Common Aerobic Isolates Research Articles

Patterns of bacterial culture and antimicrobial susceptibility test results for dogs with retrobulbar abscesses: 133 cases (2002-2019).

To evaluate patterns of bacterial culture and antimicrobial susceptibility test results for dogs with retrobulbar abscesses and generate recommendations for empirical antimicrobial selection. 133 dogs examined between 2002 and 2019. Records were retrospectively reviewed to determine type of bacterial culture, number and type of bacterial isolates, antimicrobial susceptibility test results, concurrent and recent antimicrobial exposure, effect of culture results on antimicrobial regimen, and outcome. Aerobic culture alone was performed in 37 dogs, and aerobic and anaerobic culture was performed in 96 dogs. Isolates were recovered from 96 dogs, with multiple isolates recovered from 54 (56%) of those dogs. Of the 69 dogs for which both aerobic and anaerobic culture was performed and at least 1 isolate was obtained, 34 (49%) had purely aerobic infections, 15 (22%) had mixed aerobic and anaerobic infections, and 20 (29%) had purely anaerobic infections. Pasteurella spp (n = 26), Streptococcus spp (20), and Escherichia coli (12) were the most common aerobic isolates. Bacteroides spp (n = 22), Actinomyces spp (10), and Fusobacterium (10) spp were the most common anaerobic isolates. Susceptibility test results led to changes in the antimicrobial regimen in 37 of 80 (46%) dogs. Of the 76 dogs for which outcome information was available, 78 (97%) recovered. Multipathogen and anaerobic infections were common in dogs with retrobulbar abscesses. Susceptibility data supported the use of amoxicillin-clavulanate or a combination of clindamycin and enrofloxacin as first-line treatments. Additional study is needed to characterize anaerobic antimicrobial susceptibilities and to compare results of susceptibility testing with in vivo responses to antimicrobial administration.

SCREENING OF INFERTILE FEMALES FOR LOWER GENITAL TRACT INFECTIONS

Introduction: Infertility has been known to cause serious social and emotional problems worldwide. Besides other causes of female infertility, the role of female reproductive tract infection is well recognized. Lower genital tract infection, be it symptomatic or asymptomatic, need to be diagnosed and treated properly. In view of this our study was done. Aim & Objectives: To evaluate the bacteriological profile of lower genital tract in infertile females. Methodology: It was a cross sectional type of study. After taking consent, three swabs (high vaginal swab, endocervical swab and swab from lateral vaginal wall) were taken from 100 infertile women. A questionnaire covering demographic data, menstrual history, medical history, history of infertility, etc. was completed for each of the participants. Isolation and identification of the isolates were done as per conventional techniques. Antibiotic Susceptibility Testing was done for the aerobic isolates as per CLSI guidelines. Results: In our study, 47% of females were asymptomatic and majority them showed positive microbiological growth. E.coli and S.aureus were the most common aerobic isolates and Prevotella spp. was the most common anaerobic isolate. Majority of the anaerobes were associated with bacterial vaginosis. Majority of our isolates were susceptible to Gentamicin. Conclusion: The absence of clinical symptoms does not rule out the possibility of an ongoing acute inflammatory state due infective agents. Hence, both asymptomatic and symptomatic females should be screened for lower genital tract infections as the consequences may lead to infertility.

