Bacterial Etiologic Agents Research Articles

A Comprehensive Study of Bacterial Etiological Agents in Sterile Body Fluids and Antimicrobial Susceptibility Patterns Among Hospitalized Patients at an Academic Medical Center in India

A Comprehensive Study of Bacterial Etiological Agents in Sterile Body Fluids and Antimicrobial Susceptibility Patterns Among Hospitalized Patients at an Academic Medical Center in India

Activity Assessment of Antibiotics Used Against Different Bacterial Etiological Agents of UTI in Najaf, Iraq

Activity Assessment of Antibiotics Used Against Different Bacterial Etiological Agents of UTI in Najaf, Iraq

Microbiological Profile and Antibiotic Resistance Pattern in Acuteexacerbations of COPD: A Study from Northern India

Background Chronic Obstructive Pulmonary Disorder (COPD) is a major cause of morbidity and one of the principal causes of death worldwide. The objective of this study is to identify the bacterial etiological agents in patients with acute exacerbations of COPDs by sputum culture and their antibiogram.MethodsThis is a prospective study comprising 100 diagnosed patients of COPD taken as GOLD Grade 4 who were admitted in the Department of Pulmonary Medicine, TB and Chest Hospital which comes under King George Hospital, Visakhapatnam.ResultsOut of 100 patients, 83 were males of which 87% were smokers. The most common organisms isolated were Gram negative bacilli in 51 patients and only 26 were Gram positive cocci. The most common Gram-negative isolate was Klebsiella pneumoniae 27 cases followed by Pseudomonas aeruginosa in 19 cases. The most common Gram-positive isolate was Streptococcus pneumoniae in 16 cases followed by Streptococcus pyogenes in 6 cases and Staphylococcus aureus in 2 cases.Conclusions Frequent exacerbations appear to be associated with worsening healthoutcomes and effort should focus on prompt and effective treatment of eachepisode. Bacterial pathogens, mostly Gram negative bacilli are found to be the chief etiological agents in AECOPD. Antibiotic therapy should be initiated early depending on the culture. Susceptibility patterns of that particular region should be determined to prevent antibiotic resistance and to decrease health costs.

Spectrum of Lower Respiratory Bacterial Pathogens and their Antimicrobial Susceptibility in a Tertiary Care Hospital at Rawalpindi

Objective: To study the spectrum of bacterial etiological agents causing lower respiratory tract infections and their antimicrobial susceptibility pattern in a tertiary care hospital at Rawalpindi. Methodology: A descriptive, cross-sectional study was conducted in the department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi from June to December 2021. Total 130 patients with lower respiratory tract infections (LRTIs) irrespective of age and gender were included in the study while patients of pulmonary tuberculosis, fungal diseases and patients having prior antibiotic therapy before sample collection were excluded. Non quantitative cultures were performed for sputum, non- directed bronchial lavage (NBL), pleural fluid and quantitative cultures for bronchoalveolar lavage (BAL) and endobronchial (EB) washings specimens. Antibiotic susceptibility was performed using Clinical and Laboratory Standards Institute (CLSI) 2021 guidelines. Results: Pseudomonas aeruginosa (26.9%) was found to be the most prevalent bacterial pathogen followed by Klebsiella pneumoniae (23%). Both Gram negative and Gram-positive bacteria showed highest antimicrobial resistance to flouroquinolones. Gram negative bacteria were more susceptible to aminoglycosides and carbapenems. Gram positive bacteria were most susceptible to linezolid and vancomycin. Staphylococcus aureus was isolated from 8 samples, of which 5(62.5%) were Methicillin-resistant Staphylococcus aureus (MRSA). Conclusion: This study concluded that the most frequent bacterial pathogen causing lower respiratory tract infections was Pseudomonas aeruginosa and both Gram negative and Gram-positive bacteria showed highest antimicrobial resistance to flouroquinolones.

