Clinical Characteristics and Antimicrobial Susceptibility of Mycobacterium intracellulare and Mycobacterium abscessus Pulmonary Diseases: A Retrospective Study

The incidence of nontuberculous mycobacteria (NTM) diseases is increasing every year. The present study was performed to investigate the clinical characteristics, CT findings, and drug susceptibility test (DST) results of patients diagnosed with M. intracellulare or M. abscessus nontuberculous mycobacterial pulmonary disease (NTMPD). This retrospective study included patients diagnosed with NTMPD due to M. intracellulare or M. abscessus for the first time at Anhui Chest Hospital between 01/2019 and 12/2021. The patients were grouped as M. intracellulare-NTMPD group or M. abscessus-NTMPD group. Clinical features, imaging data and DST data, were collected. Patients with M. intracellulare infection had a higher rate of acid-fast smears (66.1% vs. 45.2%, P = 0.032 ) and a higher rate of cavitation based on pulmonary imaging (49.6% vs. 19.4%, P = 0.002 ) than patients with M. abscessus infection, but both groups had negative TB-RNA and GeneXpert results, with no other characteristics significant differences. The results of DST showed that M. intracellulare had high susceptibility rate to moxifloxacin (95.9%), amikacin (90.1%), clarithromycin (91.7%), and rifabutin (90.1%). M. abscessus had the highest susceptibility rate to amikacin (71.0%) and clarithromycin (71.0%). The clinical features of M. intracellulare pneumopathy and M. abscessus pneumopathy are highly similar. It may be easily misdiagnosed, and therefore, early strain identification is necessary. M. intracellulare has a high susceptibility rate to moxifloxacin, amikacin, clarithromycin, and rifabutin, while M. abscessus has the highest susceptibility rate to amikacin and clarithromycin. This study provides an important clinical basis for improving the management of NTMPD.

Antibiotic Resistance and Molecular Biological Characteristics of Non-13-Valent-Pneumococcal Conjugate Vaccine Serogroup 15 Streptococcus pneumoniae Isolated From Children in China

Background: The isolation rate of serogroup 15 Streptococcus pneumoniae has been increasing since developing countries began administering the 13-valent pneumococcal conjugate vaccine.Methods: We detected the antibiotic resistance and molecular characteristics of 126 serogroup 15 S. pneumoniae strains isolated from children in China. Serotypes were determined via the Quellung reaction. Antibiotic resistance was tested using the E-test or disc diffusion method. Sequence types were assigned via multilocus sequence typing. Data were analyzed using WHONET 5.6 software.Results: The frequencies of S. pneumoniae serotypes 15A, 15B, 15C, and 15F were 29.37, 40.48, 28.57, and 1.59%, respectively. Continuous-monitoring data from Beijing showed that the annual isolation rates of serogroup 15 S. pneumoniae were 7.64, 7.17, 2.58, 4.35, 3.85, 7.41, and 10.53%, respectively, from 2013 to 2019. All 126 serogroup 15 strains were susceptible to vancomycin and ceftriaxone. The non-susceptibility rate to penicillin was 78.57%. All strains were resistant to erythromycin with high minimum inhibitory concentrations (MICs). The multidrug resistance rate was 78.57%. The most common clonal complexes were CC3397, CC6011, CC10088, CC9785, and ST8589.Conclusion: Serogroup 15 S. pneumoniae is common among children in China, and these strains should be continuously monitored.

Seroprevalence of CMV in Women with Bad Obstetric History in Babil/Iraq

Placental dysfunction and or fetal central nervous system infestation caused by Human cytomegalovirus (HCMV) is the leading cause of congenital non-genetic neuro-developmental problems of the newborn, worldwide. Although the highest rates of congenital infection and CMV seroprevalence occurs in developing countries like Iraq, there remains a paucity of data from that part of the world. This descriptive case control study was undertaken in Babylon/ Iraq to determine the local seroprevalence of CMV in women of child bearing age, and to identify the socio-demographic factors associated with it. This study found a seropositivity peak amongst the 26-35 yr olds which declined in the 36 – 45 yr olds. However, the evidence of current infection was stable at 25% among the 26-35 yr olds and the 36 – 45 yr old women. Overall seropositivity was at 77.32%, a susceptibility rate was at 22.68%, and seropositivity for IgG was highest among the educated, those living in overcrowded settings, and those with poor obstetric histories. Our study concludes that CMV screening of women in the Al Hamza district in Babylon/Iraq and the availability of advice on how to prevent the infection can be beneficial for health outcomes.

