Determining the need for additional training among hospital infection-control workforce - results from a multicentric survey within the multiresistance network of southern Lower Saxony (MRNS), Germany.

Infection-control nurses (ICN) and infection-control link physicians (ICLP) are both responsible for infection prevention practices in hospitals. However, their topic-specific education levels and extent of engagement in infection-control issues are diverse, creating potential needs for additional training. We aimed at determining the potential need for additional training in infection-control among ICN, ICLP and medical Chief Executive Officers (CEO) in hospitals of the Multiresistance Network of southern Lower Saxony (MRNS), via structured surveys (n=48; 55.1%). Our data suggest that the majority of ICN as well as ICLP have unmet needs for consultation and training on the topics of hospital hygiene and infection control. We observed a higher need for advice/additional information among ICLP than among ICN, e.g., concerning outbreaks (p=0.032), multidrug resistance (p=0.005) or antimicrobial stewardship (p=0.020). Therefore, future training programs might require targeting workforce-specific topics as part of their curricula. Furthermore, the improvement of the knowledge of ICN and ICLP for the implementation of infection control could contribute to improved prevention of the transmission of infectious diseases.

Infection surveillance measures during the COVID-19 pandemic in Germany.

Introduction: To address the question as to which infection surveillance measures are used during the ongoing COVID-19 pandemic in Germany and how they differ from pre-existing approaches. Methods: In accordance with the systematic approach of a scoping review, a literature search was conducted in national and international medical literature databases using a search string. The search in the databases was limited to the period from 01.01.2000 to 15.11.2020 and has been subsequently completed by hand search until 08.03.2021. A hand search, even beyond 15.11.2020, seemed necessary and reasonable, since due to the dynamics of the ongoing COVID-19 pandemic, a large number of articles and regulations are being published very quickly at short notice. Results: The literature search resulted in the following number of hits in the databases listed below: PubMed: 165 articlesCochrane: 1 review and 35 studiesWeb of Science: 217 articlesRobert Koch Institute: 49 articles Thus, a total of 467 hits were identified, with a total of 124 hits being duplicates. From these, 138 articles were considered relevant to the COVID-19 infection surveillance situation in Germany based on established criteria. After reading the full texts, 92 articles and websites were ultimately included in the scoping review. Discussion: Many of the lessons learned from previous outbreaks seem to have been implemented in the infection surveillance measures during the ongoing COVID-19 pandemic in Germany. Most of the changes compared with previous measures were based on technological streamlining of existing procedures and changes and more inclusion of the population in different infection surveillance measures.

Discrimination of Human Pathogen Clostridium Species Especially of the Heterogeneous C. sporogenes and C. botulinum by MALDI-TOF Mass Spectrometry.

Clostridium species cause several local and systemic diseases. Conventional identification of these microorganisms is in part laborious, not always reliable, time consuming or does not always distinguish different species, i.e., C. botulinum and C. sporogenes. All in, there is a high interest to find out a reliable, powerful and rapid method to identify Clostridium spp. not only on genus but also on species level. The aim of the present study was to identify Clostridium spp. strains and also to find differences and metabolic groups of C. botulinum by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS). A total of 123 strains of Clostridium spp. (C. botulinum, n = 40, C. difficile, n = 11, C. tetani, n = 11, C. sordellii, n = 20, C. sporogenes, n = 18, C. innocuum, n = 10, C. perfringens, n = 13) were analyzed by MALDI-TOF MS in combination with methods of multivariate statistical analysis. MALDI-TOF MS analysis in combination with methods of multivariate statistical analysis was able to discriminate between the different tested Clostridium spp., even between species which are closely related and difficult to differentiate by traditional methods, i.e., C. sporogenes and C. botulinum. Furthermore, the method was able to separate the different metabolic groups of C. botulinum. Especially, E gene-positive C. botulinum strains are clearly distinguishable from the other species but also from those producing other toxin types. Thus, MALDI-TOF MS represents a reliable and above all quick method for identification of cultivated Clostridium species.