Assessment of bacterial etiologic agents, antimicrobial susceptibility status and associated factors of isolates among hospitalized patients suspected for blood stream infection at Dessie comprehensive specialized hospital, northeast Ethiopia

Assessment of bacterial etiologic agents, antimicrobial susceptibility status and associated factors of isolates among hospitalized patients suspected for blood stream infection at Dessie comprehensive specialized hospital, northeast Ethiopia

Identification of common bacterial etiologic agents, antimicrobial susceptibility pattern & associated risk factors of Otitis media among pediatric patients of ENT Center of Orotta National Referral Hospital

Identification of common bacterial etiologic agents, antimicrobial susceptibility pattern & associated risk factors of Otitis media among pediatric patients of ENT Center of Orotta National Referral Hospital

Evaluation of the BioFire® FilmArray® Pneumonia plus Panel for Detecting Bacterial Etiological Agents of Lower Respiratory Tract Infections in an Oncologic Hospital. Comparison with Conventional Culture Method.

Conventional methods used to determine pneumonia pathogens are characterized by low sensitivity and long turnaround times. Introducing new tests with better parameters in patients at higher risk of infections is highly anticipated. The results of the conventional quantitative culture method (CM) in determining the bacterial etiology of pneumonia were compared with the results of the Pneumonia plus Panel test (PNP; BioFire® Diagnostics, USA) in 79 samples of bronchoalveolar lavage (BAL). Materials were collected from 79 patients with suspected pneumonia treated in an oncologic hospital due to solid tumors. Only 16/79 BAL samples (20.3%) were true positive (TP) for bacterial etiology in CM vs. 27/79 samples (34.2%) true positive in the PNP test. The total agreement between methods of interpreting the result (positive or negative) was 84.8%. The most prevalent pathogens in both methods were Staphylococcus aureus, followed by Escherichia coli, Pseudomonas aeruginosa, and Haemophilus influenzae. The PNP test identified several respiratory pathogens that were not grown in culture. The semiquantitative value reported by the PNP test was higher than that reported by culture. The PNP test vs. combined test (PNP test and CM methods) demonstrated positive predictive value (PPV) and negative predictive value (NPV) values of 100.0% and 98.1%, and the sensitivity and specificity were 96.4% and 100.0%. The PNP test is a good tool for determining the etiology of bacterial pneumonia and may support the care of an oncologic patient. However, further large-sample studies are needed to research in strictly defined groups of oncologic patients.

An Investigation of Bacterial Pathogens Associated with Diseased Nile Tilapia in Small-Scale Cage Culture Farms on Lake Kariba, Siavonga, Zambia

This study investigated disease outbreaks in farmed Oreochromis niloticus (Nile tilapia) in Siavonga among small-scale cage culture farms on Lake Kariba in order to establish bacterial etiological agents associated with fish mortality and to determine their antibiotic susceptibility. A total of 300 fish samples from 11 farms were aseptically collected and bacteria were isolated from the kidney, liver, brain, and spleen. The isolates were identified using their morphological characteristics and conventional biochemical tests. The antibiotic susceptibility of selected bacteria was determined by the Kirby–Bauer disc diffusion method. The following well-known fish pathogens were identified at a prevalence of Aeromonas spp. (13%), Pseudomonas spp. (10.3%), Micrococcus spp. (9.7%), Klebsiella spp. (8.7%), Lactococcus spp. (7.3%), Streptococcus spp. (7.0%), and Acinetobacter spp. (7.0%). All the isolates tested were susceptible to doxycycline, and complete resistance to ciprofloxacin, co-trimoxazole, and cephalothin was recorded in the Bacillus spp. The observed resistance could be attributed to bacteria from terrestrial sources as fish farmers do not administer antibiotics to fish. To our knowledge, this is the first study to establish the occurrence of several bacterial species infecting tilapia in Zambia and the first to determine the antibiotic susceptibility of fish bacteria among small-scale farms on Lake Kariba. The current study provides baseline information for future reference and fish disease management on Lake Kariba and in Zambia.

