@article{DuskeClausKroneetal.2024, author = {Duske, Helene and Claus, Heike and Krone, Manuel and L{\^a}m, Thi{\^e}n-Tr{\´i}}, title = {Prevalence of piperacillin/tazobactam resistance in invasive \(Haemophilus\) \(influenzae\) in Germany}, series = {JAC-Antimicrobial Resistance}, volume = {6}, journal = {JAC-Antimicrobial Resistance}, number = {1}, issn = {2632-1823}, doi = {10.1093/jacamr/dlad148}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350424}, year = {2024}, abstract = {Background Haemophilus influenzae (Hi) is a Gram-negative bacterium that may cause sepsis or meningitis, treatment of which mainly includes β-lactam antibiotics. Since 2019 EUCAST breakpoints for piperacillin/tazobactam have been available. Little is known about the prevalence and mechanisms of piperacillin/tazobactam resistance in Hi. Objectives To provide reliable prevalence data for piperacillin/tazobactam resistance in Hi in Germany, to evaluate different antibiotic susceptibility testing methods and to examine possible resistance mechanisms. Methods According to EUCAST breakpoints, the MIC for piperacillin/tazobactam resistance is >0.25 mg/L. All invasive Hi in Germany from 2019 were examined by gradient agar diffusion (GAD) for piperacillin/tazobactam susceptibility. Piperacillin/tazobactam broth microdilution (BMD), piperacillin GAD on tazobactam-containing agar [piperacillin GAD on Mueller-Hinton agar with horse blood (MH-F)/tazobactam) and piperacillin/tazobactam agar dilution (AD) were used for confirmation. Phenotypic testing was complemented by ftsI sequencing. Results Piperacillin/tazobactam GAD resulted in 2.9\% (21/726) resistant Hi. BMD did not confirm piperacillin/tazobactam resistance. Two strains were found resistant by AD, of which one was also resistant using piperacillin GAD on MH-F/tazobactam. Overall, we found two strains with a piperacillin/tazobactam MIC >0.25 mg/L in at least two different tests (0.3\%). Both were β-lactamase-producing amoxicillin/clavulanate-resistant with PBP3 mutations characterized as group III-like+. Relevant PBP3 mutations occurred in six strains without phenotypic piperacillin/tazobactam resistance. These mutations suggest a reduced efficacy of β-lactam antibiotics in these isolates. Conclusions Piperacillin/tazobactam resistance prevalence in invasive Hi is low in Germany. Reduced susceptibility was correlated with PBP3 mutations, in particular with group III mutations.}, language = {en} } @article{SilwedelHaarmannFehrholzetal.2019, author = {Silwedel, Christine and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Speer, Christian P. and Glaser, Kirsten}, title = {More than just inflammation: Ureaplasma species induce apoptosis in human brain microvascular endothelial cells}, series = {Journal of Neuroinflammation}, volume = {16}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-019-1413-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200711}, pages = {38}, year = {2019}, abstract = {Background Ureaplasma species (spp.) are commonly regarded as low-virulent commensals but may cause invasive diseases in immunocompromised adults and in neonates, including neonatal meningitis. The interactions of Ureaplasma spp. with host defense mechanisms are poorly understood. This study addressed Ureaplasma-driven cell death, concentrating on apoptosis as well as inflammatory cell death. Methods Human brain microvascular endothelial cells (HBMEC) were exposed to Ureaplasma (U.) urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). Resulting numbers of dead cells as well as mRNA levels and enzyme activity of key agents in programmed cell death were assessed by flow cytometry, RNA sequencing, and qRT-PCR, respectively. xCELLigence data were used for real-time monitoring of changes in cell adhesion properties. Results Both Ureaplasma isolates induced cell death (p < 0.05, vs. broth). Furthermore, Ureaplasma spp. enhanced mRNA levels for genes in apoptosis, including caspase 3 (Up3 p < 0.05, vs. broth), caspase 