Independent associations of vitamin D metabolites with anemia in patients referred to coronary angiography: the LURIC study

PURPOSE

Anemia and vitamin D deficiency are both frequent in adult patients. Whether low vitamin D metabolite levels are an independent risk factor for different subtypes of anemia remains to be studied in detail.

METHODS

In 3299 patients referred for coronary angiography, we investigated the association of 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25(OH)₂D] with anemia [hemoglobin (Hb) <12.5 g/dl] of specific subtypes.

RESULTS

Compared with patients with 25OHD levels in the adequate range (50-125 nmol/l), patients with deficient 25OHD concentrations (<30 nmol/l; 33.6 % of patients) had 0.6 g/dl lower Hb levels. Hb values were 1.3 g/dl lower in patients with 1,25(OH)₂D levels <40 pmol/l (5.4 % of patients), compared with patients in the highest 1,25(OH)₂D category (>70 pmol/l). Of the participants, 16.7 % met the criteria for anemia. In multivariate-adjusted regression analyses, the odds ratios for anemia in the lowest 25OHD and 1,25(OH)₂D categories were 1.52 (95 % CI 1.15-2.02) and 3.59 (95 % CI 2.33-5.52), compared with patients with 25OHD levels in the adequate range and patients with 1,25(OH)₂D levels >70 pmol/l. The probability of anemia was highest in patients with combined 25OHD and 1,25(OH)₂D deficiency [multivariable-adjusted odds ratio 5.11 (95 % CI 2.66-9.81)]. Patients with anemia of chronic kidney disease had the highest prevalence of 25OHD deficiency and 1,25(OH)₂D concentrations of <40 pmol/l.

CONCLUSIONS

Low 25OHD and 1,25(OH)₂D concentrations are independently associated with anemia. Patients with poor kidney function are most affected. Interventional trials are warranted to prove whether administration of plain or activated vitamin D can prevent anemia.

BD GeneOhm-MRSA assay for detection of methicillin-resistant Staphylococcus aureus directly in nasal and non-nasal swab specimens from haematologic patients

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are responsible for rising health care costs and have a high attribution to mortality. Reliable and rapid detection of MRSA carriage is essential. Real-time PCR allows an early detection of MRSA colonization within 2 h. By using the BD GeneOhm-MRSA assay we analysed directly swabs of different sampling sites and compared the assay with culture method. One thousand one hundred and sixty samples from 129 patients in Magdeburg were examined. Of the samples, 8 (0.69%) or 1117 (96.3%) were tested equally positive or negative by both methods whereas 16 (1.38%) specimens were MRSA positive only by the GeneOhm-MRSA assay and 6 (0.52%) were MRSA positive only by culture method. Thirteen samples (1.12%), which are culture negative, were unresolved by the GeneOhm-MRSA. With regard to the patients, seven were detected as MRSA carriers only by the GeneOhm-MRSA while one patient was tested positive for MRSA only by culture. Assuming 100% correct results by the culture method, sensitivity and specificity of GeneOhm-MRSA assay could be calculated as 84.4% and 96.1% for nasal swabs, 78.7% and 96.9% for all swabs under study, and 94.8% and 99.5% when focussed on patients. PPV and NPV were 70.3% and 98% for all specimens together, respectively. BD GeneOhm-MRSA assay is a sensitive test for the detection of MRSA colonization from swab specimens without the need for an initial culture, but should always be performed in parallel to the culture method for comparison reasons. Furthermore, our results indicate that in addition swabs taken from different body sites were successfully analysed by the BD GeneOhm-MRSA assay. However, we conclude that the PCR assay might not be a preferred tool for screening in haematologic patients with low MRSA rate; for screening haematologic patients, the culture method is sufficient enough.

[Spectrum of microbial colonisation and resistance of a surgical ICU in a systematic comparison of the 10-year time period 1996-2005 using routine microbiological testing]

INTRODUCTION

Knowledge on potentially pathogenic microbes including characteristics of their antibiotic resistance in septic patients as well as on the ward- and department-specific microbial spectrum can be considered essential for an efficient initiation of an adequate antimicrobial treatment, which turns out to become pivotal for patient outcome. Permanent changes in microbial patterns and antibiotic resistance can only be identified by a continuous investigation of various microbiological specimens.

AIM

Based on the retrospective evaluation of prospectively collected data on microbiological investigations of the surgical ICU in 1996, 2002, 2004 and 2005, the short- and long-term changes by trend of microbial spectrum and antibiotic resistance following reorganisation and restructuring of the University Hospital from the more traditional pavillon-based system to a multidisciplinary complex building in 2003 were investigated.

