Hospital Isolates Research Articles

Molecular characterization of colistin resistance genes in a high-risk ST101/KPC-2 clone of Klebsiella pneumoniae in a University Hospital of Split, Croatia.

Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP) has become a major concern worldwide due to multidrug resistance and the ability to spread locally and globally. Infections caused by KPC-KP are great challenge in the healthcare systems because these are associated with longer hospitalization and high mortality. The emergence of colistin resistance has significantly reduced already limited treatment options. This study describes the molecular background of colistin-resistant KPC-KP isolates in the largest hospital in southern Croatia. Thirty-four non-duplicate colistin-resistant KPC-KP isolates were collected during routine work from April 2019 to January 2020 and from February to May 2021. Antimicrobial susceptibility was determined using disk diffusion, broth microdilution, and the gradient strip method. Carbapenemase was detected with an immunochromatographic test. Identification of blaKPC and mcr genes or mutations in pmrA, pmrB, mgrB, phoP, and phoQ genes were performed by polymerase chain reaction (PCR) and positive products were sequenced. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used for epidemiological analysis. All isolates were multidrug-resistant, with colistin minimum inhibitory concentrations (MICs) from 4 to >16 mg/L, and all harbored blaKPC-2 and had a single point mutation in the mgrB gene resulting in a premature stop codon, with the exception of one isolate with four point mutations corresponding to stop codons. All isolates were negative for mcr genes. PFGE analysis identified a single genetic cluster, and MLST revealed that all isolates belonged to sequence type 101 (ST101). These results show emergence of the high-risk ST101/KPC-2 clone of K. pneumoniae in Croatia as well as appearance of colistin resistance due to mutations in the mgrB gene. Molecular analysis of epidemiology and possible resistance mechanisms are important to develop further strategies to combat such threats.

Molecular Epidemiological Characterization of Staphylococcus aureus and Staphylococcus argenteus Clinical Isolates from a National Tertiary Care Hospital in Myanmar: Co-Isolation of Multiple Clones and Identification of Novel Staphylocoagulase Genotype.

Spread of antimicrobial resistance and virulence factors among Staphylococcus aureus/Staphylococcus argenteus poses a potential public health concern in Myanmar. In this study, a total of 226 clinical isolates of S. aureus (n = 211) and S. argenteus (n = 15) collected in Yangon General Hospital during a two-year period were analyzed for their antimicrobial susceptibility and genetic features. Methicillin-resistant S. aureus (MRSA) accounted for 19% of S. aureus isolates, associated with mostly staphylococcal cassette chromosome mec (SCCmec) type IV, or V. Panton-Valentine leukocidin (PVL) genes were detected in methicillin-susceptible S. aureus (MSSA) at significantly higher rate (39%) than in MRSA (22%). Among MRSA, ST361 (clonal complex [CC] 361), ST772 (CC1), and ST239 (CC8) were frequently identified, while the most common clone in MSSA was ST2990 (CC1), followed by ST121 and CC8 comprising five STs. Novel coagulase gene genotype XVI was identified in four MSSA isolates. All the S. argenteus isolates were assigned to ST2250 and mecA negative, including only one PVL-positive isolate. MSSA and S. argenteus were co-isolated from two patients, while two different MSSA clones were simultaneously identified in eight patients. This study revealed clonal diversity and genetic characteristics of current MRSA/MSSA/S. argenteus clinical isolates in the national tertiary care hospital in Myanmar.