7 (p < 0.01), and caspase 9 (Up3 p < 0.01). Caspase 3 activity was increased upon Uu8 exposure (p < 0.01). Vice versa, Ureaplasma isolates downregulated mRNA levels for proteins involved in inflammatory cell death, namely caspase 1 (Uu8 p < 0.01, Up3 p < 0.001), caspase 4 (Uu8 p < 0.05, Up3 p < 0.01), NOD-like receptor pyrin domain-containing 3 (Uu8 p < 0.05), and receptor-interacting protein kinase 3 (p < 0.05). Conclusions By inducing apoptosis in HBMEC as main constituents of the blood-brain barrier, Ureaplasma spp. may provoke barrier breakdown. Simultaneous suppression of inflammatory cell death may additionally attenuate host defense strategies. Ultimate consequence could be invasive and long-term CNS infections by Ureaplasma spp.}, language = {en} } @article{ClausHubertBecheretal.2019, author = {Claus, Heike and Hubert, Kerstin and Becher, D{\"o}rte and Otto, Andreas and Pawlik, Marie-Christin and Lappann, Ines and Strobel, Lea and Vogel, Ulrich and Johswich, Kay}, title = {A homopolymeric adenosine tract in the promoter region of nspA influences factor H-mediated serum resistance in Neisseria meningitidis}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-39231-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200956}, pages = {2736}, year = {2019}, abstract = {Although usually asymptomatically colonizing the human nasopharynx, the Gram-negative bacterium Neisseria meningitidis (meningococcus) can spread to the blood stream and cause invasive disease. For survival in blood, N. meningitidis evades the complement system by expression of a polysaccharide capsule and surface proteins sequestering the complement regulator factor H (fH). Meningococcal strains belonging to the sequence type (ST-) 41/44 clonal complex (cc41/44) cause a major proportion of serogroup B meningococcal disease worldwide, but they are also common in asymptomatic carriers. Proteome analysis comparing cc41/44 isolates from invasive disease versus carriage revealed differential expression levels of the outer membrane protein NspA, which binds fH. Deletion of nspA reduced serum resistance and NspA expression correlated with fH sequestration. Expression levels of NspA depended on the length of a homopolymeric tract in the nspA promoter: A 5-adenosine tract dictated low NspA expression, whereas a 6-adenosine motif guided high NspA expression. Screening German cc41/44 strain collections revealed the 6-adenosine motif in 39\% of disease isolates, but only in 3.4\% of carriage isolates. Thus, high NspA expression is associated with disease, but not strictly required. The 6-adenosine nspA promoter is most common to the cc41/44, but is also found in other hypervirulent clonal complexes.}, language = {en} } @article{SilwedelSpeerHaarmannetal.2019, author = {Silwedel, Christine and Speer, Christian P. and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Schlegel, Nicolas and Glaser, Kirsten}, title = {Ureaplasma species modulate cytokine and chemokine responses in human brain microvascular endothelial cells}, series = {International Journal of Molecular Science}, volume = {20}, journal = {International Journal of Molecular Science}, number = {14}, issn = {1422-0067}, doi = {10.3390/ijms20143583}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201848}, year = {2019}, abstract = {Ureaplasma species are common colonizers of the adult genitourinary tract and often considered as low-virulence commensals. Intraamniotic Ureaplasma infections, however, facilitate chorioamnionitis and preterm birth, and cases of Ureaplasma-induced neonatal sepsis, pneumonia, and meningitis raise a growing awareness of their clinical relevance. In vitro studies are scarce but demonstrate distinct Ureaplasma-driven impacts on immune mechanisms. The current study addressed cytokine and chemokine responses upon exposure of native or lipopolysaccharide (LPS) co-stimulated human brain microvascular endothelial cells (HBMEC) to Ureaplasma urealyticum or U. parvum, using qRT-PCR, RNA