Automated Microbiology System Research Articles

Isolation and identification of histamine-producing bacteria in frigate tuna Auxis thazard

Histamine is the most common cause of human foodborne illness and is found to be associated with the consumption of fish products especially in scombroid fishes containing unusual levels of histamine. In this study, histamine-producing bacteria in the Frigate Tuna, Auxis thazard samples of the local Ukkadam fish market of Coimbatore were investigated. Among 12 isolates 4 were found to be prominent histamine producing bacteria. An automated microbiology system called VITEK, a biochemical test analyzer was used for the identification of bacteria, and four isolates were tentatively identified as Sphingomonas paucimobilis; Proteus vulgaris; Providencia rustigianii, and Neisseria zoodegmatis. The isolation of histamine-producing bacteria from the muscle emphasizes the possible importance of muscle as a reservoir for bacterial contamination. The study suggests that the practice of more hygienic and sanitary conditions during the handling and processing of fish is required to minimize the contamination of such histamine-producing bacteria.

The comparative survey of phenotypic methods and the BD Phoenix M50 automated microbiology system for detecting the genus of non-fermenting gram-negative bacteria isolated from blood samples in Isfahan, Iran

Introduction: A comparative study was conducted to identify the genus and species of non-fermenting gram-negative bacilli isolated from blood culture samples using phenotypic methods and the Phoenix method. Objectives: This study aimed to evaluate the Phoenix system compared to the currently available phenotypic process. Materials and Methods: This descriptive-analytical cross-sectional study evaluated 30 samples collected from 2019 to 2020 from patients at AL Zahra and Kashani hospitals who required blood cultures. The specimens were injected into BACTEC™. Positive cultures identified as non-fermenting gram-negative bacteria by the phenotypic method were included in the study and then evaluated using the Phoenix method to determine the genus and species of non-fermenting gram-negative bacteria. A comparison was then conducted. Results: The study identified 30 non-fermenting gram-negative bacteria. The Phoenix method revealed that 78.5% of the diagnoses were Acinetobacter, while the phenotypic approach identified 86.7% as Acinetobacter spp. Conclusion: The present study demonstrated a significant difference between the Phoenix and phenotypic methods in identifying the type of bacteria.

Antimicrobial Resistance Pattern, Pathogenicity and Molecular Properties of Hypervirulent Klebsiella pneumonia (hvKp) among Hospital-Acquired Infections in the Intensive Care Unit (ICU)

Hypervirulent Klebsiella pneumoniae (hvKp) is a new emerging variant of K. pneumoniae that is increasingly reported worldwide. The variant hvKp is known to cause severe invasive community-acquired infections such as metastatic meningitis, pyogenic liver abscesses (PLA) and endophthalmitis, but its role in hospital-acquired infections (HAIs) is little known. The aim of this study was to evaluate the prevalence of hvKp among hospital-acquired (HA) K. pneumoniae infections in the intensive care unit (ICU) and to compare between hvKp and classical K. pneumoniae (cKP) regarding antimicrobial resistance pattern, virulence and molecular characteristics. The study was cross-sectional and included 120 ICU patients suffering from HA K. pneumoniae infections between January and September 2022. K. pneumoniae isolates were subjected to antimicrobial susceptibility testing and detection of extended-spectrum-β-lactamase (ESBL) production by the Phoenix 100 automated microbiology system, string test, biofilm formation, serum resistance assay, and detection of virulence-associated genes (rmpA, rmpA2, magA, iucA) and capsular serotype-specific genes (K1, K2, K5, K20, K57) by polymerase chain reaction (PCR). Of 120 K. pneumoniae isolates, 19 (15.8%) were hvKp. The hypermucoviscous phenotype was more significantly detected in the hvKp group than in the cKP group (100% vs. 7.9%, p ≤ 0.001). The rate of resistance to different antimicrobial agents was significantly higher in the cKP group than that in the hvKp group. Fifty-three strains were identified as ESBL-producing strains, which was more frequent in the cKP group than in the hvKp group (48/101 [47.5%] vs. 5/19 [26.3%], respectively, p ≤ 0.001). The hvKP isolates were highly associated with moderate and strong biofilm formation than cKP isolates (p = 0.018 and p = 0.043 respectively). Moreover, the hvKP isolates were highly associated with intermediate sensitivity and re sistance to serum in the serum resistance assay (p = 0.043 and p = 0.016 respectively). K1, K2, rmpA, rmpA2, magA and iucA genes were significantly associated with hvKp (p ≤ 0.001, 0.004, <0.001, <0.001, 0.037 and <0.001, respectively). However, K5, K20 and K57 were not associated with hvKp. The hvKp strains have emerged as a new threat to ICU patients because of their ability to cause more severe and life-threatening infections than cKP. The string test alone as a laboratory test for screening of hvKp has become insufficient. Recently, hvKp was defined as hypermucoviscous- and aerobactin-positive. It is important to improve the awareness towards the diagnosis and management of hvKp infections.

