A typical successful case of MDT collaboration - multiple abscesses throughout the body caused by Granokia Suxin

preface

Nocardia is widely found in soil, sewage and saprophy, and non-human normal colonizing bacteria can enter the skin through trauma or enter the human body through the respiratory tract and digestive tract, and then be localized to an organ or tissue, or spread to the brain, kidney or other organs through blood circulation ^{[1, 2].}

Because Nocardia infection has no specific clinical manifestations, it is easy to misdiagnose or miss the diagnosis, and the treatment experience is relatively small
.

In this case, a patient with multiple abscesses caused by Nocardia was reported for consultation, and the diagnosis and drug treatment of Nocardia infection were analyzed and discussed, in order to provide reference for clinical diagnosis and treatment
.

Case history

Patient Ren XX, male, 83 years old, outpatient with "1.
Pulmonary interstitial fibrosis
.
2.
Lung infection
.
3.
Type 2 diabetes
.
4.
Abdominal mass (tuberculosis?) Tumor? Admitted to the hospital
on November 15, 2021.

Complaints: recurrent cough and sputum with shortness of breath after activity for 4+ years, aggravation with low back pain for 10+ days
.
In the past 11+ months, he was hospitalized in our hospital and diagnosed with chronic obstructive pulmonary disease with acute exacerbations, pulmonary interstitial fibrosis, pulmonary heart disease, lung infection, heart failure, type 2 diabetes, hypokalemia, hypoproteinemia, hyperlipidemia, chronic gastritis, mild anemia, right pleural effusion, pericardial effusion, lower extremity edema, osteoporosis
.
Oral casagliflozin 1 tablet outside the hospital, blood glucose is not monitored
once a day.
1 month ago, during the hospitalization in our hospital, it was found that the size of the left waist was about 7cm*4cm, and the right waist could palpate the size of about 4cm*2cm, which was tough, tender, no redness, swelling and ulceration, and the skin temperature increased
.
The patient refuses further tests and is automatically
discharged.

Clinical examination of this admission: the right forearm was seen to be about 3cm*4cm in size, the skin was red and swollen, hard, the boundary was not clear, the skin temperature was high, the pressure was not significantly faded, and there was no skin ulceration and pus
.
The left waist can be seen with a size of about 7cm * 5cm mass, the left hip joint can see a 7cm * 4cm mass, the two lumps are homogeneous and tough, there is a sense of fluctuation, the tenderness is obvious, red, swollen, there are multiple pus spots on it, local rupture, yellow-red pus outflow, high skin temperature, and the boundary with the surrounding tissue is not clear
.
The total number of white blood cells was 17.
03mmol/L, the percentage of neutrophils: 97.
3%, the hypersensitivity C-reactive protein: 53.
00mg/L, and the PCT: 0.
25ng/ml
.
Left waist mass pus sent to the microbiology room, general bacterial smear: Gram stain: G + bacilli, morphology? Elongated filamentous, is it stained with weak acid-fast staining? Positive, suggestive of clinical Nocardia
.
Culture result: How many 7 days to culture? , no bacterial growth
.

On November 16, CT lower abdomen and pelvic scanning: soft tissue mass of the left middle upper abdominal wall with uneven increase in fat layer density under the skin from left upper abdomen to left buttocks, uneven thickening of the skin, considering the possibility of infectious lesions, neoplastic changes to be excluded; Subcutaneous lipoma of the right lower back is possible
.
Ultrasound of lumbar skin: anechoic left lumbar and left buttocks: consider abscess
.

Figure 1 Physical examination of the patient

Microbiological examination: On November 15, 2021, the microbiology room received a secretion specimen (general bacterial smear and culture) Gram staining: the hyphae are branched and the branches are at right angles;

positive for weak acid-fast staining; Culture results are free of bacterial growth
.

Fig.
2 Gram stain of pus smear

Fig.
3 Weak acid-fast staining of pus smear

mNGS test results:

Figure 4 mNGS detection results

Case study

Clinical case studies

How are multiple abscesses all over the body treated for Nocardia?

When an abscess develops after infection with Nocardia, pus should first be drained to clear the lesion
.
For the treatment of Nocardia infection, the literature indicates that combined sulfamethoxazole is still the drug of choice ^{[3-5], followed} by linezolid, amikacin, imipenem and other drugs
.
However, for patients with severe infection and long course of disease, in order to ensure the efficacy and reduce the possibility of drug resistance of pathogenic bacteria, combination drugs
are mostly used.
Studies have shown that 26 patients in the treated and elderly groups were treated in combination [^6].

In this case, linezolid glucose injection anti-infection, 600mg intravenous drip q12h, and oral treatment with compound sulfamethoxazole, (TMP160mg SMZ 800mg) 2 tablets, q6h
.
The treatment effect is good, and multiple abscesses are controlled
.