Influence of oral bacteria on adhesion of Streptococcus mutans and Streptococcus sanguinis to dental materials.

In this study, the effect of bacterial multispecies communities on the adhesion of Streptococcus mutans and Streptococcus sanguinis to dental restorative material was investigated. The saliva-coated specimens of zirconia and composite were incubated with the following combinations: single species, S. mutans or S. sanguinis; two species, single species combined with other oral streptococci; multiple species, combination of Actinomyces naeslundii, Fusobacterium nucleatum, and Prevotella ssp.; and the two-species combinations. The adherent bacteria were counted after plating of serial dilutions. Effects of material and bacteria on adhesion of S. mutans and S. sanguinis were evaluated with multiple linear regression analyses. No significant differences between the materials regarding the adhesion of S. mutans and S. sanguinis were observed. The adhesion of S. mutans was negatively influenced by the presence of other streptococci. Enhancing effects (610.6%) were seen in the presence of Prevotella intermedia. The adhesion of S. sanguinis decreased in the presence of other bacteria, except F. nucleatum (increase of 717.4%). Significant inhibitory effects were detected in the presence of S. mutans and A. naeslundii (reduction of 95.9% and 78.5%, respectively). The results of this study suggest that adhesion of both types of streptococci to restorative materials is influenced by various bacterial interactions.

Identification of viridans streptococci With Matrix-Assisted Laser Desorption & Ionization Time-of-flight Mass Spectrometry by an In-house Method and a Commercially Available System.

Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All inhouse measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chi-square test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species.

The importance of growth kinetic analysis in determining bacterial susceptibility against antibiotics and silver nanoparticles.

Routine antibiotics susceptibility testing still relies on standardized cultivation-based analyses, including measurement of inhibition zones in conventional agar diffusion tests and endpoint turbidity-based measurements. Here, we demonstrate that common off-line monitoring and endpoint determination after 18-24 h could be insufficient for reliable growth-dependent evaluation of antibiotic susceptibility. Different minimal inhibitory concentrations were obtained in 20- and 48 h microdilution plate tests using an Enterococcus faecium clinical isolate (strain UKI-MB07) as a model organism. Hence, we used an on-line kinetic assay for simultaneous cultivation and time-resolved growth analysis in a 96-well format instead of off-line susceptibility testing. Growth of the Enterococcus test organism was delayed up to 30 h in the presence of 0.25 µg mL(-1) of vancomycin and 8 µg mL(-1) of fosfomycin, after which pronounced growth was observed. Despite the delayed onset of growth, treatment with fosfomycin, daptomycin, fusidic acid, cefoxitin, or gentamicin resulted in higher maximum growth rates and/or higher final optical density values compared with antibiotic-free controls, indicating that growth stimulation and hormetic effects may occur with extended exposure to sublethal antibiotic concentrations. Whereas neither maximum growth rate nor final cell density correlated with antibiotic concentration, the lag phase duration for some antibiotics was a more meaningful indicator of dose-dependent growth inhibition. Our results also reveal that non-temporal growth profiles are only of limited value for cultivation-based antimicrobial silver nanoparticle susceptibility testing. The exposure to Ag(0) nanoparticles led to plasma membrane damage in a concentration-dependent manner and induced oxidative stress in Enterococcus faecium UKI-MB07, as shown by intracellular ROS accumulation.

Monoclonal antibodies against all known variants of EspA: development of a simple diagnostic test for enteropathogenic Escherichia coli based on a key virulence factor.