Otitis Externa in Dogs: Distribution and Antimicrobial Susceptibility Patterns of Staphylococcus Spp. Isolates

Abstract The study aimed to investigate the Staphylococcus species from dogs with chronic otitis externa in Istanbul and to determine their antibiotic susceptibility patterns. Ear swab samples were collected from 100 dogs suspected of otitis externa admitted at the clinics of Istanbul University - Cerrahpaşa, Faculty of Veterinary Medicine. The dogs were of different age, gender, and breed. The bacterial isolation was performed by conventional methods. BD Phoenix Automated Microbiology System was used to confirm bacterial identification by conventional methods and to test antimicrobial susceptibility. Staphylococcus spp. were isolated from 36% of the samples collected from the dogs. S. pseudintermedius, S. aureus, S. epidermidis, S. hyicus and S. chromogenes were identified in 41.6%, 22.2%, 11.1%, 5.5%, and 5.5%. In Staphylococcus spp. isolates, enrofloxacin, penicillin, and ampicillin-sulbactam resistance was 8.3%, marbofloxacin resistance was 11.1%, doxycycline resistance was 16.6%, amoxicillin-clavulanic acid, erythromycin, and gentamicin resistance was 19.4%, tetracycline, clindamycin, and sulphonamide resistance was 25%. Methicillin resistance was not observed in any of the isolates. However, multiple drug resistance (MDR) was detected in 11 (30.5%) of 36 isolates. In conclusion, the early detection and antimicrobial sensitivity testing of Staphylococcus spp in dog otitis externa cases that do not respond to empiric therapy could be beneficial for appropriate antibiotic selection and treatment thus preventing MDR.

Investigation of Salmonella types and its antibiotic resistance profile and determination of parasite carrier in free-living hedgehogs in Istanbul, Türkiye

Hedgehogs, which are kept as pets worldwide, are prohibited from being sold or kept as pets in Türkiye. The aim of the study was to investigate Salmonella and endo-parasite carriage in hedgehogs and to determine the antibacterial resistance profiles of isolated Salmonella agents. Free-range hedgehogs living in parks and gardens of Istanbul that were brought to veterinary clinics by animal lovers for check-up and treatment were used for sampling. Thirty faecal samples were taken from the animals. For bacteriological examinations, samples were seeded on selective media, and then the isolates were identified by conventional methods as Salmonella spp. Identification and antibiotic susceptibilities of the isolates were determined by the BD Phoenix Automated Microbiology System. All faecal samples were also investigated by PCR for Salmonella spp. specific gene regions. The aminoglycoside and quinolone resistance profiles of the strains were analysed by PCR. On parasitological examination, samples were analysed for parasites’ eggs, oocysts, and larvae. Two Salmonella isolates were determined as Salmonella enterica serovar Typhimurium (S. Typhimurium), whose antigenic formula was 4,5,12:i:1,2. The isolates were phenotypically resistant to ciprofloxacin but did not harbour any of the genes examined. Out of 30 faecal samples, 19 (63.3%) were positive for one or more genera of parasites. The hedgehogs were infected with the species of Capillaria spp. (60%), Crenosoma spp. (13.3%), Eimeria spp. (10%) and Acanthocephala spp. (6.6%). This study is the first report of Salmonella carrier and internal parasite fauna of hedgehogs in Istanbul, Türkiye.