Prevalence of Multidrug-Resistant, Extensively Drug-Resistant and Pandrug-Resistant <i>Pseudomonas </i><i>a</i><i>eruginosa</i> Clinical Isolates in Khartoum State, Sudan

Background. Pseudomonas aeruginosa is a common opportunistic Gram-negative pathogen responsible for a wide range of hospital acquired infections that may present high rates of antimicrobial resistance. It could also become multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan drug-resistant (PDR) during a short period. The aim of the present study is to determine the prevalence of MDR, XDR and PDR-P. aeruginosa clinical isolates in Khartoum State-Sudan. Materials and Methods. A multihospital laboratory-based study was conducted to collect P. aeruginosa clinical isolates from various clinical specimen’s culture during eighteen-month period from March 2020 to December 2021. The P. aeruginosa strains were reidentified by conventional biochemical methods and genotypically by amplification of 16S rRNA gene by Polymerase chain reaction (PCR) assay. Antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion method. MDR, XDR and PDR were determined according to new recommendation of the Clinical and Laboratory Standards Institute and the European Committee for Antimicrobial Susceptibility Testing. Results. Of 512 P. aeruginosa clinical isolates were recovered from various clinical specimen’s culture, only 289 (66.4%) of the isolates were confirmed as P. aeruginosa strains genotypically, out of those P. aeruginosa strains were categorized regarding antimicrobial resistance to 98 (33.9%) MDR, 61 (21.1%) XDR and 2 (0.7%) PDR. The XDR strains were exhibited significant overall resistance to all used antibiotic classes, whereas MDR strains were insignificant resistant to fluoroquinolones and polymyxins. Patients prior of hospitalized for 1-2weeks, uses of companied antibiotics therapy with duration of one week and source of isolation from wound swab and blood specimen (P P. aeruginosa isolates. Conclusion. The study highlights the increase prevalence of MDR and XDR P. aeruginosa clinical isolates in both hospital and community settings, along with emerged two pandrug resistant strains. Thus, continuous antimicrobial resistance surveillance for this bacterium is necessary for guiding antimicrobial treatment and stewardship as well as based knowledge for future comparative studies.

Evaluation of in vitro activity of ceftazidime/avibactam among carbapenamase producing Klebsiella pneumoniae from clinical isolates in tertiary care hospital

Evaluation of in vitro activity of ceftazidime/avibactam among carbapenamase producing Klebsiella pneumoniae from clinical isolates in tertiary care hospital

Investigation of Genetic Similarities of the Isolated Pseudomonas Aeruginosa from Hospitals and their Surrounding Areas by Rep-PCR Method.

Pseudomonas (P.) aeruginosa is one of the most common causes of nosocomial infections. The aim of this study was to explore the antibiotic resistance pattern and genetic association of P. aeruginosa strains isolated from Kermanshah hospitals and their surrounding areas. The samples included both soils from around three hospitals and clinical specimens of the same hospitals. Once the samples were enriched and the colonies were isolated, the positive samples of this bacterium were confirmed using biochemical tests. Then, antibiotic susceptibility testing (AST) was performed using the disc diffusion method (DDM). Finally, the phylogenetic relationship between the isolates was examined using the rep-PCR technique. In all experiments, the standard strain (ATCC:27853) was used as a positive control. Thirteen and 36 (27 urines, 7 burns and 2 septa) isolates were detected from environmental and clinical samples, respectively. Results showed that clinical strains had the highest resistance to ceftriaxone (94.44%) and the lowest resistance to imipenem (72.2%). On the other hand, environmental strains around the hospital showed the highest resistance to amikacin (92.3%) and the lowest resistance to imipenem (53.84%). Overall, 46 patterns were observed in the strains. The dendrogram indicated that a number of clinical and environmental strains had close genetic similarities. Strains 35C and 9E (clinical strain 35 and environmental strain 9) were 100% similar, which could imply that they originated from a clonal strain. Also, strains 3C, 26C, and 13E were 100% similar. Despite the differences in antibiotic resistance pattern between hospital and environmental isolates, there were genetic similarities between the two isolates.