sequencing, multi-analyte immunoassay, and flow cytometry. Ureaplasma exposure in native HBMEC reduced monocyte chemoattractant protein (MCP)-3 mRNA expression (p < 0.01, vs. broth). In co-stimulated HBMEC, Ureaplasma spp. attenuated LPS-evoked mRNA responses for C-X-C chemokine ligand 5, MCP-1, and MCP-3 (p < 0.05, vs. LPS) and mitigated LPS-driven interleukin (IL)-1α protein secretion, as well as IL-8 mRNA and protein responses (p < 0.05). Furthermore, Ureaplasma isolates increased C-X-C chemokine receptor 4 mRNA levels in native and LPS co-stimulated HBMEC (p < 0.05). The presented results may imply immunomodulatory capacities of Ureaplasma spp. which may ultimately promote chronic colonization and long-term neuroinflammation.}, language = {en} } @article{DrayssClausHubertetal.2019, author = {Drayß, Maria and Claus, Heike and Hubert, Kerstin and Thiel, Katrin and Berger, Anja and Sing, Andreas and van der Linden, Mark and Vogel, Ulrich and L{\^a}m, Thi{\^e}n-Tr{\´i}}, title = {Asymptomatic carriage of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Group A Streptococcus and Staphylococcus aureus among adults aged 65 years and older}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {2}, doi = {10.1371/journal.pone.0212052}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201042}, pages = {e0212052}, year = {2019}, abstract = {Objective The aim of this study was to determine the prevalence of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, group A Streptococcus (GAS), and Staphylococcus aureus in asymptomatic elderly people and to unravel risk factors leading to colonization. Methods A multi-centre cross-sectional study was conducted including 677 asymptomatic adults aged 65 years or more, living at home or in nursing homes. Study areas were Greater Aachen (North-Rhine-Westphalia) and Wuerzburg (Bavaria), both regions with medium to high population density. Nasal and oropharyngeal swabs as well as questionnaires were collected from October 2012 to May 2013. Statistical analysis included multiple logistic regression models. Results The carriage rate was 1.9\% ([95\%CI: 1.0-3.3\%]; 13/677) for H. influenzae, 0.3\% ([95\%CI: 0-1.1\%]; 2/677) for N. meningitidis and 0\% ([95\% CI: 0-0.5\%]; 0/677) for S. pneumoniae and GAS. Staphylococcus aureus was harboured by 28.5\% of the individuals ([95\% CI: 25.1-32.1\%]; 193/677) and 0.7\% ([95\% CI: 0.2-1.7\%]; 5/677) were positive for methicillin-resistant S. aureus. Among elderly community-dwellers colonization with S. aureus was significantly associated with higher educational level (adjusted OR: 1.905 [95\% CI: 1.248-2.908]; p = 0.003). Among nursing home residents colonization was associated with being married (adjusted OR: 3.367 [1.502-7.546]; p = 0.003). Conclusion The prevalence of N. meningitidis, H. influenzae, S. pneumoniae and GAS was low among older people in Germany. The S. aureus rate was expectedly high, while MRSA was found in less than 1\% of the individuals.}, language = {en} } @article{MoremiClausVogeletal.2019, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {The role of patients and healthcare workers Staphylococcus aureus nasal colonization in occurrence of surgical site infection among patients admitted in two centers in Tanzania}, series = {Antimicrobial Resistance \& Infection Control}, volume = {8}, journal = {Antimicrobial Resistance \& Infection Control}, doi = {10.1186/s13756-019-0554-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224185}, year = {2019}, abstract = {Background Colonization with Staphylococcus aureus has been identified as a risk for subsequent occurrence of infection. This study investigated the relationship between S. aureus colonization of patients and healthcare workers (HCWs), and subsequent surgical site infections (SSI). Methods Between December 2014 and September 2015, a total of 930 patients and 143 HCWs were enrolled from the Bugando Medical Centre and Sekou Toure hospital in Mwanza, Tanzania. On admission and discharge nasal