Prevalence of typhoid fever among patients attending Murtala Muhammad Specialist Hospital Kano

Typhoid fever poses a serious public health problem in Nigeria and is largely diagnosed based on the Widal agglutination test which has been proven to be neither sensitive nor specific. This study determined the prevalence of typhoid fever using both Widal agglutination test and blood culture using automated microbiology systems (BD BACTEC). The study was carried out among 90 patients attending Murtala Muhammad Specialist Hospital in Kano. Out of the 90 cases recruited for the study, none of the cases (0, 0.0%) had S. Typhi isolated using blood culture. However, 18 cases (20%) had other bacteria which are not S. Typhi isolated using blood culture while 72 cases (80%) were negative. For the Widal test, 63 cases (70%) were positive for anti S. Typhi O antigen while 27 cases (30%) were negative. Similarly, 42 cases (46.7%) were positive for anti S. Typhi H antigen, while 48 cases (53.3%) were negative. Type of toilet system was found to be significantly associated with non S. Typhi bacteraemia (P=0.021). The studyrecommends the use of other diagnostic test such as molecular techniques to determine the sensitivity and specificity of both Widal and cultural methods.

P085 Prevalence and antifungal susceptibility of Candida spp. from the sputum sample of patients in a tertiary care hospital in Sikkim

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM ObjectivesThe role of Candida in sputum culture is unclear and is generally not treated when present in sputum samples. The objective of this study is to describe the clinical findings of patients with Candida spp. in sputum and their antifungal susceptibility pattern to know the local epidemiology of antifungal resistance.MethodsPatients with respiratory symptoms attending the tertiary care hospital during the study period of 6 months from June 2021 to December 2021. A total of 23 sputum samples were processed in the microbiology laboratory. Samples were processed following conventional mycological procedures including direct microscopy (visualization of budding yeast cell on grams stain), growth on sabouraud dextrose agar, Germ tube test, and CHROMagar. The isolates were identified by rapid identification (ID) of yeast and yeast-like organisms in the BD PhoenixTM Automated Microbiology System.Antifungal Susceptibility Testing (AFST) was carried out by disk diffusion susceptibility testing, Zone interpretation criteria as per M44/A2 protocol of CLSI were used. Antifungal used were amphotericin B (20 mcg), itraconazole (10 mcg), fluconazole (25 mcg), and voriconazole (1 mcg). Results of tests done on 23 isolates were collated and analyzed retrospectively.Clinical profile of the patients was taken retrospectively from record section and analyzed.ResultsOf the 23 patients, most common presentation was fever followed by cough and dyspnea. A total of 34% patients were receiving some form of steroid (injectable or inhalational). Only 2 patients were COVID positive by RT-PCR and 7(30%) patients had some radiological findings like consolidation, emphysematous changes, etc. Immunodeficiency condition was seen in 4 (17%) patients like tuberculosis and diabetes mellitus.Of the 23 samples, C. albicans showed prevalence of 91% as compared with C. tropicalis (5%) and C. glabrata (4.8%). AFST showed Candida spp. was found to be mostly sensitive to voriconazole and fluconazole. Resistance to amphotericin B was seen in most Candida spp. Itraconazole was not susceptible to even one isolate only 4 samples were intermediate (Fig. 1).ConclusionsInfections with Candida spp. are usually of low virulence and are associated with a few well-defined risk factors as immunocompromised state, malignancy, and steroid therapy. Understanding these risk factors, identifying the species with changing trends in antifungal resistance, instituting infection control practices to reduce morbidity and mortality in critical care areas can improve outcomes.Surveillance of the rates of Candida infection in critical areas, reporting of outbreaks and continuous monitoring of antifungal susceptibility patterns will help in choosing the best therapeutic management of complicated cases. Comparison of trends in infection rates amongst hospitals between various Indian cities and their resistance patterns can reveal vital information regarding the breakdown of infection control measures. Most Candida infections are of low virulence and only become significant in the vulnerable critical care areas. With the rise in prevalence of inherently azole-resistant species and rising use of echinocandins in ICUs, identifying risk factors and controlling the infection early can improve patient outcomes.

Risk Factors of Urinary Tract Infections Caused by Extended-Spectrum Β-Lactamase-Producing Escherichia Coli in Inpatients at a Tertiary Hospital In Surabaya, Indonesia