The quality of microbiological diagnostics in Poland based onthe results of external laboratory quality control programmes

<br><b>Introduction:</b> The article describes the results of the 29th edition of the Polish NationalExternal Quality Assessment Scheme in Microbiology POLMICRO created by the Centre ofQuality Control in Microbiology (CQCM).</br><br><b>Aim:</b> The aim of the scheme is the evaluation of the reliability of the results of microbiologicaltests performed by Polish medical laboratories, which includes e.g. identification andassessment of antimicrobial susceptibility of bacterial etiological agents of infections,together with the detection of antimicrobial resistance mechanisms.</br><br><b>Materials and methods:</b> The assessment of external quality control programmes organised byCQCM is based on the analysis of the results of participants of the POLMICRO, POLMICRO/MIKOLOGIA and POLMICRO/SSE programmes in a full annual cycle.</br><br><b>Results:</b> In 2022, 96.00% of POLMICRO participants, as well as 99.22% of laboratories participatingin POLMICRO/SSE and all participants of POLMICRO/MIKOLOGIA, obtained positiveresults.</br><br><b>Conclusions:</b> The results of external quality control programmes conducted by CQCM showthat medical laboratories in Poland have been maintaining a high level of microbiologicaldiagnostics.</br>

Antimicrobial resistance pattern in aerobic bacteria isolated from endotracheal aspirate in ventilator-associated pneumonia: Ten years observation from a tertiary care hospital.

Ventilator-associated pneumonia (VAP) is a nosocomial infection associated with high morbidity and mortality. This study was undertaken to monitor the trend of the demographical details, comorbid conditions, bacterial etiological agents, and their antibiogram causing VAP in adults in the year 2008, 2013 and 2018. A retrospective study conducted at the Department of Microbiology, Hospital Infection control and Quality Control at a tertiary care teaching hospital. All the adult patients with more than 48 h of the mechanical ventilator with endotracheal intubation with Clinical Pulmonary infection Score >6 with suspicion of VAP were included in the study at a difference of 5 years, i.e., 2008, 2013, and 2018. A total of 338 patients were included in the study, of which males accounted for more than two-third of the patients studied. Nearly 45% of the patients belonged to geriatric (>60 years) age group. The most common comorbid conditions were chronic obstructive pulmonary disease, hypertension and diabetes mellitus. Among the gram-negative isolates, Klebsiella pneumoniae, Acinetobacter species, and Pseudomonas aeruginosa were the most common. There is an emergence of resistance to most commonly administered antimicrobial agents like aminoglycosides, levofloxacin, piperacillin/tazobactum, and carbapenems during the study period. This is a ten-year study on the antibiotic resistance pattern of organisms causing VAP. As far as the authors are aware, this is the first study addressing the pattern of change in drug resistance in the organisms causing VAP over a decade. The emergence of multi-drug resistant (MDR) MDR pathogens, especially in intensive care unit (ICU), is a great concern for the intensivist and infection control physicians. Preventive measures need to be undertaken to control the spread of these pathogens to the patients in the ICU.

CsBZIP40 confers resistance against citrus bacterial canker by repressing CsWRKY43-CsPrx53/CsSOD13 cascade mediated ROS scavenging.

As the bacterial etiologic agent causing citrus bacterial canker (CBC), Xanthomonas citri subsp. citri (Xcc) seriously impacts citrus plantation and fruit production globally. In an earlier study, we demonstrated that CsBZIP40 can positively impact CBC resistance in the sweet orange (Citrus sinensis). However, the mechanistic basis for the protective benefits conferred by CsBZIP40 is yet to be delineated. Here, we show that CsBZIP40 positively regulates CBC resistance and reactive oxygen species (ROS) homeostasis in transgenic sweet orange overexpressing CsBZIP40. CsBZIP40 directly binds to the TGA-box of the CsWRKY43 promoter to repress its transcriptional activity. CsWRKY43 overexpression induces CBC susceptibility in transgenic sweet oranges. In contrast, its inhibition produces strong resistance to CBC. CsWRKY43 directly binds to the W-boxes of the CsPrx53 and CsSOD13 promoters to positively regulate the activities of these antioxidant enzymes, resulting in the negative regulation of ROS homeostasis and CBC resistance in sweet orange plants. CsPrx53/CsSOD13 knockdown enhances ROS accumulation and CBC resistance. Overall, our results outline a regulatory pathway through which CsBZIP40 transcriptionally represses CsWRKY43-CsPrx53/CsSOD13 cascade-mediated ROS scavenging in a manner conducive to CBC resistance. These mechanisms underscore the potential importance of CsBZIP40, CsWRKY43, CsPrx53, and CsSOD13, providing promising strategies for the prevention of CBC.