swabs, with an additional of wound swab for those who developed SSI were collected from patients whereas HCWs were swabbed once. Identification and antimicrobial susceptibility testing were done by VITEK-MS and VITEK-2, respectively. Detection of Panton Valentine leukocidin (PVL) and mecA genes was done by PCR. S. aureus isolates were further characterized by spa typing and Multi-Locus Sequence Typing (MLST). Results Among 930 patients screened for S. aureus on admission, 129 (13.9\%) were positive of which 5.4\% (7/129) were methicillin-resistant S. aureus (MRSA). Amongst 363 patients rescreened on discharge, 301 patients had been tested negative on admission of whom 29 (9.6\%) turned positive after their hospital stay. Three (10.3\%) of the 29 acquired S. aureus were MRSA. Inducible Clindamycin resistance occurred more often among acquired S. aureus isolates than among isolates from admission [34.5\% (10/29) vs. 17.1\% (22/129), P = 0.018]. S. aureus contributed to 21.1\% (n = 12) of the 57 cases of investigated SSIs among 536 patients followed. Seven out of eight S. aureus carriage/infection pairs had the same spa and sequence types. The previously reported dominant PVL-positive ST88 MRSA strain with spa type t690 was detected in patients and HCW. Conclusion A significant proportion of patients acquired S. aureus during hospitalization. The finding of more than 90\% of S. aureus SSI to be of endogenous source underscores the need of improving infection prevention and control measures including screening and decolonization of high risk patients.}, language = {en} } @article{SilwedelSpeerHaarmannetal.2018, author = {Silwedel, Christine and Speer, Christian P. and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Buttmann, Mathias and Glaser, Kirsten}, title = {Novel insights into neuroinflammation: bacterial lipopolysaccharide, tumor necrosis factor α, and Ureaplasma species differentially modulate atypical chemokine receptor 3 responses in human brain microvascular endothelial cells}, series = {Journal of Neuroinflammation}, volume = {15}, journal = {Journal of Neuroinflammation}, number = {156}, doi = {10.1186/s12974-018-1170-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175952}, year = {2018}, abstract = {Background: Atypical chemokine receptor 3 (ACKR3, synonym CXCR7) is increasingly considered relevant in neuroinflammatory conditions, in which its upregulation contributes to compromised endothelial barrier function and may ultimately allow inflammatory brain injury. While an impact of ACKR3 has been recognized in several neurological autoimmune diseases, neuroinflammation may also result from infectious agents, including Ureaplasma species (spp.). Although commonly regarded as commensals of the adult urogenital tract, Ureaplasma spp. may cause invasive infections in immunocompromised adults as well as in neonates and appear to be relevant pathogens in neonatal meningitis. Nonetheless, clinical and in vitro data on Ureaplasma-induced inflammation are scarce. Methods: We established a cell culture model of Ureaplasma meningitis, aiming to analyze ACKR3 variances as a possible pathomechanism in Ureaplasma-associated neuroinflammation. Non-immortalized human brain microvascular endothelial cells (HBMEC) were exposed to bacterial lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α), and native as well as LPS-primed HBMEC were cultured with Ureaplasma urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). ACKR3 responses were assessed via qRT-PCR, RNA sequencing, flow cytometry, and immunocytochemistry. Results: LPS, TNF-α, and Ureaplasma spp. influenced ACKR3 expression in HBMEC. LPS and TNF-α significantly induced ACKR3 mRNA expression (p < 0.001, vs. control), whereas Ureaplasma spp. enhanced ACKR3 protein expression in HBMEC (p < 0.01, vs. broth control). Co-stimulation with LPS and either Ureaplasma isolate intensified ACKR3 responses (p < 0.05, vs. LPS). Furthermore, stimulation wielded a differential influence on the receptor's ligands. Conclusions: We introduce an in vitro model of Ureaplasma meningitis. We are able to demonstrate a pro-inflammatory capacity of Ureaplasma spp. in native and, even more so, in LPS-primed HBMEC, underlining their clinical relevance particularly in a setting of co-infection. Furthermore, our data may indicate a novel role for ACKR3, with an impact not limited to auto-inflammatory diseases, but extending to infection-related neuroinflammation as well. AKCR3-induced blood-brain barrier breakdown might constitute a potential common pathomechanism.