Enteropathogenic Escherichia coli (EPEC) are a major cause of infant diarrhoea in developing countries and a significant public health issue in industrialized countries. Currently there are no simple tests available for the diagnosis of EPEC. Serology of O-antigens is widely used routinely in many laboratories throughout the world, even though it has been known for many years to be an unreliable indicator of EPEC virulence. We have developed a simple, low-cost immunodiagnostic test based on the EspA filament, an essential virulence factor of EPEC and the related enterohaemorrhagic E. coli (EHEC). Using recombinant proteins of the five major variants of EspA as immunogens, we raised a panel of three monoclonal antibodies in mice that detects all variants of the native target in bacterial cultures. The antibodies proved suitable for application in sandwich-type assays, including ELISA and lateral flow immunoassays (LFI). Prototypes for both assays were specific for EPEC and EHEC strains when tested against a panel of control micro-organisms. We have also developed a simple, affordable culture medium, A/E medium, which optimizes expression of EspA allowing improved sensitivity of detection compared with standard Dulbecco's modified Eagle's medium. Together these reagents form the basis of robust, informative tests for EPEC for use especially in developing countries but also for routine screening in any clinical laboratory.

Inguinal skin colonization with multidrug-resistant bacteria among residents of elderly care facilities: frequency, persistence, molecular analysis and clinical impact.

Frequency, persistence and molecular characteristics of multidrug resistant bacteria colonizing inhabitants of long term care facilities are topics of current concern. We performed a point-prevalence survey of 402 residents in 7 elderly care facilities in Berlin, Germany. Inguinal swabs were analyzed for the presence of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), and multidrug-resistant gram-negative bacteria. Three and six months following the initial investigation, all colonized residents were sampled again and the occurrence of intercurrent infections, hospital admissions and use of antimicrobials were registered. Genetic relatedness of the bacteria was investigated using multi-locus sequence typing (MLST), spa-typing and SmaI/XbaI-macrorestriction analysis. 33 (8.2%) residents were skin-colonized with multidrug-resistant bacteria. MRSA were found in 19 (4.7%) and ESBL-producing Enterobacteriaceae in 16 residents (3.98%). Independent risk factors for colonization with multidrug-resistant bacteria were a high level of care and the presence of chronic wounds. A large proportion of the observed bacteria persisted up to six months and showed a high degree of inter-individual diversity. Outcome analysis revealed that infections tend to occur slightly more often in residents colonized by multiresistant pathogens. We assume that a perceptible population of residents in nursing homes is at risk for individual colonization with multidrug-resistant bacteria as well as healthcare associated infections.

72 hours standby time of wet-primed cardiopulmonary bypass circuits: a microbiological quality assurance study.

In a microbiological sample study of 15 wet-primed cardiopulmonary bypass circuits in standby mode for 72 hours under regular clinical conditions, no contamination of the priming fluid or the connectors could be detected. Hand contact surfaces of the machines demonstrated environmental microorganisms. These findings indicate the safe use of primed cardiopulmonary bypass circuits in standby mode for 72 hours. A surface disinfection of hand contact surfaces immediately before use is recommended.

Adult patients with nosocomial pneumonia: epidemiology, diagnosis, and treatment.

BACKGROUND: Nosocomial pneumonia is among the most common types of infection in hospitalized patients. The increasing prevalence of multi-drug resistant organisms (MDROs) in recent years points to the need for an up-to-date clinical guideline. METHODS: An interdisciplinary S3 guideline was created on the basis of a systematic literature review in the PubMed and Cochrane Library databases, with assessment and grading of the evidence according to the GRADE system. RESULTS: 9097 abstracts and 808 articles were screened in full text, and 22 recommendations were issued. It is recommended that any antimicrobial treatment should be preceded by a microbiological diagnostic evaluation with cultures of blood and respiratory samples. The diagnosis of nosocomial pneumonia should be suspected in any patient with a new or worsened pulmonary infiltrate who meets any two of the following three criteria: leucocyte count above 10,000 or below 4000/µL, temperature above 38.3°C, and/or the presence of purulent respiratory secretions. The initially calculated antimicrobial treatment should be begun without delay; it should be oriented to the locally prevailing resistance pattern, and its intensity should be a function of the risk of infection with MDROs. The initial treatment should be combination therapy if there is a high risk of MDRO infection and/or if the patient is in septic shock. In the new guideline, emphasis is laid on a strict de-escalation concept. In particular, antimicrobial treatment usually should not be continued for longer than eight days. CONCLUSION: The new guideline's recommendations are intended to encourage rational use of antibiotics, so that antimicrobial treatment will be highly effective while the unnecessary selection of multi-drug-resistant organisms will be avoided.

