIMS: The objective of this study was to deduce and analyse equations that best describe the behaviour of faecal bacterial indicators and two decomposition parameters during broiler litter composting. Mathematical models were fitted and the order of rate equations were identified. METHODS AND RESULTS: The Levenburg-Marquardt algorithm was used to fit nonlinear mathematical models to total coliforms (TC), faecal coliforms (FC), Escherichia coli (EC), faecal enterococci (FE), organic-C and volatile solids reduction, VS Red, by the least squares procedure. The rate equations showed that TC, FC and EC reductions were expressed by second-order decay kinetics. FE reduction followed first-order decay. Temperature dependency of decomposition rate was effectively verified by applying empirically derived rate equations. CONCLUSIONS: The governing mathematical models critically compare the inactivation kinetics of faecal indicators. TC, FC and EC were rapidly destroyed while FE was more resistant. Temperature elevation, organic-C and VS Red dynamics provide an accurate understanding of composting-induced decomposition of the broiler litter. SIGNIFICANCE AND IMPACT OF THE STUDY: The conservative performance of FE with respect to the other indicators has been established. Hence, FE presents better opportunities to encompass the totality of the composting process in terms of attainment of hygiene efficacy compared with EC.

Planococcus donghaensis sp. nov., a starch-degrading bacterium isolated from the East Sea, South Korea.

A novel Gram-positive, aerobic bacterium, strain JH1T, was isolated from deep-sea sediment of the East Sea, South Korea, and identified by methods of polyphasic taxonomy. The strain was oxidase-positive, motile and coccus-shaped. The genomic DNA G+C content of strain JH1T was 47 mol%. The major fatty acid of strain JH1T was anteiso-C15:0 and the predominant menaquinones were MK-7 and MK-8. Similarity of the 16S rRNA gene sequence (1452 nt) of strain JH1T to those of species of the genera Planococcus and Planomicrobium was 96.0-98.2%. The signature nucleotides in the 16S rRNA gene sequence were compared with those of previously studied type strains of species in the genera Planococcus and Planomicrobium, and suggested that strain JH1T belongs to the genus Planococcus. In addition, phylogenetic analysis showed that strain JH1T was located within the cluster comprising Planococcus antarcticus and Planococcus kocurii. DNA-DNA hybridization showed that it had 9.3% genomic relatedness with Planococcus antarcticus DSM 14505T and 22.9% with Planococcus kocurii DSM 20747T. On the basis of the phenotypic, phylogenetic and genomic data, a novel species of the genus Planococcus, Planococcus donghaensis sp. nov., is proposed, with type strain JH1T (=KCTC 13050T=LMG 23779T).

TRAIL limits excessive host immune responses in bacterial meningitis.

Apart from potential roles in anti-tumor surveillance, the TNF-related apoptosis-inducing ligand (TRAIL) has important regulatory functions in the host immune response. We studied antiinflammatory effects of endogenous and recombinant TRAIL (rTRAIL) in experimental meningitis. Following intrathecal application of pneumococcal cell wall, a TLR2 ligand, we found prolonged inflammation, augmented clinical impairment, and increased apoptosis in the hippocampus of TRAIL(-/-) mice. Administration of rTRAIL into the subarachnoid space of TRAIL(-/-) mice or reconstitution of hematopoiesis with wild-type bone marrow cells reversed these effects, suggesting an autoregulatory role of TRAIL within the infiltrating leukocyte population. Importantly, intrathecal application of rTRAIL in wild-type mice with meningitis also decreased inflammation and apoptosis. Moreover, patients suffering from bacterial meningitis showed increased intrathecal synthesis of TRAIL. Our findings provide what we believe is the first evidence that TRAIL may act as a negative regulator of acute CNS inflammation. The ability of TRAIL to modify inflammatory responses and to reduce neuronal cell death in meningitis suggests that it may be used as a novel antiinflammatory agent in invasive infections.

Multiple-stress tolerance of ionizing radiation-resistant bacterial isolates obtained from various habitats: correlation between stresses.

Isolation of five ionizing radiation (IR)-resistant bacteria by screening of isolates from various habitats classified as common and stressed is reported. IR-resistant isolates exhibited varying degrees of resistance to gamma-radiation and were classified as highly and moderately radiation resistant. Resistance to ultraviolet (UV) radiation correlated well with gamma-radiation resistance, whereas a comparable desiccation resistance for all the highly and moderately radiation-resistant isolates was observed. However, salt tolerance failed to correlate with IR resistance, indicating a divergent evolution of the salt tolerance and radiation resistance. Characterization of isolates by the amplified rDNA restriction analysis profiling attested to the clustering of these isolates with their stress phenotype. 16S rRNA gene-based analysis of the isolates showed that the bacteria with similar-resistance physiologies clustered together and belonged to related genera. Hydrogen peroxide resistance and mitomycin survival patterns of the isolates indicated the roles of oxidative-stress tolerance in desiccation survival and recombination repair in higher radiation resistance, respectively.

Oenococcus kitaharae sp. nov., a non-acidophilic and non-malolactic-fermenting oenococcus isolated from a composting distilled shochu residue.

Six strains of lactic acid bacteria were isolated in Japan from a composting distilled shochu residue. The six isolates grew poorly on MRS agar and slowly in MRS broth. The 16S rRNA gene sequences did not show high levels of similarity to those of the recognized species of lactic acid bacteria, and formed a subcluster within the cluster comprising obligately heterofermentative lactic acid bacteria closely related to Oenococcus oeni. The levels of DNA-DNA relatedness revealed that the isolates belonged to the same taxon and were genetically separate from O. oeni. Furthermore, various phenotypic characteristics such as the optimum pH for growth, malolactic fermentation and resistance to 10 % ethanol revealed that the isolates are distinguishable from O. oeni. On the basis of their phylogenetic and phenotypic characteristics, the isolates represent a novel species, for which the name Oenococcus kitaharae sp. nov. is proposed. The type strain is NRIC 0645(T) (=JCM 13282(T)=DSM 17330(T)).