1366. Deep Neck Infections: Bacteriology and Antimicrobial Susceptibilities, Akron Children’s Experience

Abstract Background Deep neck infections (DNI’s) are uncommon (~45,000 US cases annually) but, potentially serious. Published data regarding bacteriology and antibiotic usage for DNI’s in children is limited. In addition, geographic variation in the incidence of pathogens and their antimicrobial susceptibility limits generalization of treatment guidance. Reviewing our practice at Akron childrens we noted considerable variation in the choice of empiric antibiotics (ampicillin-sulbactam vs piperacillin-tazobactam vs Ceftriaxone and Clindamycin/vancomycin/linezolid). Admission unit (floors vs intensive care) and service (hospitalist vs infectious diseases) were some important determinants that influenced choice of empiric antibiotics. This retrospective study aimed to review local data and come up with standard guidance for empiric therapy. Summary of the predominant bacterial isolates. Methods We reviewed records of 125 patients who underwent surgical drainage of DNI’s from 1/2015 – 12/2019. In addition to demographic data we gathered information on bacterial isolates and their susceptibilities. Chart review was performed for patients with staphylococcus aureus, to look for any unique presenting features. Results Up on reviewing the data- peritonsillar abscesses were common in older children (Median age 11 years). As expected, retropharyngeal and parapharyngeal infections were common in younger ones (< 5 years). Group A streptococcus remained the most common aerobic isolate followed by Hemophilus influenzae/parainfluenzae. MRSA was detected in ~7 % of all cultures (see enclosed table). Notably, none of the MRSA isolates were clindamycin resistant. However, MSSA resistance to clindamycin was about 20%. No clinical characters predicted isolation of S. aureus. Anaerobic infections (polymicrobial) were overwhelmingly common across all abscess types. Conclusion Based on our review, Ampicillin-Sulbactam is a good empiric choice antibiotic for deep neck infections in our institution. Ceftriaxone with clindamycin is another option. Clindamycin monotherapy seems to be inadequate. Staph aureus and especially MRSA, were only isolated in a small percentage of cases. Unless a patient is ill appearing, vancomycin use seems unnecessary. Clinical presentation was not helpful to suspect infection with Staph aureus. Disclosures All Authors: No reported disclosures

Chronic Suppurative Otitis Media (CSOM): Evaluation of fungal and aerobic bacterial agents and antibiotic sensitivity pattern of the bacterial isolates

Introduction: Chronic suppurative otitis media (CSOM) is an important cause of preventable hearing loss, particularly in the developing world. Aim: To determine the microbiological profile of CSOM and determine the antibiotic susceptibility testing of aerobic bacteria which will be beneficial for appropr iate treatment there by reducing complications. Methods and Materials: A total of 109 patients with CSOM attending outpatient and admitted inpatient in ENT department were included in the study. Two pus swabs each for infected ear were collected. Specimens were subjected to Gram stain and plated on to appropriate culture media to isolate bacterial and fungal pathogens. Bacterial and Fungal species identification and Antibiotic susceptibility testing of aerobic bacteria of isolated pathogens was done. Results: Out of 109 samples cultured there were 70 bacterial and 14 fungal isolates. Most common aerobic bacterial isolate was Pseudomonas aeruginosa (34.2%) followed by Proteus mirabilis (22.8%) and Staphylococcus aureus (17%). Among fungal isolate, Aspergillus niger (64.3%) was predominant followed by Aspergillus flavus (21.4%) and Candida species (14.3%). Amikacin (91.6%) and Ciprofloxacin(87.5%) showed maximum activity to Pseudomonas aeruginosa. The antibacterial susceptibility pattern of Staphylococcus aureus revealed 58.3% Methcillin resistant Staphylococcus aureus (MRSA) strains. Conclusions: Emergence of Pseudomonas aeruginosa as most common aerobic isolate and high incidence of Methicillin Resistant Staphylococcus aureus in present study indicates the necessity of continuous evaluation of bacteriological profile and antimicrobial susceptibility testing in all CSOM cases. Keywords: Chronic suppurative otitis media (CSOM), Methcillin resistant Staphylococcus aureus (MRSA).