Discrimination of Enterobacteriaceae and Non-fermenting Gram Negative Bacilli by MALDI-TOF Mass Spectrometry.

Discrimination of Enterobacteriaceae and Non-fermenting Gram Negative Bacilli by MALDI-TOF Mass Spectrometry Matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) has proven to be an effective identification tool in medical microbiology. Discrimination to subspecies or serovar level has been found to be challenging using commercially available identification software. By forming our own reference database and using alternative analysis methods, we could reliably identify all implemented Enterobacteriaceae and non-fermenting gram negative bacilli by MALDI-TOF MS and even succeeded to distinguish Shigella sonnei from Escherichia coli (E. coli) and Salmonella enterica spp. enterica serovar Enteritidis from Salmonella enterica spp. enterica serovar Typhimurium. Furthermore, the method showed the ability to separate Enterohemorrhagic E. coli (EHEC) and Enteropathogenic E. coli (EPEC) from non-enteropathogenic E. coli.

In vitro activities of levofloxacin, gatifloxacin, moxifloxacin and garenoxacin against Bacteroides fragilis strains evaluated by kill kinetics.

This study was designed to investigate the killing activity of levofloxacin, gatifloxacin, moxifloxacin and garenoxacin against 12 Bacteroides fragilis strains by kill kinetics over time. MIC values were determined by Etest and by agar dilution. B. fragilis strains were divided according to their MIC values into two groups: one group with strains with MIC <8.0 µg ml(-1) and one group with strains with MIC ≥ 8.0 µg ml(-1). For kill kinetics over time, the strains with MIC <8.0 µg ml(-1) were incubated with the antibiotics at 0.5, 1, 2 and 4 times their MIC values. The strains with MIC ≥ 8.0 µg ml(-1) were incubated with 0.5, 1, 2, and 4 times the maximum achievable concentrations of the antibiotics in human plasma (Cmax). Among the strains with MIC <8.0 µg ml(-1) levofloxacin and gatifloxacin showed equal efficacy. The growth of the strains with MIC ≥ 8.0 µg ml(-1) was barely affected by levofloxacin, while gatifloxacin had bactericidal action when concentrations of 4 × C max were used. Moxifloxacin was more effective against both groups of strains compared with levofloxacin and gatifloxacin. Garenoxacin was the most active agent against all strains investigated. Due to the varying in vitro activity of the quinolones against obligate anaerobes the treatment with quinolones of patients with intra-abdominal infections needs intensive scrutiny.

Association of periodontitis with increased colonization by Prevotella nigrescens.

AIM: To estimate differences in the prevalence of Prevotella intermedia and Prevotella nigrescens in the subgingival plaque of patients with periodontitis (including aggressive and advanced chronic periodontitis) compared to healthy controls, and to search for significant associations with clinical status. METHODS: Sixteen patients and 16 healthy controls were enrolled in this study. Interproximal plaque index, oral hygiene index, gingival index, bleeding on probing, probing depth, and clinical attachment level were recorded. Samples of subgingival plaque were taken with paper points from four teeth of each individual and immediately plated on appropriate supplemented Columbia agar. Black pigmented colonies were identified with the Rapid ID32 A system, and further differentiated using matrix-assisted laser desorption ionization-time of flight mass spectrometry. For the statistical analysis, chi-squared test and the Mann-Whitney U-test were used. RESULTS: Prevotella nigrescens was isolated from 10 patients and three controls, while P. intermedia was isolated from only two patients. P. nigrescens was found more frequently in the subgingival plaque of patients (P = 0.029), and was significantly associated with high values of clinical indices (P ≤ 0.025). Significant differences for P. intermedia were not found. CONCLUSIONS: Periodontitis seems to be associated with increased colonization with P. nigrescens. Whether or not it is a major pathogen needs to be determined.

A step towards the discrimination of beta-lactamase-producing clinical isolates of Enterobacteriaceae and Pseudomonas aeruginosa by MALDI-TOF mass spectrometry.