Highlights: ESBL frequency in women was higher than in men. Catheter use in patients with urinary tract infections and recurrent urinary tract infections has four times the risk of ESBL caused by Escherichia coli bacteria ESBL-producing E.coli bacteria are resistant to amoxicillin-clavulanic, ceftazidime, aztreonam, and ceftriaxone. Abstract: The incidence of urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) bacteria has become a global problem and has increased in recent years. The purpose of this study was to analyze the risk factors for the incidence of UTI in inpatients at Dr. Soetomo General Academic Hospital Surabaya. This research was an analytic descriptive study. Specimens were sent to the Clinical Microbiology Laboratory using sterile containers and processed according to standard laboratory procedures. It resulted in ESBL-producing E. coli that were used as a case group and non ESBL-producing E. coli as a control group. The identification and testing of antibiotic susceptibility were carried out using the BD Phoenix™ Automated Microbiology System. Ninety-four bacterial isolates were collected, consisting of 54 (57.4%) ESBL-producing E. coli bacteria and 40 (42.6%) non ESBL-producing E. coli bacteria. Recurrent UTIs (OR = 4.31; ρ =0.002; 95% CI = 1.68-11.04) and catheter use (ρ = 0.049; OR = 4.250; 95% CI = 1.050-17.210) were used as independent risk factors caused by ESBL-producing E. coli bacteria. Recurrent UTIs and catheter use were dependent risk factors caused by ESBL-producing E. coli bacteria.

Molecular Epidemiology of Penicillin-Susceptible Staphylococcus aureus Bacteremia in Australia and Reliability of Diagnostic Phenotypic Susceptibility Methods to Detect Penicillin Susceptibility.

Background: Defined by the emergence of antibiotic resistant strains, Staphylococcus aureus is a priority bacterial species with high antibiotic resistance. However, a rise in the prevalence of penicillin-susceptible S. aureus (PSSA) bloodstream infections has recently been observed worldwide, including in Australia, where the proportion of methicillin-susceptible S. aureus causing bacteremia identified phenotypically as penicillin-susceptible has increased by over 35%, from 17.5% in 2013 to 23.7% in 2020. Objectives: To determine the population structure of PSSA causing community- and hospital-onset bacteremia in Australia and to evaluate routine phenotypic antimicrobial susceptibility methods to reliably confirm penicillin resistance on blaZ-positive S. aureus initially classified as penicillin-susceptible by the Vitek® 2 automated microbiology system. Results: Whole genome sequencing on 470 PSSA collected in the 2020 Australian Group on Antimicrobial Resistance Australian Staphylococcus aureus Sepsis Outcome Programme identified 84 multilocus sequence types (STs), of which 79 (463 isolates) were grouped into 22 clonal complexes (CCs). The dominant CCs included CC5 (31.9%), CC97 (10.2%), CC45 (10.0%), CC15 (8.7%), and CC188 (4.9%). Many of the CCs had multiple STs and spa types and, based on the immune evasion cluster type, isolates within a CC could be classified into different strains harboring a range of virulence and resistance genes. Phylogenetic analyses of the isolates showed most CCs were represented by one clade. The blaZ gene was identified in 45 (9.6%) PSSA. Although multiclonal, approximately 50% of blaZ-positive PSSA were from CC15 and were found to be genetically distant from the blaZ-negative CC15 PSSA. The broth microdilution, Etest® and cefinase, performed poorly; however, when the appearance of the zone edge was considered; as per the EUCAST and CLSI criteria, disc diffusion detected 100% of blaZ-positive PSSA. Conclusions: In Australia, PSSA bacteremia is not caused by the expansion of a single clone. Approximately 10% of S. aureus classified as penicillin-susceptible by the Vitek® 2 harbored blaZ. Consequently, we recommend that confirmation of Vitek® 2 PSSA be performed using an alternative method, such as disc diffusion with careful interpretation of the zone edge.

Seroprevalence, Identification, and Pathology of Salmonellosis in Selected Poultry Farms at Barishal District of Bangladesh