Etiologies and antibiotic resistance patterns of acute bloodstream infections by gram-negative bacterial isolates in a tertiary care hospital, Sirajganj, Bangladesh

Bloodstream infections (BSI) are serious, life-threatening, and critical clinical conditions with high global human morbidity and mortality rates. This study aimed to determine the Gram-negative bacterial profiles and antimicrobial resistance patterns of acute bloodstream infections in rural patients. Three hundred forty-six blood samples were collected and analyzed with the BD BactecTM FX40 automated culture system, selective media culture, and biochemical parameters. Finally, antimicrobial susceptibility testing was performed using the disk diffusion method. The most common age group affected out of 51 cases was 41-60 years, with 20 patients (39.22%), and 1-15 years, with 2 patients (3.92%). Male patients were more susceptible (66.67%) than female patients. Among the isolates, E. coli was the most common, with 23 cases (45.1%); Cephradine was the most resistant antibiotic, and Imipenem was the most sensitive. Multiple drug-resistant pathogens were one of the most notable findings in our work. Our study will surely provide the best guide for properly treating antibacterial-resistant bacterial diseases and minimizing their critical mortality and morbidity. J. Bangladesh Acad. Sci. 46(2); 185-191: December 2022

High prevalence of cfiA positive Bacteroides fragilis isolates collected at a teaching hospital in Hohhot, China

Objectives: Carbapenem-resistant Bacteroides fragilis has emerged globally and cfiA is the key underlying factor. However, the prevalence of cfiA-positive carbapenem-resistant B. fragilis varies among countries. Therefore, we investigated the prevalence of cfiA-positive B. fragilis clinical isolates in a tertiary hospital in China.Methods: Carbapenem-resistant cfiA-positive B. fragilis isolates were identified using polymerase chain reaction. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) was used to identify the characteristic mass spectra of cfiA-positive B. fragilis.Results: The prevalence of cfiA among 153 B. fragilis isolates was 22.2% (34/153), when 20.6% (7/34) cfiA-positive B. fragilis strains were isolated from pediatric patients. Twenty-one carbapenem-resistant B. fragilis isolates were identified and were all positive with cfiA gene. Two characteristic peaks (4825 and 9642 Da) were identified using MALDI–TOF MS, and the sensitivity, specificity, and both the positive and negative predictive values of these two peaks were 100%. A new peak shift from 9627 Da for cfiA-negative isolates to 9642 Da for cfiA-positive isolates was observed.Conclusions: A high prevalence of cfiA was observed among B.fragilis isolates in this study, especially those isolated from pediatric patients. Characteristic MS spectra can accurately discriminate cfiA-positive and -negative B. fragilis isolates and can contribute to the rapid screening of cfiA-positive B. fragilis isolates in clinical laboratories.

Molecular Characteristics and Antibiotic Resistance of Staphylococcus aureus Isolated from Patient and Food Samples in Shijiazhuang, China.

Staphylococcus aureus (S. aureus) is a common opportunistic and zoonotic pathogen in the world and could easily cause human infections and food contaminations. This study investigated the sequence typing and resistance profiles of S. aureus isolates from patient and food samples in Shijiazhuang, China. A total of 101 S. aureus isolates were distributed into six clonal complexes (CCs) and 16 singletons. A total of 86 patient isolates were distributed into six clonal CCs and 12 singletons, including a new ST. CC59, CC5, CC22, and CC398 were the predominant CCs of patient isolates. A total of 15 foodborne S. aureus isolates were distributed into 3 CCs and 4 STs, and CC1 was the most prevalent CC. Moreover, 101 S. aureus isolates had high resistance to penicillin and low resistance to chloramphenicol and rifampicin. A total of 39 strains of methicillin-resistant Staphylococcus aureus (MRSA) were detected in this study, including thirty-eight strains of patient isolates (44.2%, 38/86) and one strain of food isolates (6.7%, 1/15). MRSA-ST5, MRSA-ST59, and MRSA-ST239 were the predominant MRSA isolates in hospitals. The present study explained the relationship between S. aureus isolated from patient and food samples and indicated the risks of S. aureus in infectious diseases.

Molecular patterns of clinically important fluoroquinolone resistance in multidrug-resistant Klebsiella pneumoniae isolates during nosocomial outbreaks in Shanghai, PR China.