MATERIAL AND METHODS

Twice a week, routine microbiological testing of blood and urinary cultures as well as swabs from wound areas and endotracheal swabs were initiated in septic patients (suspect, manifestation) or in case of their clinical impairment. The microbial spectrum was sub-divided according to Gram-staining (Gram-positive/ -negative), various species and fungi with descriptive absolute and relative data values. -Various groups and time periods were statistically compared using χ² test as appropriate. P values < 0.05 were considered statistically significant.

RESULTS

In total (n (Total) = 4 899), microbiological testing resulted in the detection of microbes in 699 and 833 blood and urinary cultures (14.3 % and 17 %, respectively) as well as 1 232 wound swabs (25.1 %) together with 2 135 samples from the endotracheal sites (43.6 %). During the short- (2002 vs. 2004) and long-term analyses (1996 vs. 2005), the proportion of Gram-positive microbes increased. Al-though Gram-positive bacteria can be considered the most frequent microbes for bacteriemia, there was a shift onto urinary and wound infections as well as pneumonias through the observation period. Despite the decreasing incidence of Enterococcus and the consistent proportion of MRSA, the increase of resistant Enterococcus strains (0 % vs. 43.2 %; P < 0.05) is critical. However, in the Gram-negative microbial spectrum there was an increase of the bacteraemia rate but a fall of the detection rate in wound and endotracheal swabs. In parallel, an increase of the detection rate of E. coli in blood (6.5 % vs. 45.5 %; P < 0.05) and endotracheal swabs (9.2 % vs. 16.2 %; P < 0.05) is associated with an increase of multiresistant Enterobacteriaceae strains (0 % vs. 30.7 %; P < 0.05). The portion of multiresistant strains of Pseudomonas with 31 % stayed the same through the 10-year time period. While Candida-based colonisation showed a decreased incidence (25 % vs. 15 %; P < 0.05) during the whole investigation period, there was a relative rise in the frequency of candidemia.

CONCLUSION

ICU relocation from the pavillon-based system to a new complex clinic building was not associated with any significant alteration of the microbial spectrum on the surgical ICU. Increasing incidences of resistant Enterococcus and Gram-negative problematic microbes may indicate a general spread of multi-resistant microbes under the steady selecting pressure of a not always adequately initiated antibiotic / antimicrobial therapeutic regimen and underline the required but specific and selected microbiological screening.

[Microbial spectrum in surgical infections based on a microbiological routine monitoring over the 10-year period from 1995 to 2004]

INTRODUCTION

Infections belong to the most frequent and dangerous complications in surgery. In addition to the medical aspects, these infections may have a significant impact on the costs and the overall economic efficacy of medical treatment under the present circumstances of DRG.

AIM

A systematic, prospective collection and retrospective evaluation of all consecutive microbiological analyses in specimens from the 3 medical floors (except the ICU) of the Department of Surgery at the University Hospital, Magdeburg (Germany) was performed in 1995, 2002 and 2004 to characterise i) the 10-year course (1995 vs. 2004) and ii) possible alterations due to changes in the previously existing pavillon system (2002 vs. 2004).

PATIENTS AND METHODS

The microbial spectrum was determined in the 3 most frequent specimen types (blood culture, urine sample, wound swab) including number and percentage of the single microbial groups such as gram-positive and gram-negative Enterobacteriae, pseudomonades and fungi. In addition, the antibiotic resistance of selected microbes was analysed. The primary data were registered in a database and evaluated according to the various questions.

RESULTS

Overall, 2 979 microbes were identified in 1995 (2002, 1 338; 2004, 915). On comparing 1995 with 2004, the percentage of gram-positive microbes did not change (50.5 vs. 50.3 %), whereas the percentage of gram-negative enterobacteriae increased: 37.4 vs. 29.1 %. The percentage of detected fungi was only half of that in 1995: 6.2 vs. 12.2 %. In blood cultures, the Klebsiella spp. portion in the group of gram-negative enterobacteriae distinctly increased: 29.6 vs. 18.8 %. While in 2004, MRSA was found in 24.4 % of all detected Staphylococcus aureus strains in swab specimens amounting to a considerable increase compared to 2002 (17.6 %), in 1995, MRSA was not isolated at all in this material. In the fungi group, there was a decrease of the Candida albicans portion vs. the non-C. albicans strains, which was associated with an increasing resistance against fluconazol. This requires treatment with caspofungin, resulting in increased costs vs. those necessary for fluconazol treatment.