BACKGROUND: Matrix-Assisted Laser-Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) has already proven to be a powerful tool for species identification in microbiological laboratories. As adequate and rapid screening methods for antibiotic resistance are crucially needed, the present study investigated the discrimination potential of MALDI-TOF MS among extended-spectrum-beta-lactamase (ESBL) or metallo-beta-lactamases- (MBL) producing and the nonproducing strains of Escherichia coli (n=19), Klebsiella pneumoniae (n=19), and Pseudomonas aeruginosa (n=38), respectively. MATERIAL/METHODS: We used a MALDI-TOF MS protocol, usually applied for species identification, in order to integrate a screening method for beta-lactamases into the routine species identification workflow. The acquired spectra were analyzed by visual inspection, statistical similarity analysis and support vector machine (SVM) classification algorithms. RESULTS: Neither visual inspection nor mathematical similarity analysis allowed discrimination between spectra of beta-lactamase-producing and the nonproducing strains, but classification within a species by SVM-based algorithms could achieve a correct classification rate of up to 70%. CONCLUSIONS: This shows that MALDI-TOF MS has definite potential to discriminate antibiotic-resistant strains due to ESBL and MBL production from nonproducing strains, but this performance is not yet sufficiently reliable for routine microbiological diagnostics.

In vitro activities of clindamycin, imipenem, metronidazole, and piperacillin-tazobactam against susceptible and resistant isolates of Bacteroides fragilis evaluated by kill kinetics.

The aim of the present study was to investigate the activities of clindamycin, imipenem, metronidazole, and piperacillin-tazobactam against 12 Bacteroides fragilis isolates (resistant and susceptible strains) by kill kinetics over 24 h. In contrast to the other antimicrobial agents, clindamycin did not affect strains with MICs of >8.0 µg/ml. For those strains with MICs of ≤ 8.0 µg/ml, all employed antibiotics except clindamycin showed nearly bactericidal activity. Metronidazole proved to be the most active antimicrobial agent.

Microbial profile of patients with periodontitis compared with healthy subjects.

OBJECTIVE: To define and compare the microbiologic profile of subgingival plaque in German patients with periodontitis (including aggressive and advanced chronic periodontitis) and healthy subjects and to determine significant association between isolates and clinical status. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia are major periodontal pathogens, though it is recognized that other species may also contribute to the pathogenesis of periodontal disease. METHOD AND MATERIALS: Thirty-three patients with clinical and radiologic proof of aggressive and advanced chronic periodontitis and 20 healthy subjects were enrolled in this study. Clinical indices were recorded as six-point measurements on each tooth. Samples of the subgingival plaque were taken with paper points from four teeth of each individual. The samples were divided into two parts. One part was immediately cultivated, while the other one was stored at -20°C until analyzed by real-time polymerase chain reaction. RESULTS: A total of 284 anaerobic isolates (224 isolates from patients and 60 isolates from healthy controls) were identified. Forty different anaerobic species were isolated, with a mean of 6.78 species per patient and 3 species per healthy control subject. Significant differences in prevalence (after adjusting for multiple comparisons, P < .001) were found for Prevotella intermedia and nigrescens, Fusobacterium nucleatum, T forsythia, Treponema denticola, and Veillonella parvula. The first four species were associated with the aggressive periodontitis group and V parvula with healthy subjects. CONCLUSION: When compared with healthy controls, the microbial profile of subgingival plaque from periodontitis was found to contain known periodontal pathogens with a different prevalence to that described in earlier studies. P intermedia/nigrescens, F nucleatum, T forsythia, and T denticola have been found in lower proportions and small quantities in healthy subjects.

Phenotypic detection of broad-spectrum beta-lactamases in microbiological practice.