Introduction. The soaring resistance of Klebsiella pneumoniae to fluoroquinolones in PR China has substantially limited the application of these antimicrobials, especially in those clinical settings that were threatened by persistent carbapenem-resistant K. pneumoniae (CRKP), necessitating strict implementation of antimicrobial stewardship and active enhanced surveillance of infection control.Hypothesis. There is interplay between plasmid-mediated quinolone resistance (PMQR) determinants and quinolone resistance-determining region (QRDR) mutations during the acquisition of a clinically important fluoroquinolone resistance (CI-FR) profile in multidrug-resistant K. pneumoniae (MDR-KP) isolates.Aim. To investigate the high-risk CRKP clones responsible for nosocomial spread and analyse the molecular patterns of CI-FR in MDR-KP isolates in a tertiary hospital in Shanghai, PR China.Methodology. A total of 34 isolates, including 30 CRKPs, were molecularly characterized. Investigations included antimicrobial susceptibility tests, multilocus sequence typing (MLST) and wzi genotyping, PCR sequencing and phylogenetic analysis for resistance-associated genes, and clinical information retrieval from medical records.Results. Two high-risk CRKP clones, ST11-wzi64 and ST15-wzi19/wzi24, were identified as being responsible for nosocomial outbreaks in the intensive care unit (ICU) and the neurosurgery department, potentially by the respiratory route. QRDR mutations of both gyrA and parC were detected in isolates of ST15 (S83F/D87A/S80I), ST11 (S83I/D87G/S80I) and ST218 (D87A/S80I), respectively. The PMQR genes, qnrS1, aac(6')-Ib-cr and oqxAB, were present in 32 (94.1 %) of the isolates alone or in combination, co-occurring with genes (bla) encoding β-lactamases, 16S rRNA methylases and putrescine ABC permeases. AcrR, an AcrAB transcriptional repressor, was insertion-inactivated by the IS5-like element in ST11 isolates. The encoding sequences of OmpK35 and OmpK36 genes were associated with specific STs and wzi alleles. ST11, ST15-wzi19 and ST218 isolates had frameshift disruptions in OmpK35 and specific GD insertions at position 134-135 in OmpK36. The 27 isolates with clinically important ciprofloxacin resistance (MICs ≥2 mg l-1) included 25 isolates (ST15, ST11, ST218) with multiple QRDR mutations, plus 1 with only 2 PMQR determinants (ST290-wzi21) and another with an unknown resistance mechanism (ST65-wzi72). Ciprofloxacin-susceptible isolates maintained intact ompK36 genes, including two CRKPs each with ST13-wzi74 (KPC-2 and NDM-1 coproducers) and ST65-wzi72, plus carbapenem-susceptible isolates (ST15-wzi24, ST65-wzi72, ST107-wzi173).Conclusions. Under selective pressures, the accumulation of mutations of three types (QRDR, acrR, ompK36) and the acquisition of resistance-conferring genes have continuously contributed to CI-FR in MDR-KP isolates.

Prevalence and WGS-based characteristics of MRSA isolates in hospitals in Shanghai, China.

Methicillin-resistant Staphylococcus aureus (MRSA) isolates remain a serious threat to global health despite a decrease in MRSA infections since 2005. MRSA isolates exhibit great diversity worldwide, and their lineages show geographic variation. In this study, we used whole genome sequencing (WGS) to analyze antibiotic resistance genes and virulence genes, spa, staphylococcal cassette chromosome mec, sequence types (STs), and core genome multilocus sequence typing (cgMLST) of MRSA isolates from patients and environmental surface in hospitals in China to determine their prevalence and molecular traits. The highest number of infections by MRSA isolates was observed in patients aged ≥60 years (69.8%, P < 0.05). We identified a total of 19 STs from 162 MRSA isolates from patients. A significant increase was observed in the incidence of ST764-t002-II MRSA infection, which is replacing ST5-t002-II MRSA as the predominant ST. Similarly, isolates from environmental surface were predominantly ST764-t002-II (47%). Notably, most ST764 isolates (97.7%) carried seb, but not arginine catabolic mobile element (ACME), which differed from ST764 isolates in Japan and Thailand. The potential danger of spreading requires rigorous surveillance of emerging ST764 MRSA isolates. We also found higher resistance to seven antimicrobials [OXA, cefoxitin (FOX), ERY, CFZ, ciprofloxacin (CIP), levofloxacin (LEV), and moxifloxacin (MXF)]. Resistance to gentamicin (38.3%), tetracycline (55.9%), and minocycline (41.5%) were also common. Phenotypic resistance to antimicrobials was associated with resistance genes to its content, and cgMLST clustering suggested a strong link between these strains. Overall, our findings revealed the prevalence and molecular characteristics of MRSA isolates in Shanghai, China, providing a theoretical reference for preventing and controlling clonal transmission of MRSA isolates in hospitals in China.