Salmonellosis is a critical challenge in commercial poultry farming. This study aimed to calculate seroprevalence, identify Salmonella spp., and its pathological investigation from January to December 2019. One hundred fifty (150) serum samples and fifty (50) cloacal swabs from apparently ill and healthy birds were collected in this study. Seroprevalence was observed by serum plate agglutination (SPA) tests. The tentative diagnosis of salmonellosis was made based on history, clinical signs and bacteriological studies. Salmonella spp. was further confirmed using an automated microbiological method (VITEK®2). Post mortem examination was done in apparently sick birds, and gross and microscopic pathological lesions were investigated and recorded in a datasheet. The overall seroprevalence of salmonellosis was 42.67% in commercial chickens. Age wise prevalence of avian salmonellosis showed significantly highest infection rate in adult layers (≥ 45 days old) 65.31%, then 40.74%up to 45 days. In case of broiler, the prevalence rate in 0-10 days, 11-20 days, and 21-35 days were 13.63%, 44.12%, and 16.67%, respectively. Seasonal influence showed significantly highest proportionate prevalence of salmonellosis during summer 66.15%in comparison to winter 25.00% and rainy 24.44% seasons respectively. In bacteriological study, 12 samples were positive for Salmonellae among 50 cloacal samples. Out of 12 positive samples 5 samples were selected for the automated microbiology system VITEK® 2, and only two samples were confirmed as Salmonella gallinarum. Gross pathology of representative organs revealed bronze-colored enlarged liver, hemorrhages in the spleen and lungs, and hemorrhages in the ovary with stalk development. Microscopically, multifocal nodule formation and infiltration of inflammatory cells in the liver parenchyma and marked congestion with inflammatory cells in the spleen, hemorrhage and congestion in the lungs and intestine.

To evaluate the resistivity of Klebsiella pneumonia against present antibiogram

Klebsiella pneumoniae has become a health care concern due to its production of extended-spectrum beta-lactamase (ESBL) and its resistance to carbapenem. In February 2022, a 28-year-old female patient was admitted to the CCU private ward at Anil Bhagi Hospital in Firozpur, Punjab, India. The urine sample was inoculated with CLED agar medium for microbiological investigation. B D Phoenix sophisticated automated microbiology system was utilised for identification and sensitivity of bacteria for 24 hours for confirmation of bacteria and antibiotic sensitivity. Fosfomycin, teigocyclin and colistin were sensitive whereas other antibiotics were resistant. The observed radiuses were 13mm, 12mm, and 8mm, respectively. A urine culture revealed a highly resistant K. pneumoniae strain with over 1100,000 colony-forming units (cfu) per mL. In February 2022, a 38-year-old female patient was admitted to the CCU private ward. The 7-8 ml blood sample was collected in blood culture bottles for microbiological examination and cultured for 5 days in the B D Phoenix sophisticated automated microbiology equipment. Fosfomycin, teigocyclin and colistin were sensitive while other antibiotics were resistant. The radius observed was 9mm, 4 mm and 8 mm respectively.

Biochemical Characterization and Antimicrobial Susceptibility Pattern of the Clinical Isolates of Burkholderia cepacia complex from Northern Part of Bangladesh

Background: Burkholderia cepacia complex (Bcc) bacteria are endowed with an extraordinary metabolic diversity and emerged in the 1980s as life-threatening and difficult-to-treat pathogens among the patients suffering from cystic fibrosis (CF). Recently, these bacteria became recognized as a threat to hospitalized patients suffering from other diseases, in particular oncological patients. Objectives: The objectives of the present study were to isolate, speciate, reactions to different substrates and to find out the antibiogram of Bcc from different clinical samples. Materials and Methods: These Gram negative organisms were analyzed by BD Phoenix M50 Automated Microbiology System for carbohydrates, amino acids and proteins and other substrates to observe the reactions. Antibiogram was also observed. Results: Reactions to different substrates showed similarities with other studies with some variations. Antimicrobial susceptibility pattern of the Bcc isolates was found almost similar in comparison to other studies with some differences. Conclusion: Bcc demands an early detection and diagnosis as the incidences of infection by these organisms are increasing day by day. Therefore, this automated system can be used as a tool to facilitate early identification and antimicrobial susceptibility pattern of the Bcc bacteria in routine microbiology laboratories. KYAMC Journal Vol. 13, No. 01, April 2022: 4-8

Antibiotic resistance pattern of Klebsiella pneumoniae a major problem for society

Aim: Antibiotic resistance pattern of klebsiella pneumoniae a major problem for society. Methods: After ethical approval from the institutional ethical committee this study was done in the department of microbiology from April 2021 to march 2022 in genesis institute of dental science and research centre with collaboration of anil baghi hospital, firozpur, Punjab India. Demographic profile of all the patients like age, gender, history of any diseases was noted. All the sample like urine, sputum, blood, pleural fluid and urethral discharge were collected in the department for isolation and identification of K. pneumoniae. After 24hrs those were positive sample, further proceed for grams staining. B D Phoenix advanced automated microbiology system was used for identification and sensitivity of bacteria for 24hrs. Results: The study showed that highest number of patients having Klebsiella pneumonia were from 50-70 years having 20 (40%)patients followed by 30-50 years with 16 (32%), from Above 70 years 12 (24%) and below the age of 30 years having lowest number with two (4%) patients out of all patients. The number of male patients 33(66%) is more than females 17(34%).