CONCLUSION

A systematic, microbiological, long-term monitoring is indispensable since i) microbial detection plays a growing role to include the various types of infections in the spectrum of diagnosis for DRG, ii) alterations of the microbial spectrum can only be detected through a long-term observation period (MRSA, fungi) and iii) simultaneously developing antibiotic resistances can be determined (MRSA, ESBL strains in Enterobacteriae, fluconazol-resistant fungi). This can have an infectious, biological, hygienic and cost-determining as well as a health policy relevance among others, with considerable additional costs (e. g., isolation of patients, cost-intensive substitutional medication) with necessary reimbursement.

Comparison of the performance of the rapid antigen detection actim Influenza A&B test and RT-PCR in different respiratory specimens

Nowadays, influenza antigen detection test kits are used most frequently to detect influenza A or B virus to establish the diagnosis of influenza rapidly and initiate appropriate therapy. This study was conducted to evaluate the performance of the actim Influenza A&B test (Medix Biochemica). Overall, 473 respiratory specimens were analysed in the actim Influenza A&B test and the results were compared with those from an RT-PCR assay; 461 of these samples originated from paediatric patients aged 7 weeks to 6.5 years either with influenza-related symptoms or from the intensive care unit, and 12 samples originated from adults with underlying lung or haematological diseases. Diagnosis of influenza A or B virus could be established using the actim Influenza A&B test (9/473 samples for influenza A virus and 6/473 for influenza B virus). RT-PCR revealed 23 patients with influenza virus (13/473 for influenza A virus and 10/473 for influenza B virus). The sensitivity and specificity of the actim Influenza A&B test were 65 and 100 % compared with the RT-PCR assay. However, 32 external quality assessment samples containing seven different strains of influenza A subtypes H1N1 and H3N2 and the avian H5N1 were detected correctly by the actim Influenza A&B test. No cross-reactivity to a range of bacterial, fungal and other viral pathogens was observed. In conclusion, the actim Influenza A&B test is reliable for positive results due to its high specificity. Nevertheless, negative results from this test need to be confirmed by a more sensitive assay because of the low sensitivity observed with diagnostic samples.

Influence of a pre-operative enteral supplement on functional activities of peripheral leukocytes from patients with major surgery

Following severe trauma or major surgery patients develop functional alterations of host defense mechanisms which contribute an enhanced susceptibility towards microbial infections. Several studies have demonstrated that a specialized nutritional regimen may improve immune functions. We analyzed leukocyte functions from 40 patients undergoing major upper gastrointestinal surgery in a randomized placebo-controlled double-blind study. Patients were divided into two groups, one received 5 days pre-operatively an orally given experimental supplement enriched with omega-3-fatty acids, arginine, and ribonucleic acid (RNA), the other an isocaloric, control supplement. The experimental group generated significantly more leukotriene B(5) (LTB(5)) as compared to the control group. In contrast, the capacity to generate leukotriene B(4) (LTB(4)) as well as the synthesis of interleukin-8 (IL-8) was not significantly different in both groups. Additionally, lymphocyte/monocyte proliferation was analyzed and donor specific heterogeneities were observed; but no significant differences were found between the two nutritional regimens.

Differentiation of Staphylococcus spp. by terminal-restriction fragment length polymorphism analysis of glyceraldehyde-3-phosphate dehydrogenase-encoding gene

Classical phenotypic and biochemical testing do not lead to correct identification of the distinct Staphylococcus species. Therefore, the aim of our study was to develop a method for the reliable and accurate determination of distinct Staphylococcus species. In the present study, the 931-934-bp partial sequences of the glyceraldehyde-3-phosphate dehydrogenase-encoding (gap) gene of 28 validly described Staphylococcus species were amplified and sequenced. By using the respective sequence information we performed a terminal-restriction fragment length polymorphism (T-RFLP) analysis. For T-RFLP the partial gap gene was amplified with double-fluorescently labelled primers and digested with the restriction enzymes DdeI, BspHI and TaqI. Distinctive T-RFLP patterns were rendered by the use of capillary electrophoresis with laser-induced fluorescence detection. This molecular method allowed us to identify all 28 Staphylococcus species with high specificity. This was validated by analysis of 34 Staphylococcus epidermidis and 28 Staphylococcus haemolyticus isolates. These results demonstrate the feasibility and applicability of the T-RFLP method based on the partial gap gene sequences for rapid and accurate species identification.