Antimicrobial sensitivity testing of levonadifloxacin – A novel benzoquinolizine drug against MRSA isolates in a tertiary care hospital

Methicillin-resistant Staphylococcus aureus (MRSA) adds a significant burden for health-care workers. In India there is a significant rise in prevalence of Methicillin resistant Staphylococcus aureus recently. Treatment has become very difficult among the resistant Staphylococcal isolates. Currently vancomycin and linezolid are the commonly used antibiotics. But these drugs have their adverse effects. Hence improved bactericidal antibiotics with increased tissue penetration and low possibility of developing resistance and safe to be used in chronic cases should be used for management of Methicillin resistant Staphylococcus aureus infections. The drug Levonadifloxacin acts actively against Methicillin resistant Staphylococcus aureus and Quinolone - resistant Staphylococcus aureus phenotypes. Recently in India, levonadifloxacin has been approved for the treatment of various infections like acute bacterial skin and soft tissue infections with complicating blood stream infections and also for diabetes complicating infections. Hence we evaluated the activity of levonadifloxacin (10g) by Kirby– Bauer disk diffusion assay against Methicillin resistant Staphylococcus aureus isolates in the central laboratory of a tertiary care centre for a period of 1year between May 2021 to April 2022. 296 isolates of Staphylococcus aureus were identified from various clinical samples. Based on the results of disc diffusion test using Cefoxitin disc, Of the 296 Staphylococcus aureus isolates 104 were methicillin resistant and the rest of the 192 were methicillin sensitive. Methicillin resistant Staphylococcus aureus isolates were tested against levonadifloxacin by disc diffusion which yielded 100% susceptibility rate. Hence this study displays potent activity of the drug levonadifloxacin against Methicillin resistant Staphylococcus aureus isolates and is recommended for therapeutic use.

Microbiome profiling and characterization of virulent and vancomycin-resistant Enterococcus faecium from treated and untreated wastewater, beach water and clinical sources

Vancomycin-resistant Enterococcus faecium (VREfm) is an opportunistic pathogen among the highest global priorities regarding public and environmental health. Following One Health approach, we determined for the first time the antibiotic resistance and virulence genes, and sequence types (STs) affiliation of VREfm recovered simultaneously from marine beach waters, submarine outfall of a wastewater treatment plant and an offshore discharge of untreated sewage, and compared them with the surveillance VREfm from regional university hospital in Croatia to assess the hazard of their transmission and routes of introduction into the natural environment. Importantly, VREfm recovered from wastewater, coastal bathing waters and hospital shared similar virulence, multidrug resistance, and ST profiles, posing a major public health threat. All isolates carried the vanA gene, while one clinical isolate also possessed the vanC2/C3 gene. The hospital strains largely carried the aminoglycoside-resistance genes aac(6′)-Ie-aph(2″)-Ia, and aph(2″)-Ib and aph(2″)-Id, which were also predominant in the environmental isolates. The hyl gene was the most prevalent virulence gene. The isolates belonged to 10 STs of the clonal complex CC17, a major epidemic lineage associated with hospital infections and outbreaks, with ST117 and ST889 common to waterborne and hospital isolates, pointing to their sewage-driven dissemination.To gain better insight into the diversity of accompanying taxons in the surveyed water matrices, microbiome taxonomic profiling was carried out using Illumina-based 16S rDNA sequencing and their resistome features predicted using the PICRUSt2 bioinformatics tool. An additional 60 pathogenic bacterial genera were identified, among which Arcobacter, Acinetobacter, Escherichia-Shigella, Bacteroides and Pseudomonas were the most abundant and associated with a plethora of antibiotic resistance genes and modules, providing further evidence of the hazardous effects of wastewater discharges, including the treated ones, on the natural aquatic environment that should be adequately addressed from a sanitary and technological perspective.