Imipenem Resistance in Gram-Negative Bacteria in the Central Pediatric Teaching Hospital in Baghdad, Iraq.

Antimicrobial resistance (AMR) is a serious challenge for infectious disease prevention and treatment, according to the World Health Organization. It is a worldwide problem caused primarily by inappropriate and insufficient therapy, misuse of antimicrobials without physician supervision, unnecessary hospital readmissions, and other factors. AMR has several consequences, including increased medical costs and mortality. The present study aimed to evaluate imipenem resistance in gram-negative bacteria in Central Pediatric Teaching Hospital in Baghdad, Iraq, and determine this bacteria resistance in different samples. Initially, a total of 100 different samples were collected from child patients from October 1, 2020, to August 31, 2021. Each isolate was identified using VITEK 2 automated microbiology system. The recorded data showed that the isolated organisms resistant to imipenem included Klebsiella pneumonia (n=21), Pseudomonas aeruginosa (n=19), and Acinetobacter baumannii (n=16). In the current study, Klebsiella pneumonia was the most common pathogen in males (n=57) compared to female (n=43), followed by Pseudomonas aeruginosa and Acinetobacter baumannii, particularly in the age range of 1 day- 3 years. Depending on the sample type, Klebsiella pneumonia, the most imipenem-resistant bacteria, was found more in the urine of patients with urinary tract infections. Pseudomonas aeruginosa was equally found in blood, urine, wound swab, and sputum samples. In comparison to other samples, Acinetobacter baumannii was found in greater numbers in the blood and in an equal number in urine and cerebrospinal.

Detection of Two Copies of a bla NDM-1-Encoding Plasmid in Escherichia coli Isolates from a Pediatric Patient with Diarrhea.

PurposeTo elucidate the contribution of a transferable plasmid harboring the blaNDM-1 gene in an Escherichia coli clinical isolate to the spread of resistance determinants.MethodsNine extended-spectrum β-lactamase-producing E. coli were collected from diarrhea samples from a pediatric patient and genetic linkage was investigated through enterobacteriaceae repetitive intragenic consensus polymerase chain reaction (PCR). Bacterial species were identified by 16s rRNA sequencing, susceptibility testing with the use of a BD PhoenixTM-100 Automated Microbiology System, and assessment of virulence genes by PCR. The transferability of blaNDM-1 in E. coli strain TCM3e1 was confirmed by conjugation experiments. Complete sequencing of E. coli strain TCM3e1 was determined with the PacBio and Illumina NovaSeq platforms and the characteristics were analyzed with bioinformatics software.ResultsThe results showed that all nine E. coli strains were the same clone. E. coli strain TCM3e1 was resistant to 12 antimicrobial agents and carried the virulence gene EAST-1. Conjugation transfer analysis showed that blaNDM-1 was carried on a self-transmissible plasmid. Two copies of the blaNDM-1 gene were present on an IncC plasmid and some resistance genes with two or three copies were located downstream of the blaNDM-1 gene and formed a tandem repeat fragment (blaDNM-1-bleo-sul1- aadA17- dfrA12).ConclusionA transmissible plasmid harboring two copies of the blaNDM-1 gene, including clonal dispersions of the blaNDM-1 gene, was identified in clinical isolates. These findings emphasized the necessity of surveillance of the plasmid-borne blaNDM-1 to prevent dissemination.

Prevalence, typing and antimicrobial resistance of Salmonella isolates from commercial shellfish in the North coast of Morocco

Salmonellosis is one of the most common foodborne illnesses in the world. The irrational use of antibiotics in medicine and in animal nutrition has greatly favored the emergence and spread of resistant strains of non-typhoid Salmonella. This study aims the determination of the prevalence of Salmonella in bivalve mollusks in Northern Morocco, as well as the molecular typing and antibiotic susceptibility testing of the strains isolated from positive samples. In total, 150 samples from shellfish composed of mussels (Mytilus galloprovincialis), clams (Callista chione and Ruditapes descussatus) and oysters (Magallana gigas). Isolated Salmonella were characterized by Molecular techniques PCR, MLST and MLVA, phylogenetically grouped by MLSA, and susceptibilities were determined for 30 antimicrobial drugs using microdilution method by the BD Phoenix Automated Microbiology System. Prevalence of Salmonella enterica subsp. enterica was 12.67%, grouped in four serovars identified as Chester, Hadar, Typhimurium and Kentucky. Five different MLST STs (sequence types) were detected, ST1954 being the most common, which was mostly found in Chester isolates. Forty-two percent of the isolates showed resistance to more than one antibiotic, especially trimethoprim, sulfa drugs, quinolones and β-lactam. There was a marked change in the serovars and antimicrobial resistance profiles of the Salmonella isolates in this study compared to those in previous studies.