Chronic suppurative otitis media: A microbiological review of 20 years

Chronic infection of the middle ear cleft for at least 2 weeks or more is known as chronic suppurative otitis media (CSOM). It usually manifests as a complication of acute otitis media. It is more prevalent in developing countries due to various predisposing factors such as malnutrition, overcrowding, poor hygiene, inadequate health care, and recurrent upper respiratory tract infection. Due to advancement in medical facility, India still falls under high prevalence zone. In India, the average prevalence of CSOM is 5.2%. Pseudomonas aeruginosa and Staphylococcus aureus were the predominant isolates in most of the studies. Other common aerobic isolates were Klebsiella spp., Proteus spp., Escherichia coli, Bacteroides fragilis, Prevotella spp., Candida spp., and Aspergillus spp. However, there was no significant geographical variation of pathogens in India. In recent years, there is increased preponderance of multidrug-resistant organisms due to the irrational use of antibiotics, making treatment of CSOM more difficult. Colistin and polymyxin-B were the most effective antibiotics which showed sensitivity against P. aeruginosa by up to 100%. Carbapenems were showing good sensitivity against P. aeruginosa in most of the studies, but there was decreased tendency of sensitivity for piperacillin-tazobactam, amikacin, gentamicin, ceftazidime, and ciprofloxacin. Nine studies isolated methicillin-sensitive S. aureus significantly higher in number than methicillin-resistant S. aureus. For S. aureus, vancomycin and linezolid showed ≥90% sensitivity in most of the studies. Amikacin, gentamicin, erythromycin, and ciprofloxacin were other active drugs against S. aureus, which were showing resistant pattern significantly.

Pyogenic liver abscess: Clinical features and microbiological profiles in tertiary care center

Background:Pyogenic liver abscess (PLA) is the end result of a number of pathologic processes that cause a suppurative infection of the liver parenchyma.Materials and Methods:Sixty-five patients of age more than 18 years and radiologically confirmed cases of liver abscess were included in this study. Pus and blood samples were collected. Pus was processed for microscopy of trophozoite of Entamoeba histolytica and aerobic and anaerobic bacterial culture. Blood was processed for antibody ELISA for Entamoeba histolytica and aerobic bacterial culture. Identification of aerobic and anaerobic isolates was done by Vitek2 and antibiotic sensitivity test for aerobic bacterial isolates was done by Vitek2.Result:Out of sixty five, twenty five were confirmed as PLA. All patients were male with mean age 37.9 years. Fever and upper abdominal pain were the most common symptoms. Right lobe comprised 80% of the abscess. Pus sample was more sensitive than blood sample for diagnosis. There were a total of 33 isolates in our study. Klebsiella pneumoniae (6/33) was the most common aerobic isolate and Clostridium spp. (7/33) was the anaerobic isolate. All gram-negative bacteria were showing good sensitivity for 3rd and 4th generation cephalosporins, fluoroquinolones, amikacin, gentamicin, piperacillin-tazobactam, imipenem and meropenem. Abscess >5 cm was treated with percutaneous drainage while abscess <5 cm was treated with antibiotics only.Conclusion:Diagnosis should be made with the combination of clinical suspicion, radiology, and microbiology. Empirical therapy should include anaerobic coverage too. Only antibiotic therapy can be given under consideration of size of abscess, persistence of fever after giving antibiotics, and any suspected complications.

Prevalence of multidrug-resistant bacteria isolated from patients with burn infection

Objectives The aims of the study were to determine bacterial pathogens frequently causing burn infections and their antimicrobial susceptibility patterns, to estimate the prevalence of multidrug resistance (MDR) among the isolated pathogens, and to evaluate the different risk factors for the development of burn wound infection. Background Infection in burn patients remains the significant source of morbidity and mortality. The aggressive use of antimicrobials has improved survival but led to an increased colonization and infection of pathogens that resist current therapies. Materials and methods The study was carried out by collecting swabs from 105 burnt patients during the period from October 2012 to November 2013. Semiquantitative assessment of bacterial growth was performed to distinguish between bacterial colonization and infections. MDR strains were detected including methicillin-resistance and vancomycin-resistance staphylococci and Gram-negative bacilli extended-spectrum b-lactamases and metallo-b-lactamases producers by standardized methods. Results Burn wound infections were polymicrobial in 26.6% of cases. Staphylococcus aureus was the most common aerobic isolate (32.4%). Among S. aureus, 76.5% were MDR strains, 73.5% were methicillin-resistant, and 17.6% were vancomycin resistant. Coagulase-negative staphylococci (CoNS) were represented by 16.2%. About 47% of CoNS strains were MDR strains, 47% were methicillin-resistant CoNS, and 23.6% were vancomycin-resistant CoNS. All Gram-negative bacteria isolated from burn wounds were MDR. Extended-spectrum b-lactamases were detected in 58.5%, whereas metallo-b-lactamases were detected in 43.4% of Gram-negative bacteria. The risk factors for burn wound infections were young age, low socioeconomic status, abuse of invasive procedures and antimicrobial, prolonged hospital stay, and improper control of burn-associated comorbidities. Conclusion The study highlights the high prevalence of MDR bacteria infecting burn wound in our hospitals.