Molecular typing and antibiotic resistance patterns among clinical isolates of Acinetobacter baumannii recovered from burn patients in Tehran, Iran.

Acinetobacter baumannii (A. baumannii) is now considered a highly resistant pathogen to various types of antibiotics. Therefore, tracking the source of its prevalence and continuous control is crucial. This study aimed to determine antibiotic resistance and perform various molecular typing methods on clinical isolates of A. baumannii isolated from hospitalized burn patients in Shahid Motahari Burn Hospital, Tehran, Iran. Hospital isolates were confirmed by phenotypic and molecular methods. Then the sensitivity to different antibiotics was determined using the minimum inhibitory concentration (MIC) method. In order to perform molecular typing, three-locus dual assay multiplex polymerase chain reaction (PCR), multiple-locus variable-number tandem repeat analysis (MLVA), and multilocus sequence typing (MLST) methods were used. Among the 60 isolates collected, the frequencies of multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were 90 and 10%, respectively. The most effective antibiotics were colistin with 100% and tigecycline with 83.33% sensitivity. Isolates were 100% resistant to piperacillin/tazobactam and cephalosporins, and 68.3% were resistant to carbapenem. The results of multiplex PCR showed five groups that international clone I (IC I) and IC II were the most common. The MLVA method identified 34 MLVA types (MTs), 5 clusters, and 25 singletons. Multilocus sequence typing results for tigecycline-resistant isolates showed seven different sequence types (STs). Increasing antibiotic resistance in A. baumannii isolates requires careful management to control and prevent the occurrence of the pre-antibiotic era. The results of this study confirm that the population structure of A. baumannii isolates has a high diversity. More extensive studies are needed in Iran to better understand the epidemiology of A. baumannii.

Les misérables: a Parallel Between Antimicrobial Resistance and COVID-19 in Underdeveloped and Developing Countries.

Purpose of ReviewThe COVID-19 pandemic has been responsible for more than 6.3 million deaths worldwide. During the pandemic, the indiscriminate use of antibiotics has increased, contributing to the spread of multidrug-resistant bacteria. In this review, we aim to determine the spread and impact of antibiotic treatments in patients with COVID-19, focusing on underdeveloped and developing countries.Recent FindingsMeta-analysis revealed that bacterial co-infections and secondary infections are relatively rare in COVID-19 patients, corresponding to less than 20% of hospitalized patients. Even so, most of these patients have received antibiotic treatments.SummaryThis review discusses how the COVID-19 pandemic could increase the emergence of multidrug-resistant strains to currently available antibiotics. Initially, we discussed the spread and impact of multidrug resistance of ESKAPE pathogens associated with nosocomial infections and analyzed their risk of secondary infections in patients with COVID-19. Then we highlight three factors related to the spread of resistant bacteria during the current pandemic: overprescription of antibiotics followed by self-medication. Finally, we discussed the lack of availability of diagnostic tests to discriminate the etiologic agent of a disease. All these factors lead to inappropriate use of antibiotics and, therefore, to an increase in the prevalence of resistance, which can have devastating consequences shortly. The data compiled in this study underscore the importance of epidemiological surveillance of hospital isolates to provide new strategies for preventing and controlling infections caused by multidrug-resistant bacteria. In addition, the bibliographic research also highlights the need for an improvement in antibiotic prescribing in the health system.