A Monocentric Retrospective Study of AUC/MIC Ratio of Vancomycin Associated with Clinical Outcomes and Nephrotoxicity in Patients with Enterococcal Infections

Vancomycin is an antibiotic commonly used for the treatment of enterococcal infections. However, there is no clear correlation regarding of vancomycin area under the curve/minimum inhibitory concentration (AUC/MIC) ratio and clinical outcomes for the treatment of enterococcal infections. The aims of this study were to evaluate the relationship of vancomycin AUC/MIC ratio in patients with clinical outcomes and nephrotoxicity for patients with documented enterococcal infections. A Bayesian technique was used to calculate the average vancomycin AUC0–24. The MIC was determined using the VITEK 2 automated microbiology system, and the average AUC0–24/MIC value was calculated for the first 72 h of therapy. All medical records of patients prescribed vancomycin with therapeutic drug monitoring were collected during January 2010–October 2020 at Chiang Mai University Hospital (CMUH). A retrospective single-center cohort of 312 participants were met the inclusion criteria. The results of this study showed that, a vancomycin AUC/MIC of ≥400 mg·h/L was associated with significant differences in clinical response compared to a vancomycin AUC/MIC of <400 mg·h/L (aHR: 0.50, 95% CI: 0.26–0.97; p = 0.042). Likewise, a vancomycin AUC/MIC of ≥400 mg·h/L was associated with significant differences in the microbiological response (aHR: 0.37, 95% CI: 0.14–0.94; p = 0.036), compared to a vancomycin AUC/MIC of <400 mg·h/L. However, nephrotoxicity in patients with a vancomycin AUC/MIC of ≥400 mg·h/L was higher than those with a vancomycin AUC/MIC of <400 mg·h/L (aHR: 3.96, 95% CI: 1.09–14.47; p = 0.037). Declining renal function may be a result of high vancomycin concentrations. In addition, declining renal function (e.g., failure to resolve the focus of infection, co-administration of other antibiotics) might result in higher AUC/MIC. We found a target vancomycin AUC/MIC of ≥400 mg·h/L and this AUC/MIC target value could be optimal for the use for monitoring treatment of enterococcal infections. Thus, vancomycin dosage must be adjusted to achieve the AUC/MIC target and closely monitored for renal function. These findings are not transferable to critically ill patients.

Prevalence and antibiotic resistance of bacterial pathogens in respiratory tract samples of geriatric patients

Background/Aim: The frequency and severity of respiratory tract infections increase with aging. The aim of this study was to determine the bacterial profile of respiratory tract samples in geriatric patients and evaluate the antibiotic susceptibility patterns of the pathogens. Methods: In this cross-sectional study, a total of 509 clinical samples which were obtained from 302 geriatric patients over 65 years of age and sent to the microbiology laboratory between June 2019-January 2021 were investigated retrospectively. The identification and antibiotic susceptibilities of strains were evaluated with BD-Phoenix-100 fully automated microbiology system. Results: Of the 302 geriatric patients, 166 (%55) were males and 136 (%45) were females. The most isolated pathogens were Klebsiella pneumoniae (25.3%) Pseudomonas aeruginosa (22.5%) and Acinetobacter baumannii (10.2%), Corynebacterium striatum (7.3%), Escherichia coli (6.4%), Staphylococcus aureus (6.4%) and coagulase-negative staphylococci (4.2%). The production of ESBL in Klebsiella pneumoniae strains (52.3%) was higher than in Escherichia coli (41%) strains. All Corynebacterium striatum samples were resistant to ciprofloxacin, tetracycline, rifampin, and penicillin. Methicillin resistance among Staphylococcus aureus (MRSA) isolates was 22.7% and they were 100% susceptible to vancomycin and teicoplanin. Above 90% of K. pneumoniae, P. aeruginosa and A. baumannii positive patients were hospitalized in intensive care units (P<0.05). The tobramycin-resistant E. coli and colistin-resistant A. baumannii rates were highest between 85-99 years of age (P<0.05). Conclusion: K. pneumoniae, P. aeruginosa and A. baumannii were the most common pathogens in respiratory tract samples in geriatric patients, especially those hospitalized in the intensive care units. The antimicrobial resistance rates were higher in patients aged ≥85 years. Vancomycin and teicoplanin were the most effective antibiotics against MRSA. It is thought that the results will be useful in the preparation of treatment protocols and guiding physicians about the correct use of antibiotics.