Infection in diabetic foot

Objectives The present study was carried out to determine the prevalence of aerobic and anaerobic pathogens in diabetic foot infections (DFIs), detect their susceptibility to different antimicrobial agents, investigate the microbiological profiles of DFIs in relation to different grades of Wagner classification, and assess the risk factors for DFIs. Background DFI is the most frequent reason for diabetes-related hospitalization. It develops because of several diabetes-related factors including arterial insufficiency, neuropathy, foot deformities, previous ulcers, previous amputation, and local trauma. Materials and methods The study was carried out on clinical specimens taken from 100 diabetic patients (50 patients had type I insulin-dependent diabetes mellitus (IDDM) and 50 patients had type II noninsulin-dependent diabetes mellitus (NIDDM) and 50 nondiabetic patients with foot infection during the period from May 2011 to July 2012. The specimens were cultured using aerobic and anaerobic microbiological techniques, and antibiotic susceptibility testing was performed according to the methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Multidrug-resistant organisms were detected including oxacillin-resistant and vancomycin-resistant staphylococci and gram-negative bacilli extended-spectrum beta-lactamase producers. Results DFIs were polymicrobial in 76% of cases. Staphylococcus aureus was the most common aerobic isolate (17.6%) (including 74.4% methicillin resistant and 23.1% vancomycin resistant). Peptostreptococcus spp. were the most common anaerobic isolate (39.4%). Extended-spectrum β-lactamase production was detected in 53.4% of Gram-negative bacilli. About 62% of diabetic patients were infected with multidrug-resistant organisms. The risk factors for DFIs were duration of diabetes more than 1 year, random blood sugar of at least 200 mg/dl, trauma, previous ulcer and amputation, and comorbidities related to diabetes. Conclusion Imipenem was the most effective drug against all isolates. Effective glycemic control and educating patients on the prophylactic foot care are of key importance for decreasing DFIs.

Aerobic bacteriology of Chronic Suppurative Otitis Media (CSOM) in a tertiary care hospital: A retrospective study

The present study was carried out to determine the aerobic microorganisms involved and their antibiotic sensitivity pattern in patients with Chronic Suppurative Otitis Media (CSOM) and to provide a guideline for empirical antibiotic therapy.Between March 2009 to February 2011, the ear discharge samples submitted at the microbiology laboratory were processed aerobically and all the isolates were included in this study. All organisms were identified morphologically and biochemically by standard laboratory procedures and antibiotic susceptibility pattern was determined by modified Kirby Bauer disc diffusion method as per National Committee for Clinical Laboratory Standard recommendations.Out of a total of 214 samples, microbiological culture was yielded from 202 (94.3%) specimens. Single organism were isolated from 168 (78.5%) of the culture positive specimens, while the remaining 34 (15.9%) had two or more organisms isolated. Pseudomonas aeruginosa 59 (35.1%) was the most common isolate, followed by Staphylococcus aureus 42 (25.0%) including 5 (3%) of the Methicillin Resistant Staphylococcus Aureus (MRSA). Antibiotic sensitivities of Pseudomonas aeruginosa showed that 93.2% isolates were sensitive to tobramycin, whereas, 91.5% isolates were sensitive to ceftazidime and 77.9% to amikacin.Only 50.8% of the isolates of Pseudomonas aeruginosa were sensitive to ciprofloxacin and 25.4% to gentamicin. For Staphylococcus aureus (other than MRSA) 95.2% were sensitive to cloxacillin, 83.3% to gentamicin and 78.5% to erythromycin. Only 07.1% were sensitive to ampicillin and 26.1% to ciprofloxacin.Pseudomonas aeruginosa was the most common isolate followed by Staphylococcus aureus. More than 90% of Pseudomonas and 90% of Staph aureus were sensitive to tobramycin and cloxacillin respectively. Therefore, these two drugs may be included in the formulary to cover the most common aerobic isolates involved in CSOM.Journal of College of Medical Sciences-Nepal, 2011, Vol-7, No-2, 1-8DOI: http://dx.doi.org/10.3126/jcmsn.v7i2.6673