Spa diversity and genetic characterization of t127 methicillin-resistant Staphylococcus aureus in a tertiary Greek hospital

Methicillin-resistant Staphylococcus aureus (MRSA) causes severe community and hospital acquired infections. Identification of staphylococcal cassette chromosome mec (SCCmec), multilocus-sequence typing, and sequencing of S. aureus protein A (spa) gene are used for MRSA typing. The aim was to investigate the spa types of MRSA isolates in a tertiary hospital in Greece and analyse the whole genome sequences of two t127 MRSA isolates. Totally, 39 MRSA isolates collected from July2019 to June 2020 in "Georgios Gennimatas" General Hospital of Thessaloniki, Greece, were included in the study. Identification and antimicrobial susceptibility testing were performed using VITEKII automated system, and spa typing was performed. A minimum spanning tree was used to display the spa type frequencies and the genetic distances among them. Two t127-MRSA isolates (IM-MRSA and PD-MRSA) were selected for WGS. Six isolates (15.4%) were resistant to mupirocin, 18 (46.2%) to fusidic acid, three (7.7%) to vancomycin and two (5.1%) to teicoplanin. Twenty-two different spa types were detected, with t002, t003, and t422 being the most frequent (5/39, 12.8% each), followed by t1994 (4/39, 10.3%). The isolates presented high genetic diversity and, taking into account the time between hospital admission and sampling, intrahospital spread did not occur. Even the two t127 isolates were assigned to different sequence types, ST9-XII-t127 and ST1-IVa-t127. Plasmids and genes conferring antimicrobial resistance and virulence were also identified. Various spa types were identified and together with the information about the time between hospital admission and sampling supports polyclonal MRSA spread in the hospital excluding a nosocomial infection. WGS provides a more detailed analysis distinguishing even the isolates belonging to the same spa type.

Predominance of t355/ST152/SCCmec V clonal type among PVL-positive MRSA isolates in a tertiary care hospital in Belgrade, Serbia.

Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is continually changing. Frequency of genotypes typical for community-associated MRSA (CA-MRSA) is increasing in hospitals, as well as resistance to antimicrobial agents. Moreover, different clones predominate in different geographic regions, and temporal shifts occur in the predominant clonal type. The aim of this study was to estimate the prevalence of MRSA, CA-MRSA and PVL-positive MRSA isolates from patients hospitalised in the Military Medical Academy (MMA) and from outpatients, and to perform genotyping of PVL-positive MRSA isolates. MRSA isolates were obtained by standard microbiological techniques. PVL-positive MRSA were detected by single PCR. Determination of SCCmec types in MRSA isolates was done using multiplex PCR and genotyping of PVL-positive MRSA by PFGE, MLST and spa typing. The prevalence of MRSA among S. aureus isolates from different clinical specimens was 43.4%. In outpatients the prevalence of MRSA was 3.2%. SCCmec types specific for CA-MRSA were found in 26% of MRSA isolates from hospitalised patients. In groups, hospitalised patients and outpatients, the prevalence of PVL-positive MRSA isolates was 4%, and all of them harboured SCCmec type V genetic element. PFGE revealed minor differences between four groups of PVL-positive MRSA isolates, but all of them belonged to ST152, and all except one were of the t355 spa type. High prevalence of MRSA and CA-MRSA in MMA, especially the presence of PVL-positive CA-MRSA, represent a serious health threat for patients. Genotype t355/ST152/SCCmec V is the dominant MRSA clone among PVL-positive CA-MRSA.

Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh

Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.

A 2-Year Retrospective Case Series on Isolates of the Emerging Pathogen Actinotignum schaalii from a Canadian Tertiary Care Hospital.