Test case studies

How can I help clinically diagnose and treat multiple abscesses throughout the body caused by Nocardia?

This case is a rare multiple abscess of Nocardia caused by Nocardia and the patient has an underlying medical condition and is susceptible to Nocardia infection
.
The smear result of this laboratory is G+ bacilli, and the characteristics of Nocardia are significant, so we actively contact the clinic to inform the characteristics of the bacterium and recommend treatment
.
Clinicians then took samples and sent mNGS, which were eventually identified as Nocardia Novosconia
.
Although the specimen sent for testing did not grow Nocardia, analyze the possible reasons for the non-culture, is the incubation time not enough? , there is no colony growth for seven days, and the culture time
should be appropriately extended.
But the typical features of bacteria in Gram stain smears give a clear clinical direction
.

Knowledge expansion

Nocardia morphology and staining

Nocardia Gram stain is positive or indefinite, does not form spores, and has no flagella
.
The fungus is multidirectional, branched filamentous, 0.
5-1.
2 μm in diameter, and candidate bodies
can also be seen.
Modified acid-fast staining is weakly positive
.
Direct smeared Gram staining of specimens shows typical branching hyphae, and the hyphae have 900 branching angles, which is diagnostic
.
Combined sulfamethoxazole is the drug
of choice for the treatment of Nocardia.

Fig.
5 Typical microscopic morphology of Nocardia

Nocardia culture characteristics

Nocardia is a strictly aerobic bacterium
.
Growth can be slow at room temperature or 350C on Sapaul agar or common medium, and primary isolation is often incubated for 1 week
.
Smooth to granular, irregular, surface folds or accumulation of colonies can appear on different media, and different pigments such as orange, pink, yellow, yellow-green, etc
.
can be produced.

Fig.
6 Nocardia colony morphology

Case summary

This case is an elderly man with a variety of underlying medical conditions and is susceptible to Nocardia
.
The diagnosis of multiple abscesses caused by Nocardia is clear, and the combination of linezolid glucose injection and oral compound sulfamethoxazole has a good
curative effect.

Because Nocardiodiasis infection is relatively rare, clinical manifestations, imaging examinations, laboratory test results, etc.
are relatively non-specific with other pathogen infections, and it is necessary to confirm the diagnosis through etiological examination, which is easy to misdiagnose, and the types and courses of antibacterial drugs for the treatment of Nocardiosis have their own uniqueness, so it is very important
to identify the pathogen.
In this case, smear staining microscopy plays an important role in finding pathogenic bacteria, and the test results are communicated with the clinic in a timely manner, so that the clinician has a clear direction, coupled with mNGS, a higher, faster and more accurate platform, the clinical diagnosis is accurate, and the treatment of patients is timely and effective
.

Expert reviews

Wang Liling, Chief Physician, Affiliated Hospital of Panzhihua University, Sichuan Province

This is a typical case
of successful MDT cooperation.
Nocardia infection is relatively rare, clinically difficult to distinguish from other pathogen infections, must pass etiological examination to confirm the diagnosis, misdiagnosis rate is high
.
In this case, the laboratory physician found suspicious points during the smear staining microscopic examination in the case of negative culture, communicated with the clinician in time, helped the clinician find the direction of diagnosis, and finally confirmed Nocardia infection by mNGS, so that the patient received timely and accurate treatment
.
The clinical situation is not simple, especially some rare and difficult cases, which are easy to miss and misdiagnose.

New testing technologies are emerging one after another, but laboratory physicians need to closely integrate with the clinic, in order to peel back the cocoon, accurately diagnose, reduce missed diagnosis and misdiagnosis, and give greater clinical help
.

References

Xia Yuchao, Yang Xuan, Ban Lifang, et al.
Clinical features and treatment of 10 cases of Noucia infection[J].
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)

［2］BENNURT，KUMARA R，ZINJARDES，etal.
Nocardiopsis species：incidence，ecologicalroles and adaptations[J].
Microbiol Res，2015，174：33-47.

[3] Feng Xue, Wei Hua, Mainur Abdurhman, et al.
Identification of rare Nocardia and its drug susceptibility analysis[J].
International Journal of Laboratory Medicine,2020,41(4):454-456.
)

[4] HUANG Lei, LI Xiangyan, SUN Liying, et al.
Analysis of drug resistance characteristics of 23 strains of Nocardia[J].
Chinese Journal of Clinical Pharmacology,2018,34(13):1520-1523.
)

[5] LIN Zhiqiang, CHEN Tingting, WU Namei.
10 cases of nocardiosis[J].
Chinese Journal of Infection and Chemotherapy,2021,21(6):675-678.
)

[6] ZHAO Ruijie,WANG Xin,SHI Juhong.
Clinical features and prognosis analysis of elderly patients with Noucoccia infection[J].
Chinese Journal of Geriatrics,2020,39(5),545-549.
)