Microbiologia dos abscessos peritonsilares

OBJETIVO: O objetivo deste estudo é avaliar a microbiologia dos abscessos periamigdalianos. MATERIAIS E MÉTODOS: Trinta pacientes com diagnóstico de abscesso periamigdaliano, idade média de 24,2 anos, foram submetidos à punção na região periamigdaliana de maior abaulamento com aspiração do material purulento (volume maior que 3mL). O material foi separado para realização das culturas aeróbicas e anaeróbicas. RESULTADOS: Houve um índice de positividade das culturas de 86,7%. Em 23,3% aspirados houve crescimento apenas de bactérias aeróbicas ou facultativas, 3,3% apenas de bactérias anaeróbicas e por fim em 60% aspirados houve crescimento de bactérias aeróbicas e anaeróbicas. Um total de 69 bactérias foi isolado (34 aeróbios e 35 anaeróbios). Os aeróbios predominantes foram Streptococcus sp, sendo o Streptococcus pyogenes em 23% dos casos. Os anaeróbios predominantes foram Prevotella sp e Peptostreptococcus sp. Pacientes receberam antibiótico prévio em 63% dos casos. Neste grupo foram isolados 1,8 bactérias por aspirado, menor número que nos paciente que não utilizaram antibiótico (3,0 bactérias por aspirado). Não houve diferença significativa no tipo de bactéria isolada nestes dois grupos. CONCLUSÃO: Os abscessos periamigdalianos apresentam na maioria dos casos infecções polimicrobianas, sendo os organismos anaeróbicos agentes importantes. O número de agentes isolados é maior nos pacientes que não utilizaram antibioticoterapia prévia, mas o uso de antimicrobiano não interferiu no tipo de bactéria isolada.

Microbiology of Peritonsillar Abscesses

SummaryAim: The objective of the present study was to analyze the microbiology of peritonsillar abscesses. Methods: Thirty patients, mean age 24,2 years, with peritonsillar abscesses underwent aspiration of at least 3 mL of pus, which was cultured for aerobes and anaerobes. Results: 87% samples showed positive cultures. Aerobic or facultative aerobic bacteria were isolated from 23% aspirates, mixed aerobic and anaerobic bacteria from 60%, and anaerobic bacteria from only 3% aspirate. A total of 69 bacterial isolates (34 aerobic and 35 anaerobic) were recovered. The most common aerobic isolate was Streptococcus sp, with Streptococcus pyogenes being identified in 23% of aspirates. The predominant anaerobic isolates were Prevotella sp and Peptostreptococcus sp. Patients had received previous antimicrobial therapy in 63% cases. In this group, 1.8 isolates per specimen were recovered, a lower number than in the untreated group (3.0 per specimen). No significant difference in the species isolated was observed between these two groups. Conclusion: Peritonsillar abscess is usually a polymicrobial infection, with predominance of anaerobic bacteria. The number of agents isolated was larger in patients not previously treated with antibiotics, but the use of antimicrobial drugs did not interfere with the type of bacterium isolated.

Bacterial florae of palatine tonsils in patients with IgA nephropathy

We studied bacterial florae of 52 palatine tonsils from 52 patients with IgA nephropathy treated by tonsillectomy. Wedge-shaped tonsillar tissue was homogenized, and then pharyngeal bacterial florae on the tonsillar surface were removed by washing with sterile physiological salt solution. From the total of 52 specimens, 646 bacterial strains of 70 different species were isolated, including 265 strains of aerobes, 108 strains of semianaerobes, and 273 strains of anaerobes. The most common aerobic isolates were α- streptococci (88 strains). The most commonly isolated anaerobic species was Provotella (113 strains). Among the strains for which isolated organisms per tonsillar tissue were over 10 6 μg/g, the number of strains of anaerobes was greater than that of aerobes. To understand the relationship between the tonsils and IgA nephropathy, attention should be given to the presence of anaerobic bacteria of the palatine tonsils.