Retrospective assessment of fungal pathogens isolated from various clinical samples in a tertiary care hospital in Turkey: A cross-sectional study

Background/Aim: Fungal infections are an emerging health problem worldwide and can be caused by a broad variety of fungal pathogens. This study aimed to retrospectively determine and evaluate the fungal pathogens isolated from various clinical samples in our laboratory. Methods: A total of 996 clinical samples obtained from 803 patients who visited Karabuk University Training and Research Hospital microbiology laboratory between January 2019-December 2020 were included in this study. The BD-Phoenix 100 automated microbiology system was used for the identification of strains. Results: Among 803 patients, 52.4% were female and 47.5% were male. The median age of the patients was 76 (0-99) years. Urine (49%) and blood (27.6%) samples were evaluated the most. The most common fungal pathogen was Candida albicans (48.7%), followed by Candida tropicalis (16.5%), Candida parapsilosis (10.6%), Candida glabrata (9%), Saccharomyces cerevisiae (5.7%), and Trichosporon species (3.1%). While more than 90% of fungal strains were isolated from the inpatients, 9% were isolated from the outpatients (p<0.05). Among all, 69.4% of strains were isolated from the intensive care units, followed by internal medicine (5.5%), palliative care (5%), urology (3.6%), and orthopedics and traumatology clinics (2.1%). Conclusion: Although C. albicans is still the most common fungal pathogen, the incidences of non-albicans candida and other fungi are increasing worldwide. Therefore, each country should figure out its local fungal profile and update its antifungal treatment protocols accordingly.

Antibacterial Resistance in Lower Respiratory Tract Bacterial Pathogens: A Multicenter Analysis from Turkey.

This study aimed to evaluate the etiology of lower respiratory tract infections (LRTIs) and their antibiotic resistance. Bacterial culture results of LRT samples from 17 hospitals between 2016-2019 were included in the study. All isolates were identified and AST were performed by automated microbiology systems. AST was performed according to EUCAST. Non-duplicate 30,051 (26,890 HA and 3156 CA) isolates detected as causative pathogen. LRTIs are caused by 85.1% Gram-negative bacterial pathogens and 14.9% Gram-positive. The most common isolates among HA pathogens were Acinetobacter spp. (27.4%), P.aeruginosa (22.2%), K.pneumoniae (17.9%); among CA pathogen S.pneumoniae (19.9%), P. aeruginosa (18.9%), H.influenzae (14.6%). ESBL rate was 62.5% in K.penumoniae; 53.1% in E.coli; 19.1% in Klebsiella spp; 13.9% in Enterobacter spp.; 8.6% in Proteus spp.; 6.3% in Citrobacter spp.; and 4.3% in Serratia spp. Resistance rates to carbapenems and colistin were 92.8% and 12.8% in A baumannii, 39.8% and 7.5% in P.aeruginosa, 47.3% and 18.5% in K.penumoniae. Among staphylococci, 27.3% of S. aureus and 82.4% of CoNS were methicillin resistant. 7.6% of E.faecium and 0.9% of E.faecalis were vancomycin resistant. Linezolid resistant S. aureus, CoNS, E.faecalis and E.faecium rates were 0.3%, 2.9%, 0.0% and 4.6%. Inducible clindamycin resistant rate was 17.2% in S. aureus 38.2% in CoNS. Non-susceptible S.pneumoniae isolate rate to penicillin was 37.0%. 6.5% of S.maltophilia and 4.4% of B.cepacia isolates were resistant to trimethoprim/sulfamethoxazole. Antibiotic resistance was mainly observed among A.baumannii and K.pneumoniae and continuous surveillance of antimicrobial resistance patterns in the management of LRTIs is important.