Prevalence, Risk Factors and Patterns of Different Underlying Enteropathogens in Pediatric Patients

Background: According to the WHO, diarrhea is a result of inadequate water, sanitation, and hygiene and is the second leading cause of death in pediatrics. Objectives: Therefore, the study was intended to discover enteropathogens linked with diarrhea in pediatrics less than 5 years, their prevalence, distribution patterns and risk factors. Methods: The study was conducted in selected hospitals of District Dera Ismail Khan from March 2021 to October 2022 and comprised 384 patients diagnosed with bacterial (through culture) and parasitic (through microscopic examination) agents. Their demographic characteristics and risk factors were recorded on the pre-designed questionnaire. Results: Out of 384, 123 patients (32.03%) were suffering from bacterial diarrhea (p<0.05) and 261 children (67.96%) were diagnosed with parasitic ailments. Among bacterial causes, Escherichia coli (49.78%) was predominant (p<0.05), followed by Salmonella (18.92%), Campylobacter (10.66%), Shigella (7.13%) and Vibrio (1.91%), while the major parasitic infestation (p<0.05) involved Giardia (21.12%), Ascaris (17.78%), hookworms (14.39%), Trichuris (12.98%) Entamoeba (12.84%) and Taenia (3.19%). Most infected children belonged to the rural population (59.11%) than the urban (40.88%). Practical implications: The current study will pave a path for the clinicians to differentially diagnose the bacterial and parasitic origin enteropathogens in pediatric patients. Conclusion: Most of the diarrheic patients were diagnosed with parasitic than bacterial etiological agents. The major risk factors of the infection were poor hygiene, sanitation, weak immunity and playing of children in the contaminated soil and ingesting contaminated food materials. Keywords: Acute diarrhea; Parasites; Poor hygiene; Stool culture

Bacterial profile and extended spectrum beta lactamase screening of urinary tract infection among asymptomatic and symptomatic pregnant women attending antenatal care in ALERT Hospital, Addis Ababa, Ethiopia.

The occurrence of extended spectrum beta lactamase-producing uropathogens, especially in pregnant women can result in life-threatening condition and morbidity for both the mother and the newborn due to very limited drug options for treatment of these pathogens. The aim of this study was to determine the bacterial profile, associated factors, and their antimicrobial susceptibility patterns and to identify extended spectrum beta lactamase-producing bacterial uropathogens. A hospital-based cross-sectional study was conducted from July to September 2018 on a total of 177 pregnant women with and without symptoms of urinary tract infection at ALERT Hospital, Addis Ababa, Ethiopia. From these study participants, 72 have symptoms, whereas 105 have no symptoms. All urine samples were inoculated onto cysteine lactose electrolyte deficient medium and MacConkey agar. Colonies were counted to check the presence of significant bacteriuria. Pure isolates of bacterial pathogen were characterized and identified at species level by colony morphology, gram stain, and standard biochemical procedures. All Gram-negative isolates were put into Muller-Hinton agar plates for antibiotic susceptibility test by Kirby-Bauer disc diffusion technique. Extended spectrum beta lactamase was detected using double-disk synergy methods on Muller-Hinton agar. The data were double entered into epidemiological Information system and analyzed using Statistical Package for Social Science version 26. The overall proportion of urinary tract infection among pregnant women was 14.7% (n = 26/177). Klebsiella pneumoniae was the predominant bacterial etiologic agent of urinary tract infection 26.9% (n = 7/26). The proportion of extended spectrum beta lactamase among Gram-negative isolates was 50% (n = 6/12). Among extended spectrum beta lactamase-producing isolates (100%), all are resistance to amikacin and gentamicin while intermediate level resistance rate of 66.7% was observed among trimethoprim-sulphamethoxazole. They were susceptible for some limited drugs, and these were Nitrofurantoin (83.3%) and Chloramphenicol (83.3%). Majority of extended spectrum beta lactamase-producing isolates exhibited co-resistance to other commonly prescribed antibiotics. This indicates that the option of treatment for these pathogens rapidly decreased from time to time which results serious life-threatening conditions, especially in mother and newborn unless the appropriate measure is taken.