(1) Background: Actinotignum schaalii is an emerging, opportunistic pathogen often linked with UTIs but can extend beyond the urogenital system. Data on the clinical significance of A. schaalii are still emerging. (2) Methods: A retrospective review of A. schaalii isolates in a Canadian tertiary care hospital was conducted. The clinical data of patients that grew A. schaalii from January 2020 to 2022 were documented. Demographics, site, management, and microbiological parameters surrounding culture and sensitivities were recorded. (3) Results: A total of 43 cases of A. schaalii were identified. Actinotignum schaalii was primarily involved in UTIs (n = 17), abscesses (n = 9), bacteremia (n = 6), septic arthritis (n = 5), and ulcers (n = 5). A. schaalii had a slight predilection for polymicrobial infections (51.1%, n = 22 out of 43), with Aerococcus urinae (n = 5) being the most common coisolate. Susceptibility testing was only performed in two cases that showed sensitivity to beta-lactam antibiotics and resistance to metronidazole and ciprofloxacin. Amoxicillin–clavulanate (n = 5) is the most frequently prescribed antibiotic. (4) Conclusions: The non-urogenic clinical significance of A. schaalii remains undervalued. The management of A. schaalii infection is multimodal, consisting predominantly of antimicrobials and surgical procedures specific to the etiology. Clinicians should request sensitivities for A. schaalii so that appropriate antimicrobial coverage can be provided.

Antibacterial Activity of Stachys sylvatica Against Some Human Eye Pathogens

The ethanol extracts obtained from the leaves of Stachys sylvatica L. (Lamiaceae) were evaluated for their antibacterial activity against some human eye pathogens by disc diffusion method against hospital isolates of Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus capitis, Staphylococcus aureus, Staphylococcus epidermidis, Moraxella nonliquefaciens and Cutibacterium acnes. Besides, Penicillin, Ampicillin and Tobramycin as antibacterial antibiotics were used as a positive reference standard to determine the sensitivity of the isolates. The extracts showed a potential antibacterial effect against Staphylococcus capitis, Moraxella nonliquefaciens and Cutibacterium acnes, with inhibition zones of 22.4 mm, 21.6 mm and 20.2 mm, respectively. The extracts also exhibited a moderate effect against the other bacterial isolates. The plant may be useful in the treatment of eye infections.

Clinical and microbiological features of ceftolozane/tazobactam-resistant Pseudomonas aeruginosa isolates in a university hospital in central Italy

Ceftolozane/tazobactam (C/T) is a novel cephalosporin and β-lactamase inhibitor combination with great activity against Pseudomonas aeruginosa. To assess P. aeruginosa susceptibility to C/T, a surveillance study was conducted from October 2018 to March 2019 at the University Hospital 'Ospedali Riuniti' in Ancona, Italy. Minimum inhibitory concentrations (MICs) to C/T were determined by Etest strip. Resistant isolates were characterized by phenotypic (broth microdilution antimicrobial susceptibility testing and modified Carbapenem Inactivation Method [mCIM]) and genotypic (Polymerase Chain Reaction [PCR], Pulsed Field Gel Electrophoresis [PFGE], and whole-genome sequencing [WGS]) methods. Clinical variables of patients infected by C/T-resistant P. aeruginosa were collected from medical records. Fifteen of 317 P. aeruginosa collected showed resistance to C/T (4.7%). Ten strains demonstrated carbapenemase activity by mCIM method, and PCR confirmed that eight strains harbored a blaVIM gene while the other two were positive for blaIMP. Additionally, three isolates carried acquired extended spectrum β-lactamase genes (two isolates carried blaPER and one carried blaGES). Eight strains were strictly related by PFGE and WGS analysis confirmed that they belonged to sequence type (ST)111. The other STs found were ST175 (two isolates), ST235 (two isolates), ST70 (one isolate), ST621 (one isolate), and the new ST3354 (one isolate). Most patients had received previous antibiotic therapies, carried invasive devices, and experienced prolonged hospitalization. This study demonstrated the presence of C/T-resistant P. aeruginosa isolates in a regional hospital carrying a number of resistance mechanisms acquired by different high-risk clones.