}, language = {en} } @article{MoremiClausVogeletal.2017, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {Surveillance of surgical site infections by Pseudomonas aeruginosa and strain characterization in Tanzanian hospitals does not provide proof for a role of hospital water plumbing systems in transmission}, series = {Antimicrobial Resistance and Infection Control}, volume = {6}, journal = {Antimicrobial Resistance and Infection Control}, number = {56}, doi = {10.1186/s13756-017-0216-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158168}, year = {2017}, abstract = {Background The role of hospital water systems in the development of Pseudomonas aeruginosa (P. aeruginosa) surgical site infections (SSIs) in low-income countries is barely studied. This study characterized P. aeruginosa isolates from patients and water in order to establish possible epidemiological links. Methods: Between December 2014 and September 2015, rectal and wound swabs, and water samples were collected in the frame of active surveillance for SSIs in the two Tanzanian hospitals. Typing of P. aeruginosa was done by multi-locus sequence typing. Results: Of 930 enrolled patients, 536 were followed up, of whom 78 (14.6\%, 95\% CI; 11.6-17.5) developed SSIs. P. aeruginosa was found in eight (14\%) of 57 investigated wounds. Of the 43 water sampling points, 29 were positive for P. aeruginosa. However, epidemiological links to wound infections were not confirmed. The P. aeruginosa carriage rate on admission was 0.9\% (8/930). Of the 363 patients re-screened upon discharge, four (1.1\%) possibly acquired P. aeruginosa during hospitalization. Wound infections of the three of the eight P. aeruginosa SSIs were caused by a strain of the same sequence type (ST) as the one from intestinal carriage. Isolates from patients were more resistant to antibiotics than water isolates. Conclusions: The P. aeruginosa SSI rate was low. There was no evidence for transmission from tap water. Not all P. aeruginosa SSI were proven to be endogenous, pointing to other routes of transmission.}, language = {en} } @article{MoremiClausVogeletal.2017, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {Faecal carriage of CTX-M extended-spectrum beta-lactamase-producing Enterobacteriaceae among street children dwelling in Mwanza city, Tanzania}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {9}, doi = {10.1371/journal.pone.0184592}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170331}, pages = {e0184592}, year = {2017}, abstract = {Background Data on ESBL carriage of healthy people including children are scarce especially in developing countries. We analyzed the prevalence and genotypes of ESBL-producing Enterobacteriaceae (EPE) in Tanzanian street children with rare contact to healthcare facilities but significant interactions with the environment, animals and other people. Methodology/ Principle findings Between April and July 2015, stool samples of 107 street children, who live in urban Mwanza were analyzed for EPE. Intestinal carriage of EPE was found in 34 (31.8\%, 95\% CI; 22.7-40.3) children. Of the 36 isolates from 34 children, 30 (83.3\%) were Escherichia coli (E. coli) and six Klebsiella pneumoniae (K. pneumoniae). Out of 36 isolates, 36 (100\%), 35 (97\%), 25 (69\%) and 16 (44\%) were resistant to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Beta-lactamase genes and the multilocus sequence types of E. coli and