Feeding selectivity by mantled howler monkeys (Alouatta palliata) in relation to leaf secondary chemistry in Hymenaea courbaril

This study is a quantitative examination of primate feeding selectivity in relation to secondary chemistry within a single plant species, Hymenaea courbaril. It provides the first evidence that sesquiterpenes may act as feeding deterrents in mantled howler monkeys. A free-ranging group of mantled howler monkeys at the study site of Sector Santa Rosa, Area de Conservacion Guanacaste, Costa Rica were observed for the 2-month period of H. courbaril leaf flush in 1999. Tree characteristic data and leaf specimens were collected from 22 focal trees. Gas chromatography and mass spectrometry were used to estimate relative percentages of sesquiterpenes in leaf specimens. The monkeys fed only on the youngest leaves and only from particular trees. Whereas leaf stage selectivity was likely governed by tannin content and structural carbohydrates in younger and older leaf stages, respectively, differential tree use may be related to variability in sesquiterpene content. There is evidence that alpha-copaene may have played a role in interindividual tree use, and that cyperene may also be implicated. However, there is no reported evidence of antiherbivore activity for cyperene.

Subtyping of ST22-MRSA-IV (Barnim epidemic MRSA strain) at a university clinic in Germany from 2002 to 2005

Emergence of the meticillin-resistant Staphylococcus aureus (MRSA) Barnim epidemic strain (ST22-MRSA-IV) was demonstrated recently at University Hospital in Magdeburg, Germany. To aid the study of transmission events, it is important to have an epidemiological typing method with the ability to distinguish among MRSA isolates. The aim of this study was to determine the ability of phenotypic and genotypic methods to type ST22-MRSA-IV strains within a hospital for microevolution events. Forty-two ST22-MRSA-IV strains collected from 2002 to 2005 were analysed using antimicrobial testing, toxin gene analysis, PFGE, spa typing, fluorescent amplified fragment length polymorphism (fAFLP) and determination of staphylococcal interspersed repeat units (SIRUs). Four different antimicrobial patterns were observed. The majority of the isolates (n=31) were resistant towards erythromycin, ciprofloxacin and clindamycin, in addition to penicillin and oxacillin. All strains harboured the sec gene and showed a homogeneous profile of toxin genes. One isolate was typed as spa t022, two as spa t474 and the remainder belonged to spa type t032. PFGE yielded eight profiles and SIRU typing resulted in six different patterns. The fAFLP technique subdivided the individual PFGE profiles, but the grouping of isolates differed from that obtained by PFGE or SIRU typing. These results showed a diversity of ST22-MRSA-IV strains within a narrow clinical setting, indicating microevolution of the Barnim MRSA clone. The ability to distinguish among MRSA strains within an endemic setting will lead to a greater understanding of the transmission of MRSA and is necessary to be able to control the spread of various clones.

Comparative study using various methods for identification of Staphylococcus species in clinical specimens

Coagulase-negative staphylococci (CNS) play a predominant role in nosocomial infections. Rapid, reliable identification of these organisms is essential for accurate diagnosis and prompt effective treatment of these infections. Quite recently, the VITEK 2 g-positive (gram-positive [GP]) identification card (bioMérieux) has been redesigned for greater accuracy in the identification of gram-positive cocci. We compared the BD Phoenix (Becton Dickinson) and VITEK 2 (bioMérieux) automated microbiology systems, using their respective update version cards, and the API ID32 STAPH test. The glyceraldehyde-3-phosphate dehydrogenase (gap) gene-based T-RFLP (terminal restriction fragment length polymorphism) method was used for verifying the results. In total, 86 clinical isolates of CNS and 27 reference strains were analyzed. The results show that for identification of CNS, the automated identification methods using the newest VITEK 2 and BD Phoenix identification cards are comparable. However, API ID32 STAPH revealed more correct results compared to both automated microbiology systems. Despite the increased performance of the phenotypic automated identification systems compared to the former versions, molecular methods, e.g., the gap-based T-RFLP method, still show superior accuracy in identifying Staphylococcus species other than Staphylococcus aureus.

Prevalence and spread of enterohepatic Helicobacter species in mice reared in a specific-pathogen-free animal facility