Comparison of in vitro activities of plazomicin and other aminoglycosides against clinical isolates of Klebsiella pneumoniae and Escherichia coli

Objectives To compare the in vitro activity of plazomicin and two older aminoglycosides (gentamicin and amikacin) against 180 isolates of Escherichia coli and Klebsiella pneumoniae, including subsets of 60 non-ESBL-producing, 60 ESBL-producing and 60 carbapenem-resistant (46 carrying blaOXA-48, 11 carrying blaNDM and 3 carrying blaOXA-48 and blaNDM) strains. Methods MICs of plazomicin, gentamicin and amikacin were determined by a gradient diffusion method. Gentamicin and amikacin MICs were interpreted according to CLSI criteria and EUCAST breakpoint tables. Plazomicin MICs were interpreted using FDA-defined breakpoints. Results All non-ESBL-producing and ESBL-producing isolates were susceptible to plazomicin. The plazomicin susceptibility rate (71.7%) in carbapenem-resistant isolates was significantly higher than those observed for gentamicin (45%) and amikacin (56.7% and 51.7% according to CLSI and EUCAST breakpoints, respectively). Gentamicin, amikacin and plazomicin susceptibility rates (35.6% for gentamicin; 44.4% and 37.8% for amikacin according to CLSI and EUCAST breakpoints, respectively; 64.4% for plazomicin) in carbapenem-resistant K. pneumoniae were significantly lower than those observed for carbapenem-resistant E. coli isolates (73.3% for gentamicin; 93.3% for amikacin and plazomicin). Gentamicin, amikacin and plazomicin susceptibility rates for blaNDM-positive isolates were lower than those observed for blaOXA-48-positive isolates, but differences were not statistically significant. Among the isolates that were non-susceptible to both gentamicin and amikacin, the plazomicin susceptibility rate was less than 30%. Conclusions Although plazomicin showed excellent in vitro activity against carbapenem-susceptible isolates, the plazomicin resistance rate increased to 35.6% among carbapenem-resistant K. pneumoniae and further increased to 45.5% among blaNDM-positive isolates.

Trends in Resistance to Cefazolin in a Military Hospital in Alkharj

Aim: This study aimed to describe the trends in resistance to cefazolin in a military hospital in Alkharj. Methodology: This was a retrospective study that was conducted in Alkharj to describe the trends in resistance to cefazolin from 1st of January 2020 to 30th of June 2021. The results of bacterial cultures were collected from the microbiology laboratory in the hospital. Results: The susceptibility rate of gram negative bacteria to cefazolin in 2020 was more than 50% except Enterobacter cloacae (susceptibility rate=0) and that the resistance of Escherichia coli to cefazolin was increased from 36% in 2020 to 48% in 2021. The present study showed that cefazolin should not use to treat infections caused by Enterobacter cloacae because of the high resistance rate (100%). Conclusion: The present study showed that the bacterial resistance of several pathogens to cefazolin was high. It is important to monitor antimicrobial susceptibility continuously and to use antibiotics wisely to minimize emergence of drug resistant bacteria.

Multimodal Interventions to Prevent and Control Carbapenem-Resistant Enterobacteriaceae and Extended-Spectrum β-Lactamase Producer-Associated Infections at a Tertiary Care Hospital in Egypt