K. pneumoniae were characterized. ESBL gene bla\(_{CTX-M-15}\) was detected in 75\% (27/36) of ESBL isolates. Sequence types (STs) 131, 10, 448 and 617 were the most prevalent in E. coli. Use of local herbs (OR: 3.5, 95\% CI: 1.51-8.08, P = 0.003) and spending day and night on streets (OR: 3.6, 95\% CI: 1.44-8.97, P = 0.005) were independent predictors of ESBL carriage. Conclusions/ Significance We observed a high prevalence of bla\(_{CTX-M-15}\) in EPE collected from street children in Tanzania. Detection of E. coli STs 131, 10, 38 and 648, which have been observed worldwide in animals and people, highlights the need for multidisciplinary approaches to understand the epidemiology and drivers of antimicrobial resistance in low-income countries.}, language = {en} } @article{GlaserSilwedelFehrholzetal.2017, author = {Glaser, Kirsten and Silwedel, Christine and Fehrholz, Markus and Waaga-Gasser, Ana M. and Henrich, Birgit and Claus, Heike and Speer, Christian P.}, title = {Ureaplasma Species Differentially Modulate Pro- and Anti-Inflammatory Cytokine Responses in Newborn and Adult Human Monocytes Pushing the State Toward Pro-Inflammation}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {7}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {484}, doi = {10.3389/fcimb.2017.00484}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169958}, year = {2017}, abstract = {Background: Ureaplasma species have been associated with chorioamnionitis and preterm birth and have been implicated in the pathogenesis of neonatal short and long-term morbidity. However, being mostly commensal bacteria, controversy remains on the pro-inflammatory capacity of Ureaplasma. Discussions are ongoing on the incidence and impact of prenatal, perinatal, and postnatal infection. The present study addressed the impact of Ureaplasma isolates on monocyte-driven inflammation. Methods: Cord blood monocytes of term neonates and adult monocytes, either native or LPS-primed, were cultured with Ureaplasma urealyticum (U. urealyticum) serovar 8 (Uu8) and Ureaplasma parvum serovar 3 (Up3). Using qRT-PCR, cytokine flow cytometry, and multi-analyte immunoassay, we assessed mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-12p40, IL-10, and IL-1 receptor antagonist (IL-1ra) as well as Toll-like receptor (TLR) 2 and TLR4. Results: Uu8 and Up3 induced mRNA expression and protein release of TNF-α, IL-1β and IL-8 in term neonatal and adult monocytes (p < 0.01 and p < 0.05). Intracellular protein expression of TNF-α, IL-1β and IL-8 in Ureaplasma-stimulated cells paralleled those results. Ureaplasma-induced cytokine levels did not significantly differ from LPS-mediated levels except for lower intracellular IL-1β in adult monocytes (Uu8: p < 0.05). Remarkably, ureaplasmas did not induce IL-12p40 response and promoted lower amounts of anti-inflammatory IL-10 and IL-1ra than LPS, provoking a cytokine imbalance more in favor of pro-inflammation (IL-1β/IL-10, IL-8/IL-10 and IL-8/IL-1ra: p < 0.01, vs. LPS). In contrast to LPS, both isolates induced TLR2 mRNA in neonatal and adult cells (p < 0.001 and p < 0.05) and suppressed TLR4 mRNA in adult monocytes (p < 0.05). Upon co-stimulation, Uu8 and Up3 inhibited LPS-induced intracellular IL-1β (p < 0.001 and p < 0.05) and IL-8 in adult monocytes (p < 0.01), while LPS-induced neonatal cytokines were maintained or aggravated (p < 0.05). Conclusion: Our data demonstrate a considerable pro-inflammatory capacity of Ureaplasma isolates in human monocytes. Stimulating pro-inflammatory cytokine responses while hardly inducing immunomodulatory and anti-inflammatory cytokines, ureaplasmas might push monocyte immune responses toward pro-inflammation. Inhibition of LPS-induced cytokines in adult monocytes in contrast to sustained inflammation in term neonatal monocytes indicates a differential modulation of host immune responses to a second stimulus. Modification of TLR2 and TLR4 expression may shape host susceptibility to inflammation.}, language = {en} }