Bacterial Profiles of Brain in Downer Cattle with Unknown Etiology.

Downer cow can be caused by muscular paralysis, neurological damage, metabolic disorder, and/or the complication of microbial infection. However, downer cow with unknown etiology is issued because of the non-detection of its bacterial etiological agent. In this study, differences in the bacterial community in brain tissues between downer cattle with unknown etiology and healthy slaughtered cattle are investigated. Bacterial diversity and representative genera between downer and normal cattle were significantly different (p < 0.05). There are significant differences in representative genera of downer and normal cattle, especially the significance, fold change, and area under the receiver operating characteristic curve score (p < 0.05). Furthermore, the prediction of functional genes in brain microbiota between the downer and normal cattle revealed differences in the cluster of orthologous gene categories, such as lipid transport and metabolism, secondary metabolite biosynthesis, and signal transduction (p < 0.05). This study revealed a significant difference in microbiota between the downer and normal cattle. Thus, we demonstrate that representative genera from downer cattle through 16S rRNA gene amplicon sequencing and microbiota analysis have the potential as candidates for bacterial etiological agents for downer cow.

Retrospective evaluation of gastrointestinal system infections: Investigation of viral, bacterial, and parasitic etiological agents

Retrospective evaluation of gastrointestinal system infections: Investigation of viral, bacterial, and parasitic etiological agents

Partial reproduction of ear-tip necrosis suggests an infectious, initially bacterial aetiology

Swine ear-tip necrosis (ETN) is a disease of global presence and unclear aetiology. Little evidence is available regarding the nature of this disease. The aim of this work was to investigate if ETN is an infectious disease that could be replicated using a lesion macerate inoculum.A source farm with a history of ear-tip necrosis was identified and five weeks-old pigs (n = 12) from this farm were housed under controlled conditions and intradermally inoculated with ETN lesion macerates (right ear, n = 10) or sterile inoculum (left ear, n = 10). Two pigs were not inoculated, serving as sentinels. All animals were clinically monitored daily during 21 days, and a ETN ear score was used to follow disease progression. Anaerobic (n = 2) and aerobic (n = 2) overnight cultures, as well as raw aliquots of the lesion macerate inoculum (n = 2) and control inoculum (n = 2) were submitted for metagenomic sequencing. All inoculated ears developed lesions suggestive of early ETN, but none progressed to result in loss of the ear pinna. All completely resolved 21 days post-inoculation. Post-mortem investigation revealed areas of fibrosis, characterized by a granulomatous response in the inoculated ears (5/10) and in 1/10 control ears. Metagenomic analysis identified the presence of previously suggested bacterial etiological agents, but no relevant viral, fungal or protozoan agents in the inoculum. ETN etiology remains unclear, but an infectious cause and bacterial agents are suggested to be at least partially implicated in disease pathogenesis. Virus and fungi do not seem to significantly contribute to disease.

Gut and faecal bacterial community of the terrestrial isopod Porcellionides pruinosus: potential use for monitoring exposure scenarios.