Susceptibility of microorganisms isolated from chronic suppurative otitis media to ciprofloxacin.

In order to evaluate the susceptibility of the microorganisms isolated from chronic suppurative otitis media to ciprofloxacin, cultures of specimens from 127 patients with chronic suppurative otitis media and their antibiotic sensitivity results were examined. The most common aerobic isolates were Pseudomonas sp., Proteus sp., and Staphylococcus aureus with recovery rates of 40.7%, 21.6% and 19.1% respectively. Sensitivity results showed that 6.2% of Pseudomonas isolates, 2.9% of Proteus isolates, 10% of Staphylococcus aureus isolates and 8.3% of Escherichia coli isolates were resistant to ciprofloxacin.

Bacteriologic findings in peritonsillar abscesses in young adults.

Aspirated pus samples from 124 patients with peritonsillar abscess were cultured quantitatively for aerobes and anaerobes. A total of 98% of the samples yielded bacteria. Of the 550 isolates obtained (mean, 4.4 per patient), 143 were aerobes (representing 16 species or groups) and 407 were anaerobes (representing 40 species or groups). Aerobes were isolated from 86% of patients-alone in 20 cases and together with anaerobes in 87. The most common aerobic isolates were Streptococcus pyogenes (isolated from 45% of patients), Streptococcus milleri group organisms (27%), Haemophilus influenzae (11%), and viridans streptococci (11%). Anaerobes were isolated from 82% of the samples and as a sole finding from 15 abscesses. Fusobacterium necrophorum and Prevotella melaninogenica were both isolated from 38% of patients, Prevotella intermedia from 32%, Peptostreptococcus micros from 27%, Fusobacterium nucleatum from 26%, and Actinomyces odontolyticus from 23%. The rate of previous tonsillar/peritonsillar infections was lowest (25%) among patients infected with S. pyogenes and highest (52%) among those infected with F. necrophorum (P < .01). Recurrences and/or related tonsillectomies were more common among patients infected with F. necrophorum than among those infected with S. pyogenes (57% vs. 19%; P < .0001) or with S. milleri group organisms (43% vs. 19%; P < .05). beta-Lactamase was produced by only 38% of the 73 isolates of Prevotella species tested; however, 56% of the 36 patients studied harbored one or more such strains.

A quantitative study of aerobic and anaerobic bacteria in chronic suppurative otitis media

During a period of 21 months, specimens from the ears of 130 patients with chronic suppurative otitis media (CSOM) were cultured qualitatively and quantitatively for aerobic and anaerobic bacteria. Bacteria were cultured from 95 per cent of these specimens. Proteus species, the most common aerobic isolate was grown from 61 per cent of the patients. Using an appropriate method it was possible to isolate anaerobic bacteria from 44 per cent of specimens and Bacteroides species predominated: B. melaninogenicus and B. fragilis were equally common. The main bacterial species - both aerobic and anaerobic — were present in the ear in counts which averaged 10 9 organisms per ml. Pseudomonas species were an exception, however, and regularly showed higher counts of 10 11 bacilli per ml. The high bacterial counts may be one of the reasons for the poor results of antibiotic therapy.

Microbiological studies of the bacterial flora of the external auditory canal in children.

The aerobic and anaerobic bacterial flora of the external auditory canal (EAC) was studied in 72 children. Aerobes only were isolated in 58 patients (80%) and anaerobic bacteria only in 2 (3%). Mixed aerobic and anaerobic isolates were recovered in 12 cases (17%). There were 122 aerobic and 15 anaerobic isolates accounting for 1.7 aerobes and 0.2 anaerobes per specimen. The most common aerobic isolates were Staphylococcus epidermidis (56 isolates), alpha hemolytic streptococcus (13) and Pseudomonas aeruginosa (8). The two anaerobic organisms recovered were Proprionibacterium acnes (13 isolates) and Peptococcus sp. (2). These findings demonstrate the polymicrobial bacterial flora of EAC in children where aerobic facultative and anaerobic bacteria are part of the normal flora.