The current rise of multidrug-resistant (MDR) Gram-negative Enterobacteriaceae including the extended-spectrum β-lactamase (ESBL)-producing organisms and carbapenem-resistant Enterobacteriaceae (CRE) has been increasingly reported worldwide, posing new challenges to health care facilities. Accordingly, we evaluated the impact of multimodal infection control interventions at one of the major tertiary healthcare settings in Egypt for the aim of combating infections by the respective pathogens. During the 6-month pre-intervention period, the incidence rate of CRE and ESBL-producing clinical cultures were 1.3 and 0.8/1000 patient days, respectively. During the post-intervention period, the incidence of CRE and ESBL producers continued to decrease, reaching 0.5 and 0.28/1000 patient days, respectively. The susceptibility rate to carbapenems among ESBL producers ranged from 91.4% (ertapenem) to 98.3% (imipenem), amikacin (93%), gentamicin (56.9%), and tobramycin (46.6%). CRE showed the highest resistance pattern toward all of the tested β-lactams and aminoglycosides, ranging from 87.3% to 94.5%. Both CRE and ESBL producers showed a high susceptibility rate (greater than 85.5%) to colistin and tigecycline. In conclusion, our findings revealed the effectiveness of implementing multidisciplinary approaches in controlling and treating infections elicited by CRE and ESBL producers.

Prevalence of Imipenemase and Verona Integron-Encoded Metalloβ-Lactamase in Imipenem-Resistant Pseudomonas aeruginosa

Objective: To determine the prevalence of metallo-β-lactamase (MBL) including imipenemase (IMP) and Verona integronencoded metallo-β-lactamase (VIM) in imipenem-resistant Pseudomonas aeruginosa (IRPA) isolates and investigate the in vitro activities of 9 antimicrobial agents against MBL-positive isolates. Material and Methods: Seventy-eight IRPA isolates were obtained from Songklanagarind Hospital. MBL production was detected by the combined-disk test, and the blaIMP and blaVIM genes were determined via Polymerase Chain Reaction (PCR). The in vitro activities of amikacin, gentamicin, aztreonam, ceftazidime, meropenem, ciprofloxacin, colistin, piperacillin/ tazobactam, and ticarcillin/clavulanate were determined using the E-test method. Results: Of the 78 IRPA isolates, 20 (25.6%, 95% CI 17.2-36.4%) were MBL phenotype-positive, and 30 (38.5%, 95% CI 28.5-49.6%) were MBL genotype-positive (29 Imipenemase (IMP)-type and 1 Verona integron-encoded metallo-βlactamase (VIM)-type). Ninety percent of the MBL genotype-positive isolates were MDR. Most MBL genotype- positive isolates were susceptible to colistin (susceptibility rate of 96.7% and MIC50 value of 1.5 µg/mL). Conclusion: Our results showed a high prevalence of MBL-positive isolates (38.5%) in IRPAs, and the IMP-type isolates were dominant among the metallo-β-lactamase-producing imipenem-resistant P. aeruginosa tested. Most MBL-positive isolates were susceptible to colistin and had low MIC50 values.

KERENTANAN KEBAKARAN HUTAN BERDASARKAN KARAKTER UMUR TANAMAN JATI

Forest management in Java dominated with Teak plantation that organize with community. One threats of forest damages is forest fires. Forest fires caused by susceptible fuel, oxygen rate, and fires resource. Teak plantation closed with community activities that using fires within purpose or not. This research aim to identify the effect of plant age towards forest fires susceptibility by combustion rate. This research conducted in Wanagama I EduForest. The effects of plant age towards forest fires susceptibility analysed by bark thickness and water content of bark. Teak bark samples taken on various age of 5th, 15th, and 40th. Foresf fires suceptibility observed by combustion test. The effects of teak age towards on bark thickness and water content, combustion rate analysed using anova with 10% of confident level. The results showed that 1) plant age affecting thickness and water content of teak bark; 2) bark thickness affect fire susceptibility rate of teak on various age, bark thickness has growth along age increase which more tolerant towards of combustion; and 3) Surface forest fires in Wanagama I caused by multiple sources of fire ignition that closed to road accesibility, and the damage mostly occurred until 100 cm of height from forest ground.