This work aimed to characterize the gut and faeces bacterial communities (BC) of Porcellionides pruinosus using high-throughput sequencing. Isopods were collected from the field and kept in laboratory conditions similar to those normally applied in ecotoxicology tests. Faeces and purged guts of isopods (n = 3 × 30) were analysed by pyrosequencing the V3-V4 region of 16 S rRNA encoding gene. Results showed that gut and faecal BCs were dominated by Proteobacteria, particularly by an OTU (Operational Taxonomic Unit) affiliated to genus Coxiella. Diversity and richness values were statistically higher for faecal BC, mainly due to the occurrence of several low-abundance phylotypes. These results may reflect faecal carriage of bacterial groups that cannot settle in the gut. BCs of P. pruinosus comprised: (1) common members of the soil microbiota, (2) bacterial symbionts, (3) bacteria related to host metabolic/ecological features, and (4) bacterial etiological agents. Comparison of BC of this isopod species with the BC from other invertebrates revealed common bacterial groups across taxa. The baseline information provided by this work will assist the design and data interpretation of future ecotoxicological or biomonitoring assays where the analysis of P. pruinosus BC should be included as an additional indicator. CAPSULE: Terrestrial isopods bacterial communities might support ecotoxicological assays and biomonitoring processes as a valuable tool.

Detection of Entamoebahistolytica and bacterial etiological agents in patients with clinically suspected cases of liver abscesses

Detection of Entamoebahistolytica and bacterial etiological agents in patients with clinically suspected cases of liver abscesses

Detection of Entamoeba histolytica and bacterial etiological agents in patients with clinically suspected cases of liver abscesses.

Liver abscess is one of the conditions having multiple etiological agents. It can be parasitic or can be due to bacterial among other causes. Entamoeba histolytica is one of thecommon protozoan parasites causing amoebic liver abscess. So, accurate diagnosis is important for proper management and treatment. We have tried to detect the various bacterial etiological agents along with Entamoeba histolytica using culture of bacteria and polymerase chain reaction for E. histolytica in suspected liver abscess cases. Liver aspirates/pus collected from 63 patients were subjected to bacterial gram staining and culture along with wet mount and PCR for E. histolytica. Patients' clinical details and outcomes were also noted and co-related.It was seen that 22 (34.9%) out of 63 samples showed the presence of bacteria by gram staining whereas aerobic bacterial growth was seen in 28.6% and only 1.6% in anaerobic culture. Amoebic liver abscess showed E. histolytica in 36 patients out of 63 study participants (57.1%) by PCR. The study showed that 44.4% of patients had a habit of alcohol consumption and 19.1% were chronic smokers. Abdominal pain (90.3%) was the most common presenting feature followed by fever (64.5%). The most common co-morbidities in the enrolled patients was diabetes mellitus (19.3%) and least with chronic liver disease (3.2%). Liver abscess, a multi-etiological condition needs a robust diagnostic method. Just a single method or a single sample type is not sufficient to diagnose, as it may miss out other causes. Treating its associated co-morbidities may help to lessen it.

Molecular detection and clinical characteristics of bacterial and viral main etiological agents causing respiratory tract infections in Tehran, Iran

BackgroundRespiratory tract infections are one of the most important infections among military personals, worldwide. The present study aimed to survey the prevalence of bacterial and viral main etiological agents causing respiratory tract infections among military personnel in Iran. MethodsA cross-sectional study was performed from November 2020 to March 2021. Nasopharyngeal swabs were taken from patients, military personnel with respiratory tract infection symptoms. Detection of coronavirus disease 2019 (COVID-19) was performed with one step qRT-PCR method. TaqMan probe-based real-time PCR assay was used for the detection of influenza A and B viruses. The prevalence of adenovirus and Mycoplasma pneumoniae was determined using nested PCR. Moreover, Bordetella pertussis and Streptococcus pyogenes were identified by conventional PCR assay. The detection of Haemophilus influenzae was performed by the multiplex PCR method. ResultsOverall, 145 patients were included. Among viral pathogens, COVID-19, influenza A virus, and adenovirus were identified in 85.5%, 4.1%, and 1.4% of patients, respectively. Influenza B virus was not detected among military personnel. The frequency of bacteria etiological agents was as follows: S. pyogenes (2%), M. pneumoniae (0.7%), H. influenzae (0%), and B. pertussis (0%). Muscle aches (75.9%), headache (70.3%), lethargy (69%), cough (66.2%), stuffy nose (56.6%), fever (53.8%), and sore throat (53.1%) were among the most common clinical symptoms. ConclusionsResults showed that the military personals are the susceptible group to COVID-19 infection. Therefore, the accurate detection and implementation of control strategies such as vaccination are necessary.