Infections with enterohepatic Helicobacter species (EHS) can change the results of animal experiments. However, there is little information about the prevalence of EHS in noncommercial animal facilities. The aim of this study was to investigate the prevalence and the spread of EHS in specific-pathogen-free (SPF) mice. Fecal samples of 40 mouse lines were analyzed for members of the family Helicobacteraceae using a group-specific PCR targeting the 16S rRNA gene. Additional experiments were carried out to evaluate the spread of EHS among mice harbored in different caging systems. Helicobacter species were detected in 87.5% of the mouse lines tested. Five different Helicobacter species were identified: H. ganmani, H. hepaticus, H. typhlonicus, and the putative Helicobacter species represented by the isolates hamster B and MIT 98-5357. Helicobacter infection did not spread between animals in neighboring cages when individually ventilated cages were used; in contrast, when the mice were reared in open-air cages, EHS were found to spread from cage to cage. However, the spread was prevented by adding polycarbonate filter tops to the cages. When Helicobacter-negative and infected mice shared the same cage, transmission of the infection occurred in 100% within 2 weeks. Furthermore, we found that mice from commercial breeding facilities may carry undetected Helicobacter infections. Taken together, we show that infection with EHS may frequently occur and spread easily in mice reared under SPF conditions despite extensive safety precautions. Moreover, there is a high prevalence of rather uncommon Helicobacter species that may be a consequence of the current routine procedures used for health screening of SPF mice.

Heterogeneity of methicillin-susceptible Staphylococcus aureus strains at a German University Hospital implicates the circulating-strain pool as a potential source of emerging methicillin-resistant S. aureus clones

Recently, we demonstrated rapid dissemination of different methicillin-resistant Staphylococcus aureus (MRSA) clones at the Institute for Microbiology at the University of Magdeburg (B. Ghebremedhin, W. König, and B. König, Eur. J. Clin. Microbiol. Infect. Dis. 24:388-398, 2005). The majority of them harbored the readily transmissible mec cassette type IV. Thus, theoretically, methicillin-susceptible Staphylococcus aureus (MSSA) might capture the mecA gene from circulating MRSA, or MRSA strains might catch mobile toxin genes from MSSA. Therefore, we characterized MSSA strains circulating at the University Hospital in Magdeburg. Among a total of 84 MSSA strains under study, about 40% possessed the tst (toxic shock syndrome toxin) gene and up to four additional enterotoxin genes. tst-positive MSSA strains belonged to all known agr groups (I to IV) and to 14 different spa types (t008, t012, t015, t019, t024, t056, t065, t127, t133, t162, t271, t287, t399, and t400), and they were classified by multilocus sequence typing (MLST) as ST1, ST8, ST30, ST39, ST45, ST101, ST121, ST395, and ST426. In contrast, simultaneously circulating MRSA strains (n = 24) harbored in general two or three genes of the enterotoxin gene cluster, and the tst-positive MRSA isolates belonged to the well-known epidemic types ST22, ST45, and ST228 and were classified as spa types t001, t028, and t032. From our results, one may conclude that the pool of circulating MSSA strains is an important parameter with regard to the epidemiology of hospital- and community-acquired MRSA clones and their potential virulence.

Heterogeneity of methicillin-resistant Staphylococcus aureus strains at a German university hospital during a 1-year period

Heterogeneous methicillin-resistant Staphylococcus aureus (MRSA) strains, including community-acquired MRSA strains, have been observed in Central Europe. The purpose of this study was to characterize by molecular methods MRSA isolated during the period 2002-2003 at the Otto-von-Guericke University Hospital in Magdeburg, Germany, and at a nearby chronic care facility. Strains were analyzed for their resistance phenotype. Selected isolates were typed by multilocus sequence typing (MLST), by a multiplex polymerase chain reaction (PCR) for the staphylococcal cassette chromosome mec (SCCmec), by an allele-specific PCR for the staphylococcal accessory gene regulator (agr), and by PCR for the presence of toxin genes (sea-sej, tsst-1, hlgA, C, and B, lukE/D, and luk-pvl). Of the 2,731 S. aureus isolates studied, 199 (7.3%) were MRSA, with a prevalence of 21.6%, 19.6%, and 12% in the department of dermatology, the chronic care facility, and the intensive care units. Six different sequence types (ST247, ST228, ST22, ST22a, ST225, and ST45) were observed. Of these, ST22, ST22a, and ST45 dominated (>50%) in the department of dermatology and the chronic care facility. Strains with these sequence types were usually not resistant to gentamicin and were associated with agr group I, the SCCmec type IV element, and the presence of the sec and sed toxin genes. ST228 strains were found mainly in the intensive care units and had a broader resistance phenotype and were associated with agr group II and the SCCmec type I element. All luk-pvl-positive MRSA isolates (n=8) belonged to agr group I and were typed as ST22 or ST45 and contained the SCCmec type I (n=1), type III (n=1), or type IV (n=6) element. The main observations of this study are in concordance with previously reported findings showing dissemination of MRSA in Central Europe. Through the multitude of applied methods, the data from this study contribute to a more precise knowledge about the heterogeneity of MRSA in a clinical setting. Rapid dissemination of MRSA clones at a university hospital was demonstrated, indicating that dissemination may depend on the environmental conditions within the individual departments.