Prevalence and Antimicrobial Susceptibility Pattern of Pseudomonas aeruginosa Isolated from Various Clinical Samples in a Tertiary Care Hospital

Background and Objectives: Pseudomonas aeruginosa is one of the leading causes of hospital acquired infections. Increased resistance in this organism continues to pose a significant threat to patient care because of limited therapeutic options. The main objective of this study was to find out the prevalence and current antimicrobial susceptibility pattern of P. aeruginosa isolates obtained from various clinical samples at a tertiary care hospital. Material and Methods: The study was conducted in a tertiary care hospital in Bharatpur, Chitwan, Nepal on 453 isolates of Pseudomonas aeruginosa from various clinical samples. The colonies which were grown on culture media were identified by different standard biochemical tests. Antimicrobial susceptibility testing was done using Kirby–Bauer disc diffusion method and the results were interpreted according to the CLSI guidelines. Quality control of the test was done by standards ATCC strain of P. aeruginosa 27853. Results: This present study revealed the prevalence rate of P. aeruginosa was 11.29%. Piperacillintazobactam was the most sensitive chemotherapeutic agent with 94.26% susceptibility rate, followed by imipenem 89.40% and levofloxacin 88.08%. Amikacin showed better susceptibility rate 67.33% than that of gentamicin 48.78%; the susceptibility rate to cephalosporin and aztreonam was relative very low. Most of the P. aeruginosa strains were isolated from clinical samples like sputum 206, urine 81, respiratory secretion 76, and pus 35. Out of 453 clinical isolates, 167(36.86%) clinical isolates of P. aeruginosa were found to be MDR. Conclusion: Most of the P. aeruginosa strains were isolates from sputum, urine, respiratory secretions and pus samples and were found to be MDR. Piperacillin-tazobactam was the most sensitive chemotherapeutic agent followed by Imipenem, levofloxacin.

1453. PBP2, PBP2a and PBP4 Clone-specific Polymorphisms are not Associated to Ceftaroline (CPT) Susceptibility in Chilean Clinical Isolates of Methicillin-Resistant Staphylococcus aureus (MRSA)

Background CPT is a last-generation cephalosporin active against MRSA due to its affinity for PBP2a. CPT-resistance (CPT-R) is well-described, with mutations in the active transpeptidase domain of PBP2a associated to high-level resistance. The accumulation of changes in the non-penicillin-binding domain of PBP2a has been linked to elevations of the minimal inhibitory concentration (MIC) to CPT to levels around 2-4ug/mL. PBP4 and PBP2 have also been implicated as potentially relevant mecA-independent mechanisms of CPT-R. We recently reported high rates of CPT-non-susceptibility in clinical MRSA strains from Chile. However, the mutational landscape of PBPs in clinical MRSA isolates from Chile and its relation to CPT susceptibility has not been assessed. Methods We analyzed 180 MRSA isolates collected from 2000-2018 in Santiago, Chile. Identification was confirmed by MALDI-TOF and methicillin resistance with cefoxitin disk-diffusion. CPT susceptibility was performed by BMD following CLSI-2019 guidance. Whole-genome sequencing was performed for all isolates; the mutational profile of PBPs was determined using reference sequences for PBP2 (AGY89563.1), PBP2a (NG_047938.1) and PBP4 (X91786.1). Results All isolates were phenotypically-confirmed MRSA and harbored mecA. The MIC50/MIC90 by BMD was 2/2μg/dL; only 71 (39%) isolates were CPT-susceptible (MIC <1µg/mL). Most isolates belonged to ST5/SCCmecI (70%,126/180), ST105/SCCmecII (10%,18/180) and ST8/SCCmecIV (5%, 9/180). All ST5/SCCmecI isolates carried the mutations in PBP2 (Y156D), PBP2a (M122I and E150K), and PBP4 (T189S, L234H, and T409A); CPT-susceptibility among ST5/SCCmecI was only 22%. On the other hand, all ST105/SCCmecII isolates had mutations in PBP2 (S707L) and PBP4 (T189S, L234H, and T409A) and exhibited a higher CPT-susceptibility rate (67%). All 9 isolates belonging to the ST8/SCCmecIV lineage harbored a non-coding mutation in PBP2a (g-6t) and the previously observed L234H change in PBP4. Importantly, no association between specific polymorphisms and MIC to CPT was found. Table 1. PBPs mutations compared to CPT MICs by MLST and SCCmec Conclusion Changes in the studied PBPs were frequent among MRSA circulating in Chile and were conserved among different genetic backgrounds. However, these changes were not associated with the level of CPT MIC among these isolates. Disclosures Cesar A. Arias, MD, MSc, PhD, FIDSA, Entasis Therapeutics (Scientific Research Study Investigator)MeMed (Scientific Research Study Investigator)Merck (Grant/Research Support)