BACKGROUND: Enterobacteriaceae producing ESBL and AmpC enzymes can be associated with failure of antibiotic therapy and related morbidity and mortality. Their routine detection in microbiology laboratories is still a problem. The aim of this study was to compare the sensitivity of selected phenotypic methods. MATERIAL/METHODS: A total of 106 strains of the Enterobacteriaceae family were tested, in which molecular biology methods confirmed the presence of genes encoding ESBL or AmpC. In ESBL-positive strains, the sensitivity of the ESBL Etest (AB Biodisk) and a modified double-disk synergy test (DDST) were evaluated. AmpC strains were tested by a modified AmpC disk method using 3-aminophenylboronic acid. For simultaneous detection of ESBL and AmpC, the microdilution method with a modified set of antimicrobial agents was used. RESULTS: The sensitivity of the ESBL Etest was 95%; the modified DDST yielded 100% sensitivity for ESBL producers and the AmpC test correctly detected 95% of AmpC-positive strains. The sensitivity of the modified microdilution method was 87% and 95% for ESBL and AmpC beta lactamases, respectively. CONCLUSIONS: The detection of ESBL and AmpC beta lactamases should be based on specific phenotypic methods such as the modified DDST, ESBL Etest, AmpC disk test and the modified microdilution method.

Challenging the problem of clostridial identification with matrix-assisted laser desorption and ionization-time-of-flight mass spectrometry (MALDI-TOF MS).

Diverse techniques were applied to effect the identification and classification of isolated clostridial strains. Nevertheless, the correct identification of clostridial strains remains a laborious, time-consuming task which entails a not inconsiderable degree of expertise. In addition to this, traditional methods based on the metabolic properties of the bacteria require rigorously standardized media and growth conditions to assure the attainment of reproducible results. Although DNA-based methods, like the PCR of a species specific gene, are known to yield precise and reproducible results, their degree of effectivity is circumscribed by the fact that even the incidence of a toxin encoding gene is not necessarily linked to nor consequently indicative of the presence of an infectious disease. Moreover, most of these methods postulate an initial assumption concerning the expected bacterial species involved before the choice of PCR primer for use can be made. Consequently, the scope of these methods is restricted to that of targeted analyses. The 16S rDNA sequencing which is assumed to be the gold standard for bacterial classification having the unequivocal advantage of being capable of determining even uncultivable bacteria is nonetheless a time-consuming and costly technique. In the present study we describe the utilization of matrix-assisted laser desorption and ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool to distinguish between various clostridial species. Total 64 clostridial strains of 31 different species each displayed a mass spectrum unique to the strain involved, to the effect that it was also possible not only to differentiate between the strains examined, but also to establish to which species the individual strains belonged to. Starting with a single colony it was possible to correctly identify a Clostridium species within minutes. It was even possible to identify species which are normally difficult to differentiate by traditional methods, such as C. chauvoei and C. septicum. With the results obtained we were able to assemble a dendrogram of the Clostridium species which showed considerable similarities to dendrograms based upon 16S rDNA sequencing data. To conclude, our findings indicate that, inasmuch as the MALDI-TOF MS technology employed is based on a high-quality reference database, it may serve as an effective tool for the swift and reliable identification and classification of Clostridia.

Periodontitis is associated with a loss of colonization by Streptococcus sanguinis.

The aim of this study was to estimate differences in the prevalence of oral streptococcal species in the subgingival biofilm of patients with aggressive periodontitis and of healthy controls. Thirty-three patients with clinical and radiological proof of aggressive periodontitis and 20 healthy subjects were enrolled in this study. Clinical indices were recorded in a six-point measurement per tooth. Samples of the subgingival biofilm were taken with paper points from four teeth of each individual. Alpha- and non-haemolytic, small and catalase-negative colonies were biochemically identified using a rapid ID 32 STREP system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A total of 118 strains of oral streptococci (11 species) were identified and Streptococcus sanguinis was found significantly more often in healthy subjects (P=0.001). Conversely, the absence of S. sanguinis was associated with high values of clinical indices (P=0.001-0.002). Aggressive periodontitis seems to be associated with a loss of colonization of S. sanguinis. Whether or not S. sanguinis offers protection against aggressive periodontitis needs to be determined. Otherwise, there were no significant differences in the distribution of oral streptococcal species in patients and healthy subjects.